A survey of the phosphorus and calcium contents of pastures and the serum inorganic phosphorus and calcium contents of cows on four Manawatu dairy farms

Serum inorganic phosphorus (Pi) and calcium (Ca) concentrations were assessed in 20 cows on each of four Manawatu factory supply dairy farms. Blood was taken from each cow before calving and at six-week intervals during lactation. Bleeding coincided with herd testing. Herds of Friesian or Friesian X cows and Jersey or Jersey X cows were compared on adjacent farms on a Central Yellow-brown Sand and on adjacent farms on a Peat Loam overlying a Central Yellow-brown Earth soil. Pasture mass and composition were estimated to grazing height in the next two paddocks to be grazed in the rotation. Mean serum Pi concentration was higher in cows on sandy soils (1.55 mmol Pi/l than in cows on the peat loam (1.34 mmol Pi/l (P<0.001). Concentrations were highest before calving (1.69 mmol Pi/l) but fell to low levels at peak lactation (1.17mmol Pi/l when 70% of cows were below the minima of the 'normal range', and during the drought (1.29 mmol Pi/l. Pasture phosphorus (P) concentrations were adequate to support cow nutrition for lactation (>0.33% DM, ad lib. feeding) until the summer drought when low herbage mass would have restricted milk production. Serum Ca was adequate for lactating cows and changed little between months or between cows (mean 2.12 mmol Ca/l). No metabolic disorders relating to mineral deficiencies were observed. It appears that serum Pi in a high proportion of cows falls below the normal range during peak lactation without cows displaying clinical deficiency symptoms or a depression in butterfat production.     

A survey of the phosphorus content of pastures and the serum inorganic phosphorus content of dairy cows

Serum inorganic phosphorus (Pi) concentration of 20 cows in each of ten factory supply dairy herds was assessed at monthly or two-monthly intervals during the 198243 lactation. Pasture on offer was ranked low, medium or high and the phosphorus (P) content assessed monthly on all farms from the two paddocks to be grazed next in the rotation. The mean serum Pi concentration was high (1.98 mmol/l) prior to calving but fell to low levels at peak lactation (1.28 mmol/l) and again during the drought (1.28-1.38 mmol/l) in January, February and March. Individual cows had Pi levels as low as 0.32 mmol/l. Herds on Northern Yellow-brown Earths had higher Pi levels than herds predominantly on Brown Granular Loams (P<0.01). There were differences between cows within herds (P<0.01) and Pi levels declined with cow age (P<0.01). Pasture P content was above minimum requirements for lactating cows (0.33% DM; with ad lib. feeding) from July through October but below requirements in most pastures from December through April, when pasture availability also limited production. The P content in pasture was unrelated to either its grass or legume content, but was higher in pastures given a medium or high DM ranking (P<0.05). The possibility of increasing dairy production with P supplementation in spring is discussed.     

The effect of dietary calcium and phosphorus supplementation in zeolite a treated dry cows on periparturient calcium and phosphorus homeostasis

Previous studies have proved the possibility of preventing parturient hypocalcaemia by zeolite A supplementation during the dry period, and a recent in vitro study has indicated a marked calcium (Ca) as well as phosphorus (P) binding effect of zeolite A in rumen fluid solutions. Because of the connection between the Ca and P homeostatic systems, the preventive effect against parturient hypocalcaemia may arise from zeolite induced decreased availability of dietary Ca as well as P. In the present study, the expected Ca and P binding capacity was challenged by feeding high and low levels of dietary Ca and/or P to zeolite A treated dry cows. Twenty-one pregnant dry cows were assigned to four experimental groups receiving a dry cow ration unsupplemented or supplemented with extra Ca and/or P. During the last 2 weeks of the dry period all cows additionally received 600 g of zeolite A per day. A high level of dietary P prepartum significantly decreased the plasma Ca concentration before as well as immediately after calving (day 0-3). Conversely, the plasma inorganic phosphate concentration was higher among these cows than among cows receiving no supplemental P. The prepartum dietary Ca level significantly affected the serum 1,25-dihydroxyvitamin D concentration during zeolite supplementation, whereas the periparturient plasma Ca concentration was apparently not affected by the dietary Ca level. During zeolite A supplementation plasma parathyroid hormone was significantly higher among cows receiving additional P. The urinary deoxypyridinoline/creatinine ratio was not affected by the prepartal dietary Ca or P level. Serum aluminium (Al) was significantly higher during zeolite A supplementation than during the preceding period, indicating partial destruction of the zeolite in the intestinal tract with subsequent release and absorption of Al. It is suggested that the effect of prepartum zeolite supplementation on the periparturient Ca homeostasis depends on the level of Ca as well as P in the dry cow ration.     

