Submitted to: Professional Animal Scientist
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/15/2003
Publication Date: 8/15/2003
Citation: Holt, G.A., Richardson, C.R., Nunnery, G.A., Wilson, K.F., Bramble, T.C., Rea, L.D., Wedegaertner, T.C. 2003. Performance of growing heifers fed diets containing cotton gin by-products extruded by the COBY process. Professional Animal Scientist. 19(6):404-409. Interpretive Summary: Byproducts from a cotton gin have traditionally been considered a problem that cost the ginning industry an estimated 4 to 6 million dollars a year in disposal fees. Disposal costs are incurred by the gins and passed on to the producers. A traditional use that has been studied extensively over the years is feeding the byproducts to livestock. In this paper, a heifer feeding study was undertaken to evaluate the effect that the COBY process had on adding value to cotton gin byproducts compared to traditionally fed ground burs. There were 168 heifers fed rations containing seven different roughages. Four of the rations contained COBY and three contained ground burs. The amount of roughage in the rations was 30% of the total. Results from the study showed that the COBY product had a 15% improvement in feed to gain ratio over ground burs. Overall, the heifers ate less of the COBY product and produced the same daily gain as the rations with ground burs.
Technical Abstract: A backgrounding experiment with crossbred beef heifers was conducted in the spring of 2002 to determine the effects of feeding diets containing either ground or extruded (COBY process) cotton gin byproducts on feed intake and performance. Two basal diets with ground or COBY processed cotton gin byproducts were compared with and without a feed-grade enzyme additive or a slow release urea product. Diets were completely mixed and consisted of approximately 70% concentrate and 30% cotton gin byproducts (CBP). Heifers were fed the diets for 42 d with feed intake and gain measured at each of two 21 d intervals. One hundred and sixty-eight crossbred heifers provided from one source and of known breeding were randomly assigned to the seven treatments. Heifers were initially weighed, not implanted. Initial weight was 289.8 ± 13.2 kg. Four pens of six heifers were used per treatment and pen was the experimental unit. Treatments were: 1) ground CBP; 2) ground CBP + feed-grade enzyme; 3) ground CBP + slow release urea; 4) COBY process; 5) COBY process + feed-grade enzyme; 6) COBY process + slow release urea; 7) COBY process + feed-grade enzyme + slow release urea. Dry matter intake across the three diets containing ground CBP was similar and was not different from the COBY process alone. However, dry matter intake was decreased (P < 0.05) when feed-grade enzyme or slow release urea was added to the COBY process individually or in combination. Average daily gain across all treatments was 1.55 kg per head, per day, which indicates that growing diets for cattle containing 30% CBP can be successfully and effectively used. Treatment comparisons for gain data showed that heifers fed diets without the slow release urea gained faster (P < 0.05). Feed efficiency (feed:gain ratio) was improved (P < 0.05) by the COBY process alone, by the COBY process + feed-grade enzyme, and by the ground CBP + feed-grade enzyme as compared to other treatments. These data indicate that the COBY process can be successfully used to produce backgrounding or growing diets for cattle with potential improvements in performance and efficiency of gain.