Methods and compositions for supporting normal blood calcium levels in mammals - Patents.com

Abstract

1. A composition for oral administration to a perinatal mammal at risk of developing hypocalcemia within 0-6 hours after birth, comprising calcium in a form rapidly absorbable by the perinatal mammal using passive paracellular transport across the intestinal epithelium and a 1-alpha hydroxylated vitamin D compound in an amount sufficient to stimulate active transport of calcium across the intestinal epithelium, wherein the calcium and 1-alpha hydroxylated vitamin D are administered simultaneously to support the maintenance of normal blood calcium concentrations in the perinatal mammal.

Description

[Technical field]

[0001] The present disclosure relates to oral medications and the administration of such medications to mammals during the peripartum period to prevent or treat hypocalcemia during the first few days after birth. [Background technology]

[0002] When mammals, especially dairy cows, give birth and begin lactating, the onset of lactation allows the animal's body to pump more calcium from the circulating blood into the milk than the animal's body can return to the circulating blood from dietary calcium and bone calcium stores. For calcium to perform many functions in the body, the calcium concentration in the blood (as determined in plasma or serum) of the dairy cow should be about 9-10 mg / dl (2.25-2.5 mM). However, as a result of the large and rapid calcium excretion that occurs at the onset of lactation, acute and severe hypocalcemia occurs in nearly 5% of multiparous dairy cows (Goff, 2014). These cows lie down and develop muscle paralysis, a clinical condition known as milk fever, which often leads to death if not properly treated. Approximately 50% of multiparous dairy cows and 25% of heifers experience a significant degree of hypocalcemia, called subclinical hypocalcemia, around the time of parturition. The serum calcium concentration that cows should have to be considered severely hypocalcemia varies widely in the literature, ranging from 8.0 to 8.6 mg / dL (2 to 2.15 mM). Hypocalcemia can be treated with intravenous or oral calcium, but cows with significant hypocalcemia in early lactation are at increased risk for immune dysfunction, metritis, displaced abomasum, retained placenta, mastitis, and ketosis (Goff, 2014).

[0003] Fortunately, cattle, and all mammals, generally have systems that allow them to restore normal blood calcium concentrations within a few days after calving. Calcium homeostasis is primarily mediated by the parathyroid gland, which secretes parathyroid hormone (PTH) in response to a drop in blood calcium levels. PTH stimulates calcium release from bone calcium stores, decreasing the amount of calcium lost in the urine. PTH also activates the renal enzyme that produces the vitamin D hormone, 1,25-dihydroxyvitamin D. 1,25-dihydroxyvitamin D stimulates transcellular absorption of calcium across the intestinal epithelium (also known as active transport), greatly increasing the utilization of dietary calcium (Goff, 2018). When calcium homeostasis is functioning normally, cows experience only small and brief declines in blood calcium concentrations during the periparturient period. Unfortunately, approximately half of cows in dairy herds are impaired in their ability to maintain blood calcium concentrations above approximately 8 mg / dl (2 mM) during the first few days of lactation. A decreased ability of bone and kidney cells to respond to PTH stimulation has been implicated as a defect in calcium homeostasis that results in prolonged or severe hypocalcemia (Goff, 2014). Several factors can disrupt calcium homeostasis, causing a more rapid and prolonged decline in blood calcium levels. Factors in cattle that affect calcium homeostasis include age and breed.

[0004] Nutritional factors also affect the resilience of the calcium homeostasis system. + ), Sodium (Na + ), Calcium (Ca +2 ), and magnesium (Mg +2 ), when absorbed into the blood of a cow, increases the pH of the blood of the cow. - ), sulfate (SO4 -2 ), phosphate (PO4 -3Dietary anions such as cations and anions in the diet, when absorbed into the blood, make the blood of the cow acidic. Cations and anions in the diet that are not absorbed do not affect blood pH. Blood pH is determined by the difference in the number of milliequivalents of cations and anions absorbed from the diet (Goff, 2018). Cattle diets are generally low in K + Because their diet consists of diets high in K, cows are usually in a state of compensated metabolic alkalosis. + is absorbed from the feed with nearly 100% efficiency, so the K in the feed + is strongly alkalizing. + Feed or water Na + is absorbed with nearly 100% efficiency, making it highly alkaline. +2 and Mg +2 Cations are absorbed from the feed at a rate of K + OrNa + Although it is much lower than that, it can be present in relatively high concentrations in the feed, so the absorbed Ca +2 and Mg +2 makes the cow's blood alkaline.

[0005] K +Cows that are in compensatory metabolic alkalosis as a result of being fed diets high in selenium do not respond to PTH stimulation as well as cows in compensatory metabolic acidosis caused by the addition of anions to the diet (Goff, 2014). Metabolic alkalosis inhibits bone calcium absorption (Block, 1994). In addition, the ability of PTH to stimulate the timely production of 1,25-dihydroxyvitamin D is impaired, resulting in reduced utilization of dietary calcium. Adjusting the cation-anion difference in the diet to induce compensatory metabolic acidosis is a commonly used means to reduce milk fever and hypocalcemia in dairy cows. The addition of chloride and sulfate anions to the diet of cows before calving can significantly reduce the degree of hypocalcemia experienced by cows at calving. This restores the sensitivity of bone and kidney cells to PTH and improves calcium homeostasis mechanisms. Nutritional management of peripartum diets to reduce hypocalcemia in dairy cows is well documented (Goff, 2014). Anion-supplemented diets may be less palatable and may reduce prepartum feed dry matter intake. Reducing feed intake around the time of calving may predispose cows to ketosis, metritis, and displaced abomasum. However, there are caveats to the use of anions to reduce hypocalcemia. Even if anions are added to the diet, the effectiveness of the diet to reduce hypocalcemia is greatly reduced if the cow is not sufficiently acidified to reduce urine pH to below approximately 6.8. A drop in urine pH below approximately 5.75 may lead to reduced dry matter intake and other metabolic problems associated with reduced prepartum feed consumption. Although adequate anion supplementation improves calcium homeostasis, some subclinical hypocalcemia and even clinical hypocalcemia (milk fever) may occur.

