浅谈母猪生产饲养管理要点

母猪生产的主要目的是有效地生产能活的断奶仔猪。在过去的几十年里,母猪的平均窝产仔数通过遗传选择得到了提高;然而,这与仔猪平均初生体重降低以及窝内体重变异增大有关。导致断奶前仔猪死亡率增高,断奶后仔猪体重差异大,同时很大程度上限制了管理效率的提升和生产效益的增加。为充分发挥母猪繁殖潜力和产仔性能及提高仔猪存活率,应注重做好母猪妊娠、产后和断奶后的科学管理。文章对母猪饲养、断奶仔猪饲养、产房管理、产后护理和疾病防控措施进行了综述,以期为母猪健康养殖提供参考。     

妊娠母猪营养摄入对窝产仔猪初生重均匀度的影响

<正>仔猪窝均匀度是非常重要的经济指标,因为它与仔猪断奶前死亡率有关。如果仔猪初生体重变异大,体重轻的仔猪在吸允乳头竞争中处于劣势地位,初乳和常乳摄入量低,从而导致营养不良和免疫力低下。另外,仔猪初生重变异越大,断奶时窝均匀度越低,从而增加生产中的劳动强度和管理难度。而且体重低的仔猪生长速度也慢,出栏时间延长。本文综述了影响仔猪窝均匀度的生理因素,并探讨降低仔猪初生重变异的     

N-氨甲酰谷氨酸在调控仔猪初生重中的应用及其作用机理

N-氨甲酰谷氨酸(NCG)是一种新型的饲料添加剂,可显著提升母猪的繁殖性能。近期研究表明,NCG对仔猪初生重也存在积极的调控作用。本文综述了近年来营养因子对仔猪初生重及窝内体重变异调控的研究进展,重点对NCG调控仔猪初生重及变异的应用效果和分子机理进行了挖掘和分析,以期为生猪生产中仔猪初生重及其变异的调控提供理论和实践依据。     

断奶仔猪非病原性腹泻的原因及防治措施

随着饲养规模的不断扩大和集约化程度的不断提高,现代养猪生产中已经逐步推广和普及仔猪3～5周龄断奶即早期断奶技术。早期断奶仔猪由于受营养和饲养环境等因素的影响,使仔猪易发生消化机能紊乱而腹泻,结果导致仔猪生长受阻、抗病力下降甚至死亡,给养猪生产造成巨大的经济损失。本文主要从仔猪的营养生理特点出发,阐述仔猪的非病原性腹泻的病因及其防治措施。1仔猪的营养生理特点1.1代谢机能旺盛,相对生长迅速仔猪20日龄时的体重为初生重的5倍,每千克体重的蛋白质沉积量为9～14克,而成年猪每千克体重仅为0.3～0.4克,仔猪是成年猪的30～35倍…     

美国目前和未来的保育猪饲养方案

在过去的20年内美国的猪产业发生了翻天覆地的变化。多址生产系统对畜群的健康和控制断奶仔猪链产生了极大的作用。然而一个成功的断奶仔猪营养方案其基本原则对于任何日龄断奶的仔猪来讲都是相似的。可以归纳成三点：①在断奶时,仔猪尽可能的体重大;②尽可能快的将日粮从复合日粮转化为简单日粮;③重点关注保育仔猪管理。此外,在美国过去的10年通过遗传选育的手段,使窝产仔数大约增加了1.5头,仔猪断奶的日龄也相应地增加到平均为19~23 d。当每头母猪产仔数增加以后,由于初生活仔数的增加,有更多体重轻的仔猪出生,这将是生产者所面临的挑战。因此,对生产者来说,了解影响初生体重轻的仔猪一生的生产性能以及收益的因素是非常必要的。     

大白仔猪初生重对生产性能的影响

文章主要研究规模化猪场纯种美系大白仔猪的初生重对其生产性能的影响。研究结果表明,大白仔猪初生重与产仔数呈明显负相关,同窝活仔数每增加1头,初生重随之下降30 g;仔猪初生重的大小与21日龄体重呈明显的正相关,初生重每增加100 g,其断奶重随之增加239 g;仔猪初生重与断奶成活率呈明显的正相关,初生重每增加26 g,断奶成活率随之升高1个百分点;同样,仔猪初生重还与校正达100 kg体重日龄、背膘厚、眼肌面积、育种指数等存在明显的相关。试验的统计分析数据表明,选择初生重较大而产仔数又相对适中的种猪,其后代会有更好的生产效率和经济效益。     

