Effects of microbial fermented feed on growth performance and nutrient utilization of growing pigs

  At present, a lot of research has been done on the substitutes of antibiotics at home and abroad, especially on microbial agents (probiotics). Such research attempts to improve the production performance of livestock and poultry and the digestibility of feed nutrients by adding probiotics to the feed for fermentation treatment, which has been widely reported. In this experiment, the digestion cage single column feeding technology was adopted, and the apparent digestibility of nutrients in the microbial fermented feed was measured by the full fecal collection method, and compared with the test material added with antibiotics, in order to explore the use effect of microbial fermented feed, in order to improve the production performance of animals and the utilization rate of nutrients& nbsp; 1 materials and methods   1.1 source and grouping of experimental pigs   The test pigs were selected from 12 castrated boars in Tianhua test base of a company in Changsha. The breed was Du Chang ternary hybrid pig, with an average weight of about 50 kg, healthy and disease-free, and normal growth and development. The pigs in the 12 experimental hurdles were randomly divided into 3 groups, with 4 pigs in each group. They were fed with basic feed (control group), basic feed + antibiotics, and basic feed fermentation treatment feed, that is, the test was divided into groups a, B, and C. The test was carried out in Tianhua test center of a company in Changsha, and the fermented feed test material was prepared and produced by a company in Hunan& nbsp; 1.2 experimental diet   See Table 1 for the diet formula and nutritional level of each experimental treatment group& nbsp; Fermented feed: after the basic feed is prepared, add the fermentation liquid containing lactobacillus, yeast and Bacillus (add 15% water according to the amount of ingredients), mix and bag evenly, and feed after 2 days& nbsp; 1.3 management of experimental pigs and collection of fecal samples   After the test pigs entered the digestion and metabolism cage, after a 3-day adaptation period, a 7-day pre-trial period was carried out. The same feed was fed 3 days before the pre-trial period, and the adaptation and feeding conditions of the test pigs were observed. After each condition was normal, they were grouped and weighed. Feed the corresponding groups 4 days after the pre-trial period. The formal test lasted for 28 days. In the middle of the test, fecal samples were collected (from the 15th day to the 18th day, a total of 4 days). The feed intake of each pig was recorded every day, the daily fecal output was collected and weighed (from 9:00 a.m. to 9:00 a.m. on the second day). Take about 10 g of fresh samples and store them in the refrigerator with 10% sulfuric acid. After mixing the fresh samples for 4 days, store them for crude protein determination. Other fecal samples are mixed evenly after drying, and about 100 g is sampled per pig for the determination of crude fat, crude fiber, crude ash, etc& nbsp; 1.4 test data collection   Growth rate: at the beginning and end of the test (28 days), weigh each test pig, weigh the fasting stomach of the previous night, and calculate the daily gain of the stage. Feed consumption and feed conversion efficiency: accurately record the feed consumption of each pig, and calculate the average daily feed intake and feed conversion efficiency of each experimental pig (expressed in feed meat ratio)& nbsp; Determination of nutritional components: determine the content of water, crude protein, crude fat, crude fiber, crude ash and nitrogen-free extract of collected fecal samples and feed samples. The determination of water is carried out with reference to gb/t 6435-86 method, the determination of crude protein is carried out with reference to gb/t 6432-94 method, the determination of crude fat is carried out with reference to gb/t 6433-94 method, and the determination of crude fiber is carried out with reference to gb/t 6434-94 method, The determination of crude ash is carried out according to the method of gb/t 6438-94. Nitrogen free extract is the total amount minus water, crude ash, crude protein, crude fiber and crude fat& nbsp; Determination of nutrient digestibility: calculate the digestibility of various nutrients by using the total fecal collection method& nbsp; Nutrient digestibility (%) = (feed intake × Ingredient in material - fecal quantity × Fecal composition) / feed intake × Ingredients in the material × 100 (feed intake is 15~18 days, a total of 4 days)& nbsp; 1.5 data analysis   The data were statistically analyzed by SPSS 12.0 software& nbsp; 2 results   2.1 effects of different feed treatments on the production performance