Comparative Nutritions of Calves Receiving a Concentrate Diet via Rumen or via Oesophageal Groove

Abstract

1. Nutritional effects of a diet consisted of corn , soybean meal and other common feedstuffs by-passing the rumen of calves were compared with those of the same diet undergoing the rumen fermentation . 2. An equal amount of the diet given daily to two groups of seven Holstein calves each from 7 to 12 weeks of age , eigher in a pelleted form to suffer the rumen fermentation ('dry-fed' group; DFG) or in liquid suspension from a bucket to avoid the rumen fermentation ('liquid-fed' group; LFG) .At 87 days of age, two calves each in one group were sacrificed , and jugular blood samples were taken from the remaining calves. 3. The quantity of ammonia in the rumen was similar in both groups, but that in the large intestine tended to be greater in DFG than in LFG. The quantity of volatile fatty acids (VFA) in the rumen was greater in DFG than in LFG, but their quantity in the large intestine tended to be greater in LFG than in DFG. 4. In DFG, the molar proportion in the VFA of acetic acid was higher, and that propionic and butyric acids was lower in large intestine than in the rumen .In LFG, the molar proportion of acetic acid was higher, and that of butyric and isobutyric acids was lower in the rumen than in large intestine. 5. The plasma glucose was at the same level in both groups. Plasma levels of ketone bodies (P<0.01) and glycogen content in liver (P<0.05) were significantly lower in LFG than in DFG. 6. Plasma levels of triglycerides and phospholipids were significantly higher in LFG (P <0.05).The content of total lipids in liver was significantly higher in LFG than in DFG (P< 0.05). Total lipids in liver of LFG calves had significantly increased lipid fractions of triglycerides, total cholesterol and free fatty acids (P<0.05), and contained larger amounts of highly unsaturated C18 fatty acids. 7. Riboflavin levels in blood and liver were similar in both groups.The rumen plays a very important role in the nutrition and the metabolism of ruminant animals. In our previous report1) , it was described that body-weight gains were much depressed when calves were given a diet consisted of corn, soybean meal and other common feedstuffs in liquid suspension to avoid the rumen fermentation. Apparent digestibilities of crude protein and nitrogen-free extracts were lower when the same diet was introduced into the rumen and suffered the fermentation in it. However, the digestibility of crude fibre was not lowered in calves receiving liquid feed, and these calves had more developed caecum and large intestine as well as less developed rumen and omasum than calves receiving dry feed, predicting some shifts in the

Desempenho de bezerros da raça Holandesa alimentados com proteína de soja sólida ou líquida

“…Já os ganhos de peso não confirmaram essa diferença (Tabela 4). A possibilidade de emprego da goteira esofagiana em animais adultos para administrar aminoácidos essenciais por meio de dietas líquidas foi relatada por outros autores (Iriki et al, 1992;Abe et al, 1998).…”

“…Disponibilidade insuficiente de nitrogênio degradável no rúmen limita a fermentação ruminal, diminuindo o consumo e a eficiência energética do alimento quando a maior parte dos carboidratos é digerida pela fermentação pelos microrganismos ruminais (ARC, 1980). Uma das formas para que nutrientes ultrapassem o rúmen é aquela obtida com êxito pela simples manutenção do funcionamento da goteira esofagiana, conforme registrado por Orskov (1970) com ovinos, Mikhail et al (1988 com caprinos e Abe et al (1998) com bovinos. O aproveitamento da manutenção da goteira esofagiana em animais adultos é um método eficiente para administrar nutrientes como aminoácidos essenciais (Iriki et al, 1992;Abe et al, 1998) ou lipídeos (Spanski et al, 2007.…”