Effects Of Different Nutrition Levels And Slaughter Age On Production Performance And Meat Quality Of Tibetan Pigs In South China

Tibetan pig is native to Tibet,is an excellent local breed,its body small thin skin,meat rich flavor,coarse feed resistance,strong resistance.After the introduction of feeding in south China,free-range feeding is usually adopted.Although the scale has been improved,there is still a lack of scientific feeding standards,resulting in a large difference in the time for feeding and uneven meat quality and flavor.Therefore,this study studied the standardized feeding process of Tibetan pigs in south China,discussed the reasonable ratio of fine and coarse forage and the total feeding amount of Tibetan pigs fed in the barn,explored the appropriate slaughter day age,and provided theoretical basis for scientific breeding of Tibetan pigs.A 3×3 two-factor experimental design was used to explore the reasonable feeding amount and slaughter month age of Tibetan pigs.In the experiment,three experimental groups with different feeding amounts,namely high,medium and low,were randomly assigned to each group: 10 castrated boars and 6 uncastrated sows.The growth performance of the group was measured at the age of 8 months,9 months,10 months,11 months and 12 months respectively,and the indexes of feed intake,body weight,daily gain and feed weight ratio were collected.Three different slaughtering times(10 months,11 months and 12 months)were set up for each experimental group to determine the body size characteristics,slaughtering performance and meat quality of Tibetan pigs during slaughtering.The experimental diet was composed of "basic diet + crushing emperor’s bamboo grass".The free feeding method was adopted to crush emperor’s bamboo grass in the whole feeding stage,and the collection amount was calculated.The research results are as follows:(1)in terms of average daily feed of emperor bamboo grass,with the increase of Tibetan pig months,the feed intake increased gradually,reached the maximum stable,after months of age with different feeding amount of feed intake differences between group significantly(P<0.01),low feeding group is highest(0.192 kg),significantly higher than in the feeding amount(0.137 kg)(P<0.01),high feeding amount set minimum(0.043 kg).In terms of body weight,the weight of Tibetan pigs increased gradually with the increase of month age,and there was significant difference in body weight between groups with different feeding amounts at the same month age(P<0.05),but there was no significant difference in male sows in the group.The body weight of Tibetan pigs in the high feeding group was up to62.8kg,that of the medium feeding group was up to 51 kg,and that of the low feeding group was up to 43.6kg.The average daily weight gain in each feeding group at the same month age was significantly different(P<0.05),and the average daily weight gain in the high-feeding group was up to 0.32kg/d.The maximum amount in the medium feeding group was 0.21kg/d.A maximum of 0.15kg/d was achieved in the low-dose group.In the aspect of feed weight ratio,the feed weight ratio of the group with high feeding amount was the lowest at the age of 9 months(boar 3.99;Sows 3.80),medium feeding quantity group had the lowest feed weight ratio at the age of 10 months(boar 3.90).Sows 4.20),the feed weight ratio of the low feeding amount group was the lowest at the age of 12 months(boar2.93;Sow 3.71).(2)in terms of body size traits,chest circumference,abdominal circumference,body length and tube circumference and other indicators of Tibetan pigs at the same slaughter month age were as follows: the high amount of feeding group > the medium amount of feeding group > low amount of feeding group,with significant differences between each group(P<0.05).With the same amount of feeding,the abdominal circumference and tube circumference indexes of Tibetan pigs were as follows: the 12 months old group > the 11 months old group > the 10 months old group,with significant differences between each group(P<0.05).(3)in terms of slaughter performance,with the increase of feeding quantity,the live weight,carcass weight,slaughter rate,backfat thickness,average backfat thickness,eye muscle area,suet rate and flower oil rate of Tibetan pigs at the same month of age also increased significantly(P<0.05),while the head weight rate,hoof weight rate,stomach weight rate and intestinal weight rate decreased significantly(P<0.05).With the increase of slaughter month age,the premortem live weight,carcass weight,skin thickness,backfat thickness,average backfat thickness and suet ratio of Tibetan pigs in the same feeding group also increased significantly(P<0.05),but the head weight rate,heart weight rate,lung weight rate,stomach weight rate,intestinal weight rate and body composition ratio decreased significantly(P<0.05).Carcass weight,backfat thickness,average backfat thickness and suet ratio of sows were significantly lower than those of boars in the group(P<0.05),but the head weight rate,heart weight rate,liver weight rate and spleen weight rate were significantly higher than those of boars in the group(P<0.05).(4)in terms of meat quality,with the increase of feeding quantity,marbling of Tibetan pork at the same slaughter month age was significantly increased(P<0.05),and dripping loss was significantly reduced(P<0.05).With the increase of slaughter month age,the dripping loss of pork in the same feeding group was significantly reduced(P<0.05).The meat quality b* value and p H24 of sows were significantly higher than those of boars(P<0.05),but the shear force and dripping loss were significantly lower than those of boars(P<0.05).According to the experimental results,it can be concluded that the suitable months of slaughter age of Tibetan pigs in the high,medium and low feeding groups are 9,10 and 12 months.The quality of hidden pork remained good regardless of the feeding rate and slaughter age.The meat quality of sows was better than that of boars at the same feeding amount and slaughter age.