Glycerol monolaurate (GML) is a monoester formed from lauric acid and glycerin. It is naturally found in breast milk, American palmetto and coconut oil. It is a world-recognized excellent food emulsifier and a safe, efficient and broad-spectrum. The bacteriostatic agent, which has antiviral properties at the same time, is a generally considered safe (GRAS) food additive.
At present, there are few studies on GML as a feed additive for broilers. In order to study the effects of adding GML on the growth performance, digestion ability and nutritional quality of broilers, Liu Mengyu, Chen Xiaoqian from Zhejiang University, College of Biosystems Engineering and Food Science, and Zhao Haobin from Hangzhou Kangyuan Food Technology Co., Ltd. The age of three yellow chickens was the research object. After 49 days of continuous feeding, the growth performance index, digestibility index and nutrient content of chicken in the control group and the experimental group were compared to provide a theoretical basis for the application of GML as a feed additive in broiler culture. .
Compared with the control group, the average final body mass, average daily body weight and average daily feed intake of the experimental group decreased in the first stage (1 to 21 d), but there was no significant difference in various growth performance indicators. In the second stage (22~49 d), the average daily feed intake and feed quality ratio of the experimental group decreased significantly by 4.74%, indicating that the feed utilization rate of broilers was significantly improved. From the whole experimental stage (1~49 d), the average daily body mass, average daily feed intake, average daily feed intake and material mass ratio of the experimental group were all reduced, but not significant. Based on the physical and chemical properties of GML, it is speculated that the average daily feed intake of broilers may be related to the special bitterness and poor palatability of GML.
2. Digestive capacity
2.1 intestinal structure
Compared with the control group, the experimental group significantly increased the length of the intestines of the duodenum, jejunum and ileum of broilers by 9.08%, 4.92% and 8.82%, respectively, and significantly increased the velvet ratio of duodenum and jejunum respectively. 21.08% and 45.87%, and the length of the jejunum was significantly increased by 54.43%.
2.2 nutrient composition apparent metabolic rate
The experimental group significantly increased the apparent metabolic rate of crude protein, calcium and copper by 9.21%, 18.17% and 143.52%, respectively. All three have important significance for the growth and development of animals.
3. Chicken nutrients
3.1 basic nutrients
The experimental group can significantly increase the content of crude protein in chicken meat, but has no significant effect on the content of water, crude fat and ash.
3.2 fatty acids
Compared with the control group, the proportions of linoleic acid C18:2, arachidonic acid C20:4, essential fatty acids and polyunsaturated fatty acids in the chicken breast of the experimental group were significantly increased by 7.36%, 30.58%, 11.10% and 11.02%, respectively. . The experimental results show that GML feeding can increase the accumulation of essential fatty acids and polyunsaturated fatty acids in chicken meat. After eating, it can help lower cholesterol and triglyceride in the blood, improve the activity of brain cells, and enhance memory and thinking ability.
3.3 amino acids
Compared with the control group, the addition of 150 mg/kg GML to the diet significantly increased the contents of lysine, aspartic acid, glutamic acid, tyrosine, umami amino acids and total amino acids in chicken meat. The results of this experiment showed that the feeding of 150 mg/kg in the experimental group can significantly increase the content of amino acids and other nutrients in chicken meat and improve the nutritional value of chicken. However, the related mechanism of GML on the amino acid content of chicken needs further study.
Compared with the control group, 150 mg/kg GML feeding can significantly increase the feed conversion rate of broilers for 22 to 49 days; significantly increase the length of the intestines of the duodenum, jejunum and ileum, the length of the jejunum and the duodenum. The velvet ratio of the jejunum (flock length / crypt depth), and significantly increased the apparent metabolic rate of crude protein, copper and calcium in broilers; significantly increased C18:2, C20:4, essential fatty acids, polyunsaturated fatty acids in chicken The ratio, as well as the content of crude protein, lysine, aspartic acid, glutamic acid, tyrosine, umami amino acid and total amino acid. Overall, GML feeding has a positive effect on improving broiler growth performance, digestion capacity and chicken nutritional quality.