[0006] In many cows with postpartum hypocalcemia, the calcium homeostatic response appears to be delayed compared to cows without detectable subclinical or clinical hypocalcemia. This is especially true in cows with recurrent clinical hypocalcemia (Goff et al., 1989). The traditional treatment for cows with milk fever is to administer 10-12 g of calcium intravenously to rapidly, albeit temporarily, restore blood calcium levels to levels that support normal calcium functions, including nerve and muscle function. This medical intervention often maintains blood calcium levels for 6-10 hours, allowing sufficient time for the cow's calcium homeostatic mechanisms to become activated. Once fully activated, the cow ingests enough calcium from bone and forage to maintain normal blood calcium levels, while calcium continues to be lost through milk production. However, in some cows, the calcium homeostatic mechanisms become so compromised that the cow relapses 12-24 hours after the calcium injection, resulting in a second or third milk fever. As Goff et al., (1989) showed, these cows are very slow to produce 1,25-dihydroxyvitamin D. Once 1,25-dihydroxyvitamin D production begins, they are able to regulate calcium homeostasis and maintain blood calcium levels without further treatment. Cows that develop an early rise in blood 1,25-dihydroxyvitamin D concentration after calving are better able to maintain normal blood calcium levels than cows that do not develop a rapid rise in blood 1,25-dihydroxyvitamin D concentration after calving. Other studies have shown that normocalcemic cows that produce 1,25-dihydroxyvitamin D quickly after calving have lower peak blood 1,25-dihydroxyvitamin D concentrations than cows that produce 1,25-dihydroxyvitamin D later (Goff et al., 1991). These and other studies have led many researchers to investigate the administration of 1,25-dihydroxyvitamin D as a means of preventing hypocalcemia in dairy cows.

[0007] Administration of 1,25-dihydroxyvitamin D or its analogues to dairy cows prior to calving has been successful in reducing hypocalcemia (Horst et al., 1997). Unfortunately, this approach has the drawback of being dependent on predicting the time of calving for success. If a single dose of 1,25-dihydroxyvitamin D or its analogues is administered orally or parenterally less than 12-24 hours prior to calving, or administered alone after calving, 1,25-dihydroxyvitamin D will not stimulate active calcium transport rapidly enough to affect hypocalcemia in many cows. If administered too early prior to calving (more than 3-4 days prior), a second or even third dose may need to be administered to be effective. Analogues of 1,25-dihydroxyvitamin D with longer plasma half-lives can be used to extend the therapeutic window by 1-2 days, but they still need to be administered at least 12-24 hours prior to calving to be effective. Sustained-release preparations of 1,25-dihydroxyvitamin D have been described, but must also be administered before calving to be effective. Small daily doses administered until and after calving can also effectively prevent hypocalcemia (Horst et al., 1997). However, prolonged exposure to exogenous 1,25-dihydroxyvitamin D inhibits the ability of dairy cows to make endogenous 1,25-dihydroxyvitamin D, and hypocalcemia can develop 4-10 days after the effectiveness of exogenous 1,25-dihydroxyvitamin D has worn off. Large doses of 1,25-dihydroxyvitamin D can be given to extend the effective window slightly to 5-7 days before calving, but this also exacerbates the problems associated with prolonged exposure to exogenous 1,25-dihydroxyvitamin D (Horst et al., 1997). Issues regarding timing of administration and the potential for inhibition of endogenous 1,25-dihydroxyvitamin D synthesis greatly limit the practical use of 1,25-dihydroxyvitamin D to prevent perinatal hypocalcemia.

[0008] A second method to maintain a more normal blood calcium concentration in periparturient cows is to administer large amounts of easily soluble calcium orally immediately after calving. Typically, 30-75 g of calcium is administered in the form of a bolus, paste, or liquid drench. Calcium is absorbed utilizing a passive paracellular transport mechanism by increasing the ionized calcium concentration in the fluid in direct contact with the absorptive cells (ruminal fluid or intestinal chime) to greater than about 4 mM (Goff, 2018). This mechanism is independent of stimulation by 1,25-dihydroxyvitamin D. This causes a rapid, but limited, rise in blood calcium concentration. It has been demonstrated that an oral administration of 50 g of calcium in the form of easily soluble calcium chloride results in approximately 4 g of calcium being absorbed into the cow's blood, resulting in a rise in blood calcium of approximately 1 mg / dl (0.25 mM) within 1 hour, which is sustained for approximately 6-8 hours. Larger doses can be administered, but the therapeutic window (time for blood calcium to increase to normal) is increased by only 1–3 hours (Goff and Horst, 1993). A common method to extend the therapeutic window is to administer oral calcium in a first dose, typically within a few hours after calving, followed by a second and sometimes a third dose 12–24 hours later. This requires more effort from the dairyman to locate and restrain the cow and administer each dose. It can also cause excessive absorption of chloride or sulfate, the anions of the more commonly used calcium salts. This can put the cow in a state of uncompensated metabolic acidosis, further compromising the cow's health (Goff and Horst, 1994). Only a small portion of the administered calcium is absorbed via the paracellular pathway, but the remaining calcium can be absorbed if the active calcium transport mechanism is activated by the endogenous production of 1,25-dihydroxyvitamin D. Summary of the Invention

[0009] The present disclosure describes a composition for oral administration to a perinatal mammal at risk of developing hypocalcemia within 0-6 hours after birth; the composition comprises calcium in a form rapidly absorbable by the perinatal mammal using passive paracellular transport across the intestinal epithelium and a 1-alpha hydroxylated vitamin D compound in an amount sufficient to stimulate active transport of calcium across the intestinal epithelium, wherein the calcium and 1-alpha hydroxylated vitamin D are administered simultaneously to support the maintenance of normal blood calcium concentrations in the perinatal mammal.

[0010] The disclosure further describes that the form of calcium administered includes rapidly water soluble calcium salts such as calcium chloride, calcium sulfate, calcium propionate, calcium acetate, calcium lactate, or calcium formate, either alone or preferably in combination.

[0011] The disclosure further describes that calcium chloride is incorporated in an amount sufficient to induce compensatory metabolic acidosis within 8 hours after administration to support normal sensitivity of tissues to parathyroid hormone.

[0012] The disclosure further describes that the 1-alpha hydroxylated vitamin D compound includes 1,25-dihydroxyvitamin D or 1-alpha hydroxyvitamin D, or analogs thereof, in an amount sufficient to stimulate transcellular lumenal and / or intestinal absorption of calcium.

[0013] The disclosure further describes that the 1-alpha hydroxylated vitamin D compounds are glycosides of 1,25-dihydroxyvitamin D as found in lime-producing plants or extracts prepared from lime-producing plants.

[0014] The disclosure further describes that the 1-alpha hydroxylated vitamin D compounds are not incorporated in amounts sufficient to cause significant inhibition of renal 25-hydroxyvitamin D-1-alpha hydroxylase enzyme, thereby inhibiting endogenous production of 1,25-dihydroxyvitamin D, resulting in delayed hypocalcemia 4 to 10 days after administration of the composition.

[0015] The disclosure further describes compositions in which a 1-alpha hydroxylated vitamin D compound and calcium are administered simultaneously in the form of a bolus, tablet, or pellet having a density of at least 1.2 kg / L (g / ml) and released from the bolus, tablet, or pellet over a period of less than two hours.

[0016] The present disclosure also describes a method for increasing, or normalizing, or maintaining normal or healthy blood calcium levels, or avoiding hypocalcemia in a mammal; the method comprises co-administering a 1-alpha hydroxylated vitamin D compound and a rapidly water soluble calcium source to a perinatal mammal immediately after birth.

