At present, the corn quality is low and the price is high, and the mildew is serious. It is difficult for farmers to find high quality corn in the local area, which results in chronic poisoning of chicken mold, decreased egg production performance and poor disease resistance. In addition, the upside down price difference between wheat and corn is relatively large. At the same time, the continuous harvest of wheat leads to more surplus grain in the hands of farmers, which makes it easy to organize the supply of goods. As a result, some feed enterprises and farms start to replace corn with wheat in production.
However, wheat and typical energy feed corn have their special characteristics, so we should pay more attention to rational use in chicken compound feed.
1. Nutrients of wheat:
The nutritional content of wheat varies greatly from species to region and climate to climate. According to planting time, it was divided into winter wheat and spring wheat. According to the skin color of wheat is divided into red wheat, white wheat and flower wheat; According to the grain of wheat, hard wheat and soft wheat. The nutrients of hard and soft wheat
See Table 1. Among all grains, the protein content of wheat varies the most, usually from 10% to 15% to as much as 17%. The crude protein content of most durum wheat is above 13% (soft 10% ~ 12%), lysine is 0.3% ~ 0.55%, crude fiber is 1.9% ~ 3%, and crude fat is less than 2%. Meanwhile, calcium content of wheat was 0.1% ~ 0.17% higher than that of maize, phosphorus content was 0.3% ~ 0.4% and available phosphorus was about 0.2%, which was about one time higher than that of maize. Because wheat nutrients vary widely, chemical analysis of wheat from unknown sources is needed to accurately match the chicken diet.
Table 1 Nutrients of hard and soft wheat
2. Problems to be solved by replacing corn with wheat:
(1)、amino acid balance
The protein content in wheat is 10%~15%, up to 17%, but the utilization rate of lysine is low, leucine is insufficient, and amino acid imbalance will appear after reducing the amount of soybean meal. Therefore, according to the different nutritional value of wheat and corn, the formula should be redesigned with the help of formula design software to ensure that the nutritional content of the formula remains the same and that the energy, crude protein, amino acid, calcium, phosphorus and other nutritional indicators of the formula meet the needs of the chicken population.
(2)、Energy and linoleic acid:
The content of energy and linoleic acid in wheat was lower than that in maize, which was 0.59% and 2.2% respectively. Corn - soybean meal diet can basically meet the needs of linoleic acid for chicken growth and maximum egg weight, but if wheat is used to replace corn, it is necessary to supplement corn oil, soybean oil, cottonseed oil and other oils rich in linoleic acid.
(3)、Lutein
Yellow corn is rich in lutein (22mg/kg), which deposits in fat, skin and egg yolks. Wheat, however, does not contain lutein, which should be supplemented when ingredients are used. Lutein itself has no nutritional value. The main significance for layers is to affect the color of egg yolk, supplemented by adding 2% to 3% alfalfa (lutein containing 198 ~ 396 mg/kg) or corn protein powder (crude protein 60% of corn protein powder containing lutein 253 mg/kg).
In addition, red pepper (185mg/kg), soybean oil horn (168-260mg /kg) and marigold flower petals powder (6000-10000 mg/kg) are rich in lutein, which can be added to feed to improve the appearance of egg yolk.(4) vitamin
The content of vitamin E and vitamin B6 in wheat is lower than that of maize, especially biotin. Although the total content is higher than that of maize, the utilization ratio is very low.
(5) non-starch polysaccharides
Wheat contains about 6% non-starch polysaccharides, which dissolve in water and form a viscous gel, which can increase the viscosity of gastrointestinal contents and hinder the digestion and absorption of nutrients in monogastric animals.
3. Application of wheat in the feed of broiler chickens
It is safe to use wheat to replace 15%~20% of corn in the feed of broiler chickens in the middle and late stage without adding enzyme preparation, and it will not have significant effect on the production performance of broiler chickens. In the early feed of broiler chickens, the proportion of wheat replacing corn should be limited to less than 15% without enzyme preparation. In addition, the broiler feed can be directly fed with 15% or less of the whole wheat, which will not significantly affect the production performance of broiler chickens.
4. Application of wheat in the feed of laying hens
(1) Using 20% corn and slightly more than 40% wheat in the mixed feed of laying hens has better effect, and the color of egg yolk and shell is basically unchanged.
(2) Wheat should be added gradually to replace corn, and the transition time should be about 10 days, otherwise it will cause the color of eggshell to become lighter in a short time. The reason for this is that the overall digestion of wheat in the gastrointestinal tract decreases in a short period after sudden refueling, leading to metabolic dysfunction and thus the color of eggshells becomes lighter. If the gradual feeding is adopted, the problem of eggshell color becoming lighter can be basically overcome.