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Research Note Prediction Model For Manure Zinc Excretion In Laying Hens, Kelli M. Martin, N. Vargas-Jurado, S. E. Purdum
Research Note Prediction Model For Manure Zinc Excretion In Laying Hens, Kelli M. Martin, N. Vargas-Jurado, S. E. Purdum
Department of Animal Science: Faculty Publications
The objective of this research trial was to compare 2 sources of zinc and different levels of supplementation on manure zinc excretion in laying hens. Bovan White Leghorn hens were used in this study and fed one of 6 dietary treatments. Treatments were in a 2 × 3 factorial arrangement with 2 sources of zinc (zinc sulfate or Availa R < Zn) and 3 levels (40, 80, or 120 ppm) and were randomly assigned to 48 cages with 5 hens/cage and 8 replicates/treatment. Hens were housed in a tiered manure-belt housing system providing 627.1 cm2/hen and were given access to 110 g/hen/d of feed. Manure samples were collected, and manure zinc content was calculated at 10- week intervals. Data were analyzed using the Glimmix procedure in SAS. There was a significant overall effect of source (P < 0.0001) for zinc content, such that hens fed zinc sulfate had lower amounts of zinc excretion. There was also a significant level effect (P < 0.0001) in which hens fed 120 ppm zinc excreted the greatest amount of zinc. A significant source by level interaction was observed (P < 0.0001) for both the overall and individual analyses, such that 120 ppm Availa R < Zn showed the highest zinc excretion, and both 40 ppm zinc sulfate and Availa R < Zn showed the lowest zinc excretion. Based on these results, a prediction equation was written for an estimated amount of zinc excretion based on the amount of zinc provided in the diet.
Risks Associated To Different Methods Of Increasing Pregnancy Rate Of Cows In Cow-Calf Systems, Tamara Esteves De Oliveira, Julio Otavio Jardim Barcellos, Jack Whittier, Odilene De Souza Teixeira, David Santos De Freitas, Ricardo Pedroso Oaigen, Matheus Dhein Dill, Concepta Mcmanus
Risks Associated To Different Methods Of Increasing Pregnancy Rate Of Cows In Cow-Calf Systems, Tamara Esteves De Oliveira, Julio Otavio Jardim Barcellos, Jack Whittier, Odilene De Souza Teixeira, David Santos De Freitas, Ricardo Pedroso Oaigen, Matheus Dhein Dill, Concepta Mcmanus
Department of Animal Science: Faculty Publications
This study assessed the risks of different management practices to increase pregnancy rate in beef cow-calf systems, aiming at assisting decision-making. The perception of 18 experts on animal sciences regarding the risks of 32 nutritional, breeding, and general management practices applied to increase pregnancy rate were evaluated through questionnaires. The experts were selected by a non-probability sampling of researchers on veterinary and animal sciences. In addition, five farmers and eight technical consultants were also selected. The questionnaire was applied during a face-to-face meeting. The risk of each practice was assessed according to four factors, namely, cost, technical knowledge, operational complexity, …