提高哺乳仔猪成活率的几项措施

1提高仔猪初生重 仔猪初生重是分娩母猪生产性能的重要指标,仔猪出生重越重,仔猪断奶重也越重。仔猪初生重每增加1克仔猪断奶重就增加2.34克,初生重每增加100克,断奶前死亡率可降低10%。因此,根据妊娠母猪在胚胎发育各个阶段的特点,提供合理的优质全价饲料,满足胚胎发育时营养的需求,同时还可以储备一定的能量,为分娩后母猪泌乳打好基础,提高仔猪成活率。     

提高仔猪成活率的关键措施

仔猪是指初生至70日龄的小幼猪。仔猪在生产中被分为两个时期．第一个时期是指初生至断奶的哺乳仔猪，第二个时期是指断奶至70日龄的断奶仔猪。仔猪具有独特的生长发育规律和生理特点．如果在生产过程中出现营养、环境和免疫等多方面的应激反应，就会造成初生仔猪发病率增加、死亡率增高。断奶仔猪经常出现食欲下降、腹泻、增重减缓，甚至出现消瘦，死亡等现象，从而增加了饲养成本。因此，我们在生产中应特别注重加强饲养管理，提高仔猪的成活率。     

添加活酵母菌可培育出更健康的仔猪

母猪在哺乳期喂给活酵母菌,可以提高其繁殖力,缩短断奶到发情的间隔时间,减少母猪体重损失,提高仔猪的初生重。本文重点介绍母猪在哺乳期饲喂活酵母菌对提高仔猪断奶体重、改善断奶后生产性能的影响。     

提高仔猪断奶体重的饲养技术

提高仔猪断奶体重是养猪生产中的重要一环,也是影响整个猪场经济效益的关键.实际生产中有"初生多1两、断奶多1斤"的说法.因此,要想提高养猪生产的经济效益,必须从母猪抓起,做好提高仔猪断奶体重的技术工作.     

Genetic parameters for within-litter variation in piglet birth weight and change in within-litter variation during suckling

The objective of this study was to ascertain whether maternal additive genetic variance exists for within-litter variation in birth weight and for change in within-litter variation in piglet weight during suckling. A further objective was to estimate maternal genetic correlations of these two traits with mortality, birth weight, growth, and number of piglets born alive. Data were obtained from L?vsta research station, Swedish University of Agricultural Sciences, and included 22,521 piglets born in 2,003 litters by 1,074 Swedish Yorkshire sows. No cross fostering was used in the herd. The following seven traits were analysed in a multivariate animal (sow) model: number of piglets born alive, within-litter SD in birth weight, within-litter SD in piglet weight at 3 wk of age, mean weight at birth, mean weight at 3 wk of age, proportion of stillborn piglets, and proportion of dead piglets during suckling. Maternal genetic variance for the change in within-litter SD in piglet weight during suckling was assessed from the estimated additive genetic covariance components by conditioning on within-litter SD in birth weight. Similarly, mean growth of piglets during suckling was assessed from the additive genetic covariance components by conditioning on mean weight at birth. The heritability for within-litter SD in birth weight was 0.08 and 0.06 for within-litter SD in piglet weight at 3 wk. The genetic correlation between these two traits was 0.71. Little maternal genetic variance was found for the change in within-litter SD in piglet weight during suckling, and opportunity for genetic improvement of this trait by selective breeding seems limited. The genetic correlation of within-litter SD in birth weight with proportion of dead piglets during suckling was 0.25 and of within-litter SD in birth weight with mean growth of piglets was -0.31. The maternal genetic variance and heritability found for within-litter SD in birth weight indicates that genetic improvement of this trait by selective breeding is possible. In addition, selection for sows' capacity to give birth to homogeneous litters may be advantageous for piglet survival, piglet growth, and litter homogeneity at weaning.     

