看国外 | 影响仔猪终生性能表现的4个参数

看国外 2018-12-24 18:07:57

来源:Pig Progress

Genetic selection is leading to larger litters of piglets born with lowered levels of physiological maturity. As this trend amplifies an evolutionary strategy in swine favouring survival of the fittest, it presents negative performance and animal welfare implications.

遗传选择让母猪可以生产更多仔猪,但同时也伴随着生理成熟度低的问题。尽管这个趋势体现了母猪适者生存的进化规律,但同时也给生产性能及动物福利带来负面影响。

Sow Peripartal Syndrome is a complex web of interactions affecting sows and piglets during the peripartal period. At least four parameters are present at birth that can ultimately determine piglets’ lifetime performance. The following is an update on research underway to managing the syndrome.

母猪围产期综合症是指在围产期影响母猪及仔猪性能表现的一系列复杂反应。仔猪出生时,至少有四个参数可以最终决定其一生的性能。以下是正在进行的有关治疗该综合症的研究的最新情况。

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1.Alive at birth

1.出生时活着

While genetic selection has increased the total number of pigs per litter, the number of pigs born alive has not increased at the same pace. Among stillborn piglets, 75% die during farrowing, with asphyxia being the most common cause of death. Risk factors associated with stillbirths include prolonged farrowing, birth order, birth weight and intra-uterine growth retardation. 

While traditional strategies to reduce the number of stillborn piglets have focused on supervision and intervention during the farrowing process. Trouw Nutrition research is focusing on changes occurring throughout all phases of the reproductive cycle which may affect the number of piglets born alive. For example, as most stillborn piglets died during the farrowing process, we are finding solutions to make piglets more resilient through the challenging farrowing process.

虽然遗传选择技术增加了窝产仔数,但是窝产活仔数却没有相应提高。死产仔猪中,75%死于分娩时,而窒息是最常见的死因。与死产相关的风险因素包括分娩时间延长、出生次序、初生体重及子宫内生长迟缓。减少死产仔数的传统策略侧重于分娩过程的监督与干预。泰高动物营养研究则侧重于生殖周期每个阶段出现的变化,这些都可能影响活产仔数。比如,由于很多死产仔猪是死于分娩阶段,我们正在想办法让仔猪适应这个阶段。

2.Adequate birth weight

2.初生体重够重

A piglet’s birth weight significantly affects survival and weight gain up until slaughter. For example, researchers found piglets with a birth weight of 1 kg showed a survival rate of 94%, compared to just 50% for piglets with a birth weight below 1 kg. 

In addition, piglets with a birth weight of 1.5 kg were shown on average to be 4 kg heavier at 9 weeks of age and reached slaughter weight one week earlier compared to their counterparts weighing 1 kg at birth. Multiple factors leading up to farrowing can affect piglets’ birth weight. One factor is the degree of back fat change throughout the reproductive cycle of a sow.

仔猪的初生体重对其成活率及出栏前的体重增长有着重要影响。例如,研究人员发现,初生重为1kg的仔猪,其成活率为94%,而相比之下,初生重不足1kg的仔猪,成活率只有50%。再比如,与初生重为1kg的仔猪相比,初生重为1.5kg的仔猪,9周龄时,平均体重多了4kg,并且提前一周达到出栏体重。有许多因素会影响初生重,其中一个是母猪在整个生殖周期的背膘厚度变化。

Research by Dr Anne Wientjes, Wageningen University, the Netherlands, showed variation in birth weight was reduced when sows lost only 2 mm of back fat compared to sows losing 5 mm of back fat in the previous three-week lactation period. Other factors that may affect birth weight include vascularisation of the placenta and uterine blood flow, as well as a sow’s protein intake during gestation. 

Variation in birth weight within a litter is determined during the first month of gestation and seems to be determined by the variation in placental size. Genetics may explain some of the variation. Researchers are also focusing on how to address physiological immaturity as low birth weight is not a sole factor inhibiting optimal performance.

荷兰瓦根宁大学的Anne Wientjes博士研究发现,与母猪在泌乳期前三周背膘减少5mm相比,背膘只减少2mm时,初生重的差异会减少。其他可能影响初生重的因素包括胎盘血管化、子宫血流量,以及妊娠期母猪的蛋白质摄入量。妊娠的第一个月决定了同窝初生重的差异,并且似乎也由胎盘大小的变化决定。遗传学也许可以解释一部分原因。研究人员也在关注如何解决生理不成熟的问题,因为低初生重并不是限制最佳性能表现的唯一因素。

Figure 1 – Mortality among piglets consuming insufficient colostrum compared to pigs receiving sufficient colostrum intake.

图1  - 与摄入足量初乳的仔猪相比,初乳摄入不足的仔猪死亡率

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3.Adequate colostrum intake

3.摄入足量初乳

A critical component in a piglet’s diet, colostrum delivers nutrients, maternal immunity and many bioactive factors key to tissue and organ development in piglets. Colostrum intake has been linked to positive associations with a piglet’s weight at six weeks of age and at time of slaughter. 

