SOME BIOMETRIC AND ALLOMETRIC GROWTH TRAITS OF PUREBRED HEAVY ECOTYPE OF THE NIGERIAN LOCAL CHICKEN
Fifty five (55) experimental birds were randomly replicated into 5 deep litter pens in the ratio of 1 cock: 10 hens. Like to like random mating was ensured to raise 200 chicks in the F1 generation. Chicks were subjected to measurements like body weight, body length, shank length, shank colour, beak colour, feather colour, feed conversion ratio, mean feed consumption, egg colour, egg fertility, egg hatchability, dead embryo and mortality at hatch and subsequently at 4 weekly intervals. Data obtained from these traits at ages of 0 (day old) – week, 4-weeks, 8-weeks,12-weeks 16-weeks and 20 weeks were subjected to analysis of variance (ANOVA) in a nested or hierarchial design and in a paternal half sib analysis using SAS (2004) statistical procedure. Body weight was significantly different among the progeny and ranged from 30.33g at day old to 1334.67g at 20 weeks of age. Sire had no significant effect in average body weight gain (ABWG), expect at 8-12weeks of age. ABWG ranged from 85.05g at 4 weeks to 441.20g at 20 weeks of age. There was significant (p<0.001) difference in feed conversion ratio (FCR) at 12 weeks of age. Sire had highly significant (p<0.001) effect on average feed consumption (AFC) from 4-20 weeks of age. Sire had significant (p<0.05) effect on body length (BL) at 12 and 20 weeks of age. Sire had significant (p<0.05) effect on shank length at 0 week of age. Sire had highly significant (p<0.001) effect on shank colour at day old and it ranged from cream colour to cream black colour. Sire had highly significant (p<0.001) effect on the beak colour at 0 week, which ranged from cream to cream hazenut. There were highly significant differences (p<0.001) in the number of white, light brown and brown eggs laid by the hens mated to the siresfreeresearchproject.com.ng. With respect to the down feather colour of the progeny, sire did not make any difference. Sire used made no differences (p>0.05) in the number of infertile eggs laid throughout the experiment. Sire significantly (p<0.001) influenced the hatchability of eggs laid, the number of embryos that died in the shell and the number of chicks that died after hatching. The heritability estimates of body weight (BW) ranged from 0.05 at 4 weeks to 0.54 at 12 weeks of age. The body length (BL) heritability estimates ranged from 0.06 at 4 weeks to 0.80 at 0 weeks. Heritability estimates of shank length (SL) ranged from -0.12 at 16 weeks to 0.80 at 0 week of age. Heritability estimates for shank colour, beak colour and feather colour were 1.38, 0.80 and 0.17 respectively. The average feed consumption heritability estimates ranged from 0.16 at 4 weeks to 2.00 at 8 weeks. Heritability estimates for feed conversion ratio ranged from -0.15 at 4 weeks to 1.15 at 12 weeks. Heritability estimates ABWG ranged from -0.10 at 16 weeks to 1.16 at 12 weeks of age. The phenotypic correlation (rP) was in the range of -0.0178 between BW and BC at hatch to 0.6496 between BL and SL at 20 weeks of age. The genetic correlation, rG (sire) ranged from -0.22 between BW at 8 weeks and BW at 20 weeks of age to 1.7298 between BW and SL at hatch. The data on all the traits studied indicate that the heavy ecotype could form a foundation stock for layer, meat and dual purpose breed development in Nigeria.