Nutritional parameters of steers receiving different levels of sunflower crushed in partial replacement of soybean meal.

To evaluate of the sunflower crushed in nutritional parameters in steers, supplemented at pasture, we used four steers in 4×4 Latin square design. The supplements were provided in 6 g/kg of body weight/animal/day, consisting of sunflower crushed, corn, soybean meal and mineral. All the supplements was isonitrogenous and soybean meal was replaced in 0, 20, 40, and 60% for sunflower crushed. The determination of ruminal pH and ammonia was at 0, 2, 4, 6 and 8 h. after feeding and for short-chain fatty acids it was collected at 0 and 6 h. post-feeding. The dry matter intake was not affected (P>0.05) by inclusion of sunflower crushed (mean=6.59 kg/day). There was no significant effect (P>0.05) for pH for the inclusion of sunflower crushed (mean=6.41). For contents of ruminal NH3-N was a significant effect (P <0.05) only for collection time, and ammonia peaks occurred between 2 and 4 h after feeding, with values of 22.56 and 21.40 mg/dL. The total concentration of short chain fatty acids and the C2:C3 ratio was reduced in 9.6 and 15.43%. The ruminal degradability of NDF was not affected by the supplements. The supplementation with sunflower crushed to beef steers grazing, in partial replacement of soybean meal did not alter nutrition parameters.

Utilização de aditivos alimentares microbianos na alimentação de bovinos de corte e leite: Revisão / The use of Feeding Microbial Addictive, in the Feeding of Beef and Milk Cattle. Review / Utilización de aditivos alimentarios microbianos en la alimentación de bovinos de carne y leche revisión

Durante muitos anos, nutricionistas e microbiologistas, dedicados ao estudo de animais ruminantes, têm mostrado um interesse comum e progressivo sobre as formas ou meios utilizados para se manipular o ecossistema microbiano do rúmen, com o intuito de melhorar a eficiência produtiva. Atualmente, os métodos empregados na manipulação da fermentação ruminal envolvem a adição de substâncias na dieta, como enzimas, ionóforos, antibióticos e leveduras. Esta revisão tem o objetivo de discutir o modo de ação e os resultados com a utilização de leveduras na alimentação de bovinos de corte e de leite.

ABSTRACT: During many years, nutritionists and microbiologists, dedicated to the study of ruminant animals, have been showing a common and progressive interest on the forms or means used to manipulate the microbial rumen ecosystem, with the intention of improving the productive effi ciency. Nowadays, the employed methods in the manipulation of the ruminal fermentation, involve the addition of substances in the diet, as enzymes, ionospheres, antibiotics and fi nally, the yeast. This revision has the objective of discussing the ways of actions and the results with the use of yeasts in the feeding of beef and milk cattle.

Resumen - Durante muchos años, nutricionistas y microbiologistas se dedicaron al estudio de animales rumiantes, y ellos han mostrado un interés común y progresivo en las formas o medios de manipulación del ecosistema del rumien microbiano, con la intención de mejorar la efi ciencia de la producción. Actualmente, los métodos empleados en la manipulación de la fermentación ruminal, envuelve la adición, en la dieta, de substancias como enzimas, ionophoros, antibióticos y levadura. Esta revisión tiene el objetivo de discutir la manera de acción y los resultados del uso de levaduras en la alimentación de losbovinos de carne y de leche.