[0017] The disclosure also describes a method in which a 1-alpha hydroxylated vitamin D compound and calcium are administered simultaneously in the form of a bolus, tablet or pellet having a density of at least 1.2 kg / L (g / ml) and released from the bolus, tablet or pellet over a period of less than two hours.

[0018] The present disclosure further describes methods in which 1-alpha hydroxylated vitamin D compounds and their calcium salts can support more normal blood calcium levels when co-administered in a single dose without any additional doses.

[0019] The present disclosure further describes methods in which the composition can support normal blood calcium levels or reduce hypocalcemia when administered to a perinatal mammal within six hours after parturition, most preferably within three hours after parturition.

[0020] The present disclosure further describes methods of reducing hypocalcemia in periparturient mammals, such as dairy cows, that are at risk of developing hypocalcemia upon the onset of lactation.

[0021] The disclosure further describes a method in which the form of calcium administered comprises calcium chloride or calcium sulfate in an amount sufficient to induce compensatory metabolic acidosis in the animal to support tissue sensitivity to parathyroid hormone so as to improve calcium homeostasis within 8 hours after administration.

[0022] The disclosure further describes methods wherein the form of calcium is calcium chloride, calcium sulfate, calcium propionate, calcium acetate, calcium lactate, or calcium formate, alone or preferably in combination, in an amount sufficient to promote passive, vitamin D-independent, paracellular absorption of calcium to support normal blood calcium concentrations and to reduce hypocalcemia during the first 6-12 hours after administration without inducing uncompensated metabolic acidosis in the animal.

[0023] The disclosure further describes methods in which a 1-alpha hydroxylated vitamin D compound, including 1,25-dihydroxyvitamin D or 1-alpha hydroxyvitamin D or analogs thereof, is administered in an amount sufficient to stimulate transcellular lumenal and / or intestinal absorption of calcium to support normal blood calcium levels or reduce hypocalcemia for up to 12 to 72 hours after administration.

[0024] The disclosure further describes a method in which the 1-alpha hydroxylated vitamin D compound is a glycoside of 1,25-dihydroxyvitamin D obtained from a lime-producing plant or an extract prepared from a lime-producing plant, and is administered in an amount sufficient to stimulate transcellular lumenal and / or intestinal absorption of calcium to support normal blood calcium levels or to alleviate hypocalcemia for up to 12 to 72 hours after administration.

[0025] The disclosure further describes methods in which the 1-alpha hydroxylated vitamin D compounds are not incorporated in amounts sufficient to cause significant inhibition of renal 25-hydroxyvitamin D-1-alpha hydroxylase enzyme, thereby inhibiting endogenous production of 1,25-dihydroxyvitamin D, resulting in delayed hypocalcemia 4 to 10 days after administration of the composition. [Brief description of the drawings]

[0026] [Figure 1] FIG. 1 is a graph showing the increase in plasma 1,25-dihydroxyvitamin D over a 4-hour period following bolus administration. [Diagram 2] 1 is a graph showing postpartum blood calcium levels comparing treated and untreated cows. [Diagram 3] 1 is a graph showing postpartum blood calcium levels comparing treated and untreated cows. [Figure 4] 1 is a graph showing postpartum blood calcium levels comparing treated and untreated cows. [Diagram 5] 1 is a graph showing plasma calcium levels after parturition. [Figure 6] 1 is a graph showing plasma calcium levels after treatment and no treatment. [Figure 7] 1 is a graph showing plasma calcium levels after treatment and no treatment. [Figure 8] 1 is a graph showing plasma calcium levels after treatment and no treatment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0027] The present disclosure describes a method for providing a rapidly soluble source of oral calcium salt that promotes rapid paracellular absorption of calcium and acidifies the cow to increase tissue sensitivity to parathyroid hormone, along with exogenous 1,25-dihydroxyvitamin D or its 1-alpha hydroxylated analog, to promote longer and more efficient transcellular absorption of dietary calcium to prevent or reduce hypocalcemia and milk fever. The method preferably provides the soluble calcium salt source and exogenous 1,25-dihydroxyvitamin D or its analog immediately after calving. The soluble calcium salt source and exogenous 1,25-dihydroxyvitamin D are provided only once. Immediately after calving means that the soluble calcium salt source and exogenous 1,25-dihydroxyvitamin D or its analog are given within 6 hours after calving.

[0028] The terms 1,25-dihydroxyvitamin D and 1,25-OH2D are used interchangeably herein and should be considered to refer to the same structure.

[0029] The basic structure of 1,25-OH2D comprises a steroid, the carbons of which are numbered according to the convention described in Maestro et al., (2019). Numerous other potential vitamin D compounds that are 1-alpha hydroxylated can be utilized in addition to or in place of 1,25-OH2D, including but not limited to those listed in Maestro et al., (2019).

[0030] Unless otherwise noted, "vitamin D" without a subscript may be used alone, as a suffix or prefix, or as a modifier to refer to any of vitamin D2 (ergocalciferol), vitamin D3 (cholecalciferol), vitamin D4 (22-dihydroergocalciferol), and vitamin D5 (cytocalciferol).

[0031] Vitamin D secosteroids hydroxylated at carbon number 1 in the alpha configuration are referred to as "1-alpha hydroxylated vitamin D" compounds. 1-alpha-hydroxylated vitamin D compounds include 1,25-dihydroxyvitamin D compounds (i.e., 1,25-dihydroxyvitamin D2, 1,25-dihydroxyvitamin D3, 1,25-dihydroxyvitamin D4, 1,25-dihydroxyvitamin D5); active analogs thereof; or inactive analogs thereof that increase blood, tissue or cellular levels of the 1,25-dihydroxyvitamin D compounds or their active analogs.

[0032] "Analog" as used with respect to 1-alpha-hydroxyvitamin D compounds refers to a biological precursor of a 1,25-dihydroxyvitamin D compound, a biological metabolite of a 1,25-dihydroxyvitamin D compound, or a natural or synthetic compound recognized in the art as having structural similarity to or derived from a 1,25-dihydroxyvitamin D compound.

[0033] "Active" as used with respect to 1-alpha-hydroxyvitamin D compounds and analogs thereof refers to analogs that directly exert a vitamin D-dependent effect in a target tissue or cell without being modified or further metabolized in non-target tissues, cells, or other sites in the body. When used to modify "1-alpha-hydroxyvitamin D", the term "active" refers to 1,25-dihydroxyvitamin D compounds or active analogs thereof. "Inactive" analogs of 1-alpha-hydroxyvitamin D compounds, also useful in the present invention, are those that are unable to directly exert a vitamin D-dependent effect in a target tissue or cell without being modified or further metabolized in non-target tissues, cells, or other sites in the body. "Vitamin D-dependent effects" include any of the effects disclosed herein, known in the art, or hereafter discovered that result from administration or treatment with 1,25-dihydroxyvitamin D compounds. Examples of vitamin D-dependent effects include, but are not limited to, stimulation of transcellular absorption of calcium through the rumen and intestinal epithelium, and anabolic and catabolic effects on bone.

