Response of Calves to Diets That Varied in Amounts of Ruminally Degradable Carbohydrate and Protein

Abstract

Holstein calves were used wk 1 to 12 after birth to evaluate three sources of nonstructural carbohydrates that differed in ruminal degradability (corn, barley, and dried whey) with two sources of CP (normal and extruded soybean meal) that also differed in ruminal degradability. Nonstructural carbohydrates were most degradable in the dried whey diets and least degradable in the corn diets, and protein was more degradable in soybean meal than in extruded soybean meal. Pelleted diets were formulated to be isonitrogenous at 18% CP and contained (DM basis) 20% ground alfalfa hay, the respective carbohydrate and protein sources, vitamins, minerals, and antibiotic premix. All calves received 4.5 kg/d of milk during wk 1 to 4 and 2.3 kg/d during wk 5. The BW gains during wk 1 to 12 were higher (.80, .70, and .70 kg/d) for calves fed corn than for those fed barley and dried whey, respectively, and were slightly higher for calves fed extruded versus normal soybean meal (.76 and .71 kg/d). Corresponding DMI (1.47, 1.34, and 1.31 kg/d) were higher for calves fed corn than for those fed barley and dried whey and were higher for calves fed extruded versus normal soybean meal (1.43 and 1.32 kg/d). Trends in BW gains and feed intakes for wk 1 to 5 and 6 to 12 were similar. Feed to gain ratio was similar for all diets in all periods. The BW gains of calves tended to be greater when they were fed diets containing nonstructural carbohydrates and protein that was less ruminally degradable.

Effects of Feeding Different Carbohydrate Sources and Amounts to Young Calves

“…From the results of studies 2 and 3, it does not appear that a calf less than 12 wk old requires more digestible fiber than is provided from the non-soyhull ingredients of the starter. Maiga et al (1994) fed calves pelleted diets containing 20% alfalfa from birth to 12 wk of age to compare corn, barley, and whey as ingredients. They reported the best ADG in calves fed corn.…”

“…tion to be lower in calves fed beet pulp. Collectively, the research of Maiga et al (1994) and Williams et al (1987) suggests that calves fed barley, citrus pulp, or beet pulp will have a lower ADG than calves fed corn and that the digestion of pulp appears lower than that of grain. Again, these data provide little evidence that a digestible fiber source is needed in the diet of a young calf, as suggested by the NRC (2001).…”

Alimentação de bezerros ruminantes com dieta líquida, via goteira esofageana: parâmetros ruminais

“…Contrariamente, o aumento na ingestão de matéria seca, em ruminantes jovens, quando se utilizam fontes protéicas que sobrepassam o rúmen é relatado por diversos autores (Sampath & Sivaraman, 1986;Dawson et al, 1988;Guthrie & Wagner, 1988;Petit et al, 1991;Swartz et al, 1991;Mir et al, 1991;Iriki et al 1992;Reddy et al, 1993;Maiga et al, 1994;Bunting et al 1996;Sampath et al, 1996). A explicação para os melhores resultados de consumo e ganhos de peso seria o maior afluxo de aminoácidos essenciais para o intestino delgado, segundo Koeln & Paterson (1986).…”

Alimentação de bezerros ruminantes com dieta sólida ou líquida, via goteira esofageana: formação da goteira e escape ruminal

“…Contudo, ∅rskov et al (1973), com ovinos, observaram aumento linear na ingestão de matéria seca e Hedde et al (1974), com bezerros, aumentos lineares nos ganhos de peso quando suplementaram a proteína dietética, via líquida, com formação de goteira esofágica, ao invés de na forma sólida. O aumento nos ganhos de peso e/ou ingestões de alimentos, em ruminantes jovens, quando se utilizam fontes protéicas que sobrepassam o rúmen é relatado por diversos autores (Sampath e Sivaraman, 1986;Drevjany, 1987;Dawson et al, 1988;;Swartz et al, 1991;Iriki et al, 1992;Reddy et al, 1993;Maiga et al, 1994;Bunting et al, 1996;Sampath et al, 1996). Aumentos na ingestão de alimento e/ou na produção láctea em fêmeas adultas foram evidenciados por Murphy & Kennelly (1986), Garnswortthy & Jones (1987), Ramachandra & Sampath (1995).…”

“…O desempenho de bezerros recebendo fontes de proteína não degradável é, na maioria das vezes, superior ao dos que não as recebem (Sampath & Sivaraman, 1986;Drevjany, 1987, Swartz et al, 1991Iriki et al, 1992;Reddy et al, 1993, Maiga et al, 1994Bunting et al, 1996;Sampath et al, 1996), devido ao maior fluxo de aminoácidos que chegam ao intestino delgado (Koeln & Paterson, 1986). Uma forma de impedir a degradação protéica no rúmen, evitando a perda de aminoácidos dietéticos essenciais, seria o fornecimento de fontes protéicas, via goteira esofágica.…”