This study investigated the effect of exposing heifers to individual feed components on the extent and pattern of feed sorting upon transition to a novel ration. Holstein heifers (394 ± 62 d old, weighing 409.8 ± 37.3 kg; mean ± SD), consuming a familiar mixed silage-based ration [55% corn silage and 45% haylage, dry matter (DM) basis], were transitioned to a novel total mixed ration [TMR; 41.6% haylage, 36.5% corn silage, 14.6% high-moisture corn, and 7.3% protein supplement, DM basis] by 1 of 2 treatments: direct transition to novel TMR (DIR; n = 5) or exposure to novel TMR components individually before receiving novel TMR (COM; n = 6). During the baseline period (d 1 to 4), all heifers were offered the familiar silage-based ration. During transition (d 5 to 12), DIR heifers received the novel TMR, whereas COM heifers received the novel TMR components offered separately, in amounts according to TMR composition (target 15% orts). After transition (d 13 to 20), all heifers received the novel TMR. Feed intake and feeding time were determined daily and fresh feed and individual orts were sampled every 2d for particle size analysis and neutral detergent fiber content. The particle size separator consisted of 3 screens (18, 9, and 1.18 mm) and a bottom pan, resulting in 4 fractions (long, medium, short, and fine). Sorting activity for each fraction was calculated as actual intake expressed as a percentage of predicted intake. We detected no effect of treatment on dry matter intake or feeding time. After transition to the novel TMR, COM heifers sorted to a greater extent than did DIR heifers, sorting against long particles (95.4 vs. 98.9%) and for short particles (101.7 vs. 100.6%). Differences in sorting patterns resulted in COM heifers tending to have lower neutral detergent fiber intake as a percentage of predicted intake (98.9 vs. 100.5%). The results of this study suggest that the degree of feed sorting may be influenced by method of transition to a novel ration.
O leite cru refrigerado precisa ser obtido de maneira higiênica, seguindo protocolos rigorosos para que não haja a possibilidade de alterações em sua composição. Portanto este trabalho teve como objetivo avaliar parâmetros estabelecidos pela Instrução Normativa (IN) nº 76/18 e 77/18 do Ministério da Agricultura, Pecuária e Abastecimento (MAPA), num grupo de 30 produtores de uma Agroindústria da Serra Gaúcha-RS. Foram analisados os parâmetros físico-químicos de gordura, proteína total, lactose anidra, sólidos não gordurosos e sólidos totais, e os parâmetros microbiológicos de Contagem Padrão em Placas (CPP) e Concentração de Células Somáticas (CCS), além de análise de resíduos de produtos de uso veterinário e contaminantes. Os valores encontrados para os parâmetros de CPP em sua maioria estão em acordo com o que preconiza a legislação, porém a CCS parece ser o problema maior dos produtores da região devido aos elevados índices apresentados em 50% dos produtores avaliados. Também há resultados em desacordo para as análises de proteína, lactose anidra, sólidos não gordurosos. Quanto à detecção de resíduos de antibiótico, nenhum produtor teve resultado positivo, e na detecção de fraudes, 3 produtores apresentaram resultados positivos para o teste de cloretos coincidindo com as maiores taxas de CCS no leite cru refrigerado. Palavras-Chaves: qualidade do leite, instrução normativa 76, instrução normativa 77, detecção de fraudes, resíduos de antibióticos
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