Resumen

MARTINEZ-TINAJERO, Jaime Jorge; AGUIRRE-MEDINA, Juan Francisco; MARTINEZ-PRIEGO, Gilberto  y  TORRES-HERNANDEZ, Glafiro. Productive and reproductive performance of three cattle genotypes in the Soconusco region, Chiapas, Mexico. Zootecnia Trop. [online]. 2006, vol.24, n.2, pp.109-120. ISSN 0798-7269.

To evaluate the effect of genotype on productive and reproductive performance under conditions of the Soconusco region, Chiapas, Mexico, Australian Friesian Sahiwal (AFS, n=10), Criollo Lechero Tropical (CLT, n=10), and Dual Purpose (DP, n=10) cows in their second parity with their calves were utilized. Cows grazed ad libitum a pasture established with African Star grass (Cynodon plechtostachyus), while in corral were given 2 kg/animal of a commercial concentrate during milking. Calves were artificially reared with a milk substitute. Cows were mechanically milked twice a day, without the presence of their calves, and the interval from calving to first estrus (ICFE), milk production per day (MP), and body weight changes in both cows (BWCO) and calves (BWCA) were registered every 14 days. It was utilized a completely randomized design with three treatments (genotypes) and 10 replications, taking a cow as the experimental unit. ICFE was shorter (P<0.01) in AFS and CLT cows (37.2±7.4 and 55.1±20.3 d, respectively), than in DP cows (93±1.8 d). MP in AFS cows (11.9±4.4 L/d) was higher (P<0.05) than in DP and CLT cows (8.3±1.8 and 6.6±1.9 l/d, respectively). BWCO was similar (P>0.05) in CLT, AFS, and DP cows (1±12.8, -2±14.4 and -7.4±9.8 kg, respectively). On the other hand, BWCA was similar (P>0.05) in AFS (39.7±5.7 kg), CLT (33.5±13.3), and DP (37.7±4.6 kg) calves. It is concluded that Australian Friesian Sahiwal and Criollo Lechero Tropical cows showed a better productive and reproductive performance than Dual Purpose cows under the environmental and management conditions of the Soconusco, Chiapas, Mexico.

Palabras clave : Friesian Sahiwal; criollo lechero tropical; dual purpose; humid tropic; grazing.