1a. Objectives (from AD-416)
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.
1b. Approach (from AD-416)
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.
3. Progress Report
This is a new project, with the goal of evaluating cottonseed meal as an appropriate dietary component for commercial broiler chicken production. Emphasis is on meal from cottonseed having low levels of the toxic form of gossypol. Work in FY 2011 focused on processing the cottonseed in preparation for the feeding experiment. Commercial cottonseed and cottonseed grown during the 2010 season that has a low percentage of (-)-gossypol were dehulled. During this process, the seed kernels were crushed into small pieces. The second step was to pass these pieces through a small oil seed press to remove the oil. Multiple problems were encountered during the pressing, and it was not possible to process these cottonseed kernels. The dehulled commercial and low (-)-gossypol seed pieces were sent to Cotton Incorporated for processing on one of their oil presses. Cotton Incorporated also encountered problems due to the small size of the dehulled cottonseed kernels. Since we were unable to press the low (-)-gossypol dehulled kernels, the experiment planned to begin in mid-FY 2011 had to be postponed. A modified protocol was written to determine if 10% commercial cottonseed meal could appropriately be used as commercial broiler diet. As work under this project progresses, the information developed will benefit the cotton industry by identifying/developing new commercial uses for cottonseed, and will benefit the poultry industry by identifying an alternate, and perhaps more cost-efficient high protein source for incorporation into poultry diets. The ADODR of this project and the cooperator are located in close physical proximity, and are in contact with each other on a regular basis for discussion of the progress and direction of the work.