ABSTRACT
Rambouillet and Merino×Rambouillet lambs were assigned to production systems varying in physical environment and diet: RF (raised-floor, open-sided barn/85% oat hay-10% wheat-5% molasses), FL (feedlot/high-concentrate), and P (pasture/grazing plus supplement). Although treatment duration was varied to produce similar final weights, RF lambs were heavier than P lambs, but dressing percentages were similar. Backfat thickness was less with P and for Merino cross lambs. RF feed was higher in saturated fatty acids (SFA) percentage than FL feed and P supplement, but lower compared to pasture plants. For both breed types, muscle tissue from RF was higher in SFA and lower in polyunsaturated fatty acids (PUFA) percentage than that from FL or P. In adipose tissue, SFA and PUFA tended to be higher and monounsaturated fatty acids were lower with RF for Merino cross lambs. Nevertheless, 16:0 or 18:1 percentage differences among P, FL and RF lamb tissue samples were minor vs. large variations among their respective diets.
ABSTRACT
Rambouillet lambs were assigned to three production systems varying in physical environment and diet: RF (a new, raised-floor feeding structure, with animals fed a pelleted mixture of 85% oat hay, 7.5% barley and 7.5% molasses); FL (a feedlot, with animals fed high-concentrate rations); and P (a pasture, with animals given access to the pasture and a high-concentrate supplement). Lengths of time on feed were adjusted to produce similar final shorn weights for each system. Ground meat patties were made with knife-separable lean from hind legs and aerobically refrigerated. Fat content of patties was not significantly different between RF and FL or P, while total unsaturated fatty acid percentage was slightly lower (P<0.05) for RF treatment. Patty color (redness) was most stable for RF. Lipid oxidation in raw patties also was lower (P<0.05) for RF than FL, but oxidation in cooked patties was greater for RF.
ABSTRACT
Twenty Boer x Spanish goats, at the age range of 90-118 days, were assigned to two dietary treatments, with 10 animals fed a grain ration (G) and the other 10 grazed in rangeland. The grain ration contained sorghum grain (67.5%), cottonseed hulls, dehydrated alfalfa meal, cottonseed meal, soybean meal, molasses, and mineral and vitamin supplements. Animals were slaughtered at the age range of 206-234 days. Intramuscular fat (IF) and the diet specimens - representative samples of G and the parts of range plants (RPs) that goats were expected to have consumed - were analyzed for fatty acid composition. The percentage of 16:0 was higher in RPs than in G, but not different between IF from range goats and that from grain-fed goats. Total unsaturated fatty acid (UFA) percentage was higher in G than in RPs. The major UFAs were 18:2 and 18:3 in RPs, and 18:1 and 18:2 in G. In IF, 18:1 constituted more than two-thirds of UFAs, regardless of diet type.
ABSTRACT
Ten gilts were randomly assigned to either a control sorghum-soybean diet or a similar diet containing 12% high-oleic sunflower oil (HOSO). No significant differences between the two groups were found in feedlot performance, carcass muscling and marbling score, but animals fed the HOSO diet had softer carcass fat and oilier carcasses than those fed the control diet. The ratio of monounsaturated fatty acids to saturated fatty acids (M/S) for subcutaneous fat increased from 1·58 in the control group to 3·76 in the HOSO group (138% increase); the M/S ratio for muscles (longissimus dorsi, semimembranosus and semitendinosus) increased from 0·96-1·19 to 1·84-1·88 (73% increase on an average). The percentage of polyunsaturated fatty acids in both adipose or muscle tissue was generally similar between the two diet treatments.