Six aspects to note in breeding good-quality sows
1. When selecting and retaining sows, one must look at the production performance of the previous generation of sows. Retain sows that conform to the characteristics of the breed, are physically strong, have a high litter size, strong lactation ability, good mothering ability, high piglet survival rate and strong feed intake. The specific requirements are: the head and neck should be relatively light and refined, the lower jaw flat with no dewlap, and the head length about 18-24% of body length. If the head is large and the body small, or the head small and the body large, it cannot be retained as a new sow. The forehead should be broad (those with a broad forehead develop faster), the ears should be thin with a slightly firm base, and the snout should be even. The eyes should be round, large, bright and spirited. The neck should be of medium length, and the head and neck as well as the neck and trunk should join well without depressions.
2. When selecting and retaining sows, attention should be paid to the general appearance: the body should be broad and large, the back and loin straight, the hindquarters broad and well developed, the limbs sturdy and slightly long, all parts of the body well proportioned, the coat glossy, neither too fat nor too thin, with more than 6 pairs of functional teats, with a certain spacing between teats and neatly arranged, and no supernumerary teats or poorly developed teats.
3. The teats should be neatly arranged; the two rows of teats should be symmetrical or arranged in a staggered (herringbone) pattern, with no blind teats, inverted teats or non-functional teats, and according to breed standards there should be at least a specified number of pairs of normally developed teats. At the same time, attention should also be paid to teat shape: choose "bubble-through teats" and not "nail teats". So-called bubble-through teats describes teats shaped like tongcao (rice-paper plant pith), long, large and blunt; so-called nail teats describes teats like iron nails, shorter than bubble-through teats, small and pointed. The difference is especially obvious in teats just before farrowing and during lactation. Bubble-through teats have a full and well-developed teat mound, good lactation function; the teat cistern is enlarged, storing more milk; the teat canal is relatively thick, allowing fast milk ejection. Nail teats are the opposite. The difference between the two teat types in suckling piglets is relatively obvious in the middle and late stages of lactation. The retained sows should be used for about 4 years, that is, they should be culled and replaced after 7-8 farrowings.
4. On the basis of selecting and retaining the offspring of excellent boars and sows, purposefully and systematically focus on raising 2-3 piglets during the lactation period, fix the pre-selected piglets to suckle at the 2-4 pairs of teats on the front side of the sow that produce more milk, and do a good job of disease prevention and control.
5. After the newly retained sows are weaned, good green and roughage feed should gradually become the main feed. Feeding replacement sows with green and roughage feed can exercise their gastrointestinal function, so that after maturity they can adapt to the needs of high reproductive capacity and high lactation capacity. Leguminous forage contains estrogen, which can improve the reproductive capacity of sows, so leguminous forage is best for feeding replacement sows as green and roughage feed. To ensure comprehensive nutrition, bran-type feed should also be appropriately added, along with a certain amount of protein feed such as oilseed cakes and fish meal.
6. The pens for newly retained sows should be provided with an exercise yard to let them move around more, so as to enhance the sow's metabolic function. Keep the pig house clean and dry, disinfect regularly, and frequently change and sun-dry the bedding straw. Carry out deworming and preventive injections regularly.