Avaliação do ganho compensatório em novilhos mestiços Holandês-Gir: consumo e desempenho

Abstract

RESUMO -Avaliou-se a influência da restrição alimentar durante um período de pastejo de 104 dias (fase 1) sobre o consumo e a conversão alimentar, o conteúdo de digesta no trato gastrintestinal e os ganhos de peso corporal, da carcaça e dos constituintes não-carcaça em bovinos durante o período de realimentação em confinamento (fase 2). Foram utilizados 39 novilhos mestiços Holandês-Gir, com idade inicial de 19,3±5,1 meses e 202,0±49,1 kg de PV, distribuídos em três grupos segundo o regime alimentar proposto: controle -pastejo ad libitum na fase 1 e ração ad libitum na fase 2 (nove animais); ganho compensatório -pastejo restrito na fase 1 e ração ad libitum na fase 2 (15 animais); mantença -pastejo restrito na fase 1 e níveis de proteína e energia 15% acima da mantença na fase 2 (15 animais). Nos dias 1, 28, 56, 84 e 112 de confinamento, foram abatidos três animais do regime ganho compensatório e três do regime de mantença. Nos dias 1, 28 e 112, foram igualmente abatidos três animais do grupo controle. Em comparação aos animais do grupo controle, os novilhos do ganho compensatório ganharam mais peso corporal durante os primeiros 28 dias de confinamento (ganharam mais peso dos constituintes não-carcaça), porém, não diferiram quanto ao ganho de peso da carcaça. Após o início do confinamento, com a ingestão de alimentos concentrados, verificou-se redução contínua do conteúdo de digesta (em % PV) nos animais dos três regimes de alimentação, mas não foi observada diferença entre os regimes de alimentação. Nos grupos controle e ganho compensatório, os 28 dias iniciais de confinamento constituíram o período de melhor conversão alimentar, pois coincidiram com o período de maior consumo por unidade de tamanho metabólico e em porcentagem do peso vivo.Palavras-chave: carcaça, conversão alimentar, digesta, ganho de peso Evaluation of compensatory growth in crossbred Holstein-Gyr steers:intake and performance ABSTRACT -The objective of this trial was to evaluate the effect of feed restriction during a grazing period of 104 days (phase I) on intake, feed conversion, and digesta load as well as body weight (BW) change and weights of carcass and non-carcass components during a feedlot period (phase II) in crossbred steers. Thirty nine crossbred Holstein-Gyr steers averaging 19.3±5.1 months of age and 202.0±49.1 kg of BW at the beginning of the study were used. Animals were assigned to one of the following three treatments: 1 -control -ad libitum grazing in phase I and ad libitum concentrate in phase II (nine animals); 2 -compensatory growth -restricted grazing in phase I and ad libitum concentrate in phase II (15 animals); or 3 -maintenance -restricted grazing in phase I and protein and energy supplementation 15% above maintenance in phase II (15 animals). At 1, 28, and 112 days of feedlot, three animals from treatments 1, 2 and 3 were slaughtered. In addition, three animals from treatments 2 and 3 were also slaughtered at 56 and 84 days of feedlot. Animals from the compensatory growth treatment gained more BW than those from t...

Body composition and net requirements of protein and energy for weight gain of Nellore and crossbreed steers finished under grazing

“…This would indicate that in animals under restriction, the passage rate was lower and, therefore, the retention time of digesta was higher. In fact, the higher content of digesta in restricted animals, compared to ad libitum animals, have been attributed to a reduction in the rate of passage (Sainz, 1998, Fontes et al, 2007. This same principle could be observed, conversely, with increasing passage rate, due to the pelletization of diet, which would result in a reduction in the digesta content (Mertens & Ely 1979;Daenicke & Rohr, 1984).…”

<b>Nutrient intake, productive performance and body measurements of dairy heifers fed with different sources of protein</b> - doi: 10.4025/actascianimsci.v35i3.18749

“…Thus, probably the experimental animals were under malnutrition conditions, and this nutritional state causes accented growth or high gains in weight when they have access to adequate feeding, characterizing what is known as compensatory gain. During this stage, the animals increase the energy utilization efficiency and reduce the maintenance requirements and alterations in the body composition, compared with animals fed unrestrictedly (FONTES et al, 2007). The extension of the period of compensatory gain will depend on the degree and duration of the restriction period and on the diet in the re-feeding period.…”

Carcass and non-carcass components of Santa Ines lambs subjected to food restriction

“…This situation has encouraged producers and food scientists to seek alternative methods of farming that would improve meat production in this region. It has been proposed that food restriction, which is used in goats (YÃNÉZ et al, 2006), bovines (FONTES et al, 2007) and sheep (ALMEIDA et al, 2011) to reduce spending on feed in drought periods and results in compensatory growth, might provide a low-cost alternative to current extensive sheep farming methods. It is important to determine that food restriction would not impair the quality of carcasses, the main link between the producer and the consumer.…”