Principles of feed design for pregnant sows and problems currently faced and solutions available
The breeding objectives of pregnant sows are as follows:
1. More litter
On the basis of a fixed annual base consumption per sow, the higher the number of healthy sows produced each year, the greater the benefit. At present, the domestic production is basically maintained at about 18 heads, but it is expected to reach 28 heads.
2. The birth of a baby is a big one
Birth weight has a huge impact on the lifetime development of the breeding pigs, so it directly affects the overall benefit of the pig farm. According to the current standard internal sows evaluation, the ideal state of birth weight of Suckling pigs should exceed 1500 grams per head on average. However, the current domestic pig farm basically maintains at 1350 grams per head, so there is a great potential to be tapped.
3. Large gastrointestinal volume ensures large feed intake during lactation
The ideal postpartum lactating sows is to achieve maximum feed intake within one week of postpartum and to maintain it all the way through. This requires optimal pre-natal gastrointestinal exercise, which is one of the key points in the feed design of pregnant sows. Following the cause and effect theory of the pig industry, the gastrointestinal tract of pregnant sows is not fully developed, and the feed intake during lactation has no way to reach the maximum.
4. Don't constipation
Constipation on the harm of sows, has been recognized by the industry. Constipation during gestation is a common problem in sows. One of the key points in designing pregnant sows' feed is that they are not constipated.
5. High blood calcium concentration
High blood calcium concentration in perinatal period is one of the key points in feed design of pregnant sows. Many problems in perinatal period are obviously related to low blood calcium. It is one of the key points for pregnant sows to ensure high blood calcium concentration through pregnant sows feed design.
Common problems are as follows:
1. constipation in pregnancy
Needs and current breeding sows during pregnancy because of body condition control concept of error, and physiological characteristics of gastrointestinal peristalsis slow during pregnancy, about 60% will appear constipation, southern hot climate, incidence of constipation is above 80%, the pregnancy sow feed, crude fiber content is extremely low, raising management and control in body condition (relative to the current sow breed, a lot of it is wrong, a lot of farms without implementing control according to the thickness of subcutaneous fat, but just be carried out according to the sow obese degree of eye view control, and the varieties of sows, more and more focus on lean, normal size itself is eye view full-figured), Different degree of restricted feeding always causes different degree of constipation.
In the southern summer, the average temperature in the pigsty during pregnancy exceeds 30 degrees for 7 months (because of intensive feeding, the temperature in the pigsty is always 3-5 degrees higher than the ambient temperature), and the high temperature naturally forms the restricted feeding situation. In addition, the ambient temperature inhibits the gastrointestinal peristalsis frequency and aggravates the occurrence of constipation.
Another result of the severe restriction of feeding is that due to insufficient total energy intake during gestation, breast development is inhibited. Examination of sows reveals that several milk pools are always dry and breast development is stagnated. Such sows, with extremely low production efficiency, are on the brink of elimination.
2. The number of small, major and small birth is uneven
Due to the pregnancy sow to absorb the total nutrient concentration is not enough, leading to excessive competition, intrauterine fetal natural elimination rate increases, so the result of the nature is: less number of litter, born big small, to sow supply enough nutrition, have led to sow the danger of partial fat again, in regulating the sow body condition, ensure litter, fetal weight big enough and uniform, gave the design of the pregnancy sow material higher difficulty, at present the industry the most ignored, is also the design of the pregnancy sow and scientific use.
Sow feed intake, nutrient concentrations in the blood for intrauterine fetal quantity, directly affect fetal development, often because of pregnancy the limited feeding, the sow in the blood concentration of nutrients that are always high and low, volatility - as the signal of fetus, will naturally cause competition, this is the direct cause of fetal birth weight uniformity is poor.
3. Reduction of gastrointestinal tract volume during pregnancy due to restricted feeding
At present, few people in the industry consider the exercise of the gastrointestinal volume of pregnant sows. There is a physical competition between the gastrointestinal volume of pregnant sows and the uterine volume, but the maintenance of the gastrointestinal volume and function of pregnant sows is crucial for the feed intake during lactation. This problem is common in all domestic pig farms at present because of the daily and prenatal feeding restrictions. This problem, led to raise pig farm whole benefit to drop directly.
4. Hypocalcemia
At present, most nutritionists in the industry have not realized the physiological needs of sows, which is the starting point for designing sows' feed. As a result, perinatal blood calcium is often low in sows, resulting in prolonged labor process, slow uterine recovery, postpartum weakness, decreased lactation, and so on.
Currently available solutions include:
1. Green feed during pregnancy
History has gone back more than 200 years, and it has come back to its original point. Despite the introduction of new nutrition concepts, repeated production and use have shown that large amounts of green feed can indeed guarantee high litter size. Up to now there is no theoretical system of modern nutrition can clearly reveal this phenomenon. It can be clear that feeding the green feed, can improve the litter size, but also conducive to the expansion of the pregnant sows gastrointestinal tract volume, provide enough potassium ions, thereby inhibiting the blood sodium concentration, so as to improve the perinatal blood calcium concentration, a series of benefits. Although large-scale pig farms are difficult to operate, the practice is often worth promoting when considering the economic benefits of pig farms, especially in the south, where green feed is readily available all year round.