The effect of gestation and lactation on bone calcium, phosphorus and magnesium in dairy cows

A study was conducted to monitor changes in cortical bone mineral in the dairy cow in response to demands of lactation and pregnancy using rib bone biopsies in serial sampling. Sixteen Friesian cows from the University dairy herd were used to collect 9 samples during the lactation period and 5 samples during the dry period. The data were analysed using a split-plot design analysis of variance. There were no significant (P > 0.05) differences in cortical bone phosphorus concentrations in rib bone during the lactation period, but calcium concentrations in cortical bone were significantly (P < 0.05) higher at parturition and during the first 30 days of lactation compared to the next 30 days and between 90 and 120 days. Results reported here indicate that the cow resorbs cortical bone during the middle of the lactation period and not during the periparturient period as previously thought. Magnesium concentrations were also significantly (P < 0.05) higher at the beginning of lactation compared to some of the other sampling times, but cortical bone was significantly (P < 0.05) thinner at the beginning of lactation compared to several of the other sampling times. There were no significant (P > 0.05) differences in cortical bone Ca or Mg concentrations during the gestation period. Cortical bone P concentrations significantly (P < 0.05) decreased during the first 180 days, but significantly (P < 0.05) increased at 181-230 days and significantly (P < 0.05) decreased again at 231 days to term. Cortical bone thickness decreased significantly (P < 0.05) from the beginning of gestation to term. There were no significant (P > 0.05) differences in cortical bone thickness or Ca or Mg concentrations in cortical bone during the dry period, but cortical bone P concentrations were significantly (P < 0.05) greater at the end of the dry period compared to the first 30 days of the period. In general, cortical bone Ca and Mg values decreased as milk production increased up to 20 kg/day and cortical bone P values and bone thickness increased. In animals producing over 20 kg/day, however, cortical bone mineral values were greater and cortical bone thickness was lower compared to those animals producing less than 20 kg.     

Effects of dietary calcium, phosphorus, calcium: phosphorus ratio and vitamin K on performance, bone strength and blood clotting status of pigs

Three factorial experiments were conducted to evaluate the effects of various Ca:P ratios (1:1, 2:1 and 3:1) in diets having deficient (.3%), adequate (.6%) and excess (.9%) levels of dietary P on rate and efficiency of gain and bone strength of 192 pigs from 18 to 40 kg BW. A corn-soybean meal diet fortified with minerals and vitamins (but not vitamin K) was fed. Levels of Ca and P were achieved by adjusting the amounts of dicalcium phosphate and ground limestone in the diet. The corn was free of detectable mycotoxins. A hemorrhagic condition occurred in Exp. 1 in pigs fed the higher dietary Ca levels; all eight of the pigs fed 2.7% dietary Ca died of internal hemorrhage within the initial 28 d of the experiment. Vitamin K (5 mg menadione [as menadione dimethylpyrimidinole bisulfite]/kg) was added to half of the diets of the remaining animals and the experiment was continued for an additional 14 d. Prothrombin and whole blood clotting times were increased (P less than .01) in pigs fed high Ca without vitamin K but were normal in pigs fed high Ca with added vitamin K. Similar trends in clotting times occurred in a second experiment. A third experiment was conducted to determine whether the addition of vitamin K could reverse the hemorrhagic condition induced by feeding high dietary Ca for 28 d. As in the other two experiments, clotting times were increased (P less than .01) in pigs fed high Ca and no vitamin K. Addition of vitamin K after 28 d resulted in a return to basal prothrombin values by d 50. In regard to the original objectives, increasing the Ca:P ratio from 1:1 to 2:1 or 3:1 tended to reduce rate and efficiency of gain at all levels of P. Increasing the Ca:P ratio to 2:1 resulted in increased bone strength only when P was at or above the dietary requirement.     

Treatment of cows with milk fever using intravenous and oral calcium and phosphorus

