Utilization of fats based on the composition of sow milk fat in the diet of weanling pigs

Three dietary fats (A, B and C) were formulated by mixing various plant oils and animal fats so that their overall fatty acid composition would be similar to the fatty acid composition of sow milk fat. Dietary fat A was formulated to have a maximum concentration of palmitoleic acid (C16 : 1) and a similar ratio of saturated to unsaturated fatty acids as sowʹs milk. Dietary fat B was high in myristic acid (C14 : 0) and fat C was formulated by substituting the tallow part in formulation A with lard. Twelve crossbred male pigs, weaned at 27 days of age at a mean weight of 8.0 ± 0.5 kg, were allocated for 4 weeks to three dietary treatments, containing either A, B or C fat at 5%. The main experimental period was 4 weeks and for each week the digestibility of the dietary components was determined and the pig performance for each treatment evaluated. There were no significant differences among the treatments regarding the digestibility of dry matter, organic matter, crude fiber and nitrogen free extract. The digestibility of crude protein for treatments B (84.9%) and C (85.1%), was similar, but significantly higher compared to treatment A (82.7%), while there were no significant differences in nitrogen retention among the treatments. Apparent fat digestibility was significantly (p ≤ 0.05) higher in treatment B (82%) followed by treatment C (79.9%) and treatment A (78.9%). The apparent digestibility of both fat and protein increased with respect to the age of the pigs, reaching their maximum values during the third experimental period. Apparent digestibility of fatty acids was high for all dietary treatments (77.6–90.2%), and significantly higher (p ≤ 0.05) for those of treatment B. In all treatments only the stearic acid (C18 : 0) showed low digestibility (33.4–57.8%). There were no significant differences in average weight gain and the respective feed conversion ratios between treatments. In all treatments there was a large increase in the overall weight gain (a mean of approximately 23 kg), combined with an overall low feed conversion ratio (a mean of approximately 1.63). The experimental results indicate that dietary fat B was the most efficient in the diets of weaned and growing pigs.