Effect of dietary cation-anion difference on ruminal metabolism, total apparent digestibility, blood and renal acid-base regulation in lactating dairy cows

Autor(es)

Martins, C. M. M. R. ^[1] ; Arcari, M. A. ^[1] ; Welter, K. C. ^[2] ; Goncalves, J. L. ^[1] ; Santos, M. V. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Sch Vet Med & Anim Sci, Dept Nutr & Anim Prod, BR-13635900 Sao Paulo - Brazil

^[2] Univ Sao Paulo, Sch Food Engn & Anim Sci, Dept Anim Sci, BR-13635900 Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: ANIMAL; v. 10, n. 1, p. 64-74, JAN 2016.
• Citações Web of Science: 3

Resumo

The present study aimed to evaluate the effect of dietary cation-anion difference (DCAD) on ruminal fermentation, total apparent digestibility, blood and renal metabolism of lactating dairy cows. Sixteen Holstein cows were distributed in four contemporary 4x4 Latin Square designs, which consisted of four periods of 21 days and four treatments according to DCAD: +290; +192; +98 and -71 milliequivalent (mEq)/kg dry matter (DM). Ruminal pH and concentrations of acetic and butyric acid increased linearly according to the increase of DCAD. Similarly, NDF total apparent digestibility linearly increased by 6.38% when DCAD increased from -71 to 290 mEq/kg DM {[}Y=65.90 (SE=2.37)+0.0167 (SE=0.0068)xDCAD (mEq/kg DM)]. Blood pH was also increased according to DCAD, which resulted in reduction of serum concentrations of Na, K and ionic calcium (iCa). To maintain the blood acid-base homeostasis, renal metabolism played an important role in controlling serum concentrations of Na and K, since the Na and K urinary excretion increased linearly by 89.69% and 46.06%, respectively, from -71 to 290 mEq/kg DM. Changes in acid-base balance of biological fluids may directly affect the mineral composition of milk, as milk concentrations of Na, K, iCa and chlorides were reduced according to blood pH increased. Thus, it can be concluded that the increase of DCAD raises the pH of ruminal fluid, NDF total apparent digestibility, and blood pH, and decreases the milk concentration of cationic minerals, as well as the efficiency of Na utilization to milk production. (AU)

• Processo FAPESP: 12/22165-9 - Composição e estabilidade do leite de vacas alimentadas com dieta aniônica
• Beneficiário: Cristian Marlon de Magalhães Rodrigues Martins
• Modalidade de apoio: Bolsas no Brasil - Mestrado
• Processo FAPESP: 13/07041-4 - Efeito da dieta aniônica para vacas em lactação sobre o metabolismo e concentração de caseína do leite
• Beneficiário: Verônica Lopes Schvartzaid
• Modalidade de apoio: Bolsas no Brasil - Iniciação Científica
• Processo FAPESP: 12/23212-0 - Composição e estabilidade do leite de vacas alimentadas com dieta aniônica
• Beneficiário: Marcos Veiga dos Santos
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 13/02227-2 - Efeito da dieta aniônica sobre a estabilidade e composição do leite bovino
• Beneficiário: Maria Libera Tietz Cavalcanti
• Modalidade de apoio: Bolsas no Brasil - Iniciação Científica