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dc.contributor.advisorKrueger, W. F.
dc.creatorFotoohi, Hamid
dc.description.abstractThe economics of egg production is greatly affected by the feeding program, rate of egg production and length of production. Profit can be maximized by controlling these three factors. This study has investigated the biological influence and economic impact of certain feeding regimes on commercial egg-type hens in two experiments. In addition, an economic approach to determining when laying hens should be replaced was evaluated. In the first experiment, two isonitrogenous diets differing by 100 kcal ME/kg feed produced similar rates of egg production, feed per dozen egg, feed intake, egg weight, and livability. Only shell thickness was affected by the level of energy in the diet. The hens on the high energy diet consistently produced eggs with the thickest shells. Hens receiving 2728 kcal ME/kg of feed had a 0.309 mm mean shell thickness, while the hens receiving 2828 kcal ME/kg of feed had an average shell thickness of 0.315 mm, a statistically significant difference (P[less than or equal to] 0.01) . Appetite enhancers, Extra Taste and Sure Fresh #2, when added to either diet had little advantageous affect on hen performance. Body size differences, small hens versus large hens, did not significantly influence hen-day production, feed per dozen egg, livability, percent cracked eggs and shell thickness; however, egg size, percent shell, feed intake and albumen height were significantly influenced by body size (P[less than or equal to] 0.01, P[less than or equal to] 0.01, P[less than or equal to] 0.10, and P[less than or equal to] 0.10 respectively). An economic evaluation of this experiment suggested that small body size hens perform more profitably on a low energy diet, while large body size hens produced a greater profit when fed the high energy diet. Net profit decreased when the appetite enhancers were added to the low energy diet, irrespective of hen size. Net profit increased when appetite enhancers were added to the high energy diet and fed to small hens, while net profit decreased when appetite enhancers were added to the high energy diet and fed to the large hens...en
dc.format.extentxii, 84 leavesen
dc.rightsThis thesis was part of a retrospective digitization project authorized by the Texas A&M University Libraries. Copyright remains vested with the author(s). It is the user's responsibility to secure permission from the copyright holder(s) for re-use of the work beyond the provision of Fair Use.en
dc.subjectMajor poultry scienceen
dc.subject.classification1980 Dissertation F761
dc.subject.lcshFeed utilization efficiencyen
dc.titleA biological and economic evaluation of certain feeding regimes in commercial layersen
dc.typeThesisen A&M Universityen of Philosophyen
dc.contributor.committeeMemberGardner, F. A.
dc.contributor.committeeMemberGilbert, R. F.
dc.contributor.committeeMemberJenkins, O. C.
dc.contributor.committeeMemberMellor, D. B.
dc.contributor.committeeMemberRyan, C. B.
dc.format.digitalOriginreformatted digitalen
dc.publisher.digitalTexas A&M University. Libraries

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