Effects Of Daily Dynamic Feeding With Crude Protein Levels On Muscle Fat Deposition Of Fattening Pigs

To study the effects of daily dynamic feeding with different crude protein levels on muscle fat deposition, one hundred and twenty DLY (Duroc ×Landrace× Yorkshire) finishing pigs (54.2±0.1 kg) were chosen, and divided into 3 groups according to the body weight:control group (pigs fed all basal diet), high-low group (pigs fed high crude protein of diet for breakfast and low crude protein of diet for supper) and low-high group (pigs fed low crude protein of diet for breakfast and high crude protein of diet for supper). Each group had 4 replicates with 10 pigs per replicate. Three corn-soybean diets with similar digestive energy and different crude protein levels were formulated:basal diet (crude protein, CP 14.30%), high crude protein levels diet (CP 16.06%) and low crude protein levels diet (CP 12.55%). All pigs were weighted on an empty stomach before and after the experiment in order to test pig performance. And some individuals in each replicates were randomly selected. Fasting blood was got before slaughter to blood biochemical composition. Pigs were slaughtered for carcass quality. Muscle of longissimus dorsi was got for specimens after slaughter were tested for ratio of long chain fatty acid and meat quality.The results showed as follows:compared with all basal diet feeding group, average daily gain (ADG) in the high-low group was increased 19 g/d. Loin eye muscle area in high-low group and low-high group were lower than the control group by 20.6%(0.05<P<0.1) and 8.7%(P<0.05). Compared with the control group and high-low group, crude fat of muscle in the low-high group were increased by 14.6% and 19.6%(P>0.05). Blood total cholesterol, calcium and albumin levels reduced in the high-low group when compared with the control group (P<0.05), as well as blood glucose was obviously increased (P<0.05). And total cholesterol and immunoglobulin M were lower than the low-high group (P<0.05). The contents of total cholesterol in blood was increased on low-high group comparing with the control group (P<0.05). Compared with control group, Eicosenoic acid was significantly increased and Myristoleic acid and Linoleic acid decreased significantly in muscle fat on high-low group (P<0.05). Moreover, the ratio of Margaric acid, Eicosenoic acid and the sum of linoleic acid were higher than low-high group (P<0.05). Margaric acid and Myristoleic acid were significantly decreased in muscle fat in the low-high group comparing with control group (P<0.05).These findings suggested that compared with traditional all basal diet feeding way, daily dynamic feeding with different crude protein levels could affect blood total cholesterol and ratio of long chain fatty acid in muscle (longissimus dorsi), and fat deposition was also affected in this way.