|Byrd Ii, James - Allen|
Submitted to: Bioresource Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/9/2007
Publication Date: 12/27/2008
Citation: Landers, K.L., Moore, R.W., Herrera, P., Landers, D.A., Howard, Z.R., McReynolds, J.L., Byrd II, J.A., Kubena, L.F., Nisbet, D.J., Ricke, S.C. 2008. Organ weight and serum triglyceride responses of older (80 week) commercial laying hens fed an alfalfa meal molt diet. Bioresource Technology. 99(14):6692-6696.
Interpretive Summary: One of the costs of producing eggs is the replacement of the laying hen. In order to save on the cost of producing eggs, farmers will molt the laying hen, which causes the bird to lose their feathers and reduces their reproductive tract. Normally, the farmer will molt the bird by removing the feed for several days. However, this program may lead to an increased chance of the bird acquiring an infection like Salmonella. A less stressful way of molting the hens is by providing a low energy diet such as alfalfa which will still cause the bird to lose their feathers and reduces the size of their reproductive tract. A study was performed to examine if causing molt by removing feed or by providing an alfalfa diet will cause changes in the weights of the major body organs of the bird. Birds that had feed removed for several days had lighter weights in the liver, heart, ovary, and pancreas compared to birds that were fed a normal chicken diet. Serum triglycerides, a type of fat in the blood, were higher in birds fed normal chicken feed, less in hens fed alfalfa, and lowest in birds that had the food removed. The results of this study suggest that a farmer could get the same results of molting the bird by providing alfalfa diet as they would in removing the feed for several days.
Technical Abstract: Since one of the costs in the commercial egg industry is that of replacement pullets, commercial egg layer managers have opted to induce molt older hens in order to extend their productive life for additional egg laying cycles. Conventional molt induction involves the complete removal of feed for several days. However, this management practice can lead to deleterious physiological responses by the hen and subsequent susceptibility to infection by pathogens. Consequently less stressful molting regimens involving the feeding of low energy diets such as alfalfa have been developed. In this study, 80 wk old laying hens that were deprived of feed or fed alfalfa meal during a nine day induced molt. Full-fed hens were used as the control. On day 8 serum triglycerides were quantified and on d 9 hens were euthanized and the liver, spleen, heart, intestine, pancreas, ovary, and kidney were collected and weighed. Intestinal weight were highest in the non-molted hens, lower in the hens fed alfalfa, and lower still in the hens deprived of feed. Molted hens exhibited reduced weights of liver, heart, ovary, and pancreas compared to the non-molted hens. Serum triglycerides were highest in the non-molted hens, less in alfalfa fed hens, and the lowest in feed deprived hens. These results suggest that a comparable molt could be achieved with feeding alfalfa meal to 80 wk hens compared to feed deprivation.