Utilization of Micro-Hematocrit Technique on Body Weight and Reproductive Traits Prediction in Broiler Chickens

[摘要] - Hematocrit is an indirect method used to monitor ascites, which might be used also on body weight and reproductive traits evalution in broiler chickens. The aim of this paper was to evaluate the micro-hematocrit technique on body weight and reproductive traits (fertility, hatchability of fertile eggs and overall hatchability) possibiliting its aplication by poultry genetic breeding programs. Two contrasting groups were established based on phenotypic selection from 630 males and females of 18 genotypes to hematocrit characteristic. This work used 74 chicks produced by selected males and females (40 of the high and 34 of the low hematocrit group), which were raised under conventional conditions. Their body weights and hematocrit values were measured at 14 and 42 days of age. Eggs from 42 females (22 of the high and 20 of the low hematocrit group) were hatched to evaluate the reproductive traits. Means were estimated by a linear model with genetic group as fixed effect. Broilers of the low group showed highest values of body weight at 14 and 42 days of age (305.59 and 1,387 g, respectively), differing from those of the high group, which weighted 243.56 and 1,128 g. The groups differed also significantly for hematocrit value. There were no significant differences between the two groups for reproductive traits, and the general averages were 93.8 and 94.9% for fertility, 98.2 and 93.9% for hatchability of fertile eggs and 89.3 and 82.4%, for overall hatchability respectively, for high and low groups. In conclusion, the hematocrit technique may be used to evaluate body weight, but not to evaluate reproductive traits.

[学科分类] 兽医学

[关键词] animal breeding;ascites;erythrocyte;genotype    Introdução Em 1920;os frangos de corte levavam 120 dias para atingir 1500 g de peso corporal;porém;em 1980 esse tempo reduziu-se para 44 dias e mais recentemente;em 1998;apenas 33 dias para atingir o mesmo peso (Albers;1998)