What are the growth and development patterns of finishing pigs
On the basis of understanding the physiological characteristics of finishing pigs, it is very important to grasp the growth and deposition changes of body tissues during the growth and development of finishing pigs. On the one hand, the corresponding feed nutrition can be determined according to the changes in tissues such as muscle, fat, skin and bone of pigs at different stages; on the other hand, the appropriate slaughter weight of pigs can be determined.
Pictured: live pigs
(1) Composition of various body tissues The muscle tissue of growing-finishing pigs is composed of skeletal muscle, cardiac muscle and smooth muscle, among which skeletal muscle accounts for the vast majority. Adipose tissue is mainly composed of a large amount of fatty acids, and morphologically it is divided into leaf fat, caul fat and subcutaneous fat. The pig skeleton is formed by the accumulation of minerals, and the bones contain large amounts of calcium and phosphorus; pig skin is composed of many connective tissues and collagen. The skeleton and skin of pigs account for a relatively small proportion of the pig's body tissues.
The proportional relationships of various tissues in growing-finishing pigs are affected by many factors. For example, different breeds, different feeding methods and environments, and the influence of certain external factors will all lead to certain changes in the proportional relationships. Even if the breed and feeding method are the same, different growth stages will still cause certain changes in the proportional relationships of pig tissues.
(2) Tissue growth and deposition changes In the first stage, growing-finishing pigs are dominated by bone growth, followed by muscle, and fat growth is the slowest. In the second stage, adipose tissue grows with a relatively large advantage, while bone and muscle are in a declining trend. With the growth of various tissues and the increase in body weight, the proportions of muscle, fat, skin and bone tissues in the body of finishing pigs will undergo certain changes. When the proportions of fat, skin and bone gradually decline, this is precisely when the proportion of muscle rises by a relatively large margin, and when the proportions of fat, skin and bone rise, the proportion of muscle shows a declining trend. When body weight continues to increase, the three curves gradually tend to stabilize. According to what is shown in the tissue growth intensity chart, for the current lean pig production in our country, for a commercial pig with a reasonable ratio of muscle to fat and relatively high economic returns, its suitable market weight should be 90-100 kg, but for different breeds and different cross combinations, the suitable slaughter weight is slightly different.