2. Water insoluble cellulose was added to the feed during pregnancy
During pregnancy, especially in the later period of pregnancy, the use of water-insoluble fiber with high water retention rate (the water retention rate of high-quality products can be as high as 1:8) maximizes the gastrointestinal volume of pregnant sows and lays a physical foundation for the high feed intake of postpartum sows on the premise of saving formula space as much as possible so as to maintain high nutrient concentration. This is the most effective and reliable method of dilating gastrointestinal volume. Use this plan additionally, still can make hind bowel excrement is soft, prevent constipation effectively.
3. It doesn't absorb ionic salts
The addition of non-absorbable ionic salts such as potassium and magnesium sulfate to the feed can effectively increase intestinal osmotic pressure continuously, thus preventing constipation. However, it may cause different degrees of dehydration, lead to intestinal wall mucosa swelling, reduce the palatability of feed, affect the intake of food. With this scheme, the average sow's service life will be shortened.
4. Oligosaccharide
Sows itself to survive in the gut bacteria, but limited to the pregnancy period for feeding, often the cause of constipation after intestinal bacteria need nutrients content is limited, the environment is not conducive to their breeding, good bacteria are hard to survive in great quantities, so give them enough nutrition, promote their breeding, is an effective means of nutrition. The oligosaccharides cannot be absorbed and utilized by animals, so they all enter the posterior intestinal segment through the stomach and small intestine. Beneficial bacteria such as yeast and lactobacillus can effectively utilize the oligosaccharides as the energy source of reproduction. Once they multiply, they soften up their faeces so they don't become constipated. The fermentation products of beneficial microorganisms, which are absorbed and utilized by animals, can effectively promote animal health and maintain animal immunity.
Modern bioengineering technology has turned the mass production of low cost and high purity oligosaccharides into reality. At present, human beings have been widely used in high-quality infant milk powder, yogurt, and beverages. Animal feed can be used for reference.
5. Acidulant
Pregnant sows, especially in late pregnancy, the use of acidifying agents, can effectively improve the blood calcium concentration of sows, thereby improving the smooth muscle contraction activity of sows, reduce the occurrence of constipation, shorten the labor process. The requirements for acidizing agents are preferably released slowly. After intestinal fermentation of fatty acids is the best, slow release acidifier second, direct action of acidifier is poor. Among the types of acidifying agents, large-molecule fatty acids such as citric acid, malic acid and lactic acid are preferred, followed by small-molecule fatty acids such as propionic acid, acetic acid and formic acid, with weak phosphoric acid effect.
The feed design principles for pregnant sows are as follows:
1. Properly increased nutrient concentration
The current pig breed, with the requirement of lean meat ratio of commercial pigs increased year by year, sows remind year by year to be larger, maintain the demand and therefore increase; In order to increase the birthing rate and birth weight of piglets, more nutrients are also needed; Is actually a modern sows amount of nutrients in each production cycle need to use more and more, but is not only nutrient concentrations increase, also must carry on the overall adjustment of feeding amount, to investigate good livestock feed feeding conditions, make to the overall customer feed using evaluation, according to the daily feeding amount, decide the appropriate nutrition concentration
2. At the same time of increasing the nutrient concentration of feed, pay attention to the gastrointestinal dilatation function of feed.
Feed one of the natural attribute of: to expand the total capacity of gastrointestinal tract, providing full feeling, less hunger stress, and design the pregnancy sow material must be fully considered, the first reference, according to the daily feeding amount, decided to provide gastrointestinal contents and the expansion of the raw material consumption, if the dosage increase, but also adjust overall nutrition concentration - because these material takes up space, the work to the computer with the software adjustment, concise and lively. Accurate and reliable.
Many of our pig farms, based on textbooks or traditional experience, have been using limited feeding to maintain and control the body condition of sows. Such a program increases the incidence of constipation, resulting in prolonged labor, endometritis and other problems. Considering that the total capacity of gastrointestinal tract should be expanded during pregnancy, satiety should be provided and hunger stress should be reduced, the traditional low-nutrient concentration and quality limited feeding scheme is not unreasonable. However, the total amount of nutrition needed by sows today is much larger, and the traditional low-nutrient crude feeding scheme cannot meet the requirements. At this time, the need for refined cellulose raw materials, in the maintenance of its gastrointestinal expansion function at the same time, as far as possible to reduce the formula space, improve the nutrient concentration of feed. The extra supply of green feed is also an effective tool.
3. Pay attention to the nutrition of beneficial microorganisms in the postintestinal stage of sows
Practice has proved that in the sow stage, the plan of using antibiotics in large quantities is not the best economic benefit. On the contrary, attention should be paid to cultivate the intestines of sows for beneficial maintenance, so as to improve the body health of sows and reduce the occurrence of adverse problems such as constipation, which can now be done at a lower cost.
4. Pay attention to regulate blood calcium concentration of sows:
In order to improve the plasma calcium concentration during pregnancy, especially in the later period of pregnancy, it is necessary to pay attention to the use of trace elements, and pay attention to the acid and alkali substances in the feed, appropriate use of acidifying agents. Large supply of green feed, the use of oligosaccharides, are effective means.
