What are the key points for the feeding and management of breeding boars?
(1) Nutrition and rational feeding of breeding boars
The diet of breeding boars should have good palatability, and its volume should not be too large, so as to avoid causing a big belly. Each kilogram of diet contains 12.9 megajoules of digestible energy, 17% protein, 7.9 grams of lysine, 2.6 grams of methionine, and a moderate calcium-to-phosphorus ratio, 15 grams of calcium, 10 grams of phosphorus, and 10 grams of salt. Vitamin A 4,100 international units, vitamin D 230 international units, vitamin E 11 milligrams.
The daily feeding amount for replacement boars is 2.0-2.5 kg, and for adult boars 2.5-3.0 kg. In winter and during the breeding season, increase it by 15%-20%. An appropriate amount of green, juicy feed may be added, 0.5-1.0 kg per day. Boars are fed 2 times a day, and either dry or wet feed is acceptable.
(2) Management of breeding boars
1. Group housing and individual housing: Breeding boars can initially be kept in small groups, and after reaching adulthood they are kept in individual pens to prevent fighting.
2. Appropriate exercise: Appropriate exercise can promote appetite, aid digestion, and strengthen the physique. Boars should exercise no less than 1 hour per day, about 1,000 meters, and this can be done in the morning and evening.
3. Maintain pig body hygiene: Brush the pig's body 1-2 times a day, and regularly trim the pig's hooves to reduce the occurrence of hoof problems. In summer, boars can be washed frequently to reduce the occurrence of skin diseases.
4. Regularly check semen quality: Boar semen motility should be greater than 0.7, abnormality should not exceed 18%, and density should be grade 7-8. During the breeding season, check once a week. For unqualified semen, promptly adjust nutrition, mating frequency, and environmental conditions, and promptly cull some boars.
5. Training of replacement boars: Replacement boars begin training at 7-8 months of age. Select multiparous sows with obvious estrus and small body size for mating. Be patient during training and do not beat the boar. Each training session should last 20-30 minutes, once a day.
The issue that needs attention is that most boars do not have problems with genetics, disease, or libido, but because the boar lacks experience and the trainer is rough, the boar becomes afraid and loses confidence in mating. Therefore, the boar should be allowed, under relaxed conditions, to build confidence in mating and accumulate experience through repeated learning.
6. Heat preservation and cooling: Low winter temperatures reduce the resistance of pigs and affect mating results. The feeding amount can be appropriately increased and the temperature inside the barn raised. What affects pigs most is high-temperature stress in summer. When the temperature exceeds 33°C, it will severely reduce semen motility, increase the number of dead sperm, and significantly reduce the conception rate of mating. Therefore, cooling can be carried out by means such as wet curtains, fans, spraying, shading, and flushing with water. Vitamin C, vitamin E, baking soda, raw gypsum, and others can be added to the feed to buffer heat stress and improve mating ability.