[0034] Biologically inactive analogs of 1,25-dihydroxyvitamin D that act in the body to form biologically active 1,25-dihydroxyvitamin D or analogs thereof may be used. They are generally less expensive to utilize than 1,25-dihydroxyvitamin D. One such compound is 1-alpha vitamin D3, which is hydroxylated at the 25 carbon to form the active 1,25-OH2D3. Other inactive 1-alpha-hydroxylated vitamin D compounds useful in the practice of the invention may contain one to five promoieties, which may be present at either the C-1, C-3, C-24, or C-25 positions, or indirectly at the C-26 position. For purposes of this disclosure, it is understood that the promoieties may be added to any hydroxyl group present in the truncated (free) form of 1,25OH2D. For example, in 1,25-dihydroxyvitamin D3, the promoieties may be added to the hydroxyl group at the C-24, C-25, C-3, or any combination thereof.

[0035] In 1-alpha hydroxylated vitamin D compounds, the pro-site can contain a sulfate group or a glycone group. By "glycone moiety" is meant glycopyranosyl or glycofuranosyl, as well as other moieties such as their amino sugar derivatives and glucuronides. The glycone moiety of vitamin D glycosides can contain up to 20 glycone units. Preferred are those with β-glycosidic bonds, such as those present in lime-producing plants such as Solanum glaucophyllum, Cestrum diurnum, and Trisetum flavescens.

[0036] The amount of 1-alpha hydroxyvitamin D compound required to maintain normal blood calcium levels or reduce hypocalcemia will, of course, vary with the individual mammal being treated and is ultimately at the discretion of the veterinary practitioner or animal breeder. Factors to be considered include the nature of the formulation, the mammal's body weight, surface area, age, general condition, and the particular compound being administered. In general, suitable effective doses of 1,25-dihydroxyvitamin D3 equivalent activity range from about 0.1 to about 2 μg / kg body weight, preferably 0.2 to 1 ug / kg, and most preferably 0.25 to 0.5 ug / kg.

[0037] Exogenous 1-alpha hydroxylated vitamin D and calcium salts are administered to the mammal in the preferred form, preferably a bolus. In the present application, a bolus includes a rounded mass, typically cylindrical, with a density greater than 1.2 g / ml so as not to float on the ruminant ruminal raft. Any shape suitable for administration to the particular mammal being treated is within the scope of the present disclosure. Also, in the present application, the term mammal as used herein is intended to apply to all domestic animals, such as all cattle, buffalo, pigs, horses, mules, donkeys, sheep, and goats. Of particular interest are dairy cows.

[0038] As summarized in Horst et al. (1997), there are numerous descriptions in the literature of the use of 1-alpha hydroxylated compounds administered prior to parturition as a means of preventing or reducing the severity of hypocalcemia that animals may experience at the onset of lactation. These compounds are effective because they stimulate the transcellular or active transport of calcium through the intestinal tract and also promote the release of bone calcium. The use of vitamin D compounds to control hypocalcemia has not been widely adopted due to three issues. These are the timing of administration of vitamin D compounds relative to parturition, the potential for causing toxicity from excess hypercalcemia, and the potential for causing inhibition of endogenous synthesis of 1,25-dihydroxyvitamin D, which results in hypocalcemia approximately 4-10 days later, when the efficacy of the administered vitamin D compound has waned. Prior art administration timing required vitamin D compounds to be administered within a window of several days prior to parturition to be effective. Prior art 1-alpha vitamin D compounds had to be administered at least 12-24 hours prior to calving because 1-alpha vitamin D requires 12-24 hours to initiate transcription and translation of proteins involved in active transport of calcium across the intestinal epithelium. For example, administration of 1-alpha hydroxyvitamin D3 or 1,25-dihydroxyvitamin D3 more than 4 days prior to calving is ineffective because the beneficial effects of these compounds on active calcium transport fade before the cow calves. It is very difficult to accurately predict that a cow will calve between 24 and 96 hours after administration of a 1-alpha hydroxyvitamin D compound. Because of this difficulty, the prior art generally recommends administering a second dose if the cow does not calve within 4-5 days after the first dose (Horst et. al., 1997). Increasing the dose or using a more potent analogue of 1,25OH2D can extend the window of efficacy by 1-3 days, but can also cause problems associated with acute hypercalcemia and toxicity. Complicating this is a third issue.As described by Horst et al., (1997), repeated or high doses of vitamin D compounds administered to prevent hypocalcemia or milk fever can result in substantial inhibition of the endogenous synthesis of 1,25-dihydroxyvitamin D. This can result in hypocalcemia 4-10 days after the beneficial effects of exogenous vitamin D compounds have worn off.

[0039] According to the teachings of US Patent No. 9,757,415, a composition containing willow willow glycosides for preventing and / or treating hypocalcemia and stabilizing blood calcium levels in dairy cows can be produced that does not cause excessive hypercalcemia or excessive inhibition of endogenous synthesis of 1,25-dihydroxyvitamin D. The composition utilizes 1,25-OH2D3 glycosides from willow willow leaves as a source of 1-alpha hydroxylated vitamin D compounds that are converted to 1,25-OH2D3 by ruminal microbial cleavage of the glycosides to release 1,25-OH2D3. The advantage of this method is that the leaf material is not expensive and can be considered as a natural feed source of 1-alpha-vitamin D compounds. Dolomite calcium is mixed with willow willow glycosides to form a hard compressed bolus that is only slowly solubilized in ruminal fluid and therefore can release willow willow glycosides into ruminal fluid for a longer period of time. To be most effective, the compositions of this patent should be administered 24-72 hours before calving. Calcium in the form of dolomitic limestone is poorly soluble in ruminal fluids and is poorly absorbed by the vitamin D-independent paracellular pathway across the rumen and intestinal epithelium. Thus, dolomitic calcium does not contribute substantially to maintaining normal blood calcium levels before the transcellular calcium absorption pathway initiated by 1,25-OH2D released from 1,25-OH2D glycosides in the leaves of willow tree is activated. The compositions can be administered up to 72 hours before calving, which is similar to the prior art. Since the time of calving can be difficult to predict in cows, if calving does not occur within 5 days after the administration of the sustained release bolus, a second bolus will probably be administered. The main obstacle in using this formulation, as with most of the prior art using vitamin D compounds to prevent periparturient hypocalcemia, is the precise timing of administration.

[0040] According to the teachings of U.S. Pat. No. 5,395,622, a bolus containing calcium salts, including calcium chloride and calcium sulfate, can support improvement of blood calcium levels in periparturient cows for 4 to 8 hours after administration to the cow. Therefore, as taught in U.S. Pat. No. 5,395,622, it is recommended that a second bolus of calcium salt be administered 12 or 24 hours after the first bolus to improve blood calcium levels for a longer period of time. Goff and Horst (1993) showed that the length of time that blood calcium levels rise after oral administration of calcium can be extended by 1 to 4 hours by increasing the dose of calcium administered. However, the dose must be limited because hypercalcemia can develop. More importantly, if large doses of calcium chloride, exceeding 3 to 3.5 equivalents of chloride, are utilized, the cow is at risk of developing uncompensated metabolic acidosis. As shown by Goff and Horst (1994), calcium propionate is also a rapidly soluble calcium source but does not acidify. Calcium propionate may also extend the period over which an administered dose is able to elevate blood calcium levels compared to calcium chloride (Goff and Horst, 1993).

