Abstract: The objective of this study was to determine apparent nutrient digestibilities and nitrogen retention of a cracked cotton seed diet compared to a whole cottonseed diet. To determine apparent nutrient digestibilities and N retention, 10 male goats (28±5.6 kg) were housed in metabolism crates and fed diets consisting of 22.5% alfalfa pellets, 56% milo, 1.5% mineral premix and either: 20% cracked cottonseed (CRACKED); or 20% whole cottonseed (WHOLE). Dry matter intake was greater for wethers consuming WHOLE compared to those consuming CRACKED (p = 0.0057, 0.92 and 0.58 kg day-1, respectively; p = 0.0560, 3.20 and 2.36% BW day-1, respectively). There were no differences (p>0.10) between WHOLE and CRACKED for DM digestibility (76.8 and 73.7%, respectively) and OM (77.8 and 75.4%, respectively). However, ash digestibility was greater (p = 0.0083) for WHOLE compared to CRACKED (58.8 and 44.0%, respectively). Neutral detergent fiber tended to be more (p = 0.0683) digestible by animals fed WHOLE (55.6%) than CRACKED (42.8%). Digestibility of ADF was not different (p>0.10) for wethers consuming WHOLE and CRACKED (38.8 and 35.7%, respectively). Wethers consuming WHOLE (84.9%) digested more (p = 0.0051) fat than those fed CRACKED (76.0%). Additionally, crude protein was more digestible (p = 0.0002) for WHOLE (75.5%) compared to CRACKED (65.2%) and N retention was greater (p = 0.0005) by goats fed WHOLE (15.8 g day-1) compared to those fed CRACKED (1.2 g day-1). To further investigate, the effect of cracking cottonseed a timed (0.5-48 h) IVDMD was performed. Degradation of DM was different for all incubation times (p = 0.0001; from 0.5-48 h) for cracked cottonseed compared to whole cottonseed. These results indicate that cracking cottonseed has a negative influence on apparent nutrient total tract digestibilities of whole cottonseed.
B.E. Hagens , C.W. Dunaway , N.C. Whitley and B.J. Rude , 2009. The Effects of Cracking Whole Cottonseed on Apparent Nutrient Digestibilities, N and Energy Retention and in vitro Dry Matter Disappearance When Fed to Goats. Journal of Animal and Veterinary Advances, 8: 1372-1376.