Seabrook, Jill L., authorPeel, R. Kraig, advisorCallan, Robert J., committee memberEngle, Terry E., committee member2022-07-012022-07-012010https://hdl.handle.net/10217/235402The objective of this study was to investigate the performance and physiological effects imposed on finishing lamb (n = 60, BW x= 41.6 ± 1.4 kg) feedlot performance and carcass characteristics by replacing dietary carbohydrate with calcium salts of fatty acids (CSF A). Upon arrival, lambs were weighed on 2 consecutive d and randomly assigned to 1 of 4 dietary concentrations of CSF A. Treatments included 1) 0% CSF A (Control); 2) 4% CFSA; 3) 7% CSFA and 4) 11% CSFA on a DM basis. Diets were formulated to be isoenergetic (TDN basis) and isonitrogenous (DIP and UIP) and consisted of 75% concentrate, and 25% roughage ( com silage). Ration TDN was kept similar between treatments; rations with less com had a higher concentration of CSF A-pellet. Intake was controlled to balance TDN per kilogram of BW across treatments; all treatments met 2006 NRC requirements for growing lambs [18]. Lambs were weighed and bled every 14 ± 2 d. Blood samples were analyzed for glucose, lactate and insulin concentrations. On d 61, lambs were transported and slaughtered at a commercial abattoir. Hot carcass weight (HCW) was determined at the time of slaughter, and longissimus muscle (LM), liver and subcutaneous adipose tissue samples were collected at slaughter and snap-frozen for later analysis of FA composition. Longissimus muscle area (LMA) and back fat (BF) carcass measurements were determined after 48 h storage at 0°C chill. There was a treatment by time interaction for overall ADG (P = 0.01). Lambs receiving 11 % CSFA had lower ADG, lighter HCW (P < 0.001) and smaller LMA (P < 0.01) than all other treatments. Control lambs had greater (P < 0.05) BF than lambs receiving 11 % CSF A, but had similar BF to lambs receiving 4 and 7% CSF A. There was no treatment effect on dressing percentage. There was a treatment by time interaction observed for blood glucose (P = 0.02); lambs fed the control diet had a tendency to have higher blood glucose concentrations. Blood insulin values were not different (P = 0.36) between treatments, and insulin to glucose ratios were similar among treatments. Overall blood lactate levels had a tendency to be lower as dietary CSF A concentration increased, although not significantly (P = 0.11). Fatty acid profiles for LM, liver and subcutaneous adipose were similar across treatments. Overall, the data suggest that CSF A can be used to replace a carbohydrate source such as com; at rates up to 7% DMI before performance is negatively affected.masters thesesengCopyright and other restrictions may apply. User is responsible for compliance with all applicable laws. For information about copyright law, please see https://libguides.colostate.edu/copyright.Sheep -- Feeding and feedsCalcium saltsLamb (Meat) -- QualityText