[0041] The preventative approach of the present disclosure has several advantages over prior art approaches. A bolus can be administered as soon as the dairy farmer confirms that the cow has delivered a calf. The dairy farmer does not have to try to predict the correct time to administer exogenous 1-alpha hydroxyvitamin D to the pre-calving cow. Additionally, the preferred bolus form of the present disclosure is administered in a single dose, eliminating the need to locate and restrain the cow to administer multiple doses of oral calcium supplements to promote normocalcemia, as is often recommended when utilizing currently available calcium boluses. These advantages are achieved by feeding a mixture of soluble calcium salts, such as calcium chloride and calcium propionate, which promotes passive absorption of calcium across the rumen and intestinal epithelium, maintaining blood calcium levels for up to 12 hours after administration of the formulation. This allows the exogenous 1-alpha hydroxyvitamin D in the formulation the time it needs to stimulate active transport of calcium across the rumen and intestinal tissues that support more normal blood calcium levels for the next 60-72 hours. Oral calcium salts contain calcium chloride and are administered in a manner that promotes a small amount of metabolic acidosis, thus facilitating the release of bone calcium and the endogenous synthesis of 1,25-dihydroxyvitamin D, which may support eucalcemia. By also including calcium propionate or other non-acidifying, rapidly absorbed calcium sources in the formulation, a larger total amount of calcium may be safely administered, and more normocalcemic blood calcium concentrations may be maintained for 12 hours or more after administration. Exogenous administration of 1-alpha-hydroxyvitamin D rapidly raises blood 1,25-dihydroxyvitamin D concentrations in less than 4 hours, initiating the process of activating active transcellular calcium transport 4 to 12 hours before endogenous synthesis of 1,25-dihydroxyvitamin D would normally be expected to occur in response to an episode of hypocalcemia. Exogenous 1-alpha-hydroxyvitamin D allows for greater utilization of dietary calcium and bolus calcium remaining in the intestinal lumen.This synergistic effect of an orally soluble calcium salt and an exogenous 1-alpha hydroxylated vitamin D compound provides greater efficacy and is easier to use for treating perinatal hypocalcemia than either prior art approach alone.

[0042] The amount of calcium salt administered should be sufficient to support normal blood calcium levels for up to 12 hours. This protects the cow from hypocalcemia until the exogenous 1-alpha hydroxyvitamin D has had enough time to stimulate more efficient active transport of calcium from the intestinal lumen into the cow's blood. The amount of 1,25-dihydroxyvitamin D should be sufficient to stimulate calcium absorption in the intestinal tract within 12-18 hours of administration. Prior art compositions, which must be administered before calving to be effective, typically contained doses of 1-alpha hydroxyvitamin D compounds in the range of 300-600ug total to ensure sufficient blood levels of 1,25-dihydroxyvitamin D activity during the potential period of administration before calving (24-96 hours) to stimulate active calcium transport during the first few days after calving. Because the compositions of the present invention are administered at a readily identifiable time point within 6 hours after calving, the amount of 1-alpha hydroxyvitamin D of the present invention that has been found to be effective is less than a 300ug total dose. This may reduce the risk of inhibition of the renal 25-hydroxyvitamin D-1-alpha hydroxylase enzyme, which reduces endogenous synthesis of 1,25-dihydroxyvitamin D, as has been observed to occur 4 to 10 days after administration of large doses of 1-alpha hydroxylated vitamin D compounds.

[0043] Manufacturing method The method described below utilizes the amounts of calcium and 1-alpha-hydroxyvitamin D compound that have been found to be most effective for dairy cows weighing 500-700 kg. Doses for other species will need to be adjusted for differences in body weight.

[0044] Preparation of solid dose oral formulations (i.e., boluses) In this most preferred formulation for administration to cattle, a calcium salt (preferably 80-150 g CaCl2·xH2O (where x is 0 or more and 6 or less) and up to 250 g calcium propionate) and a 1-alpha hydroxylated vitamin D compound (preferably equivalent to 100-280 ug 1,25-dihydroxyvitamin D) are mixed with other ingredients including, but not limited to, compounds that support gluconeogenesis (i.e., propylene glycol, glycerin, propionate), electrolyte balance (potassium and sodium chloride, magnesium sulfate and magnesium chloride), yeast, nonsteroidal anti-inflammatory drugs, and rumen fermentable feed (i.e., alfalfa meal, soybean meal). These ingredients are mixed with water until a pumpable mixture is formed. Alternatively, water can be added to a mixing vessel and the above ingredients added to the water and mixed until a homogenous pumpable mixture is formed. Regardless of the preparation method utilized to make the pumpable mixture, the pumpable mixture can then be utilized to fill a mold made of paper, polymer, metal, or other material that will be shaped into an article (i.e., tablet or bolus) that can be swallowed by an animal. Once the homogeneous pumpable mixture is filled into the mold, the mold is allowed to rest (preferably under refrigeration) for 0.5 to 24 hours until the homogeneous pumpable mixture solidifies. Once solidified, the solid product may or may not be coated with the mixture to make the product easier to swallow. The resulting product is packaged to protect it from breakage and exposure to the elements. The product is administered orally to the animal. Methods for making a bolus are described in detail in U.S. Pat. No. 5,395,622 and U.S. Patent Application Publication No. 2007 / 0098810, both of which are incorporated herein by reference in their entireties.

[0045] For ease of administration to the cow, effective doses of the calcium salt and exogenous 1-alpha hydroxylated vitamin D compound can be distributed into one large bolus or multiple smaller boluses.

[0046] Preparation of tablets In this version, a calcium salt (preferably 80-150 g of calcium chloride and up to 250 g of calcium propionate) and a 1-alpha hydroxylated vitamin D compound (preferably equivalent to 100-280 ug of 1,25-dihydroxyvitamin D) are mixed with materials commonly utilized in the manufacture of compressed tablets or boluses. These materials are called excipients and can include items such as binders (i.e., dextrose, microcrystalline cellulose), lubricants (i.e., magnesium stearate), flow agents (i.e., dicalcium phosphate, silicon dioxide), disintegrants (i.e., starch), and other excipients. Sufficient force is then applied to the mixture to compress the flowable materials into a solid mass. Once a solid mass is formed, any number of these units can be administered to the animal utilizing applicators and techniques known to those skilled in the art of veterinary or animal husbandry. To facilitate administration to the cattle, the effective dose of calcium salt and exogenous 1-alpha hydroxylated vitamin D compound can be dispensed into one large tablet or multiple small tablets.