Fifteen cows with milk fever were treated with 500ml of 40 % calcium borogluconate (group A) administered intravenously. Fifteen other cows with milk fever received the same treatment, supplemented with 500ml of 10 % sodium phosphate administered intravenously, and 80g calcium as calcium lactate and 70g inorganic phosphorus as sodium phosphate administered orally in drinking water. The cows were monitored and blood samples collected for 3 days to measure the concentrations of total and ionized calcium, inorganic phosphorus and magnesium and the activity of creatine kinase. The two groups did not differ significantly with respect to the course of the disease. In each group 14 cows were cured. A rapid and significant increase in serum calcium concentration from the hypo- to the hypercalcaemic range occurred in both groups within 10min of the start of treatment, followed by a slow and steady decrease to the hypocalcaemic range. Calcium lactate did not prevent the calcium concentration from returning to the hypocalcaemic range, and the calcium profiles of the two groups did not differ significantly. As expected, treatment had little effect on the concentration of inorganic phosphorus in group A. In group B, treatment caused a rapid increase in the concentration of inorganic phosphorus to a maximum 20min after the start of treatment. This was followed by a slow decrease in the phosphorus concentration to the normophosphataemic range. Our findings confirmed that combined intravenous and oral administration of sodium phosphate in cows with periparturient paresis attributable to hypocalcaemia and hypophosphataemia results in a rapid and sustained increase in serum phosphorus, but not in serum calcium concentration. This modified therapy did not improve the success rate of milk fever treatment and further studies are needed to improve treatment of periparturient paresis.     

The effects of calcium,phosphorus and zinc supplementation on reproductive performance of crossbred dairy cows in Tanzania

The effects of calcium (Ca), phosphorus (P) and zinc (Zn) supplementation on reproductive performance of grazing dairy cows was studied. Forty-eight cows in their first to third parity were allocated to eight groups of 6 animals each, based on stage of lactation and milk yield. Groups 1 (control), 2 (Ca), 3 (P) and 4 (Zn) received, respectively, no mineral supplement, 10 g Ca, 8 g P and 400 mg Zn. The rest of the groups received a combination of Ca/P, Ca/Zn, P/Zn or Ca/P/Zn. Animals were drenched daily. Ovarian activity was determined by progesterone concentrations in milk. Prepartum body condition score (BCS) measured using scale 1–5 was 2.5–3.5. Reproductive problems were observed in all groups except that supplemented with Ca. Cows supplemented with Ca, P, Ca/P, Ca/Zn and Ca/P/Zn had significantly (p < 0.05) shorter interval (30 days) from calving to resumption of oestrus as compared to control (69 days). Intervals from calving to conception and between calvings did not differ significantly between groups (p > 0.05), but were shorter in Ca-supplemented cows. Furthermore, cows in groups 2 and 3 needed an average of 2 services per conception against 3 for cows in other groups. Hence, supplementation with Ca, P and Zn of deficient dairy cows appears to improve reproductive performance.     

Prognostic value of blood lactate, blood glucose, and hematocrit in canine babesiosis

Canine babesiosis typically causes hemolytic anemia but also can result in multiple organ dysfunction. Human patients with severe disease often have persistent hyperlactatemia, and blood lactate concentration is correlated with survival rate. In dogs, blood lactate concentration has been shown to be of prognostic value in patients with gastric dilatation-volvulus and in dogs admitted to intensive care units. Serial blood lactate and glucose concentrations and hematocrit on admission were determined in 90 dogs with naturally occurring, severe or complicated canine babesiosis. Forty-five dogs (50%) had hyperlactatemia (blood lactate concentration >22.5 mg/dL) and 20 (22.2%) had hypoglycemia (blood glucose concentration <59.4 mg/dL) at presentation. Measurements significantly associated with mortality were hypoglycemia on admission, blood lactate concentration >45 mg/dL on admission, blood lactate concentration >22.5 mg/dL at 8, 16, and 24 hours after admission, and increase or <50% decrease in blood lactate concentration within 8 and 16 hours after admission. Blood lactate concentration persistently >40 mg/dL indicated a very poor prognosis. We conclude that serial blood lactate measurements are useful in predicting survival in dogs with severe and complicated canine babesiosis.     

Effectiveness of calcium chloride in increasing blood calcium concentrations of periparturient dairy cows.

Calcium chloride supplements such as gels and drench were studied to determine their effectiveness for increasing blood serum Ca concentrations in periparturient dairy cows. Multiparous, pregnant Holstein dairy cows (n = 36) were assigned to one of four treatments. After calving, cows in four treatments received basal diet and two doses of either control inert gel (CON), gel containing CaCl2 and vitamins (CVG), gel containing CaCl2 and minerals (CMG), or CaCl2 as drench containing vitamins (CVD). The first dose was given within 2 h after calving and the second dose 12 h after the first dose. Each dose provided .07, 54.5, 56.0, and 33.2 g of elemental Ca in CON, CVG, CMG, and CVD treatments, respectively. Blood samples were collected at 0, 15, 30, 60, 180, and 360 min after each oral dose. The blood serum Ca concentrations were 6.26, 7.56, 6.20, and 5.96 mg/dL during the pretreatment period and deviated -13.5, 7.1, 9.3, and 18.1% from pretreatment levels at 18 h after the first dose in CON, CVG, CMG, and CVD treatments, respectively. The average changes in serum P from pretreatment levels were not different among treatments. Serum Mg concentrations remained below the pretreatment levels in all four treatments. Blood serum beta-hydroxybutyrate during the first 2 wk and milk yields during the first 4 wk of lactation were the same in all treatments. Three cases of clinical milk fever were observed in CON treatment and one case in CVD treatment. The oral supplements of CaCl2 as gel or drench increased the blood Ca levels in periparturient dairy cows. Increased supply of Ca through oral supplements of CaCl2 may prevent milk fever in cows that are marginally hypocalcemic.     