The amount of colostrum intake has been shown to affect pre-weaning mortality. Mortality averaged four-to-five times higher among piglets consuming insufficient colostrum compared to pigs receiving sufficient colostrum intake. It’s been shown multiple times that over 30% of piglets do not get sufficient amounts of colostrum.

作为仔猪日常饮食中的一个重要组成部分,初乳提供了营养、母源抗体和许多生物活性因子,这些因子对仔猪的组织和器官发育至关重要。初乳摄入与6周龄仔猪体重及出栏体重呈正相关。初乳摄入量已被证明会影响断奶前的死亡率。与摄入足够初乳的仔猪相比,初乳摄入量不足的仔猪的死亡率平均高出四到五倍。研究多次显示,超过30%的仔猪没有足够的初乳摄入量。

One factor affecting colostrum intake is the sow’s ability to produce sufficient colostrum. As sows produce larger litters, this challenge may be exacerbated. Total colostrum production by the sow is not related to number of liveborn piglets.

 It is as if the sow does not know beforehand how large her litter will be and as such cannot adapt her colostrum production to it. It is known that the amount of functional mammary tissue is a determinant for a sow’s milk production, and the same is most likely true for total colostrum production.

影响初乳摄入量的其中一个因素是母猪是否能够分泌足够的初乳。而随着窝产仔数的增加,这个挑战也会加剧。母猪分泌初乳的总量与活产仔数并没有关联。就像母猪无法事先知道自己会生产多少仔猪,因此也就无法对初乳产量进行相应调整。已知功能性乳腺组织的数量会影响母猪的泌乳量,对于初乳总量而言,很可能也是如此。

A second factor influencing colostrum intake is the piglet’s ability to suckle in the neonatal period, partly determined by piglet vitality at birth. Oxygen deficiency (hypoxia) by a difficult farrowing process, has been shown to be a risk factor for too low colostrum intakes. Considering neonatal piglets, a cold environment can trigger hypothermia and -glycemia, which negatively impact vitality and colostrum intake.

影响初乳摄入的第二个因素是仔猪在新生儿期的吸食能力,部分取决于出生时仔猪的活力。分娩时缺氧已被证明是初乳摄入量过低的风险因素。就新生仔猪而言,寒冷的环境会引发体温过低和血糖过低,从而对其生命力和初乳摄入产生负面影响。

Sow nutrition also comes into play. Well-designed peripartal feeding strategies have been shown to increase the sow’s total colostrum production, but also specific nutrients can play their role as the availability of certain n-3 PUFA’s in the sow’s diet have in some cases affected piglet vitality at birth.

母猪营养也应列入考虑范围。精心设计的围产期喂养策略已被证明可以增加母猪的初乳产量,但特定营养素也可以发挥作用,因为在某些情况下,母猪饲料中一些n-3多不饱和脂肪酸会影响仔猪的出生活力。

Trouw Nutrition research is evaluating various pathways that could improve a sow’s ability to produce colostrum and milk as well as how proper nutrients can help manage challenges such as constipation in the sow.

泰高动物营养研究正在评估各种提高母猪分泌初乳及乳汁能力的途径,以及评估一些营养素在解决母猪便秘等问题上的效果。

4.Adequate vitality

4.足够的活力

Vitality affects a piglet’s chance to be competitive at the udder, start suckling and maintain body temperature. Hypoxia and splayleg have been shown to negatively affect colostrum intake. 

From a timing perspective, research has shown that piglets who began suckling within 30 minutes following birth had a pre-weaning mortality rate of 6%, compared to a 21% mortality rate for pigs that initiated suckling more than one hour after birth. While hypoxia is a common cause of stillbirth, mild levels of hypoxia can compromise vitality among pigs born alive.

活力足够的仔猪寻找到乳头的几率更大,并开始吮吸、维持体温。缺氧及八字腿对初乳摄入有负面影响。从时间角度来看,研究表明,出生后30分钟内开始摄入乳汁的仔猪,断奶前死亡率为6%,而出生后1小时才开始摄入乳汁的仔猪,断奶前死亡率高达21%。缺氧是死产仔猪的常见原因,而轻度缺氧则会降低活产仔猪的活力。

Piglet vitality thus seems to be a determinant factor for lifetime performance but in itself is affected by many other factors. Trouw Nutrition understands the importance of piglet vitality in the neonatal period and aims to improve it by tackling the underlying causes resulting in improved profitability without increasing labour.

仔猪活力也因此被当做影响终生产性能的决定性因素,但仔猪活力本身也受很多别的因素所影响。泰高动物营养了解仔猪活力在新生儿期的重要性,并旨在通过解决根本原因来改善它,从而在不增加劳动力的情况下提高盈利能力。

(文/爱猪网记者刘坤颖编译,爱猪网原创请勿转载)


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