of growing pigs (see Table 2)   From table 2, compared with the control group (group A), feeding fermented feed or adding antibiotic feed can increase the average daily gain of pigs from 807.9 g/d to 847.4 g/d and 863.2 g/d respectively (p> 0.05); The feed to meat ratio decreased from 2.68 to 2.52 (p> 0.05) and 2.35 (p< 0.05) respectively. It can be seen that the average daily gain of pigs fed fermented feed increased by 4.89%, and the feed to meat ratio decreased by 5.97%. Different treatments had no significant changes in average daily intake and appearance score& nbsp; 2.2 effects of different processed feeds on the digestibility of nutrients in feeds (see Table 3)   It can be seen from table 3 that compared with the unfermented control group, the digestibility of crude fat (p< 0.01) of pigs was significantly improved after feeding microbial fermented feed, and the effect of adding antibiotics was achieved; However, the digestibility of crude fiber was reduced (p< 0.05); The digestibility of crude protein has a certain trend of improvement (p> 0.05); There was no significant effect on the digestibility of feed dry matter, nitrogen-free extract and other nutrients& nbsp; 3 discussion   3.1 effect of non anti microbial fermented feed on growth productivity of growing pigs   In recent years, the experiment of feeding growing pigs with microbial fermented feed has been reported at home and abroad. Reports show that fermented feed can improve growth rate and reduce feed meat ratio, and feeding EM (effective microorganisms) fermented feed can significantly improve the weight gain effect of finishing pigs (yuan Shuqin et al., 1999; Zhao Zhengxing, 2006). Wei Jintao (2009) reported that after weaning piglets were fed microbial fermented feed, the feed meat ratio was significantly reduced and the daily gain of piglets was increased. Hu Xinxu (2013) increased the average daily gain of the experimental group by 6.37% and reduced the feed weight ratio by 5% by adding 20% non anti fermentation feed. 54%。 Fermented full price feed can improve feed intake, daily gain and feed efficiency of weaned piglets (camibe et al., 2008). However, camibe et al. (2007) reported that fermented materials can reduce the production performance of weaned piglets& nbsp; Compared with antibiotic feed, there is no significant difference in average daily gain, feed intake and feed meat ratio of growing and finishing pigs with fermented feed (Hu Jiankun, 2008). This test found that compared with the control group, the use of fermented material has little difference in growth rate, but there is still a great difference in the ratio of material to meat& nbsp; After microbial fermentation, the feed produces a unique aromatic flavor, which can improve the appetite of animals and improve the palatability of the feed (Li Jianjun et al., 2014). Liu Ruili (2011) showed that the daily feed intake of growing finishing pigs increased by 7.13% after feeding the unconventional diet fermented by probiotics, but no increase in feed intake was found in this test, which may be related to the basic diet formula& nbsp; 3.2 effect of non anti microbial fermented feed on nutrient digestibility of growing pigs   After microbial fermentation, the digestibility of nutrients in feed may be improved. This experiment found that the digestibility of crude protein in the fermented feed group was improved, but the digestibility of crude fat was significantly improved (increased by 27.59%). Hong et al. (2007) reported that the ileal digestibility of crude protein and crude fat was significantly improved after feed fermentation. Zamora et al. (1979) and Feng et al. (2007) all got the conclusion that the digestibility of crude fat was improved, while only Wei Jintao (2009) found that the digestibility of crude fat was decreased. Liuruili (2011) showed that the apparent digestibility of feed dry matter, organic matter, crude protein and crude fiber were significantly improved. The reason may be that a large number of beneficial bacteria are produced in the fermentation process of the feed, which can supplement acidic substances and active lactic acid bacteria for the gastrointestinal tract, promote the acid-base balance and microecological balance of the gastrointestinal tract of pigs, and lactic acid bacteria can degrade the substrate during the fermentation process to improve the utilization rate of nutrients& nbsp; 4 conclusion   After microbial fermentation of fermented pig feed, the digestibility of crude fat of pigs was improved, and the production performance of growing finishing pigs was improved to a certain extent. The average daily gain of pigs was increased by 4.89%, and the feed meat ratio was reduced by 5. 97%； It is close to the feeding effect of adding antibiotics.