RESUMEN
The objective of this study was to determine a suitable level of concentrate using pineapple stem by-product as a roughage source for the growth performance, carcass traits and meat quality of Holstein steer. Forty Holstein steers with an average initial body weight of 404.2 ± 38.2 kg (18 months of age) were used in a completely randomised design. The treatments consisted of four levels of restricted concentrate (4, 5, 6 and 7 kg/head/day as fed basis), and the animals were fed ad libitum pineapple stem by-product as a roughage source. The data were analysed by using orthogonal polynomial contrasts of trend response, represented by the linear and quadratic effects of the concentrate levels. Total dry matter intake (DMI) increased with increasing concentrate levels and was the highest in the dairy steer fed 6 kg/head/day (P < 0.05). Pineapple stem by-product intake was decreased by 5.51, 4.70, 4.04 and 2.59 kg DM/day with increasing concentrate levels, and the linear effect was significant (P < 0.01). Ruminal pH decreased with increasing concentrate levels (6.54, 6.46, 6.12 and 6.00), and the linear effect was significant (P < 0.01). The overall carcass characteristics were not affected by the treatments. The steers fed 4 kg/head/day of the concentrate presented the lowest feed cost per gain. These results indicated that pineapple stem by-product is suitable for use as a roughage source.
