ECONOMIC EVALUATION OF HATCHABILITY AND EFFECT OF BROILER BREEDER AGE AND EGG WEIGHT ON HATCHABILITY, CHICK QUALITY AND BROILER PRODUCTION

Abstract

This study was divided into four phases. The main objective of the first phase of study was to evaluate the performance of broiler breeders. For this purpose, a complete production data of 20 Hubbard Classic broiler breeder flocks from 26 to 60 weeks of age was collected at random for the years 2005 to 2011. The average percentages of egg production, hatchable eggs, egg weight and egg hatchability was found as 65.7%, 96.3%, 64.7 g and 79.3%, respectively during production period. At 60 week of age, average egg weight, hen housed eggs, hen housed hatchable eggs and number of chicks produced per hen housed were 69.8 g, 149.8, 145.1 and 119.10, respectively. Feed consumptions per hatchable egg and day-old chick were 395 and 486 g, respectively. Male and female body weights at 60 week were observed as 4785 and 3929 g, respectively. Only 30% flocks were spiked during production cycle. Spiking of young males with aged males was started from 41 week and continued to 55 week. The average production performances differed significantly (p≤0.05) with strain standards and most of production parameters were below the strain standards. It was also observed that a strong positive correlation (r2 =0.980) between hatchability and number of chicks produced per hen housed, and a strong negative correlation (r2 = -0.833) between the number of chicks produced per hen housed and feed consumed to produce one day-old chick per hen housed exist in broiler breeders. Generally, it was observed that poultry breeders who, followed poor management practices, resulted in low numbers (119.1) of day-old chicks per hen house than strain standard (139). 24 In second phase, the objective was to study the effect of egg size and age on egg quality traits during early (30wk), mid (45wk) and late (60wk) stages of production period in broiler breeder. A commercial broiler breeder flock of Hubbard Classic strain (25 week old) was selected for study. A total of 2000 Hubbard Classic females and 180 males (male to female ratio 1: 11) were selected and reared in the poultry house. During 4-8 hour of light periods, a total of 930 hatchable eggs were selected at the early, mid and late stage of production period and equally distributed into 3 egg-sized categories (small, medium and large). Ten (10) eggs from each egg category were analyzed for the egg quality parameters within 24 hours of laying. At an early stage of production period, the results revealed that yolk weight augmented (p≤0.05) with increase of egg size but all other egg quality parameters (shell weight, shell thickness, albumen weight, yolk to albumen ratio, shape index and specific gravity) were not influenced (p≥0.05) by egg size. At mid stage of production period, shell weight, shape index and specific gravity were reduced (p≤0.05) with increase in egg size and shell thickness, yolk weight, albumen weight and yolk to albumen ratio were not influenced (p≥0.05) by egg size. At late stage of production cycle, shell weight, shell thickness, shape index and specific gravity were reduced (p≤0.05) with increase of egg size and yolk weight, albumen weight and yolk to albumen ratio were not influenced (p≥0.05) by egg size. The egg weight increased (p≤0.05) with age. Yolk weight and yolk to albumen ratio were improved (p≤0.05) while shell thickness, albumen weight, shape index and specific gravity were reduced (p≤0.05) with advancing of broiler breeder age. In third phase, the objective was to study the effects of egg size (small, medium and large) and flock ages (30, 45 and 60 wks) on hatchability 25 and chick quality traits. A total of 300 hatchable eggs from each egg category were selected at early, mid and late stage of production period. These eggs were shifted to broiler hatchery and stored at 20 oC and 75% relative humidity for 3 days prior to incubation. The results showed that egg weight loss percentage decreased (p≤0.05) with increase of egg size at all stages of production period, and advancing age of breeder hen. Fertility and hatchability parameters were influenced (p≤0.05) by egg size and age. The best combination of fertility and hatchability values were recorded in medium-sized eggs (60-69g) and at mid stage of production period. Maximum (p≤0.05) embryonic deaths during incubation and higher percentage (p≤0.05) of infertile eggs were observed in small-sized eggs (<51g) and extralarge-sized eggs (>70g) but the embryonic deaths were not influenced (p≥0.05) by age of breeder hen. Maximum (p≤0.05) infertile eggs, pipped-not-hatched eggs and culled chicks were recorded in older (60wk) as compared to younger (30, 45wk) broiler breeders. Chick weight and chick length were amplified (p≤0.05) with increase of egg size at all stages and chick yield at late stage of production period. Chick weight and chick length were improved (p≤0.05), however chick yield was not influenced (p≥0.05) by age of breeder hen. In fourth phase, the objective was to determine the effect of broiler breeder egg size and age on post-hatching performance of broiler chicks. A total of 90 day-old chicks (45♂ and 45♀) from each egg-sized category were reared for 5 weeks at early, mid and late stage of production period. The results showed that live body weight of both sex of broiler improved (p≤0.05) with increasing the egg size during the first 3 week and become insignificant 26 (p≥0.05) from 4th week of age at all stages of production cycle. Similarly, the chick growth improved (p≤0.05) during first 2 week with age of breeder hen. However, the influence of age on chick growth from 3rd to 5th weeks was non-significant (p≥0.05). At 3rd week of broiler age, feed intake of broiler (both sex) at early stage, feed intake of female at mid stage and feed intake of male at late stage of production period increased significantly (p≤0.05) with increasing in egg size. However, influence of egg size on broiler (both sex) feed intake during first, second, fourth and fifth week of growing period was non-significant (p≥0.05). Breeder age had non-significant (p≥0.05) effect on broiler feed intake from 1st to 5th weeks of age. Generally, egg size had non-significant (p≥0.05) effect on broiler FCR. However, female broiler FCR significantly (p≤0.05) improved with increasing of egg size during 2nd and 3rd week of growth period at early and late stage of production period. Broiler chicks (regardless sex) hatched from 45 week old breeder had efficient FCR at 5th week than broiler from younger (30wk) or older (60wk) breeders. Egg size at different stages of production cycle, and breeder age had non-significant (p≥0.05) effect on mortality of broiler chicks, reared from 1st to 5th weeks of age.