RESUMEN
Four experiments were conducted to evaluate lipid digestibility in finishing swine fed chemically hydrogenated fats. Dietary chromic oxide was used as an inert marker to measure the apparent digestibility of supplemental fat (SF) that consisted of fully hydrogenated (FH), partially hydrogenated (PH), or PH products blended with other fat sources. In Exp. 1, diets containing 5% SF (as-fed basis) comprising 100, 66.7, 33.3, or 0% FH animal fat (iodine value = 2.5), with the balance contributed by soy oil, were fed to gilts (n = 24). Apparent digestibility increased linearly (-12.0, 26.0, 61.2, and 72.6%; P < 0.001) as the amount of FH fat in the diet decreased, suggesting the digestibility of FH to be near zero. Experiment 2 (2 x 4 factorial; n = 48) evaluated diets containing 5% (as-fed basis) blended fat (FH tallow and yellow grease) to achieve iodine values of 20, 30, 40, or 50 compared with PH tallow with identical iodine values. Digestibility of diets formulated with PH tallow was greater than those containing blended fat (73.4 vs. 67.2%; P < 0.01), especially at lower iodine values (interaction; P < 0.10). In Exp. 3, digestibility was measured in pigs (n = 96) fed 5% (as-fed basis) PH choice white grease with iodine values of 20, 40, 60, or 80. Increasing iodine value did not alter digestibility (66.2, 69.2, 68.2, and 69.7%). Experiment 4 investigated digestibility (n = 32) of diets formulated with 8% (as-fed basis) PH fat (iodine value 20 or 50) with 0.10% lysolecithin as an emulsifier. Lipid digestibility was 14.5% greater in the 8% SF diet with an iodine value of 50 compared with the diet with an iodine value of 20 (79.15 vs. 69.12%; P < 0.001), but lysolecithin was without effect. These experiments indicate that partial hydrogenation is superior to blending unsaturated fat with saturated fat sources and that digestibility is not greatly affected by decreasing the iodine value via partial hydrogenation.
Asunto(s)
Alimentación Animal , Grasas de la Dieta/metabolismo , Metabolismo de los Lípidos , Animales , Emulsionantes , Ácidos Grasos , Femenino , Hidrogenación , Masculino , Carne , Valor Nutritivo , PorcinosRESUMEN
Interest in fortification of human foods, including pork, with conjugated linoleic acid (CLA) is growing and may provide benefits as a neutraceutical based on research evaluating CLA as an anticarcinogen, immune modulator, antiatherogenic agent and a body composition modulator. This study evaluated the combined effects of dietary CLA and supplemental fat source on growth, fatty acid composition and belly quality of lean genotype gilts (n = 144). Pigs (49.3 kg) were randomly assigned to six diets (3 x 2 factorial) varying in supplemental fat (none, 4 g/100 g yellow grease or 4 g/100 g tallow) and linoleic acid [1 g/100 g corn oil (CO) or 1 g/100 g CLA (CLA-60)] for 47 d. Both the cis-9, trans-11 and the trans-10, cis-12 isomers of CLA were increased in belly and longissimus fat depots from pigs fed CLA, and that increase was up to 92% greater when CLA was fed with 4 g/100 g supplemental fat (fat source x linoleic acid interaction, P < 0.05). Pigs fed CLA had a greater concentration of 18:0 and less 18:1 cis-9 (P < 0.01) in various fat depots, suggesting a reduction in Delta(9) desaturase activity. The iodine value of belly fat from pigs consuming tallow and CLA combined was reduced to 62.0 from an initial value of 70.4. CLA supplementation also increased belly weights (P < 0.05). CLA did not affect longissimus muscle area, backfat depth and the percentage of fat-free lean (P > 0.10), but it increased the subjective intramuscular fat score by 18.8% (P < 0.01). In conclusion, CLA enrichment of pork products may be enhanced when combined with additional supplemental dietary fat, and together with tallow can be used to increase the saturated fatty acid content of pork.
Asunto(s)
Tejido Adiposo/metabolismo , Grasas de la Dieta/administración & dosificación , Ácido Linoleico/metabolismo , Carne/normas , Porcinos/crecimiento & desarrollo , Tejido Adiposo/anatomía & histología , Tejido Adiposo/química , Alimentación Animal/normas , Animales , Composición Corporal/efectos de los fármacos , Suplementos Dietéticos , Ácidos Grasos/análisis , Femenino , Isomerismo , Ácido Linoleico/administración & dosificación , Músculo Esquelético/anatomía & histología , Músculo Esquelético/química , Músculo Esquelético/metabolismo , Distribución Aleatoria , Porcinos/genéticaRESUMEN
In a field trial conducted on a commercial swine farm, lean-genotype sows (n = 485) were fed diets containing 0 or 10% supplemental fat as either medium-chain triglyceride or choice white grease from d 90 of gestation until weaning (15.5 d). Effects on standard sow and litter production traits were examined together with assessment of sow body condition using live ultrasound. Daily feed intake during lactation was 10% higher in sows consuming diets without added fat (7.2 vs 6.5 kg; P < 0.01); however, lactation ME (23.9 Mcal/d) and digestible lysine (54 g/d) intakes were unaffected (P > 0.10). Sows supplemented with fat were 4 kg heavier on d 109 of gestation (220 vs 224 kg; P < or = 0.01), 1 d after farrowing (210 vs 214 kg; P < or = 0.01), and at weaning (210 vs 214 kg; P < or = 0.01). Expressed as overall gain, this amounted to a 23% increase (0.66 vs 0.86 kg/d; P < or = 0.01) and was accompanied by a 49% increase in backfat (0.82 vs 1.68 mm; P < or = 0.03) from d 90 to farrowing. Changes in sow weight (-0.01 kg/d) and backfat (+4.2 mm) over lactation were minimal and were not affected by fat supplementation (P > or = 0.10). Longissimus muscle area at weaning was slightly greater (44.96 vs 46.2 cm2) in sows consuming fat than in control sows (P < or = 0.05), but changes in longissimus muscle area were not significant from d 90 to weaning (P > or = 0.10). Gestation length, pigs born alive, average birth weight, survival (d 3 to weaning), and days to estrus were not affected by diet (P > 0.10). However, supplemental fat increased pig ADG (192 vs 203 g/d; P < 0.01) and average pig weaning weight (4.3 vs 4.5 kg) at 15.5 d (P < or = 0.02). No differences between the two fat sources were detected. This large-scale study demonstrated that supplemental fat during gestation and lactation effectively improved sow condition and improved suckling pig performance without affecting energy intake during lactation, implying improved efficiency of sow energy utilization.