Parâmetros nutricionais e metabólicos de novilhos nelore recriados em pastos de diferentes alturas e doses de suplemento
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Data
2016-02-29
Autores
Delevatti, Lutti Maneck [UNESP]
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Universidade Estadual Paulista (Unesp)
Resumo
Objetivou-se avaliar o consumo, a digestibilidade da dieta, parâmetros ruminais e síntese de proteína microbiana de novilhos suplementados na fase de recria em pastagens durante o período das águas. Foram utilizados 12 piquetes de Brachiaria brizantha cv. Marandu, pastejados a 15, 25 e 35 cm por bovinos de corte canulados em fase de recria, em lotação contínua, com taxa de lotação variável. Foram utilizadas as estratégias de suplementação: suplementos múltiplos na quantidade de 0,3% e 0,6% do peso corporal (PC) para os animais dos pastos de 15 cm; 0,1% e 0,3% do PC nos pastos de 25 cm; e mistura mineral e 0,1% do PC nos pastos de 35 cm. Foram mensurados o consumo e digestibilidade da dieta, síntese de proteína microbiana, dinâmica da degradação da fibra em detergente neutro (FDN) e parâmetros ruminais dos animais recriados em cada sistema correspondente às alturas de pastejo associado a suplementação. O delineamento estatístico adotado foi quadrado latino duplo incompleto, com doze animais cânulados no rúmem, seis tratamentos, e quatro períodos experimentais na estação chuvosa. Foram aplicados testes para pressuposições estatísticas sobre os dados obtidos, análise de variância, e teste Fisher’s Protected Least-Significant Difference (LSD) para comparação de médias e avaliação do efeito dos tratamentos (P<0,10). Não foram observadas diferenças no consumo de forragem e matéria seca total pelos animas (P≥0,14), porém observou-se maior consumo de proteína bruta (PB) e nutrientes digestíveis totais (NDT) (P≤0,03), nos animais dos tratamentos com suplementação a 0,3 e 0,6% do peso corporal. Não foram verificadas diferenças nas digestibilidade de PB, matéria seca e fibra em detergente neutro (P≥0,21). As taxas de degradabilidade da FDN não variaram entre os tratamentos (P≥0,19). Os resultados de concentração molar de ácido acético e butírico apresentaram variação no tempo (P≤0,06), apresentando seus menores valores logo após a suplementação, já os valores de pH, N-amoniacal e ácido propiônico apresentaram interação entre tratamento e tempo (P≤0,04). A suplementação não alterou os parâmetros ruminais, porém foi capaz de aumenta a ingestão total de nutrientes em tratamentos com maiores níveis de suplementos.
The dry matter intake, diet digestibility, ruminal fermentation and microbial protein synthesis of supplemented bulls during the growing phase at pastures during the wet season were evaluated. Twelve paddocks of Brachiaria brizantha Marandu (palisade grass) were used, grass grazing heights were 15; 25 and 35 cm by cannulated yearling steers in growing phase, in continuous stocking with variable stocking rate. The supplementation strategies used were: multiple supplements in the amount of 0.3% to 0.6% of body weight (BW) to the animal grazing pasture of 15 cm; 0.1% and 0.3% PC in pastures of 25 cm; and mineral mixture and 0.1% of the PC in the pastures of 35 cm. Were estimated the dry matter intake and digestibility of forage and supplement, microbial protein synthesis, dynamics of neutral detergent fiber (NDF) degradation, dietary nitrogen balance and ruminal parameters by yearling steers growing while grazing pasture with different heights and supplement level. The experimental design used was incomplete double Latin square with twelve cannulated animals, six treatments and four experimental periods during the wet season. Statistical tests were applied for assumptions on the obtained data, analysis of variance, and Tukey test for mean comparison and evaluation of the treatment effect (P <0.10). There were no differences on the forage and total dry matter intake per animal (P≥0.14), however it was exhibited higher crude protein (CP) and total digestible nutrients (TDN) (P≤0.03) intake for the animals of the different treatments with supplementation 0.3 and 0.6% of BW. There was no differences in the CP, DM and NDF digestibility (P≥0.21). The NDF degradability rates did not differ among the treatments (P≥0.19). Results of the molar concentration of acetic acid and butyric acid exhibited variation during time (P≤0.06) showing their lowest values after supplementation, as pH values, ammonia-N and propionic acid exhibited interaction among treatment and sampling time (p ≤ 0.04). Supplementation shows no ability to change the ruminal parameters as expected, however was able to increase the total intake of nutrients in the diets with higher levels of supplements.
The dry matter intake, diet digestibility, ruminal fermentation and microbial protein synthesis of supplemented bulls during the growing phase at pastures during the wet season were evaluated. Twelve paddocks of Brachiaria brizantha Marandu (palisade grass) were used, grass grazing heights were 15; 25 and 35 cm by cannulated yearling steers in growing phase, in continuous stocking with variable stocking rate. The supplementation strategies used were: multiple supplements in the amount of 0.3% to 0.6% of body weight (BW) to the animal grazing pasture of 15 cm; 0.1% and 0.3% PC in pastures of 25 cm; and mineral mixture and 0.1% of the PC in the pastures of 35 cm. Were estimated the dry matter intake and digestibility of forage and supplement, microbial protein synthesis, dynamics of neutral detergent fiber (NDF) degradation, dietary nitrogen balance and ruminal parameters by yearling steers growing while grazing pasture with different heights and supplement level. The experimental design used was incomplete double Latin square with twelve cannulated animals, six treatments and four experimental periods during the wet season. Statistical tests were applied for assumptions on the obtained data, analysis of variance, and Tukey test for mean comparison and evaluation of the treatment effect (P <0.10). There were no differences on the forage and total dry matter intake per animal (P≥0.14), however it was exhibited higher crude protein (CP) and total digestible nutrients (TDN) (P≤0.03) intake for the animals of the different treatments with supplementation 0.3 and 0.6% of BW. There was no differences in the CP, DM and NDF digestibility (P≥0.21). The NDF degradability rates did not differ among the treatments (P≥0.19). Results of the molar concentration of acetic acid and butyric acid exhibited variation during time (P≤0.06) showing their lowest values after supplementation, as pH values, ammonia-N and propionic acid exhibited interaction among treatment and sampling time (p ≤ 0.04). Supplementation shows no ability to change the ruminal parameters as expected, however was able to increase the total intake of nutrients in the diets with higher levels of supplements.
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Palavras-chave
Consumo, Parâmetros ruminais, Suplementação, Intake, Ruminal parameters, Supplementation