Abstract: Data on 547 lambing records of 59 Blackbelly ewes from 1997-2004 in a commercial flock located in Centla, Tabasco and Mexico were studied to determine the productive and reproductive performance of Blackbelly ewes under grazing >6 years. Ewes were under grazing and with a marginal level of commercial feed during lactation. Reproductive management consisted of continuous exposure of ewes to ram. The date of first lambing was the beginning of the study for each ewe and the end date was determined by adding 2190 days (6 years) to the date of first lambing. The variables studied were lambing total per ewe >6 years, lambing interval interval lambing to conception, lambs born and weaned per ewe >6 years of production and number of lambs weaned per ewe considering the number of years in production or the number of lambing. Total lambing per ewe >6 years of study was 9.3±1.3. Whereas the productive performance was Lamb born and weaned per ewe >6 years of production 11.6±2.0 and 10.1±2.3, respectively. In conclusion, the number of lambing of Blackbelly ewes under grazing had effect (p<0.05) on weight of the hybrid litter at weaning and interval lambing to conception.
P.J. Cadenas-Cruz, J. Oliva-Hernandez and J.A. Hinojosa-Cuellar, 2012. Productivity of Blackbelly Ewes and Their Hybrid Litter under Grazing. Journal of Animal and Veterinary Advances, 11: 97-102.