[0047] Preparation of Drench Product In this version, calcium salts (preferably 80-150g calcium chloride and up to 250g calcium propionate) and 1-alpha hydroxylated vitamin D compounds (preferably equivalent to 100-280ug 1,25-dihydroxyvitamin D) are mixed with other ingredients including, but not limited to, compounds that support gluconeogenesis (i.e., propylene glycol, glycerin, propionate), electrolyte balance (i.e., potassium and sodium chloride, magnesium sulfate and magnesium chloride), yeast, nonsteroidal anti-inflammatory drugs, and rumen fermented feed (i.e., alfalfa meal, soybean meal). These ingredients are mixed together and packaged as a dry matter that is approximately 85-90% dry matter. If 1,25-dihydroxyvitamin D or a similar fat-soluble vitamin D compound is utilized as the form of 1-alpha hydroxylated vitamin D, an agent must be incorporated to keep the water-insoluble 1,25-dihydroxyvitamin D in solution. Such materials are numerous and well known in the art, and include agents such as medium chain triglycerides that form an emulsion with 1,25-dihydroxyvitamin D and keep it suspended in the water of the drench. When the source of 1-alpha hydroxyvitamin D is a glycoside or glucuronide, which may be found, for example, in materials derived from lime-producing plants such as botrytis, no emulsifier is required as these vitamin D compounds are already water-soluble. On the feedlot, the drench mix is ​​added to a suitable amount of water (usually 0.5-20 L) in a bucket or other suitable container and administered orally to the cow immediately after calving via a drench gun, esophageal tube, or tube extending into the rumen, as is common practice in large animal veterinary medicine.

[0048] Preparation of gel or paste In this case, the calcium salt (preferably 80-120 g calcium chloride and 100-250 g calcium propionate) and 1-alpha hydroxylated vitamin D compound (preferably equivalent to 100-280 ug 1,25-dihydroxyvitamin D) are mixed with a carrier (i.e., propylene glycol, glycerol, water, or vegetable oil) and a thickener (i.e., xanthan gum, silicon dioxide) to form an emulsion or suspension, which is placed into a tube, typically 250-400 ml in volume. Other compounds can also be included, as described above. The tube containing the mixture is typically designed to fit into a caulking gun, using techniques familiar to animal husbandry and veterinary arts, for oral administration to the back of the cow's mouth. For ease of administration to the cow, the effective dose of calcium salt and exogenous 1-alpha hydroxylated vitamin D compound can be dispensed into one large paste tube or into multiple smaller tubes.

[0049] Since numerous modifications and variations within the scope of this disclosure will be apparent to those of ordinary skill in the art, the following examples are intended as illustrative only. EXAMPLES

[0050] Example 1 Calcium salt boluses were prepared incorporating either 150ug 1,25-dihydroxyvitamin D3 or 5, 7.5 or 10g of solanum glaucophyllum leaves (a plant that contains 1,25-dihydroxyvitamin D3 glycoside in its leaves). In the cow's rumen, the biologically inactive 1,25-dihydroxyvitamin D3 glycoside is cleaved by ruminal bacterial enzymes to the biologically active 1,25-dihydroxyvitamin D3. The batch of leaves used in this and all subsequent experiments described herein was determined to contain the equivalent of 14ug of 1,25-dihydroxyvitamin D3 per gram of leaves using a modified method from Gil et al., (2007). The Holstein cows used in this study were pregnant, near the end of lactation, and were scheduled to dry off within 2 weeks of the study. These cows were used because they were in positive calcium balance and therefore had relatively low endogenous 1,25-dihydroxyvitamin D concentrations in blood, which would allow a better understanding of the bolus-induced rise in plasma 1,25-dihydroxyvitamin D. Although our study animals were postpartum cows, previous studies have shown that plasma 1,25-dihydroxyvitamin D concentrations can vary considerably (low to very high) depending on the degree of hypocalcemia the cow experienced before calving and the time of blood sampling. The cows weighed 600-720 kg and produced 16-28 kg / day of milk. Two single-bolus treatments were administered so that each cow received a bolus containing, in total, either 300 ug 1,25-dihydroxyvitamin D or 10, 15, or 20 g of S. glaucophyllum leaves providing 140, 210, and 280 ug of 1,25-dihydroxyvitamin D activity equivalents. Blood samples were collected from the jugular vein of each cow into lithium heparin vacutainer tubes immediately before bolus administration (time 0) and at 1, 4, 24, 48, 72, and 96 hours after bolus administration. Plasma 1,25-dihydroxyvitamin D3 concentrations were analyzed by liquid chromatography-mass spectrometry.

[0051] As shown in Figure 1, plasma 1,25-dihydroxyvitamin D increased significantly in all cows by 4 hours after bolus administration. Plasma 1,25-dihydroxyvitamin D concentrations remained significantly elevated above pre-administration 1,25-dihydroxyvitamin D concentrations at 48 hours after administration, but not at 72 and 96 hours after administration. Plasma 1,25-dihydroxyvitamin D in cows receiving synthetic 1,25-dihydroxyvitamin D3 increased more quickly than in cows receiving 1,25-dihydroxyvitamin D3 glycoside derived from willow leaves. This may reflect the time it takes for ruminal bacteria to convert the glycoside to the active form 1,25-dihydroxyvitamin D so that it can be absorbed into the blood.

[0052] For Examples 2-5, statistical analysis consisted of repeated measures analysis of variance with cows nested within treatment and time after bolus as the repeated measure. Mean treatment plasma calcium values ​​at each time point were compared using Tukey's mean comparison test, and differences were declared significant when the probability that the null hypothesis was true was P<0.075.

[0053] Example 2 Example 2 was conducted on a dairy farm where both Jersey and Holstein cows were fed a pre-calving diet with a high anion loading designed to help control hypocalcemia. Only prolific cows were used and cows assigned to treatments were blocked by parity. Treatment effects for each breed were shown separately and then combined. Treatment protocols were identical for Jersey and Holstein cows, which were housed together for the last 21 days before calving.

[0054] Holstein The average urine pH for the Holsteins during the 2 weeks prior to calving was 5.68. Precalving dry matter (DM) intake for these cows was estimated at 23 lbs. (10.5 kg) / day. Seven Holsteins did not receive a bolus at calving. Nine cows received a commercial oral calcium bolus, providing approximately 50 g of calcium, primarily from calcium chloride. These Holsteins were treated at calving and then again the following morning (12-24 hours after the first bolus). Ten Holsteins received two calcium salt boluses, both containing willow leaf, at one time within 2 hours of calving. The two boluses provided a total of 78 g of calcium, mostly from calcium chloride and some from calcium propionate, which was determined to be equivalent to 196 μg of 1,25-dihydroxyvitamin D3 from willow leaves, which provided 1-alpha hydroxyvitamin D in the form of 1,25-dihydroxyvitamin D glycoside. Plasma samples were taken from each cow before treatment and at 3, 12, 24, 36, 48, and 72 hours after treatment. Plasma calcium concentrations were measured using the Arsenazio III reagent method.

