Dietary Cation-Anion Balance and Cation Source Effects on Production and Acid-Base Status of Heat-Stressed Cows

Abstract

Two 4 x 4 replicated Latin square studies, each containing 8 lactating Holstein cows, were conducted simultaneously in south Georgia during the summer. The effects of dietary cation source (Na or K) and increasing dietary cation-anion balance (milliequivalents of Na + K - Cl per kilogram of feed DM) within cation source (control = 120.4 meq/kg of feed DM; Na source = 219.7, 347.8, 464.1 meq/kg of feed DM; K source = 231.2, 352.6, 456.0 meq/kg of feed DM) were determined on performance and acid-base chemistry during hot, humid weather. Cow body temperatures were elevated by environmental conditions but were not affected by dietary cation-anion balance. Differences in body temperature from dietary cation source probably were related to differences in cow BW. Intake of DM increased linearly, but yields of milk and FCM did not change with increasing dietary cation-anion balance, and cation source had no effect. Milk fat and protein percentages were not altered by dietary cation-anion balance, and greater milk fat and protein percentages from cows offered the Na versus K source diets probably were due to differences between cows in the two Latin squares. Alterations in blood acid-base chemistry with increasing dietary cation-anion balance were as expected. Greater blood buffering capacity, indicated by blood base excess and bicarbonate content, may be responsible for the improved feed intake.

Nutrient intake, acid base status and growth performance of growing male buffalo calves fed varying level of dietary cation anion difference

“…Ruminant kidneys are highly sensitive to blood acid base status and increase the excretion of Ca during acidosis, independent of the hormonal action usually associated with Ca metabolism (Stacy and Wilson, 1970). These results are in concordance with West et al (1992) who observed an increased urinary Ca: creatinine (0.30 versus 0.09) excretion with increased (120 versus 465 mEq/kg) level of DCAD. Alteration in fecal Ca excretion might be attributed to dietary concentration of this mineral.…”

“…Tucker et al (1988) also reported decreased feed intake in cows fed CaCl 2 . Decreased DMI with reduced DCAD level of diet had also been reported by West et al (1991West et al ( , 1992.…”

Influence of varying dietary cation anion difference on serum minerals, mineral balance and hypocalcemia in Nili Ravi buffaloes

“…In the present study CaCl 2 (1.75%) was used to achieve the required (− 110) DCAD level. Decreased DMI with reduced DCAD level of diet has also been reported by other workers (West et al, 1991(West et al, , 1992Spanghero, 2004).…”

Balanço cátion-aniônico da dieta na composição do leite

“…O teor de gordura do leite não se alterou em função do BCAD (P>0,05). Este resultado concorda com aquele observado por WEST et al (1992), os quais, estudando diferentes níveis de BCAD e duas fontes de cátion (Na e K) para vacas holandesas em lactação sob estresse térmico, não verificaram alterações nas concentrações de gordura do leite em função dos diferentes níveis de BCAD. Entretanto, houve aumento da gordura do leite para a fonte de Na quando comparada com a fonte de K, para um mesmo valor de BCAD.…”