The Use of Nonprotein Nitrogen Compounds, Sugar Beet Molasses, and Their Combinations in Growing Chick and Laying Hen Rations

Abstract

Two experiments were conducted to study the utilization of nonprotein nitrogen sources (urea and diammonium citrate), sugar beet molasses, and their combinations by laying hens and growing chicks. Basal diets containing 12 and 20% protein and all essential amino acids according to NRC recommendation (1977) were formulated for laying hens and growing chicks, respectively. Basal diets were supplemented with 3% protein equivalent from soybean meal, urea, or diammonium citrate (DAC) both with and without 10% molasses. In the laying hen experiment, molasses was used also at 15 and 20% in the diet containing 3% supplemental protein from soybean meal.Egg production was increased significantly when the basal diet was supplemented with soybean protein or urea; however, the response to soybean meal supplementation was significantly greater than to that of urea. Diammonium citrate significantly decreased egg production and it had an adverse effect on feed consumption, egg weight, and nitrogen retention. Molasses failed to increase utilization of urea for egg production, but it reduced the adverse effect of DAC on egg production.In the chick studies a growth response was obtained when the basal diet was supplemented with soybean meal, but no response was obtained from urea or DAC. Molasses did not improve the performance of chicks with or without protein supplementation.Molasses per se can be used effectively as an energy source as it had no adverse effects on performance of laying hens and growing chicks up to the maximum levels which were used in these experiments. (

Determinação da exigência nutricional de treonina para poedeiras leves e semipesadas

“…Poedeiras recebendo rações contendo baixo conteúdo protéico, suplementadas com aminoácidos essenciais, têm apresentado bons resultados, mas não o máximo desempenho (JOHNSON e FISHER, 1959;NOVACEK e CARLSON, 1969;e Fisher e Morris (1970), citados por HARMS e RUSSELL, 1993), sugerindo que a suplementação com aminoácidos em rações com baixo nível de proteína não resulta, necessariamente, em produção máxima de massa de ovos. KESHAVARZ et al (1980) e KESHAVARZ (1984KESHAVARZ ( , 1986 observaram, em vários estudos, que o desempenho de aves alimentadas com rações de baixo conteúdo de proteína bruta e suplementadas com aminoácidos foi inferior àquelas aves, cuja ração continha altos níveis protéicos. Do mesmo modo, SUMMERS et al (1991), alimentando poedeiras com rações contendo 10,0% PB, suplementadas com lisina, metionina, arginina e triptofano, obtiveram 11,0% menos massa de ovos, quando comparadas às aves, recebendo rações contendo 17,0% PB, indicando que a produção e o peso de ovos respondem de maneira similar, ao elevar o nível protéico da ração.…”