TY - GEN

T1 - Supplements with different ruminal undegradable protein levels for dairy heifers in tropical pasture

T2 - International Symposium on Energy and Protein Metabolism and Nutrition

AU - Oliveira, RL

AU - Pereira, JC

AU - Vieira, RAM

AU - do Nascimento, D

AU - Pacheco, BM

AU - Ribeiro, MD

AU - Leonel, FP

PY - 2003

Y1 - 2003

N2 - The effects of supplements with different levels (high, medium, low) of ruminal undegradable protein (RUP) by Brown-Swiss heifers grazing Brachiaria brizantha cv. Marandu on the intake, digestibility and plasma urea nitrogen concentrations were evaluated. The experiment lasted 90 days, divided in three periods of 30 days, corresponding to May, June and July 2000. Fifteen purebred Brown Swiss heifers (five by treatment), averaging 19.7 months and 394 kg live weight (LW), were used. The pasture availability was monitored to maintain offer of 6% LW, in green dry matter (GDM). The heifers were fed 2.5 kg/head/day of concentrate supplement, offered twice a day. Extrusa was collected in animals fistulated in the esophagus. Indigestible neutral detergent fiber (NDF) in the feeds and feces was used to determine the intake and digestibility. There were no effects of supplements on the pasture, however there were differences among periods, because, as dry season progressed, the forage availability decreased and leaf/colm ratio and senescent material proportion increased. There was no effect of treatments on forage intake or forage + supplement. DM, organic matter (OM) and CP digestibility, and total digestible nutrients (TDN) content were lower for the diets with high RUP content. The animals fed supplement with high RUP content showed average plasma N-urea concentrations lower than those fed supplement with average RUP contents, followed by those fed diets with low RUP.

AB - The effects of supplements with different levels (high, medium, low) of ruminal undegradable protein (RUP) by Brown-Swiss heifers grazing Brachiaria brizantha cv. Marandu on the intake, digestibility and plasma urea nitrogen concentrations were evaluated. The experiment lasted 90 days, divided in three periods of 30 days, corresponding to May, June and July 2000. Fifteen purebred Brown Swiss heifers (five by treatment), averaging 19.7 months and 394 kg live weight (LW), were used. The pasture availability was monitored to maintain offer of 6% LW, in green dry matter (GDM). The heifers were fed 2.5 kg/head/day of concentrate supplement, offered twice a day. Extrusa was collected in animals fistulated in the esophagus. Indigestible neutral detergent fiber (NDF) in the feeds and feces was used to determine the intake and digestibility. There were no effects of supplements on the pasture, however there were differences among periods, because, as dry season progressed, the forage availability decreased and leaf/colm ratio and senescent material proportion increased. There was no effect of treatments on forage intake or forage + supplement. DM, organic matter (OM) and CP digestibility, and total digestible nutrients (TDN) content were lower for the diets with high RUP content. The animals fed supplement with high RUP content showed average plasma N-urea concentrations lower than those fed supplement with average RUP contents, followed by those fed diets with low RUP.

KW - Brachiaria brizantha

KW - rotational grazing

KW - escape protein

KW - supplementation

KW - DIETS

M3 - Article in proceedings

SN - 90-76998-24-8

T3 - EAAP EUROPEAN ASSOCIATION FOR ANIMAL PRODUCTION PUBLICATION

SP - 635

EP - 639

BT - PROGRESS IN RESEARCH ON ENERGY AND PROTEIN METABOLISM

A2 - Souffrant, WB

A2 - Metges, CC

PB - Wageningen Academic Publishers

Y2 - 13 September 2003 through 18 September 2003

ER -