Abstract
To observe the effect of Induced molting on the recovery patterns of abdominal fat, visceral organs, and muscle tissues in spent laying hens after induced molting, three hundred sixty 77-wk-old, Babcock White hens were divided into 36 experimental units of 10 hens each and subjected to molt induction for seven wk. The post-molt production phase was spread over 84 to 126 wks of age. Thirty-six birds were randomly slaughtered and dressed at the pre-molt, 5% egg production, Peak, and end Phases of e99 Production. The body weight, abdominal fat, relative weight and length of visceral organs were measured. Proximate compositions of breast and thigh muscles were analyzed at each stage. The body weight was found to be minimal at the 5% egg Production stage, but increased as the egg Production increased for the rest of production. The pattern of abdominal fat change was very similar to that of body weight. The relative weight of the liver decreased to the lowest at the start of Post molting stage, but Peaked at the end Phase of egg Production (P<0.05). However, he heart and gizzard were observed to reach their maximum weight at the 5% egg Production (P<0.05), whereas they were, similar to those of the pre-molt phase for the rest of the production stages. Both intestine and reproductive tracts were found o be significantly smaller at 5% egg Production than at the other stages; however, their sizes increased gradually, reaching leak at the end Phase of e99 Production (P<0.05). Fat contents in breast and thigh muscles decreased significantly to the lowest at the start of the Post-molt stage, but increased to the highest at the end Phase of e99 Production (P<0.05). Thus, he Present study indicated that the molting process reduced body weight by decreasing the weights of abdominal fat and other visceral organs. Molting also influenced the breast and thigh muscle composition by decreasing fat content.
산란노계에서 강제환우가 체중, 복강지방, 장기, 근육조직의 변화에 미치는 영향을 고찰하고자 77주령 산란계 360수를 7주간 강제환우를 시행하였다. 강제환우전, 산란율 5%, 산란피크, 실험종료 시기인 126주령에 단계별로 각각 36수씩 희생시킨 후에 체중, 복강지방, 장기 및 번식기관의 길이와 무게를 조사하였으며, 가슴과 다리근육에서 지방함량을 분석하였다. 체중은 산란 5% 시기에 제일 낮았으며 산란율이 증가하면서 실험 종료시기에 극대화되었다. 복강지방도 체중의 변화와 비슷한 경향을 보였다. 간의 체중에 대한 비율도 강제환우 후에 제일 낮았지만 실험 종료시에 현저하게 높았다(P<0.05). 심장과 근위의 무게는 산란율이 5%에 도달하였을 때 제일 높았지만, 그 후에는 강제환우 이전과 동일한 경향을 보였다. 산란율이 5%에 도달한 시점에서 장기와 번식기관의 무게는 다른 시기에 비하여 현저하게 낮았지만 산란율이 높아지면서 그 무게가 증대되었으며 실험 종료시에 제일 높게 나타났다(P<0.05). 가슴과 다리근육의 지방함량도 산란율이 5% 도달시에 제일 낮게 나타났으며, 실험 종료시에 현저하게 높았다(P<0.05). 본 실험의 결과 산란노계에서 강제환우 전후시기에 체중, 장기, 근육의 변화의 주요 원인은 주로 복강지방과 다른 장기 및 근육에서 지방의 함량감소에 기인하였음을 확인하였다.