5 research outputs found
Relative value of ruminally degradable and undegradable protein on the utilization of low-quality prairie hay by steers
An experiment was performed to investigate
the impact of providing six levels of ruminally degradable protein (RDP; protein that is available to ruminal microbes) in combination with two levels of ruminally undegradable protein (RUP; protein that is not available to the ruminal microbes, but can be digested directly by cattle) on the intake and digestion of low-quality prairie hay. Twelve steers were provided unlimited access to low-quality prairie hay (5.3% crude protein and 71.7% neutral detergent fiber) throughout the trial. To simulate
dietary RUP, casein was infused abomasally
once daily at either 0 or 0.087% of body
weight. To simulate dietary RDP, casein was
infused ruminally once daily at 0, 0.029,
0.058, 0.087, 0.116, or 0.145% of body weight. As provision of RDP increased, forage
intake and fiber digestion increased. Supplementing with RUP alone increased forage
intake but not fiber digestion, although the
intake response was not as large as providing
the same amount of RDP. In conclusion, RUP
is less efficient than RDP in stimulating forage intake and digestion
Incorporação de uréia encapsulada em suplementos protéicos fornecidos para novilhos alimentados com feno de baixa qualidade
Effects of frequency of supplementation on the intake and digestion of low-quality forage by beef steers
A 43% CP (dry basis) supplement was fed
to 16 ruminally fistulated steers on 2, 3, 5, or 7
days a week. Supplement was offered at .36%
BW (dry basis) daily for steers that received
supplement every day. For other treatments,
the same amount of supplement was split
equally among supplementation events. Forage
intake and digestibility increased with increasing
supplementation frequency. However, the
difference in forage intake tended (cubic,
P=.07) to be most prominent for the two extremes;
the 3- and 5-days-a-week treatments
tended to be similar. Forage intake for steers
supplemented on 2 days a week decreased on
the days when they were supplemented. Although
forage utilization may improve with
increasing frequency of supplementation, the
impact on performance is likely to be small
unless differences in frequency of
supplementation are extreme
Effects of frequency of supplementation on performance of beef cows grazing winter pasture
One hundred twenty spring-calving Hereford
× Angus cows grazing low-quality
tallgrass-prairie forage during the winter of 1998
were fed a 43% crude protein supplement 2, 3,
5, or 7 days a week. Supplement was fed at 4
lb/head daily to cows supplemented daily. The
other cows still received 28 lb per week but
divided equally among feedings. Cumulative
performance (measured by changes in body
condition score and body weight) was slightly
better with increased supplementation frequency.
However, the magnitude of differences
in body condition and body weight changes,
even for the most extreme treatment comparisons,
were relatively small
Consumo e digestibilidade de feno de baixa qualidade suplementado com nitrogênio não protéico em bovinos Intake and digestibility of low-quality hay with nonprotein nitrogen supplementation in cattle
O objetivo deste trabalho foi avaliar o efeito de níveis de inclusão de nitrogênio não protéico, em suplementos fornecidos a tourinhos Hereford, com 17 meses e peso médio de 220 kg, alimentados com feno de tifton (Cynodon dactylon) ad libitum. Os tratamentos avaliados foram: feno + suplemento sem uréia; feno + suplemento com 0,28 g de uréia kg-1 PV0,75; feno + suplemento com 0,55 g de uréia kg-1 PV0,75; feno + suplemento com 0,83 g de uréia kg-1 PV0,75 e feno + suplemento com 1,11 g de uréia kg-1 PV0,75. O feno apresentou, na média, 3,86% de proteína bruta e 84,66% de fibra em detergente neutro. Não se constatou efeito da suplementação sobre a digestibilidade da matéria orgânica, matéria orgânica do feno, fibra em detergente neutro, celulose e hemicelulose; o consumo total desses itens respondeu quadraticamente à suplementação com níveis crescentes de nitrogênio não protéico. A suplementação não afetou a excreção fecal metabólica de matéria orgânica, o que sugere aumento na taxa de passagem (variação no consumo) e na taxa de digestão (digestibilidade constante). O consumo de matéria orgânica digestível apresentou comportamento quadrático com aumento dos níveis de uréia na dieta. Quando o nível de proteína degradável no rúmen foi equivalente a 8,1% da matéria orgânica digestível, a relação de consumo entre esses componentes foi otimizada.<br>The objective of this work was to evaluate the effect of nonprotein nitrogen supplementation levels on the digestibility of low-quality hay (Cynodon dactylon), which was offered ad libitum to Hereford bulls aging 17 months and weighing 220 kg. The evaluated treatments were: hay + no urea supplement; hay + supplement with 0.28 g urea kg- 1 BW0.75; hay + supplement with 0.55 g urea kg-1 BW0.75; hay + supplement with 0.83 g urea kg- 1 BW0.75 and hay + supplement with 1.11 g urea kg- 1 BW0.75. Hay composition presented 3.86% of crude protein and 84.66% of neutral detergent fiber. Digestibility of organic matter, organic matter of forage, neutral detergent fiber, cellulose and hemicellulose were not affected by nonprotein nitrogen level; total intake of these components showed a quadratic response to nonprotein nitrogen supplementation. Organic matter metabolic fecal excretion was not affected by supplementation, suggesting a simultaneous increase in both passage (intake increase) and digestion rates (stable digestibility). The digestible organic matter intake showed a quadratic response with the increase of urea supplementation levels. The relationship between rumen degradable protein intake and digestible organic matter intake showed a maximization point, when rumen degradable protein intake was equivalent to 8.1% of digestible organic matter intake