[0055] Figure 2 shows the mean blood calcium ± standard error of the mean in Holstein cows. Plasma calcium at 36 and 48 hours after calving was significantly higher in Holstein cows receiving the Ca+SG bolus than in those receiving either no bolus or Ca bolus. All Ca-containing boluses significantly increased plasma calcium at 3 hours after calving compared with those receiving no bolus. Only Holstein cows receiving the Ca+SG bolus had mean plasma calcium above 8.25 mg / dl (2.06 mM) during the study. No bolus or Ca bolus groups had mean plasma calcium levels that did not reach 8.0 mg / dl (2 mM) during the 3 days after calving.

[0056] Jersey The mean urinary pH of Jersey cows prior to calving was 5.85, with 25% of Jersey cows having a urinary pH below 5.5. Dry matter intake prior to calving was estimated at 18 lbs. (8.2 kg) DM / day. Ten Jersey cows received a commercial oral Ca bolus at calving followed by a second Ca bolus 12-24 hours later. Fourteen Jersey cows received two Ca+SG boluses containing calcium and willow leaf only at calving. Three Jersey cows were left untreated (no bolus) after calving. Bolus composition and timing of blood sampling were as described above for the Holsteins in this example.

[0057] As shown in Figure 3, at 3 hours, the Ca+SG bolus and Ca bolus cows had significantly increased plasma calcium compared to the no-bolus cows. From that point on, the Ca bolus and no-bolus cows had similar plasma calcium concentrations. The Ca+SG bolus cows had significantly increased plasma calcium compared to the no-bolus cows at 3, 12, 24, and 36 hours after calving. The plasma calcium of the Ca+SG bolus cows was statistically better than that of the Ca bolus cows at 24 and 36 hours after calving. Only the Ca+SG bolus cows had mean plasma calcium greater than 8.5 mg / dl from 12 to 72 hours into the study.

[0058] Jersey and Holstein mixed data All cows were raised and fed similarly before and after calving, so the results for all cows in Example 2 are combined in Figure 4. Increasing the number of cows at each time point increases the statistical power of the study. The Ca+SG bolus treatment group had higher plasma calcium levels 3-48 hours after calving than the non-bolus treatment group, and higher plasma calcium levels 24, 36, and 48 hours after calving than the Ca bolus treatment group. Only the Ca+SG bolus treatment group had an average plasma calcium level of over 8.5 mg / dl from 12 to 72 hours.

[0059] Example 3 In Example 3, cows in a dairy herd were fed anions in the diet to achieve a urinary pH of 6-6.8. This is generally considered an effective means of preventing clinical hypocalcemia in dairy cows. The milk yield of this herd was 103 lds. (46.8 kg) / day with 3.9% fat. The average urinary pH of these cows in the weeks prior to calving was 6.6. In this study, nine prolific cows received one commercial calcium bolus (Ca bolus) at calving (43 g Ca / bolus) and again 12-24 hours after calving for a total of 86 g Ca, primarily from calcium chloride. Six cows received two Ca+10 g SG boluses at calving only. These two boluses contained 78 g calcium, primarily from calcium chloride and calcium propionate, and 10 g of willow leaf providing 140 ug of 1,25-dihydroxyvitamin D equivalent as the glycoside of 1,25-dihydroxyvitamin D3. Seven cows received two Ca+15 g SG boluses at calving only. These two boluses contained 78 g calcium, primarily from calcium chloride and calcium propionate, and 15 g of willow leaf providing 210 ug of 1,25-dihydroxyvitamin D equivalent as the glycoside of 1,25-dihydroxyvitamin D3. Plasma samples were taken from the jugular vein before bolus administration (time=0) and at 4, 12, 24, 48, and 72 hours post-calving.

[0060] As shown in Figure 5, Ca bolus cows had slightly higher plasma calcium concentrations prior to treatment than cows in either Ca + SG bolus treatment. The Ca + 15g SG bolus cows had plasma calcium concentrations above 9mg / dl by day 2. The Ca bolus cows had plasma calcium concentrations below 8.5mg / dl for the first 3 days after calving. The Ca + 10g SG group cows had plasma calcium above 8.5mg / dl by day 2. These data suggest that the 15g dose of willow leaf was more effective than the 10g dose of willow leaf for incorporation into a bolus to prevent hypocalcemia.

[0061] Example 4 This example involved high-yielding Holstein and Holstein x Jersey cross cows on a large commercial dairy farm, fed anions to prevent milk fever and hypocalcemia. Urinary pH averaged 5.7 in the weeks prior to calving.

[0062] Sixty cows were assigned to one of three parity- and breed-blocked treatment groups based on expected calving date (Holstein, Holstein x Jersey, with approximately equal numbers of cows in each group entering 2nd parity (N=10) or 3rd parity or more (N=10)). Treatments were as follows: A. Two Solanum glaucophyllum leaf calcium boluses (providing 78 g calcium and 1,25-dihydroxyvitamin D3 glycoside equivalent to 196 ug 1,25-dihydroxyvitamin D) at calving only; B. One calcium-containing gelatin capsule bolus containing calcium chloride providing 40 g calcium / dose. These were given at calving and again 12-24 hours post-calving for a total of 80 g calcium / cow; C. Cows that did not receive a bolus after calving. Plasma samples were collected immediately after delivery and before treatment (time=0), and at 24, 48, 72, 96, and 120 hours post-delivery.

[0063] Data are presented based on cow parity. There were 10 cows in each treatment group. In 2-parity cows (Figure 6), cows in the Ca+SG bolus treatment group had higher blood calcium concentrations 24-96 hours after treatment than any of the other treatment groups. Figure 7 shows plasma calcium concentrations in 3+ parity cows. In the Ca+SG bolus treatment group, mean plasma calcium concentrations exceeded 8 mg / dl within 24 hours. 3+ parity cows in the non-bolus treatment group had plasma calcium concentrations exceeding 8 mg / dl 48 hours after treatment. 3+ parity cows receiving Ca bolus achieved plasma calcium concentrations by 72 hours after treatment.

[0064] Example 5 In Example 5, high-yielding cows from several small farms not using anionic diets were used to reduce the incidence of hypocalcemia in cows. Within hours of calving, cows were treated with one of four different treatments. Six cows were not treated with a bolus after calving (No Bolus). Four cows were treated with intravenous calcium (10.5 g calcium in the form of calcium gluconate) after calving (IV Ca). Twenty-two cows received two boluses of calcium salt and willow leaf after calving, providing 78 g calcium and 1,25-dihydroxyvitamin D3 glycoside equivalent to 196 ug of 1,25-dihydroxyvitamin D3 (Ca+SG Bolus). Twenty-four cows were treated with a commercial oral calcium salt bolus at calving and 12-24 hours after calving. Each calcium salt bolus provided 40-44 g calcium, with a total calcium dose of 80-88 g, primarily from calcium chloride (Ca Bolus).

