Effects Of Dietary Digestive Energy Levels On Growth Performance And Blood Biochemical Indices Of Fattening Pigs

Objective: To determine the optimum dietary digestive energy(DE)level for Three-way Crossbred finishing pigs,and achieve the effect of fine feeding.This study was divided into two stages: growth stage and fattening stage,according the different energy requirement in two growth stages.Then fed the diets with different digestive energy levels in two stages and determined the changes of daily feed intake,daily gain,feed-to-weight ratio and blood biochemical indices.Methods: Experiment 1: Effect of dietary digestive energy level on growth performance of fattening pigs.According to the principle of similar body weight and half male and half female to select 480 healthy,disease-free crossbred finishing pigs with initial body weight of 22�2kg in the growth stage experiment.They were randomly divided into 3 treatment groups,each treatment group consisted of 4 columns,40 pigs per column(according to the actual enclosure 35~40 in each group).The digestible energy level of the experimental feed was 13.18 MJ/kg(Trial 1),13.39 MJ/kg(Matched group)and 13.60 MJ/kg(Trial 2)respectively.According to the same principle to select 450 fattening pigs with initial body weight about 60 kg and randomly divided them into five groups.They were fed with diets of different digestive energy levels,12.76 MJ/kg(Trial 1),12.97 MJ/kg(Matched group),13.18 MJ/kg(Trial 2),13.39 MJ/kg(Trial 3)and 13.60 MJ/kg(Trial 4).During the experiment,fattening pigs were fed freely and drank freely.Feeding experiments were carried out according to the requirements of the experimental scheme.Recording the initial weight,final weight,feed consumption per feed digestive energy level and test date.And figure out the ADG,ADFI and F/G of each trial,then analyzed them by single factor variance method.Experiment 2: Effect of dietary digestive energy level on blood biochemical indicators of fattening pigs.Randomly selected 3 pigs in each column at the end of the growth stage trial,and 6 pigs were randomly selected from each group at the end of the fattening trial.Ten ml fresh blood was collected from the front cavity vein of each selected pig,then prepared serum by centrifugal and determined the routine blood biochemical indicators.Results:(1)The results showed that when the dietary digestive energy level increased from 13.18 MJ/kg to 13.39 MJ/kg at the growth stage,the individual weight,average daily gain and feed-Weight ratio of finishing pigs were relatively high.When the digestive energy level further increased to 13.60 MJ/kg,the feed intake,daily gain and feed-Weight ratio of finishing pigs in the two trials reduced.But in statistics,there was not differ statistically between the Matched group and the Trial 1 and the Trial 2(P > 0.05).There were no significant difference in daily gain among groups at different digestive energy levels in the fattening stage(P > 0.05).The daily intake fluctuated with the increase of digestive energy level among groups.There was no significant difference between the Trial 1,the Trial 2 and the Trial 3 compared with the Matched group. The Trial 4 was notable over-top the Matched group and the Trial 1(P < 0.05).And there was no significant difference among the Trial 2,the Trial 3 and the Trial 4(P > 0.05).Compared with the Matched group,there was undisturbed in the feed conversion ratio between the Trial 1,the Trial 2 and the Trial 3.Compared with the Matched group,the Trial 4 increased by 0.35,and the Trial 2 increased by 0.69,the diversity was obviously(P < 0.05).There was not obviously diversity in the feed conversion rate among Trial 1,Trial 3 and Trial 4(P > 0.05).(2)The data of blood biochemical indexes showed that there was no significant difference in total cholesterol level between the Trial 1 and the Matched group at different digestive energy levels(P > 0.05).The cholesterol level of the Trial 1 and the Matched group was obviously less than that of the Trial 2(P < 0.05).Except for cholesterol level,there was undisturbed in other blood biochemical quotas among the trials(P > 0.05).In the fattening stage,the triglyceride content in the Trial 2 was less clear than Trial 3 and Trial 4 at different digestive energy levels(P < 0.05),but there was not obviously contrast between the Trial 2,the Matched group and the Trial 1(P > 0.05).The total cholesterol content of the control group,the Trial 1 and the Trial 2 was significantly lower than Trial 3 and Trial 4(P < 0.05).There was no palpable dissimilarity in total cholesterol content among Matched group,Trial 1 and Trial 2(P > 0.05),but there was not noticeable between Trial 3 and Trial 4(P > 0.05).Except for triglyceride and total cholesterol,there was no significant difference among the other indicators(P > 0.05).Conclusion: In this study,the results showed that the digestive energy level had no significant effect on the growth performance of each group at the growth stage.However,the health status of fattening pigs were improved at the digestive energy level of 13.39 MJ/kg.In the fattening stage,the results of growth performance and blood biochemical indicators showed that the optimum digestible energy level of feed was 13.18 MJ/kg.The results of blood biochemical indices showed that the appropriate digestive energy level can increase the concentration of albumin and total protein in serum,reduce the concentration of triglyceride and total cholesterol,and to affect the metabolism of protein and cholesterol in animals on the certain extent.In other words,it can improve the nutritional value of the feed and the health status for fattening pigs,promote the utilization rate of nutrients and enhance the absorption and utilization of protein and cholesterol.Together these experiments showed that the growth performance and health of fattening pigs could be improved by increasing the digestive energy level of feed properly on a certain extent.