Interactions of sodium, potassium, and chloride on lactation, acid-base status, and mineral concentrations.
Objectives were to determine responses to graded dietary concentrations of Na, K, and Cl and to cation-anion difference. The design was a partially balanced incomplete block with 48 cows, four 28-d periods, and 15 treatments. Five concentrations each of Na, K, and Cl, ranging from .31 to .85%, .86 to 1.96%, and .32 to 1.15%, respectively, were fed in a TMR based on corn silage. Cation-anion difference (Na+K-Cl) ranged from +12 to +62 meq/100 g of dietary DM. Dry matter intake was affected by interactions between Na and K and between Na and Cl. Yield of 3.5% FCM increased as Na increased (independent of K and Cl concentrations); FCM yield response to dietary K depended on dietary Cl. Milk fat percentage responded quadratically to Na, K, and Cl. Milk fat percentage was maximum at .60% Na, 1.34% K, and .69% Cl. Dry matter intake, BW gain, and blood partial pressure of CO2 responded in a cubic fashion; FCM yield, milk protein percentage, and blood HCO3 concentrations responded quadratically; and blood base excess increased linearly with increasing cation-anion difference. Based on regression models, 3.5% FCM yield and DMI were highest when the cation-anion difference was between +30 and +50. These results indicate that interrelationships among Na, K, and Cl were abundant and were related to blood acid-base status and mineral element concentrations.
Sanchez
W K
WK
Dairy Science Department, University of Florida, Gainesville 32611.
Beede
D K
DK
Cornell
J A
JA
D000136:Acid-Base Equilibrium / Q000187:drug effects*; D000818:Animals; D002412:Cations; D002417:Cattle / Q000502:physiology*; D002712:Chlorides / Q000008:administration & dosage / Q000494:pharmacology*; D004032:Diet; D004347:Drug Interactions; D004435:Eating; D005260:Female; D007774:Lactation / Q000187:drug effects*; D008055:Lipids / Q000032:analysis; D008892:Milk / Q000737:chemistry; D008903:Minerals / Q000378:metabolism*; D011188:Potassium / Q000008:administration & dosage / Q000494:pharmacology*; D012044:Regression Analysis; D012964:Sodium / Q000008:administration & dosage / Q000494:pharmacology*; D015430:Weight Gain
D002412:Cations; D002712:Chlorides; D008055:Lipids; D008903:Minerals; D012964:Sodium; D011188:Potassium