Resumen

MENDEZ, Getulio et al. Effect of two levels of maize cobs in diets with poultry litter on the productive behaviour of growing lambs. Zootecnia Trop. [online]. 2004, vol.22, n.1, pp.15-28. ISSN 0798-7269.

To evaluate two levels of maize cobs (t) in diets containing poultry litter on the productive behaviour of growing lambs, an experiment was conducted for 60 days, using a split plot design. The main plots where the animals and the secondary plots the different measurements in the time, to compare two treatment according to maize cob level in the diet: T1: 26% and T2: 13%. Other ingredients were poultry litter (50%), sugar cane molasses (5%), tallow (3%) and wheat meadling, included to complete 100% of the complete rations. Fourteen crossbred (West African x Barbados Black Belly) male lambs (initial body weight mean 15.5±1.4 kg) were divided in two groups and were located in individual pens. The chemical composition of the rations T1 and T2 were: 16.9 and 17.5% CP, 6.7 and 5.8% EE, 36.1 and 37.8% NDF, 11.3 and 9.4% Ca, and 2.0 and 1.9% P, respectively. Average DM consumption was 856 g/day and no differences between treatments were found (P> 0.05). Body weight gains (BW gain) in T1 and T2 were 58.2 and 99.2 g/day (P <0.05), respectively. Feed conversions were 18.5 and 9.4 g DM feed/g BW gain. It was concluded that in complete rations with 50% poultry litter, an increase in the content of maize cobs from 13 to 26% did not affect DM intake, but decreased the BW gain and increased the feed conversion. The use of low cost abundant resources in rations for lambs, such as maize cobs and poultry litter, may allow similar BW gain to those usually found in tropical conditions.

Palabras clave : poultry litter; maize cobs; lambs; body weight gain.