|
初产母猪断奶后不发情、再次配种困难、二胎产仔数降低，是现代母猪生产中最常出现的问题。造成这一问题的根源是进入第2繁殖周期时母猪体营养储备严重不足，因为生殖系统在营养分配的优先权弱于其他器官和系统，故营养缺乏对生殖系统影响最大。当然，初产母猪断奶不发情也与母猪健康状况尤其是生殖道健康以及诱情环境相关。下面主要从营养管理着手解决初产母猪断奶后不发情等一系列繁殖障碍问题。
营养原理与理念
发情所需要的营养储备，不仅需要大营养储备，而且也需要生殖营养储备。大营养储备主要指淀粉、蛋白质、脂肪、常量矿物质等营养物质的储备，体现在体重和膘情上面；生殖营养储备主要指与生殖结构和生殖功能相关的关键营养如特殊的维生素、特殊的微量元素等营养的储备。这两类营养物资的足够储备都是完成繁殖过程不可或缺的。
大营养储备不足的主要原因有：初产母猪自身增重（初产母猪自身增重约为50kg）、初配不达标、妊娠早中期限饲不够/不当、日进食营养总量不够、哺乳期采食量不够、攻胎不够。大营养储备主要目标是：断奶时，母猪失重不超过10kg，膘情达到体况评分2.5～3分。要实现这一体储目标，光增加哺乳期采食量是不够的，需要从初产母猪培育全过程着手（如下图）。
图1 泌乳期体重损失对断奶至发情间隔的影响
生殖营养储备方面，一要注意限饲期因为精料采食量减少而导致生殖营养摄入不足；二要注意哺乳期的哺乳营养需要与生殖的营养需要是有差异的，在配种准备期，即使饲喂营养相对丰富的哺乳料，也满足不了发情所需的生殖营养需求；三是还要考虑高温季节对生殖营养需求的增加；四要考虑环境因素对饲料中生殖营养的破坏；五要考虑商品饲料添加量可能不足。
解决初产母猪断奶不发情的措施
1）初配要达标。引进的国外品种，初次配种标准要达到：体重140kg以上，背膘18～22mm，日龄230d以上。如果体重轻、背膘薄、年龄未到的母猪过早配种会导致：初产母猪断奶后发情延迟、再次配种返情率高；二胎窝产仔数少；寒冷季节流产机会增加；泌乳量低，利用年限缩短。
2）初次怀孕母猪，怀孕期的某些营养水平相对于经产母猪而言可以适当提高10%左右，如CP14%，赖氨酸（Lys）0.7%，钙0.9%，总磷0.8%，有效磷0.45%。
3）初产母猪怀孕后期，仍然需要适度增料攻胎。因为胎儿的2/3的体重是在母猪妊娠期最后1/3的时间增加的，如果不攻胎，根据后代优先的营养分配原理，母猪的营养优先供应胎儿，在摄入不足的情况下，可能动用母猪体脂肪甚至体蛋白来供应胎儿的生长，意味着初产母猪在怀孕后期就在失重和掉膘！再者如果不攻胎，会导致母猪体质下降反而影响分娩；此外，胎儿初生重不足会影响哺乳期仔猪成活率。实际上，调查发现，初生重在1.5kg以内不会因初生重过大而出现难产。
4）锻炼母猪肠道功能。胃好，胃口才好。这里的“胃好”，指的是胃肠功能好和胃肠道容积大。2014年在欧洲召开的“营养与肠道健康国际学术会议”上，与会专家认为：一是动物的肠道除了消化功能外，还有化学感应和接收机体信号的功能，小肠不仅是被动吸收通道，实际上在吸收之前还有调节控制功能。因此，饲养动物必须先养好小肠；二是对仔猪腹泻的控制手段，不能仅仅考虑病原的因素，也不要滥用抗生素，而是从改善环境、调整水质和强化营养上下功夫；三是通过母猪的饲喂调控仔猪肠道健康，因此，猪场要把母猪作为核心要素从强化营养和加强管理上下功夫，把母猪奶水调养好；四是在炎热环境下需要特别注意母猪饲养管理的改善。
怀孕母猪尤其是初产怀孕母猪，在整个怀孕期补充优质粗纤维特别是青绿饲料非常必要，可以减少便秘、锻炼肠道功能、撑大胃肠容积、促进生殖器官发育、增加母猪幸福指数。试验研究发现临产前3d和产后7d补喂青绿饲料，对于减少泌乳障碍、增加7d后的采食量很有帮助。
5）集中猪场优势资源，增加初产母猪哺乳期采食量。从图1可以看出，泌乳期体重损失越多，断奶至发情的时间间隔越长，但这一特征主要在头胎表现得更明显（Vesseuret al.,1994）。所以，增加哺乳期采食量是减少初产母猪断奶掉膘的最有效措施，必须达到理想的采食量目标（kg）：1.8+0.5×（母猪哺乳仔猪数）。
The English version
First farrowing sows after weaning estrus, breeding difficult again, a second litter size is reduced, is most commonly occurs in the production of modern sow. The cause for this problem is to enter 2 nutrient reserves of the sow breeding cycle, because the reproductive system in nutrient allocation priority weaker than other organs and systems, so the nutrient deficiency had the greatest influence on the reproductive system. First-timer sow weaning estrus not, of course, also with the sow health, especially reproductive tract health and induced environment related. Below mainly from nutrition management to address a first-timer sows after weaning estrus problem of a series of reproductive barriers, such as.
