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Effect of dietary cation-anion difference on acid-base status and dry matter intake in dry pregnant cows.
Zimpel, R; Poindexter, M B; Vieira-Neto, A; Block, E; Nelson, C D; Staples, C R; Thatcher, W W; Santos, J E P.
Afiliação
  • Zimpel R; Department of Animal Sciences, University of Florida, Gainesville 32611; DH Barron Reproductive and Perinatal Biology Research Program, University of Florida, Gainesville 32611.
  • Poindexter MB; Department of Animal Sciences, University of Florida, Gainesville 32611.
  • Vieira-Neto A; Department of Animal Sciences, University of Florida, Gainesville 32611; DH Barron Reproductive and Perinatal Biology Research Program, University of Florida, Gainesville 32611.
  • Block E; Arm and Hammer Animal Nutrition, Princeton, NJ 08540.
  • Nelson CD; Department of Animal Sciences, University of Florida, Gainesville 32611.
  • Staples CR; Department of Animal Sciences, University of Florida, Gainesville 32611.
  • Thatcher WW; Department of Animal Sciences, University of Florida, Gainesville 32611; DH Barron Reproductive and Perinatal Biology Research Program, University of Florida, Gainesville 32611.
  • Santos JEP; Department of Animal Sciences, University of Florida, Gainesville 32611; DH Barron Reproductive and Perinatal Biology Research Program, University of Florida, Gainesville 32611. Electronic address: jepsantos@ufl.edu.
J Dairy Sci ; 101(9): 8461-8475, 2018 Sep.
Article em En | MEDLINE | ID: mdl-29970257
ABSTRACT
The objective was to determine if the reduction in dry matter (DM) intake of acidogenic diets is mediated by inclusion of acidogenic products, content of salts containing Cl, or changes in acid-base status. The hypothesis was that a decrease in intake is mediated by metabolic acidosis. Ten primigravid Holstein cows at 148 ± 8 d of gestation were used in a duplicated 5 × 5 Latin square design. The dietary cation-anion difference (DCAD) of diets and acid-base status of cows were manipulated by incorporating an acidogenic product or by adding salts containing Cl, Na, and K to the diets. Treatments were a base diet (T1; 1.42% K, 0.04% Na, 0.26% Cl; DCAD = 196 mEq/kg); the base diet with added 1% NaCl and 1% KCl (T2; 1.83% K, 0.42% Na, 1.23% Cl; DCAD = 194 mEq/kg); the base diet with added 7.5% acidogenic product, 1.5% NaHCO3, and 1% K2CO3 (T3; 1.71% K, 0.54% Na, 0.89% Cl; DCAD = 192 mEq/kg); the base diet with added 7.5% acidogenic product (T4; 1.29% K, 0.13% Na, 0.91% Cl; DCAD = -114 mEq/kg); and the base diet with 7.5% acidogenic product, 1% NaCl, and 1% KCl (T5; 1.78% K, 0.53% Na, 2.03% Cl; DCAD = -113 mEq/kg). Periods lasted 14 d with the last 7 d used for data collection. Feeding behavior was evaluated for 12 h in the last 2 d of each period. Reducing the DCAD by feeding an acidogenic product reduced blood pH (T1 = 7.450 vs. T2 = 7.436 vs. T3 = 7.435 vs. T4 = 7.420 vs. T5 = 7.416) and induced a compensated metabolic acidosis with a reduction in bicarbonate, base excess, and partial pressure of CO2 in blood, and reduced pH and strong ion difference in urine. Reducing the DCAD reduced DM intake 0.6 kg/d (T1 = 10.3 vs. T4 = 9.7 kg/d), which was caused by the change in acid-base status (T2 + T3 = 10.2 vs. T4 + T5 = 9.6 kg/d) because counteracting the acidifying action of the acidogenic product by adding salts with strong cations to the diet prevented the decline in intake. The decline in intake caused by metabolic acidosis also was observed when adjusted for body weight (T2 + T3 = 1.75 vs. T4 + T5 = 1.66% BW). Altering the acid-base status with acidogenic diets reduced eating (T2 + T3 = 6.7 vs. T4 + T5 = 5.9 bouts/12 h) and chewing (T2 + T3 = 14.6 vs. T4 + T5 = 13.5 bouts/12 h) bouts, and extended meal duration (T2 + T3 = 19.8 vs. T4 + T5 = 22.0 min/meal) and intermeal interval (T2 + T3 = 92.0 vs. T4 + T5 = 107.7 min). Results indicate that reducing the DCAD induced a compensated metabolic acidosis and reduced DM intake, but correcting the metabolic acidosis prevented the decline in DM intake in dry cows. The decrease in DM intake in diets with negative DCAD was mediated by metabolic acidosis and not by addition of acidogenic product or salts containing Cl.
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Texto completo: 1 Coleções: 01-internacional Base de dados: MEDLINE Limite: Animals / Pregnancy Idioma: En Ano de publicação: 2018 Tipo de documento: Article

Texto completo: 1 Coleções: 01-internacional Base de dados: MEDLINE Limite: Animals / Pregnancy Idioma: En Ano de publicação: 2018 Tipo de documento: Article