添加甘氨酸铁螯合物对母猪血红蛋白含量、红细胞压积和繁殖性能的影响

本试验旨在研究甘氨酸铁螯合物对妊娠晚期和哺乳期母猪繁殖性能的影响。产仔前在母猪料中添加62.5g/t的甘氨酸铁,分别饲喂0（对照组）、2、4、6、8周,测定母猪和所产仔猪的血红蛋白含量和红细胞压积值,记录并计算分娩活仔数、断奶活仔数、初生重、死亡率、木乃伊胎儿率、哺乳仔猪生长率和断奶体重,观察母猪及仔猪的贫血发生率。母猪的红细胞压积平均为33.7±2.7%,仔猪的红细胞压积平均为32.2±3.9%,母猪血红蛋白含量为11.3±0.9g/100mL,仔猪血红蛋白含量为10.8±1.3g/100mL。母猪和仔猪贫血症（血红蛋白含量低于8g/100mL）的发病率很低,各组间的差异不显著。整个试验期间,母猪和仔猪都没有发生附红细胞体病。母猪和仔猪的红细胞压积和血红蛋白含量间存在显著的相关性。初生活仔数、初生重、断奶活仔数各组间没有显著差异,但对照组窝产死仔率和木乃伊胎儿率在各组中最高,而且试验组哺乳仔猪生长率显著高于对照组。试验结果显示在母猪日粮中添加螯合铁有利于哺乳仔猪的生长。     

A note on post partum utero vaginal prolapse in Gir cows: estimation of serum calcium, phosphorus, proteins, and cholesterol

Reported are results obtained from determination of calcium, phosphorus, protein, and cholesterol in blood serum of 10 Gir cows with uterine prolapse. Particular reference is made to possible adverse effects of hypocalcaemia in conjunction with physiological stress resulting from pregnancy and parturition.     

Phosphorus in swine. VI. Utilization of nitrogen, calcium and phosphorus and reproductive performance of gravid gilts fed two dietary phosphorus levels for five parities

Sixty-two gilts were paired at breeding and assigned randomly to one of the following dietary treatments: (1) low P or (2) high P during gestation and lactation. Two sets of diets (A and B) were formulated; each set to provide a low (10 g) and high (15 g) daily P intake (equal Ca daily intake, 15 g) when fed at 1.82 and 2.27 kg daily, respectively for sets A and B. Females were fed 1.82 kg daily of set A diets during the first 11 wk of gestation, 2.27 kg daily of set B diets for the next 3 wk and 3.34 kg of the appropriate set B diets containing 20% wheat bran until farrowing, at which time the bran was gradually removed from set B diets and the feed level increased to 4 kg daily until weaning. The proportions of defluorinated phosphate and limestone were varied to provide the appropriate level of Ca and P (low and high). At approximately 5 wk before farrowing at each parity, up to 12 females from each group were used in Ca, P and N balance trials that lasted about 2 wk. Dietary P intake did not affect the apparent absorption and retention of N and Ca; 88% of the consumed N was absorbed and one-half of the absorbed was retained, and 37% of the Ca was absorbed and 94% of the absorbed was retained. Females fed the higher P intake, although excreting higher levels of P in the feces and urine, absorbed and retained a larger amount of P; but the low P-fed sows were more efficient in the retention of P when expressed as a percentage of intake or as a percentage of the absorbed P. With the exception of average total litter weight at birth that favored high P-fed sows, live, dead and total pigs at birth, average birth weight and breeding performance were not statistically different between P levels. Except for the first parity, most characteristics favored sows fed the higher P intake. Serum Ca and P levels and hair P concentration were similar between P levels. Hair Ca concentration, however, was higher for the high P-fed sows. Sows fed the higher daily P intake retained more P and there was a trend for better farrowing performance. However, breeding performance, serum Ca and P levels, hair P concentrations and Ca and N balance were similar between dietary P intakes. These results would support current National Research Council-suggested Ca and P levels for sows.