Poultry litter supplementation of dual purpose cows grazing maize stubble during the dry season

An experiment was carried out on a commercial farm located at Guarico state, Venezuela, to evaluate the effect of poultry litter supplementation during the dry season on productive and reproductive variables of dual purpose cows grazing maize stubble. Sixty Bos taurus x Bos indicus cows (thirty per year) were used in a randomized design and a 2x2 factorial arrangement, to compare two supplementation treatments during two years. The treatments were (0) a control without any supplement and (C) 2 kg/day of a concentrate with 83.5% poultry litter, 15% cotton meal and 1.5% common salt, offered after the morning milking during the last 4 months of the dry season (February-May) of each year (1995 and 1996). The supplementation increased milk yield during the first 90 days of lactation, but this effect disappeared when the complete lactation was considered. The carving interval was high in all animals and was significantly reduced in 86 days with the supplementation. These results indicate that the use of a supplement based on poultry litter under these conditions improves pregnancy rate, but has a small non-significant effect on milk yield.