Processamento de milho (floculado vs. laminado a vapor) e adição de monensina para bezerras leiteiras, pré e pós-desmama precoce

Abstract

RESUMO -A suplementação de fontes de amido de maior digestibilidade e o uso de aditivos com atividade coccidiostática e promotora de crescimento podem melhorar o desempenho de bezerros leiteiros pré e pós desmama. O objetivo deste trabalho foi avaliar o efeito de concentrados contendo milho laminado a vapor ou floculado, com ou sem a adição de monensina, no consumo, ganho de peso e parâmetros sanguíneos de bezerras leiteiras, antes e após a desmama realizada a sexta semana de vida. Foram utilizadas 32 bezerras holandesas do nascimento a 12 semanas de vida, em um delineamento experimental do tipo blocos ao acaso, com arranjo fatorial 2 x 2. Do nascimento à desmama os animais receberam concentrado ad libitum até o consumo de 2 kg/d, quatro litros diários de leite e tiveram acesso livre à água. Após a desmama, realizada na sexta semana de vida, os animais continuaram recebendo 2 kg de concentrado e passaram a ter acesso a feno picado ad libitum. O tipo de processamento de grão ou a adição de monensina não afetaram o consumo médio de concentrado ou feno, assim como o peso final e o ganho de peso diário. As concentrações plasmáticas de glicose e ácidos graxos livres (AGL) médios do período experimental não foram afetadas pelos tratamentos; entretanto, as concentrações de n-uréico foram inferiores no plasma de animais recebendo concentrado com grãos laminados e monensina. Houve efeito da idade do animal nas concentrações plasmáticas de glicose, n-uréico e AGL. Somente os parâmetros glicose e AGL plasmáticos foram afetados pelo horário após o fornecimento do alimento. A inclusão de monensina ou de grão processados na dieta de bezerras leiteiras não resultou em melhor desempenho animal, antes ou após a desmama. Palavras-chave: ácidos graxos livres, desempenho, glicose, ionóforo, N-uréico, plasma Corn Processing (Steam-Flaked Vs. Steam-Rolled) and Monensin for Pre and Post Early Weaning Dairy CalvesABSTRACT -The supplementation of more digestible starch sources and feed additives with coccidiostatic and growth promoting activities may improve pre and post weaning calves performance. The objective of this trial was to evaluate the effects of concentrates containing processed grains (steam-flaked vs. steam-rolled), with or without monensin, on intake, weight gain and blood parameters of baby calves, before and after weaning at six weeks of life. Thirty-two female calves were utilized on a completely randomized block, with a 2 x 2 factorial arrangement. The animals received concentrate ad libitum up to 2 kg/d, plus 4 L of milk. Calves had free access to water. After weaning, at the sixth week of life, calves received concentrate and chopped hay. The treatments did not affect concentrate or hay intake, final live weight, average daily gain, plasma glucose and NEFA cocentration. PUN was lower on calves fed steam-rolled corn and monensin. There was a significant effect of age on glucose, PUN, and NEFA concentrations. Only glucose and NEFA were affected by time after feeding. Addition of monensin or processed grain to dairy cal...

Performance and plasma metabolites of dairy calves fed starter containing sodium butyrate, calcium propionate or sodium monensin

“…There were no significant treatment effects for plasma glucose concentration in any of the evaluated periods. Observed values are in agreement with those found in the literature for calves of similar age (Quigley and Bernard, 1992;Nussio et al, 2003a).Owing to the ruminal fermentation pattern modification, as a result of monensin supplementation, with higher propionate concentrations (McGuffey et al, 2001), a higher plasma glucose concentration was expected for calves fed starter containing the ionophore. Similarly, the direct supplementation of propionate via calcium propionate should have resulted in the same response, since propionate is the main glucose precursor in the liver (Bergman, 1990).…”

“…However, these effects would be seen only in animals with the rumen already developed. Nussio et al (2003a) also have not observed differences in plasma glucose concentration in calves fed starter with or without monensin.…”

“…Martin et al (1959) replaced calves' diets with organic acid salts infused directly into the rumen and observed a reduction in plasma glucose concentration with progressing age. Other authors have also found a similar pattern for glucose plasma concentrations according to animal age (Quigley et al, 1991a;Nussio et al, 2003a). However, Quigley and Bernard (1992) have not seen reductions in glucose levels according to week of age during the milk-feeding phase, probably because of the low DM intake observed and consequent delayed rumen development.…”

“…However, Nussio et al (2003a) observed low intake by calves receiving starter with or without monensin inclusion during the milk feeding period, which may have decreased animal performance during the subsequent period.…”

“…However, these effects would be seen only in animals with the rumen already developed. Nussio et al (2003a) also have not observed differences in plasma glucose concentration in calves fed starter with or without monensin.Even though there were no differences among treatments, a significant age effect was observed on plasma glucose concentration. A reduction of the glucose concentration as animals aged, response correlated to the rumen development and the transition of calves from pre-ruminant to functional ruminant, was observed.…”