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Effects Of Cold Stress During Transportation On Hatchability And Chick Quality Of Broiler Breeder Eggs, Ahmad Salahi, Mozhdeh Moosanezhad Khabisi, Abbas Pakdel, Ali Baghbanzadeh
Effects Of Cold Stress During Transportation On Hatchability And Chick Quality Of Broiler Breeder Eggs, Ahmad Salahi, Mozhdeh Moosanezhad Khabisi, Abbas Pakdel, Ali Baghbanzadeh
Turkish Journal of Veterinary & Animal Sciences
In this experiment 72,000 broiler breeder eggs (Ross 308 strain) collected from 36-week-old flocks were subjected to cold stress during transportation. Eggs were allocated to 4 temperature groups (treatments): 1.2 °C, 1-2 °C, 2.5-3.9 °C, 4-6 °C, and a control group, 21-22 °C. Each treatment had 14,400 eggs, and data were analyzed in a completely randomized design. The results of this study showed that cold stress had a significant effect on percentage of egg weight loss (P < 0.001), and minimal egg weight loss occurred in the control group. The percentage of exploders and early hatched chicks and chick weight were higher in the below zero temperature treatment than the other groups (P < 0.01). Cold stress had a significant effect on chick length, hatchability, and the hatching of fertile eggs (P < 0.001). The effects of cold stress on chick yield and body weight uniformity were significant (P < 0.01). The effect of cold stress on hatchery byproduct efficiency was significant (P < 0.001), but did not affect fertility. Cold stress also had significant effects on early (1-8 days), middle (9-17 days), and late mortality (20-21 days); total embryo mortality; and exposed brain. Ectopic viscera was significant (P < 0.001), and most mortality was observed in below 4 °C treatments. Total percentages of malpositions and deformity (P < 0.001) and egg contamination at 1-9 days (first stage) and 10-21 days (second phase) were affected by cold stress (P < 0.001). Cold stress also had a significant impact on the number of cull chicks; percent of string navel, button navel, total string, and button; omphalitis; full body cavity; red hocks; dehydration; dirty chickens; and stubby down. Cold stress affects performance during incubation and overall chick quality.
The Influence Of Egg Shell Crack Types On Hatchability And Chick Quality, Mozhdeh Moosanezhad Khabisi, Ahmad Salahi, Seyed Naser Mousavi
The Influence Of Egg Shell Crack Types On Hatchability And Chick Quality, Mozhdeh Moosanezhad Khabisi, Ahmad Salahi, Seyed Naser Mousavi
Turkish Journal of Veterinary & Animal Sciences
Fertile eggs were obtained from a commercial flock of Ross broiler breeders (51 weeks old) and candled to determine the presence of hairline or star cracks. Eggs (5400 total) were assigned in equal numbers to 3 treatments (hairline-cracked, star-cracked, and normal eggs) and incubated for 21 days. Upon hatching, 10 chicks per treatment were euthanized, and organ weights were measured. Compared with normal eggs, the presence of egg shell cracks (regardless of type) resulted in higher egg weight loss at the time of transfer; a decrease in hatchability, hatch of fertile eggs, chick length, yolk-free body mass (P < 0.01), and percentage of hatchling breast and liver weight (P < 0.05); and an increase in the contamination rate of eggs (P < 0.01). Weight loss in hairline-cracked eggs was significantly higher than in star-cracked eggs (P < 0.001). Percentage hatchability and body weight of chicks hatched from star-cracked eggs was higher than in chicks from hairline-cracked eggs (P < 0.001). Crack type did not have a significant effect on chick length and body weight uniformity; however, the Pasgar score as a quality indicator was higher in chicks hatched from star-cracked eggs than those from hairline-cracked eggs (P < 0.05). There were no significant differences among treatments in terms of heart and small intestine weight. The contamination rate of hairline-cracked eggs was higher than that of star-cracked (P < 0.01). A higher incidence of embryonic mortality was observed during days 1-8 of incubation for shell-cracked eggs (P < 0.001). Total embryonic mortality in hairline-cracked, star-cracked, and normal eggs was 51.1%, 36.6%, and 13.3%, respectively. This study showed that egg shell cracks reduced incubation parameters and chick quality. The negative effects of hairline cracks were more pronounced than those of star cracks.