Biological evaluation of two breeding systems of intensive production in the Columbia breed sheep
Por:
Tron, JD, Quintero, LAZ, Padilla, EG, Perez, JT, Pelaez, CV
Publicada:
1 abr 2009
Categoría:
Veterinary (miscellaneous)
Resumen:
The biological efficiency of two breeding systems for sheep in the Mexican high plateau was evaluated. A total of 300 adult and 60 replacement sheep of the Columbia breed were randomly distributed into two groups of 150 adults and 30 young ones (mean age to first birth of 18 months). Mates of 36 days with natural mount every eight months (March, November and July) were done in the first group (intensive system). In the second group (annual system), a 45-day mating was done starting on November every year. Marker males were introduced 15 days before mating in all cases, which were replaced on the first day of mating for stallions at a one male for every 20 female ratios. The physical condition of all females was evaluated every month. The animals grazed 8 to 9 hours in grasslands of alfalfa (Medicogo sativa) and Orchard (Doctylis glomerato) and Rye (Lolium perenne) grasses irrigated by aspersion. Only the sheep in the intensive system received supplement during lactation and re-mating.
Filiaciones:
Tron, JD:
Univ Nacl Autonoma Mexico, Fac Estudios Super Cuautitlan, Cuautitlan 54700, Estado Mexico, Mexico
Quintero, LAZ:
Univ Nacl Autonoma Mexico, Fac Med Vet & Zootecnia, Mexico City 04510, DF, Mexico
Padilla, EG:
Univ Nacl Autonoma Mexico, Fac Med Vet & Zootecnia, Mexico City 04510, DF, Mexico
Perez, JT:
Univ Nacl Autonoma Mexico, Fac Estudios Super Cuautitlan, Cuautitlan 54700, Estado Mexico, Mexico
Pelaez, CV:
Univ Nacl Autonoma Mexico, Fac Med Vet & Zootecnia, Mexico City 04510, DF, Mexico
|