Abstract: Growth and feed efficiency were evaluated for pure and F1 crossbred Pelibuey (Pb) male lambs. Four different genotypes were used: pure PelibueyxPelibuey (PbPb), Black Head DorperxPb (BHDPb), White DorperxPb (WDPb) and KatahdinxPb (KdPb). Thirty six lambs with an average live weight (average±SD) of 20.81±2.7 kg, were distributed in a randomized block design with a 4x3 factorial arrangement: 4 genotypes and 3 dietary ME concentrations (2.2, 2.5 and 2.8 Mcal kg-1 DM). There were 2 experimental periods, representing the initial (33 days) and final phases (42 days) of lamb fattening. During these 2 phases, 19 and 14.8% dietary crude protein concentration, respectively were used. A higher (p<0.05) DMI, CPI and MEI was observed in the KdPb lambs in comparison with PbPb in the final phase of growth, however not an effect was found (p<0.05) due to the genotype upon the variables in the total growing phase. The ADG, DMI, CPI and MEI observed (average±SEM) was 182±6 (g animal-1), 79±1.4 and 12.8±0.2 (g kg-1 LW0.75) and 197±3.6 (kcal kg-1 LW0.75), respectively. Lambs fed with 2.8 (Mcal ME kg-1 DM), had (p<0.01) the highest DMI, CPI, ADG and better FG in the initial phase and a highest (p<0.05) ADG in the final stage of growth. The animals fed with a highest levels energy had (p<0.01) a better FG in the whole fattening period (6.5a, 5.1b and 4.7b±0.3). No interaction effect (p>0.05) were detected between the genotype and energy level. The genotypes specialized for meat production, expressed a similar ADG and feed efficiency to the pure pelibuey lambs. The best performance for all genotypes was obtained using a 2.8 Mcal ME kg-1 DM diet.
G.J. Canton , Q.R. Bores , R.J. Baeza , F.J. Quintal , R.R. Santos and C.C. Sandoval , 2009. Growth and Feed Efficiency of Pure and F1 Pelibuey Lambs Crossbred with Specialized Breeds for Production of Meat. Journal of Animal and Veterinary Advances, 8: 26-32.