Teresa Castro

FATTY ACID COMPOSITION AND CARCASS CHARACTERISTICS OF GROWING LAMBS FED DIETS CONTAINING PALM OIL SUPPLEMENTS

Thirty 45-day-old male Ojalada lambs were used to investigate the effect of palm oil (as such or in the form of calcium soap) on carcass characteristics and fat composition. Dietary palm oil did not significantly affect dorsal fat thickness, carcass fatness or carcass conformation. The palm oil supplement did not affect C16:0 levels in intramuscular and subcutaneous fat, but did increase the percentage of C16:0 and reduce PUFA and MUFA content in internal fat depots. Supplementation with palm oil in the form of calcium soap did not cause significant differences in the composition of intramuscular fat. Subcutaneous and perirenal fat of lambs fed treatments including palm oil as such contained higher levels of some saturated fatty acids than that of those fed fat in the form of calcium soap. Mesenteric fat of lambs that received calcium soap had less % C18:1 and more % C18:3 than that of those given palm oil.

Animal performance and fatty acid composition of lambs fed with different vegetable oils.

Twenty-seven lambs were used to investigate the effects of the inclusion of 4% hydrogenated palm oil (HPO) or sunflower oil (SFO) in the concentrate on animal performance, carcass and meat quality and fat characteristics and fatty acid composition. Animals (16.2±0.27kg initial weight) were fed concentrate (Control, HPO or SFO) and barley straw ad libitum and slaughtered at 25kg. SFO lambs tended to eat less concentrate than HPO animals (P<0.10). Neither HPO nor SFO affected any of the carcass characteristics studied, meat pH and meat and fat colour (P>0.05). SFO decreased proportions of C16:0, C18:1 cis-11 and C18:3 (P<0.05) and increased C18:1 trans (P<0.001) and C18:2/C18:3 ratio (P<0.05). Atherogenicity index was lower (P<0.05) when SFO was included in the concentrate. HPO did not affected and SFO improved fatty acid composition of fattening lambs without affecting animal performance.

Feeding vegetable oils to lactating ewes modifies the fatty acid profile of suckling lambs.

The objective of this study was to evaluate the effects of vegetable oil supplementation of ewe diets on the performance and fatty acid (FA) composition of their suckling lambs. Forty-eight pregnant Churra ewes (mean BW 64.3±0.92 kg) with their 72 newborn lambs (prolificacy=1.5) were assigned to one of four experimental diets, supplemented with 3% of hydrogenated palm (PALM), olive (OLI), soya (SOY) or linseed (LIN) oil. Lambs were nourished exclusively by suckling from their respective mothers. Ewes were milked once daily, and milk samples were taken once a week. When lambs reached 11 kg, they were slaughtered and samples were taken from musculus longissimus dorsi (intramuscular fat) and subcutaneous fat tissue. No changes were observed in milk yield, proximal composition or lamb performance (P>0.10). Milk and lamb subcutaneous and intramuscular fat samples from the PALM diet had the highest saturated fatty acid concentration, whereas those of the OLI, SOY and LIN diets had the lowest (P<0.05). The greatest monounsaturated fatty acid concentration was observed in milk from ewes fed OLI, and the least in milk and in lamb subcutaneous and intramuscular fat samples from LIN and PALM diets. Milk and lamb fat from ewes fed PALM displayed the highest 16:0 proportion and the lowest 18:0 (P<0.05). There were higher concentrations of cis-9 18:1 in OLI samples (P<0.05), more 18:2n-6 in SOY lambs and milk fat (P<0.001) and the highest levels of 18:3n-3 and 20:5n-3 in LIN samples (P<0.01). Milk and lamb subcutaneous and intramuscular samples from SOY and LIN diets contained the most cis-9, trans-11 conjugated linoleic acid, whereas PALM samples had the least (P<0.01). Sheep diet supplementation with different oils, constituting up to 3% of their diets, resulted in changes in the FA composition of milk and the subcutaneous and intramuscular fat of suckling lambs, but did not affect either milk production or lamb performance.

Effect of either once or twice daily concentrate supplementation of wheat straw on voluntary intake and digestion in sheep

Abstract Eighteen mature Merino ewes were used to study the effect of either once or twice daily concentrate supplementation of wheat straw on voluntary intake and diet digestibility. Diets consisted of wheat straw, fed as the only feed (S0) or supplemented with 0.450xa0kg of concentrate per day (850xa0g cracked barley grain, 120xa0g soya-bean meal and 30xa0g vitamin–mineral supplement per kg of concentrate) given either in a meal (S1) or in two equal meals (S2). Concentrate supplementation tended ( P P P >0.05) by the frequency of concentrate feeding. Rumen fermentation were studied using three rumen-cannulated Merino sheep in a 3×3 Latin square design. Concentrate supplementation decreased ( P P P P P >0.05) ruminal pH, ammonia–N or VFA concentrations, but increased ( P P P >0.05) the in situ degradation of either wheat straw or concentrate.

Animal performance and meat characteristics in steers reared in intensive conditions fed with different vegetable oils.

Enhancing the quality of beef meat is an important goal in terms of improving both the nutritional value for the consumer and the commercial value for producers. The aim of this work was to study the effects of different vegetable oil supplements on growth performance, carcass quality and meat quality in beef steers reared under intensive conditions. A total of 240 Blonde D Aquitaine steers (average BW=293.7±38.88 kg) were grouped into 24 batches (10 steers/batch) and were randomly assigned to one of the three dietary treatments (eight batches per treatment), each supplemented with either 4% hydrogenated palm oil (PALM) or fatty acids (FAs) from olive oil (OLI) or soybean oil (SOY). No differences in growth performance or carcass quality were observed. For the meat quality analysis, a steer was randomly selected from each batch and the 6th rib on the left half of the carcass was dissected. PALM meat had the highest percentage of 16:0 (P<0.05) and the lowest n-6/n-3 polyunsaturated fatty acids (PUFA) ratio (P<0.05), OLI had the highest content of t11-18:1 (P<0.01) and c9,t11-18:2 (P<0.05) and SOY showed the lowest value of monounsaturated fatty acids (MUFA) (P<0.001), the highest percentage of PUFA (P<0.01) and a lower index of atherogenicity (P=0.07) than PALM. No significant differences in the sensory characteristics of the meat were noted. However, the results of the principal component analysis of meat characteristics enabled meat from those steers that consumed fatty acids from olive oil to be differentiated from that of steers that consumed soybean oil.