Nutrition principles and ideas
Heat needed nutrients reserves, not only need big nutritional reserves, but also need reproductive nutrition reserves. Large nutrient reserves refers to starch, protein, fat, constant minerals and other nutrients reserves, reflect on body weight and body condition; Reproductive nutrition reserve refers to related to reproductive structure and reproductive function of key nutrients such as special vitamins, such as special trace element nutrition reserves. The two kinds of nutrition supplies enough reserves are indispensable to complete reproduction process.
Nutrition are the main reasons of the lack of reserve: first-timer sow weight (first-timer sow weight at about 50 kg), not up to standard, at the beginning of the pregnancy early in the term improper feeding/enough, daily feeding amount not enough nutrition, not enough lactation feed intake, tapping tyres. Nutrition reserve main aim is to: when weaning, sow weightlessness not more than 10 kg, body condition of body condition scoring 2.5 ~ 3 points. To realize the goal of this store, the light is not enough to increase lactation feed intake, the first-timer sow breeding process need to begin (pictured).
Figure 1 lactation weight loss effects on weaning to estrus interval
Reproductive nutrition reserves, one must pay attention to the limited feeding period by a decrease in grain feed intake causes reproductive nutrition deficiency; To pay attention to the nursing nutritional needs of nursing and reproductive have different nutritional needs, in the run-up to mating, even feeding relatively rich nutrition of lactation, also cannot satisfy the requirement of reproductive nutrition for the heat; Three is to consider the high temperature season increased demand for reproductive nutrition; Fourth, we need to consider environmental factors on the feed in reproductive nutrition; Five to consider commodity feed additives may be insufficient.
Solve the first-timer pigs weaned measures are not in heat
1) early to amount to mark. Introduce foreign varieties, breeding standards to achieve: first time more than 140 kg of body weight and backfat 18 ~ 22 mm, more than 230 d day age. If the weight is light, back fat thin, age not to sow breeding early causes: first farrowing sows after weaning estrus delay, high rate of breeding return mood again; Less two nest litter size; Increased opportunities for cold season abortion; Mammary volume is low, use fixed number of year shortened.
2) the first pregnancy sow, some of the nutrition level during pregnancy may be appropriately increased by 10% compared to the multiparity sows, such as CP14 %, 0.7% lysine (Lys), calcium is 0.9%, 0.8% of the total phosphorus, effective phosphorus 0.45%.
3) the first-timer sows late pregnancy, still need to moderate increase is expected to attack. Because two-thirds of fetal weight is increased in pregnancy period finally a third of the time, if you don't attack, according to the principle of offspring priority nutrition distribution, sow nutrition supply priority fetus, in the case of inadequate intake, may use the sow body fat and body protein to supply the growth of the fetus, means a first-timer sows in late pregnancy in weightlessness and DiaoBiao! Moreover if they don't attack, instead, to cause a decline in the sow physique affect delivery; In addition, the lack of fetal birth weight will affect lactation piglet survival rate. In fact, the survey found that the primary emphasis on within 1.5 kg will not occur during childbirth by birth weight is too large.
4) exercise sows the intestinal function. The stomach is good, appetite is good. Here "stomach", refers to the gastrointestinal function and large volume of gastrointestinal tract. Held in Europe in 2014's "nutrition and intestinal health international academic conference", the participating experts believe: one is the animal's gut besides digestive function, as well as chemical sensors and the function of the body's reception, the small intestine is not only the passive absorption channel, actually before absorption and adjust the control function. Animals, therefore, must first raise good small intestine; Second, the control of diarrhea piglets, not only consider the factor of pathogen, also don't abuse of antibiotics, but from the improvement of the environment, adjust the water quality and strengthening nutrition fluctuation kongfu, 3 it is through the sow feeding control piglets intestinal health, therefore, pig farms to sow as core elements from strengthening nutrition and strengthening management, put milk and nurse; Four is in the hot environment need to pay special attention to sow breeding management improvement.
Pregnant sows first-timer pregnant sows, especially in the high quality coarse fiber supplements during pregnancy, especially it is necessary to green feed, can reduce constipation, intestinal function exercise, enlarged gastric volume, promote the development of reproductive organs, increase the sow happiness index. Experimental studies have found that 3 d before labor and postpartum 7 d fill hello green feed, to reduce lactation disorder, increase feed intake after 7 d is very helpful.
5) concentrated pig advantage resources, increase the first-timer sow lactation feed intakes. Can be seen from the figure 1, lactation weight loss, the more weaning to heat the longer the time interval, but this feature is mainly in the first act more obvious (Vesseuret al., 1994). So, increase lactation feed intake is the most effective measures to reduce the first-timer sow weaning DiaoBiao must achieve the ideal intake (kg) : 1.8 + 0.5 x (the sow lactation piglet number).
|
