Resumo

TEODORO, A.L. et al. Increasing levels of protein in the diet of heifers of Pantaneira Breed: performance and digestibility. Arch. zootec. [online]. 2013, vol.62, n.239, pp.369-378. ISSN 1885-4494.  https://dx.doi.org/10.4321/S0004-05922013000300005.

The objective of this experiment was to verify the influence of increasing levels of dietary protein on performance, apparent digestibility and plasma and urinary urea in Pantaneira breed. The data were obtained from 15 heifers, 18 months old and 146 kg initial body weight, fed diets containing 11, 13, 15 and 17 % of crude protein (CP). The animals were confined for 114 days. At intervals of 28 days they were weighed and blood samples and spot samples of feces from the rectum and of urine were taken. The increase in dietary CP content did not influenced dry matter (DM) intake and average daily weight gain (ADG), but improved nutrient digestibility, increased blood nitrogen levels and increased excretion of urinary urea. A mean intake of 5.13 kg DM/animal/day and an ADG of 570 g were observed. Apparent digestibility values of 40.9, 59.6, 39.2, 41.3 and 34,0 % for DM, CP, total carbohydrate, neutral detergent fiber and acid detergent fiber, respectively, were found. Plasma urea concentration was 49.6 mg/dL; and an urinary urea loss of 110,0 g/animal/day was observed.

Palavras-chave : Feedlot; Tucura.

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