Performance and energy, protein and minerals requirements of beef cattle at pasture, submitted to different supplementation strategies

Autor: Moraes, Eduardo Henrique Bevitori Kling de
Přispěvatelé: Valadares Filho, Sebastião de Campos, Valadares, Rilene Ferreira Diniz, Paulino, Mário Fonseca, Detmann, Edenio, Zervoudakis, Joanis Tilemahos
Jazyk: portugalština
Rok vydání: 2006
Předmět:
Zdroj: LOCUS Repositório Institucional da UFV
Universidade Federal de Viçosa (UFV)
instacron:UFV
Popis: Conselho Nacional de Desenvolvimento Científico e Tecnológico This thesis was elaborated based upon four experiments that amaid to evaluate the effects of different supplementation strategies on performance and nutritional characteristics of beef cattle during dry, rainy and rainy/dry seasons at pastures of Brachiaria decumbens; as well as estimate the body composition and the energy, protein, calcium (Ca), phosphorus (P), magnesium (Mg), potassium (K) and sodium (Na) requirements of beef cattle at pasture. In the Experiment 1 (Dry season), 25 zebu calves, with age and initial weights of 7.5 months old and 194. kg, respectively, were used for performance evaluation and five Holstein-Zebu steers fistulated in rumen and esophagus, with 290.0 kg of LW were used to evaluate nutritional characteristics. The different supplementation strategies evaluated were: self-feed supplementation (SF) and infrequent supplementation (1.0 kg/animal/day). The frequencies of supplementation evaluates were: three times/week (Monday, Wednesday and Friday 3X), five times/week (Monday to Friday 5X), six times/week (Monday to Saturday 6X) and daily (7X). There were no effects of different strategies (P>0.10) on intake expressed in kg/day or perceptual of LW. However, DM total apparent digestibility and crude protein ruminal apparent digestibility were higher in SF strategic. No differences (P>0.10) were observed on microbial N and DM flux and its efficiency. Serum and urine concentrations were higher in animals consuming SF strategic. In Experiment 2 (Rainny season), 25 steers with initial age and live weight (LW), respectively, 10.5 mouths old and 222.4 kg grazing in five paddocks of Brachiaria decumbens were used for evaluate the performance. The different supplementation strategies evaluated were: mineral supplementation (MIS), self-feed supplementation (SF) and infrequent supplementation (0.500 kg/animal). The frequencies of supplementation evaluates were: three times/week (Monday, Wednesday and Friday 3X), five times/week (Monday to Friday 5X) and daily (7X). Supplement dry matter (DM) intake on animals that receive SF supplementation was 0.523 g/day. The ADG and final LW was smaller (P0.10). The ADG was 726.0; 891.0; 895.0; 885.0 and 892.0 g, respectively, for strategies MIS, SF, 3X, 5X and 7X. In experiment 3 (Rainny/dry season), 20 steers with initial age and live weight (LW), respectively, 14.0 mouths old and 311.0 kg grazing in four paddocks of Brachiaria decumbens were used for evaluate the performance. The different supplementation strategies evaluated were: mineral supplementation (MIS) self-feed supplementation (SF) and infrequent supplementation (0.550 kg/animal). The frequencies of supplementation evaluates were: three times/week (Monday, Wednesday and Friday 3X) and daily (7X). Supplement dry matter (DM) intake on animals that receive SF supplementation was 0.598 kg/day. The ADG and final LW was smaller (P0.10). The ADG was 661.40; 812.7; 811.5 and 819.2 g, respectively, for strategies MIS, SF, 3X and 7X. Independent of strategy, the protein supplementation increased nutrients and pasture intake (P0.10) were observed between SF and infrequent supplementation, as well as for different frequencies of supplementation on total, ruminal and intestinal apparent digestibility. No differences (P>0.10) were observed on microbial nitrogen and DM flux and its efficiency. Less nitrogen balance was observed in animals feeding only MIS (P0,10) dos tratamentos sobre os consumos expressos em kg/dia ou % PV. Observou-se efeito significativo da estratégia de suplementação (P0,10). O GMD foi de 726,0; 891,0; 895,0; 885,0 e 892,0 g, respectivamente, para as estratégias SM, AC, 3X, 5X e 7X. No Experimento 3 (Período de transição águas/seca), para avaliar o desempenho produtivo foram utilizados 20 novilhos anelorados não-castrados com idade e pesos médios iniciais, respectivamente, de 14 meses e 311,0 kg. Para avaliar as características nutricionais, foram utilizados quatro novilhos mestiços Holandês-Zebu, não-castrados, com peso médio inicial de 367 kg, fistulados no esôfago e rúmen. As estratégias de suplementação estudadas foram: suplementação mineral (SM) e suplementação protéica de autocontrole de consumo (AC) e infreqüente (0,550g/animal). As freqüências estudadas foram: três vezes/semana (segunda, quarta e sexta - 3X) e diariamente (7X). O consumo diário de matéria seca (MS) de suplemento dos animais que receberam suplemento do tipo AC de consumo, foi de 0,598 g, próximo ao consumo de 0,550 g preconizado durante a formulação do suplemento. Foi verificado menor ganho médio diário (GMD) e PV final para os animais que receberem apenas suplementação mineral (P0,10). O GMD foi de 661,40; 812,7; 811,5 e 819,2 g, respectivamente, para as estratégias SM, AC, 3X e 7X. Independente da estratégia, a suplementação protéica propiciou aumento no consumo de nutrientes e de pasto (P0,10) entre a suplementação tipo AC e a infreqüente. Quanto à digestibilidade, foram observados efeitos positivos (P0,10) sobre as digestibilidades aparente total, ruminal e intestinal dos nutrientes. Não houve efeito (P>0,10) tanto da estratégia de suplementação quanto da infreqüência de suplementação sobre a concentração de nitrogênio microbiano e eficiência microbiana. Verificou-se que animais que receberam apenas suplementação mineral apresentaram menores valores (P
Databáze: OpenAIRE
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