The experiment was divided into two treatment groups, namely, control group and mos group, each with 18 heads, and the addition amount of mos in mos group was 4g/ head/day.
The daily gain, dry matter intake (decimeter), digestible total nutrients (tdn) and crude protein (cp), feed conversion rate, fecal score, the number of Escherichia coli in feces and feed reward were measured.
The results showed that compared with the control group, the daily gain, feed intake and feed conversion rate increased significantly after adding mos (p0.0l). Through the comprehensive evaluation of fecal score and the number of Escherichia coli in feces, the diarrhea rate and feed reward decreased significantly (p0.0l).
The results showed that adding mos to calf diet could reduce calf diarrhea, improve growth performance and reduce feed reward.
Function of Mannan Oligosaccharides
2~3 months after birth, the health status and growth rate of calves affect the economic benefits of the whole growth stage.
Because the early nutrition of calves is very important, many feed additives have been applied to calf diets to obtain ideal results, and prebiotics have always been the focus of research.
As a non-digestible food ingredient, prebiotics have beneficial effects on the host by selectively stimulating the growth and activity of bacteria in one or several colonies, thus improving the health of the host.
Prebiotics are not digested and absorbed by the digestive tract, but can selectively stimulate the growth of beneficial bacteria (roberfroid et al., l998).
Oligosaccharides are prebiotics, and the common ones are mannose oligosaccharides (mos) and fructooligosaccharides (fos). These nutrients can be added to calf milk replacer and starter for utilization.
Mos can be obtained from yeast by hydrolysis, separation and spray drying.
Mannan on the surface layer of yeast cells is the main antigen of the whole yeast or yeast cell wall.
Mos can bind to glucomannan-binding proteins on the surface of some bacteria, and prevent the colonization of harmful bacteria by interfering with carbohydrate receptors on the surface of intestinal epithelial cells, thus optimizing the microbial flora in the intestine.
This experiment mainly studied the effects of adding mos in diet on growth performance and feed reward of calves.
Materials and methods
In the experimental design, 36 5-day-old Holstein hybrid calves were randomly divided into control group and mos group, and the experiment was continued until 2 months old.
Calves were weaned after birth, and calves in mos group were fed 4g more every day.
Mos (mixed with milk every morning), the control group did not add mos.
Food area
Calves were kept in a naturally ventilated cowshed, fed separately and drank freely. Each pillar adopts cement floor, with the top covered with asbestos and the other part open. Each column provides an independent sink and sink. Clean the cowshed and disinfect it every day.
Dietary composition and feeding amount
The experimental calf is a 5-day-old calf fed with colostrum. It is fed with milk twice a day, and the milk temperature and body temperature are kept at the same level. The feeding scheme of the whole experimental period is as follows: before the third week, the feeding amount of whole milk is L/l0 of body weight; From the 4th week to the 7th week, the feeding amount was L/L5 of body weight; The eighth week is l/25. From the 4th week to the 7th week, the feeding amount of skim milk is l/25 of body weight, and l/l5 in the 8th week. From the 4th week to the 7th week, the daily concentrate of each calf was120g, and it was 250g in the 8th week. In the 4th week, 5th week, 6th week, 7th week and 8th week, the daily intake of green feed was 700g, 750g, 850g,1000g,1100g respectively, and the concentrate (starter) was composed of 35% corn,/.
Experimental materials The experimental group was fed 4gmos every day from 5 days old to 2 months old. Isolation of Mos from yeast cell wall.
Index determination and methods Weigh before feeding every morning, count the intake every day, and analyze the nutritional components of feed and forage once a week.
The formula of feed conversion efficiency is decimeter (dry matter) conversion efficiency = decimeter daily feed intake/daily gain; Tdn (total digestible nutrients) conversion efficiency =tdn daily intake/daily gain; Cp (crude protein) conversion efficiency =cp daily intake/daily gain.
Fecal score was carried out according to 4 points (L was divided into normal formation; 2 is divided into mild diarrhea-soft stool, which can be formed; Moderate diarrhea 3 points-sticky and shapeless; 4 is divided into severe diarrhea, which is liquid and unformed.