Cássio André Wilbert

Effect of crude glycerol on in-vitro ruminal fermentation kinetics

O interesse na utilizacao da glicerina bruta na alimentacao animal ressurge, devido ao aumento na disponibilidade e preco favoravel, como consequencia da expansao das industrias de biocombustiveis. O objetivo deste trabalho foi avaliar os efeitos da substituicao do milho por diferentes niveis de glicerina bruta na dieta sobre a fermentacao ruminal atraves da digestibilidade in vitro verdadeira. As dietas experimentais consistiram na substituicao do milho por glicerol (0; 4; 8 e 12%) na materia seca da dieta (MS). As dietas eram compostas por 60% de feno de alfafa e 40% de grao de milho e o glicerol foi adicionado, substituindo o milho nas dietas. Alem de trabalhar com as 48 horas tradicionais, foram utilizados diferentes horarios de digestibilidade in vitro (0; 4; 8; 16; 48; 72 e 96 horas), com a finalidade de estudar a cinetica da digestao. A substituicao do milho por niveis crescente de glicerina bruta na dieta nao afetou a concentracao de N-NH3, o teor de energia metabolizavel, as digestibilidades in vitro da materia orgânica da fibra em detergente neutro, bem como os parâmetros da degradacao ruminal. Portanto, esse subproduto da producao do biodiesel deve ser testado in vivo como uma alternativa energetica na formulacao de dietas para ruminantes.

Manejo da comercialização em leilões e seus efeitos no preço de bezerros de corte

The commercialization process of 1.757 lots of calves was evaluated, totaling 28.495 animals, including the order and time of permanence in track, the divulgation strategies to the buyers and uniformity of the lots, as well as the final price (R

Suplementação energética e proteica de um volumoso de baixa qualidade pela técnica de produção cumulativa de gás in vitro

/kg WL) and number of biddings. The model proposed was efficient in showing unfavorable scenarios for the breeding activity, and in periods of great offer of calves and low prices, the studied variables can influence the final price per kilogram of live weight. This indicates that some aspects out of the control of breeders but very close to them can influence the final value; therefore, are of extreme importance in the follow-up of the commercialization process of animals.

Crude glycerin as an alternative energy feedstuff for dairy cows

It was conducted an experiment using the semi-automatic in vitro cumulative gas production with the objective of evaluating the combination of energy and protein supplementations in diets based on low quality roughage, Tifton hay (Cynodon dactylon L.), with 7.69% of crude protein; 70.34% of neutral detergent fiber and 57.98% of organic matter in vitro digestibility. It was evaluated two sources of rumen degradable protein (urea or isolated soybean protein); four levels of ground corn grain (0, 20, 40 and 60%) and four supplementary levels of rumen degradable protein (0; 2.8; 5.6 and 8.4%) in complete random design in a 2 × 4 × 4 factorial arrangement. The organic matter in vitro digestibility increased linearly in response to grain corn inclusion with a greater slope by using isolated soybean protein. The partitioning factor was higher with isolated soybean protein and it was detected a linear increase in response to increasing rumen degradable protein with 20% of grain corn. The maximum gas production of the fraction of fast (A) and slow (D) degradation increased linearly in response to the grain corn inclusion, with isolated soybean protein, and it quadratically increased with urea. The A degradation rate was increased with inclusion of up to 20% of grain corn and the degradation rate of D was higher with urea. The A lag-time increased linearly with the inclusion of grain corn and in the D lag-time it was observed a decrease with up to 20% of grain corn unchanged at high levels. The supplementation with up to 60% of grain corn was beneficial to digestibility of diets with low quality roughage. The association between energy and protein supplementation was positive in some studied parameters. Urea gave better responses at moderate levels of ground grain corn.