Parturient hypocalcemia in jersey cows fed alfalfa haylage-based diets with different cation to anion ratios.
Jersey cows were fed three alfalfa haylage-based diets with different cation-anion balances beginning 6 wk preceding third or later calving and ending 24 to 36 h postpartum. Sodium and Cl as percentages of dietary DM were .08 and 1.66 in diet 1 (anionic, 5 cows), .44 and .91 in diet 2 (intermediate, 6 cows), and 1.60 and .34 in diet 3 (cationic, 6 cows). Cation-anion balances were 22, 60, and 126 meq/100 g DM; Ca:P ratios averaged 4:1. Cows fed diet 1 in comparison with cows fed diets 2 or 3 over 6 wk had similar concentrations of Ca, P, and Na but higher concentrations of Mg and K in plasma and higher urinary excretions of Ca and Mg. Concentrations of 1,25-dihydroxyvitamin D 3 d before parturition were higher in cows fed diet 1 than in cows fed diets 2 or 3. Within 36 h after calving, mean concentrations of Ca in plasma (mg/dl, range) of cows fed diets 1 to 3, respectively, were 7 (8.7 to 6.2), 6.5 (7.8 to 3.9), and 6.3 (7.8 to 3.8). Number of cases of clinical milk fever by diet were 0 of 5, 2 of 6, and 1 of 6 cows. Alteration of dietary cation-anion balance by addition of Cl may effectively reduce incidence and severity of parturient hypocalcemia.
Gaynor
P J
PJ
Dairy Experiment Station Lewisburg, TN 37091.
Mueller
F J
FJ
Miller
J K
JK
Ramsey
N
N
Goff
J P
JP
Horst
R L
RL
D000821:Animal Feed / Q000032:analysis*; D000818:Animals; D000838:Anions / Q000032:analysis*; D002118:Calcium / Q000097:blood; D002412:Cations / Q000032:analysis*; D002417:Cattle; D002418:Cattle Diseases / Q000209:etiology / Q000378:metabolism; D005260:Female; D006996:Hypocalcemia / Q000209:etiology / Q000378:metabolism / Q000662:veterinary*; D007743:Labor, Obstetric; D000455:Medicago sativa; D010319:Parturient Paresis / Q000209:etiology*; D010758:Phosphorus / Q000097:blood; D011247:Pregnancy; D012964:Sodium / Q000097:blood
D000838:Anions; D002412:Cations; D010758:Phosphorus; D012964:Sodium; D002118:Calcium