Effect of hatching time on yolk sac percentage and broiler live performance

This study investigated the effects of broiler chick hatching time on the percentage of the yolk sac and subsequent broiler live performance. Broiler hatching eggs were obtained from a commercial flock at 55 wk of age and were stored for 2 d at 18°C and 75% relative humidity (RH) prior to incubation. Chicks were identified as hatching Early (471-477 h), Middle (480-486 h), and Late (494-510 h). All chicks were removed from the trays at 510 h of incubation. Body weight (BW) and yolk weight (YW) were determined at emergence from the shell (initial hatch time) and at placement on feed. Chicks were permanently identified by hatch time with neck tags, feather sexed, weighed, and introduced to feed and water in litter floor pens. Broiler BW and feed consumption (FC) were then determined 7, 21, and 35 d of age. Mortality was recorded daily. Although the percentage of the yolk was similar at hatch time, it was less in Early compared to Middle and Late chicks at placement (p≤0.05). Broiler chick BW was greater at placement in Late chicks compared to Early and Middle chicks (p≤0.05) but this advantage disappeared by 7 d because Late chicks consumed less feed to 7 d (p≤0.05). Early hatched broilers exhibited greater BW than Late with Middle broilers intermediate at 35 d (p≤0.05). There were no significant differences in feed consumption and feed conversion ratio (FCR) at 35 d of age. Additionally, late hatch chicks exhibited greater mortality. Overall, live performance of Late hatching chicks, judged by mortality and BW at 35 d, was reduced compared to Early hatching chicks.(AU)

Effect of hatching time on yolk sac percentage and broiler live performance

This study investigated the effects of broiler chick hatching time on the percentage of the yolk sac and subsequent broiler live performance. Broiler hatching eggs were obtained from a commercial flock at 55 wk of age and were stored for 2 d at 18°C and 75% relative humidity (RH) prior to incubation. Chicks were identified as hatching Early (471-477 h), Middle (480-486 h), and Late (494-510 h). All chicks were removed from the trays at 510 h of incubation. Body weight (BW) and yolk weight (YW) were determined at emergence from the shell (initial hatch time) and at placement on feed. Chicks were permanently identified by hatch time with neck tags, feather sexed, weighed, and introduced to feed and water in litter floor pens. Broiler BW and feed consumption (FC) were then determined 7, 21, and 35 d of age. Mortality was recorded daily. Although the percentage of the yolk was similar at hatch time, it was less in Early compared to Middle and Late chicks at placement (p≤0.05). Broiler chick BW was greater at placement in Late chicks compared to Early and Middle chicks (p≤0.05) but this advantage disappeared by 7 d because Late chicks consumed less feed to 7 d (p≤0.05). Early hatched broilers exhibited greater BW than Late with Middle broilers intermediate at 35 d (p≤0.05). There were no significant differences in feed consumption and feed conversion ratio (FCR) at 35 d of age. Additionally, late hatch chicks exhibited greater mortality. Overall, live performance of Late hatching chicks, judged by mortality and BW at 35 d, was reduced compared to Early hatching chicks.

The effect of eggshell thickness on hatching traits of partridges

Incubation is an important factor in poultry production, particularly in species with relatively low fertility and hatchability rates. This study examined the effect of eggshell thickness on hatching traits of partridges (A. chukar). A total of 462 eggs from intensively reared partridges were separated into three groups according to eggshell thickness, which was measured ultrasonically before incubation. Hatchability, chick weight, and chick length were assessed at the end of the incubation period. Hatching times were recorded during hatching. Embryonic mortalities in unhatched eggs were classified according to mortality stage at the end of incubation. The effect of eggshell thickness on hatchability was found to be insignificant for all groups. Moreover, eggshell thickness had no significant effect on chick weight or length.

The effect of eggshell thickness on hatching traits of partridges

Incubation is an important factor in poultry production, particularly in species with relatively low fertility and hatchability rates. This study examined the effect of eggshell thickness on hatching traits of partridges (A. chukar). A total of 462 eggs from intensively reared partridges were separated into three groups according to eggshell thickness, which was measured ultrasonically before incubation. Hatchability, chick weight, and chick length were assessed at the end of the incubation period. Hatching times were recorded during hatching. Embryonic mortalities in unhatched eggs were classified according to mortality stage at the end of incubation. The effect of eggshell thickness on hatchability was found to be insignificant for all groups. Moreover, eggshell thickness had no significant effect on chick weight or length.(AU)

Temperatures for fertilization and hatching and their influence ondetermining the sex ratio of the silver catfish Rhamdia quelen / Temperatura de fertilização e incubação e sua influência na determinação da proporção sexual do jundiá, Rhamdia quelen

This study aimed to evaluate the effects of water temperature duringfertilization and egg incubation in the determination of the sex ratio of fingerlings of silvercatfish Rhamdia quelen. Water temperatures of 19, 25 and 30°C were used during the eggfertilizations, and the eggs were then incubated at temperatures of 19, 25 or 30°C for eachfertilization temperature condition. An increase in temperature reduced the fertilization rateof R. quelen, while the final number of fish was reduced when a lower temperature was usedduring egg incubation. The temperatures of fertilization and incubation that were tested didnot alter the sex ratio.

Temperatura de fertilização e incubação e sua influência nadeterminação da proporção sexual do jundiá, Rhamdia quelen. O presente estudo tevecomo objetivo avaliar o efeito da temperatura da água de fertilização e de incubação nadeterminação da proporção sexual do jundiá, Rhamdia quelen. Para tanto, foram utilizadastrês temperaturas de água de fertilização de ovos (19, 25 e 30°C), e para cada uma delas osovos foram incubados nas temperaturas de 19, 25 e 30°C. O aumento da temperaturareduziu a taxa de fertilização de Rhamdia quelen, enquanto o número final de indivíduos foireduzido quando a menor temperatura de incubação foi utilizada. As temperaturas defertilização ou incubação testadas não alteram a proporção entre os sexos.

Temperatures for fertilization and hatching and their influence ondetermining the sex ratio of the silver catfish Rhamdia quelen / Temperatura de fertilização e incubação e sua influência na determinação da proporção sexual do jundiá, Rhamdia quelen

This study aimed to evaluate the effects of water temperature duringfertilization and egg incubation in the determination of the sex ratio of fingerlings of silvercatfish Rhamdia quelen. Water temperatures of 19, 25 and 30°C were used during the eggfertilizations, and the eggs were then incubated at temperatures of 19, 25 or 30°C for eachfertilization temperature condition. An increase in temperature reduced the fertilization rateof R. quelen, while the final number of fish was reduced when a lower temperature was usedduring egg incubation. The temperatures of fertilization and incubation that were tested didnot alter the sex ratio.(AU)

Temperatura de fertilização e incubação e sua influência nadeterminação da proporção sexual do jundiá, Rhamdia quelen. O presente estudo tevecomo objetivo avaliar o efeito da temperatura da água de fertilização e de incubação nadeterminação da proporção sexual do jundiá, Rhamdia quelen. Para tanto, foram utilizadastrês temperaturas de água de fertilização de ovos (19, 25 e 30°C), e para cada uma delas osovos foram incubados nas temperaturas de 19, 25 e 30°C. O aumento da temperaturareduziu a taxa de fertilização de Rhamdia quelen, enquanto o número final de indivíduos foireduzido quando a menor temperatura de incubação foi utilizada. As temperaturas defertilização ou incubação testadas não alteram a proporção entre os sexos.(AU)