Effect of induced hypocalcemia in nonlactating, nonpregnant Holstein cows fed negative DCAD with low, medium, or high concentrations of calcium
| Autor: | Marisa Klister, Austin P Prichard, Dennis Nuzback, Adrienne A. Cheng, Laura A Amundson, P.M. Crump, S. S. Bascom, Laura L. Hernandez, Angela D Rowson, Ken P Zanzalari, Collin E Wimmler, Samantha R. Weaver |
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| Rok vydání: | 2018 |
| Předmět: |
Anions
0301 basic medicine Deoxypyridinoline Sodium Animal Health and Well Being chemistry.chemical_element Urine Urinalysis Calcium Hematocrit Random Allocation 03 medical and health sciences chemistry.chemical_compound Animal science Cations Genetics medicine Animals Egtazic Acid Whole blood Calcium metabolism Minerals Hypocalcemia medicine.diagnostic_test 0402 animal and dairy science 04 agricultural and veterinary sciences General Medicine Hydrogen-Ion Concentration Animal Feed 040201 dairy & animal science Diet Calcium Dietary EGTA 030104 developmental biology chemistry Cattle Female Animal Science and Zoology Food Science |
| Zdroj: | Journal of Animal Science. 96:5010-5023 |
| ISSN: | 1525-3163 0021-8812 |
| DOI: | 10.1093/jas/sky371 |
| Popis: | The main objective of this study was to determine how feeding different dietary calcium (Ca) concentrations in combination with a negative dietary cation–anion difference (DCAD) would affect the cow’s response to induced hypocalcemia. We conducted an experiment with multiparous, nonlactating, nonpregnant Holstein cows fed a negative DCAD (average −18.2 across all diets) for 21 d with low (LC; 0.45% Ca; n = 5), medium (MC; 1.13% Ca; n = 6), or high (HC; 2.02% Ca; n = 6) concentrations of dietary Ca. Urine and blood samples were collected and urine pH measured daily during the 21-d feeding period prior to hypocalcemia challenge. Cows were then subjected to a controlled induction of hypocalcemia to determine how dietary Ca intake affected the response to a hypocalcemia challenge. On days 22, 23, and 24, hypocalcemia was induced with an intravenous infusion of 5% EGTA in 2 different cows from each treatment daily. During infusion, blood samples were collected every 15 min until 60% of prechallenge ionized calcium (iCa) concentrations were achieved. Samples were collected postinfusion at 0, 2.5, 5, 10, 15, 30, and every 30 min thereafter until 90% of prechallenge iCa was reached. Blood pH, hematocrit, and serum total Ca (tCa), sodium (Na), potassium (K), phosphorous (P), magnesium (Mg), and serotonin did not differ (P > 0.05) among treatments during the feeding period. Blood iCa (P = 0.04) and glucose (P = 0.03) were significantly elevated in HC compared with LC and MC cows during the feeding period. Urine pH was less than 6.0 in all cows, but was lowest in LC (P = 0.02) compared with MC and HC cows during the feeding period. Urine Ca, P, Mg, and deoxypyridinoline did not differ among treatments (P > 0.05). Cows fed HC maintained higher concentrations of iCa (P = 0.03) during the challenge period than MC (P = 0.04), and LC (P = 0.004), and required a longer time to reach 60% of whole blood iCa, and required more EGTA to reach 60% iCa than MC or LC cows (P = 0.01). Serum tCa decreased in all cows during infusion (P < 0.0001) but did not differ among treatments. Serotonin concentrations were elevated in MC cows compared with HC and LC cows during EGTA infusion (P = 0.05), suggesting an interdependent relationship between iCa and serotonin. Cows fed HC had a slower rate of decrease in iCa, but not tCa, when induced with hypocalcemia, indicating potential metabolic benefits of feeding higher dietary Ca in combination with a negative DCAD. |
| Databáze: | OpenAIRE |
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