[0065] All cows had plasma calcium levels measured before treatment was administered, and all were considered hypocalcemic (plasma calcium <8.0 mg / dl). Cows receiving the no-bolus treatment after calving experienced a further decline in blood calcium during the first 4 hours after calving. As shown in Figure 8, cows receiving the no-bolus treatment had blood calcium levels below 8.0 mg / dl (generally considered an indicator of cows with subclinical hypocalcemia) until nearly 96 hours after calving. Cows in the Ca bolus treatment group had a smaller decrease in calcium at 4 hours and had significantly better blood calcium levels at 4 hours than cows receiving no bolus. However, their plasma calcium levels from 12 to 120 hours after calving were similar to those of cows receiving no bolus after calving. Intravenous administration of calcium solution (Ca IV) resulted in the highest plasma calcium levels at 4 hours after calving. However, from 24 to 84 hours after calving, these cows had the lowest plasma calcium levels. Intravenous administration of calcium disrupted the calcium homeostasis mechanism in cows, and more hypocalcemia was observed on the second and third days of lactation than in untreated cows. Cows treated with Ca+SG bolus showed elevated plasma calcium concentrations at each time point after calving, and their blood calcium concentrations exceeded the subclinical hypocalcemia threshold of 8.0 mg / dl by 24 hours after calving. From 4 hours to 84 hours after treatment, cows that received a Ca+SG bolus only at calving had significantly higher plasma calcium concentrations than cows that received a commercial oral calcium bolus twice after calving.

Claims

1. 1. A composition for oral administration to a perinatal mammal at risk of developing hypocalcemia within 0-6 hours after birth, comprising calcium in a form rapidly absorbable by the perinatal mammal using passive paracellular transport across the intestinal epithelium and a 1-alpha hydroxylated vitamin D compound in an amount sufficient to stimulate active transport of calcium across the intestinal epithelium, wherein the calcium and 1-alpha hydroxylated vitamin D are administered simultaneously to support the maintenance of normal blood calcium concentrations in the perinatal mammal.

2. 10. The composition of claim 1, wherein the form of calcium administered comprises a rapidly water soluble calcium salt, including calcium chloride, calcium sulfate, calcium propionate, calcium acetate, calcium lactate, or calcium formate, alone or in combination.

3. 2. The composition of claim 1, wherein calcium chloride is incorporated in an amount sufficient to induce compensatory metabolic acidosis within 8 hours after administration to support normal sensitivity of tissues to parathyroid hormone.

4. 2. The composition of claim 1, wherein the 1-alpha hydroxylated vitamin D compound comprises 1,25-dihydroxyvitamin D or 1-alpha hydroxyvitamin D or an analog thereof in an amount sufficient to stimulate transcellular lumenal or intestinal absorption of calcium.

5. 2. The composition of claim 1, wherein the 1-alpha hydroxylated vitamin D compound is a glycoside of 1,25-dihydroxyvitamin D found in lime-producing plants or extracts prepared from lime-producing plants.

6. The composition of claim 1, wherein the 1-alpha hydroxylated vitamin D compound is not incorporated in an amount sufficient to cause significant inhibition of renal 25-hydroxyvitamin D-1-alpha hydroxylase enzyme, thereby inhibiting endogenous production of 1,25-dihydroxyvitamin D, resulting in delayed hypocalcemia 4 to 10 days after administration of the composition.

7. 2. The composition of claim 1, wherein the 1-alpha hydroxylated vitamin D compound and calcium are administered simultaneously in the form of a bolus, tablet, or pellet having a density of at least 1.2 kg / L (g / ml) and are released from the bolus, tablet, or pellet over a period of less than 2 hours.

8. 1. A method for increasing, normalizing, or maintaining blood calcium levels or avoiding hypocalcemia in a mammal, said method comprising simultaneously administering to a perinatal mammal shortly after birth a composition of a 1-alpha hydroxylated vitamin D compound and a rapidly water soluble calcium source.

9. 9. The method of claim 8, wherein the 1-alpha hydroxylated vitamin D compound and calcium are administered simultaneously in the form of a bolus, tablet or pellet having a density of at least 1.2 kg / L (g / ml) and are released from the bolus, tablet or pellet over a period of less than 2 hours.

10. 9. The method of claim 8, wherein 1-alpha hydroxyvitamin D and the calcium salt of said compound support more normal blood calcium levels when administered simultaneously in a single dose without any additional doses.

11. 9. The method of claim 8, wherein the composition is capable of supporting normal blood calcium levels or reducing hypocalcemia when administered to a perinatal mammal within 6 hours of parturition, most preferably within 3 hours of parturition.

12. 12. The method of claim 11, wherein the composition is capable of supporting normal blood calcium levels or reducing hypocalcemia when administered to a perinatal mammal within three hours of parturition.

13. 9. The method of claim 8, which reduces hypocalcemia in a periparturient mammal, such as a dairy cow, that is at risk of developing hypocalcemia at the onset of lactation.

14. 9. The method of claim 8, wherein the administered calcium is in a form containing a sufficient amount of calcium chloride or calcium sulfate to induce compensatory metabolic acidosis in the animal to support tissue sensitivity to parathyroid hormone so as to improve calcium homeostasis within 8 hours after administration.

15. 9. The method of claim 8, wherein the calcium comprises calcium chloride, calcium sulfate, calcium propionate, calcium acetate, calcium lactate, or calcium formate, alone or in combination, in an amount sufficient to promote passive, vitamin D-independent, paracellular absorption of calcium to support normal calcium concentrations and reduce hypocalcemia during the first 6 to 12 hours after administration without inducing uncompensated metabolic acidosis in the animal.

16. 9. The method of claim 8, wherein the 1-alpha hydroxylated vitamin D compound comprises 1,25-dihydroxyvitamin D or 1-alpha hydroxyvitamin D or an analog thereof and is administered in an amount sufficient to stimulate transcellular lumenal or intestinal absorption of calcium to support normal blood calcium levels or to reduce hypocalcemia for 12 to 72 hours after administration.

17. 9. The method of claim 8, wherein the 1-alpha hydroxylated vitamin D compound comprises a glycoside of 1,25-dihydroxyvitamin D obtained from a lime-producing plant or an extract prepared from a lime-producing plant, and is administered in an amount sufficient to stimulate transcellular lumenal or intestinal absorption of calcium to support normal blood calcium levels or to alleviate hypocalcemia for 12 to 72 hours after administration.

18. 9. The method of claim 8, wherein the 1-alpha hydroxylated vitamin D compound is not incorporated in an amount sufficient to cause significant inhibition of renal 25-hydroxyvitamin D-1-alpha hydroxylase enzyme, thereby inhibiting endogenous production of 1,25-dihydroxyvitamin D, resulting in delayed hypocalcemia 4 to 10 days after administration of the composition.

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