TY - JOUR

T1 - Consumo e desempenho de novilhas em pastagem recebendo suplementos com diferentes niveis de proteína não-degradável no rúmen

AU - Ribeiro, Marinaldo Divino

AU - Pereira, José Carlos

AU - Vieira, Ricardo Augusto Mendonça

AU - Pacheco, Bevaldo Martins

AU - De Paula Leonel, Fernando

PY - 2005

Y1 - 2005

N2 - The objective of this trial was to study the intake and production at pasture of 15 Holstein-Gyr heifers (5 per treatment) averaging 16.5 ± 4.2 months of age and 211.97 ± 34.28 kg of body weight (BW) and fed supplements containing either 40% or 60% of rumen-undegradable protein (RUP). Forage availability was monitored to maintain a supply of 6% of BW. Both chromic oxide (10 g/day/heifer) and indigestible neutral detergent fiber (INDF) were used as external and internal markers, respectively. Intakes of dry matter (DM), crude protein (CP), fiber, and INDF were estimated and adjusted to the average body mass of the heifers as the covariable applying an allometric relationship and were then expressed in metabolic size unit. Weight gain was measured at the beginning and end of the experimental period in fasted heifers. Heifers at the pasture + supplement treatment consumed approximately 1.8 kg of concentrate DM per day that was offered at 8 a.m. and 4 p.m. Except for intakes of DM and CP of the total diet (pasture + supplement), significant treatment, period, and interaction effects were found for all remaining intake variables of forage and total diet. Therefore, intake was affected by pasture quality and supply of extra nutrients from the supplements with increasing RUP levels and for intake of INDF the use of the covariable was worthwhile. No significant changes on weight gain of heifers were observed within the different levels of RUP (40 vs. 60%) as well as comparing supplementation versus pasture alone and averaged 509 g/animal/day during the water-dry transition period.

AB - The objective of this trial was to study the intake and production at pasture of 15 Holstein-Gyr heifers (5 per treatment) averaging 16.5 ± 4.2 months of age and 211.97 ± 34.28 kg of body weight (BW) and fed supplements containing either 40% or 60% of rumen-undegradable protein (RUP). Forage availability was monitored to maintain a supply of 6% of BW. Both chromic oxide (10 g/day/heifer) and indigestible neutral detergent fiber (INDF) were used as external and internal markers, respectively. Intakes of dry matter (DM), crude protein (CP), fiber, and INDF were estimated and adjusted to the average body mass of the heifers as the covariable applying an allometric relationship and were then expressed in metabolic size unit. Weight gain was measured at the beginning and end of the experimental period in fasted heifers. Heifers at the pasture + supplement treatment consumed approximately 1.8 kg of concentrate DM per day that was offered at 8 a.m. and 4 p.m. Except for intakes of DM and CP of the total diet (pasture + supplement), significant treatment, period, and interaction effects were found for all remaining intake variables of forage and total diet. Therefore, intake was affected by pasture quality and supply of extra nutrients from the supplements with increasing RUP levels and for intake of INDF the use of the covariable was worthwhile. No significant changes on weight gain of heifers were observed within the different levels of RUP (40 vs. 60%) as well as comparing supplementation versus pasture alone and averaged 509 g/animal/day during the water-dry transition period.

KW - Heifer reraising

KW - Indigestible fiber

KW - Weight gain

UR - http://www.scopus.com/inward/record.url?scp=33645039214&partnerID=8YFLogxK

U2 - 10.1590/s1516-35982005000700037

DO - 10.1590/s1516-35982005000700037

M3 - Tidsskriftartikel

AN - SCOPUS:33645039214

VL - 34

SP - 2486

EP - 2495

JO - Revista Brasileira de Zootecnia

JF - Revista Brasileira de Zootecnia

SN - 1516-3598

IS - 6 SUPPL.

ER -