Project Number: 3091-22000-031-13-S
Project Type: Specific Cooperative Agreement
Start Date: Oct 20, 2010
End Date: Oct 19, 2015
Determine the maximum level of cottonseed meal (CSM) that can be effectively included in broiler diets without negatively influencing growth performance, and investigate the levels of gossypol in tissue and organs from broilers fed varying levels of CSM.
Commercial cottonseed will be dehulled. The resulting cottonseed kernels will be analyzed for total and percent (+)- and (-)-gossypol. The cottonseed will then be passed through an oil seed press, and the resulting cold pressed cottonseed meal (P-CSM) will be analyzed again for total and percent (+)- and (-)-gossypol. The P-CSM will be combined with the control diet and pelletized. The pelletized CSM diet will be analyzed for total and percent (+)- and (-)-gossypol. Three hundred 1-day-old chicks will be weighed and randomly allotted to battery pens and dietary treatment based on body weight upon arrival to the research farm. Body weights and feed consumption will be determined on days 7, 14, and 21. On day 19, all manure pans will be cleaned, allowing for a 24-hour collection period of fecal material for gossypol analysis. On day 21, five broilers from each replicate pen will be euthanized, and tissue and organ samples collected to include liver, breast tissue, thigh tissue, and intestinal samples. Chicken tissues will be frozen and then freeze dried and ground to a fine powder. The ground tissue will be analyzed for percent (+)- and (-)-gossypol and for total gossypol using d-alaninol as the Schiff base reagent. The resulting derivatized extract will be analyzed for total and (+)- to (-)-gossypol via the established HPLC method. Intestinal tissues from two birds/replicate will be taken for histology measurements. In a second experiment, 600 1-day-old chicks will be weighed and randomly allotted to floor pens and dietary treatment based on body weight upon arrival to research farm. Based on the results from the first experiment, four diets will be utilized, consisting of a control diet (a basal starter diet will be corn and soybean meal-based and will be typical of diets fed in the U.S. poultry industry), a commercial CSM diet, and a diet derived from CSM containing a low percentage of (-)-gossypol. Percentage of CSM will be determined based on the results obtained in experiment 1. The total gossypol between the commercial CSM and the low percent (-)-gossypol CSM will be adjusted to the same value by adding glandless CSM to the CSM with the highest level of total gossypol. The length of time the birds are held on the CSM diets will be determined based on the results from experiment 1, but probably at the end of 21 days all birds will be transferred to the control diet. All pens will be weighed on days 7, 14, 28, 35, and 42.