Within-litter variation of birth weight in hyperprolific Czech Large White sows and its relation to litter size traits, stillborn piglets and losses until weaning

Data from about 2900 litters (approximately 40,000 piglets) originating from 1063 Czech Large White hyperprolific sows were analyzed. The phenotypic and genetic relations between litter size traits, piglet mortality during farrowing and from birth to weaning and several statistics referring to the distribution of the birth weight within litter were analyzed. All genetic parameters were estimated from multi-trait animal models including the following factors: mating type (natural service or insemination), parity, linear and quadratic regression on age at first farrowing (1st litter) or farrowing interval (2nd and subsequent litters), herd-year-season effect and additive-genetic effect of the sow. The phenotypic correlations of the mean birth weight with the total number of piglets born and piglets born alive were − 0.30. Traits describing the variability of the birth weight within litter (range, variance, standard deviation, coefficient of variation) were mostly positively correlated with litter size. A statistically significant phenotypic correlation (− 0.09 to − 0.15) between mean birth weight and losses at birth and from birth to weaning was found. The heritability for the number of piglets born, piglets born alive and piglets weaned was around 0.15. The number of stillborn piglets had only a very low heritability less than 0.05, whereas the heritability for losses from birth to weaning was 0.13. The heritabilities of the mean, minimal and maximal birth weight were 0.16, 0.10 and 0.10, respectively. The heritability for all statistics and measures referring to the variability of the birth weight within litter was very low and did never exceed the value of 0.05. An increase in litter size was shown to be genetically connected with a decrease in the mean piglet birth weight and an increase in the within-litter variability of birth weight. Selection on litter size should be accompanied by selection on mortality traits and/or birth-weight traits. Losses from birth to weaning and the minimal birth weight in the litter were proposed as potential traits for a selection against piglet mortality.     

Results of four generations of a canalising selection for rabbit birth weight

A divergent selection experiment based on the homogeneity of birth weight in rabbit was carried out at the INRA experimental farm of Auzeville. The two lines were created by selecting breeding does and bucks from the female strain AGP22 bred at the Grimaud Frères Sélection company for environmental variability of birth weight. This involved a new model incorporating a genotypic value for the mean and a genotypic value for the environmental variance. There was a selection response with a significant difference in the within-litter standard deviation of birth weight between the lines after four generations of selection (6.93 g vs. 8.13 g). The mortality of kits at birth and from birth to weaning was lower in the “homogeneous” line than in the “heterogeneous” line (16.6% vs. 18.6% and 17.7% vs. 32.7%, respectively). The litter size at weaning was higher in the “homogeneous” line (7.22 vs. 5.39). The selection on the homogeneity of birth weight had no significant influence on the other traits. It was concluded that selection for reduced environmental variance of birth weight improved young rabbit survival without reducing the mean of birth weight.     

Analysis of birth weight variability in pigs with respect to liveborn and total born offspring

Reduction in the variability of piglet birth weight within litter and increased piglet survival are key objective in schemes aiming to improve sow prolificacy. In previous studies, variation in birth weight was described by the sample standard deviation of birth weights within one litter, and the genetic impact has been proved. In this study, we additionally considered the sex effect on piglet's birth weight and on its variability. The sample variance of birth weights per litter separated by sex was assigned as a trait of the sow. Different transformations of the trait were fitted by linear and generalized linear mixed models. Based on 1111 litters from Landrace sows, the estimates of heritability for the different measures ranged from 11 to 12%. We analysed the influence of including birth weight of stillborn piglets on the variability of birth weight within litter. With omitted stillborns, the heritability was estimated approximately 2% higher than that in investigations of all born piglets, and the impact of sex on birth weight variability was increased. Because the proportion of intrapartum deaths is rather high, it is recommended to consider the total number of piglets born per litter when analysing birth weight variation.     

胎次与产仔数对广东小耳花猪初生仔猪均匀度的影响

初生仔猪均匀度常用窝初生个体均重的标准偏差及变异系数表示,是反映母猪孕期繁殖效率的重要指标之一。为了研究不同胎次及产仔数对初生仔猪均匀度的影响,研究对1011窝广东小耳花猪的历史分娩数据进行分析。结果表明:窝初生个体均重为0.67 kg,窝初生个体均重的标准偏差为0.13 kg,窝初生个体均重的变异系数为19%;窝初生个体均重与窝初生个体均重标准偏差的相关系数是0.296,呈极显著正相关(P约0.01);窝初生个体均重变异系数与总产仔数的相关系数是0.028,与产活仔数的相关系数为0.024,均呈现弱正相关。研究建议在地方猪开发利用中,合理调整群体胎龄结构,改善饲养管理方式,合理调整孕期母猪营养水平,进一步提高群体初生仔猪均匀度。     

Evaluation of genetic, common-litter, and within-litter effects on preweaning mortality in a birth cohort of puppies.

OBJECTIVE: To determine relative impact of genetic, common-litter, and within-litter factors on puppy mortality. ANIMALS: 2,622 Boxer puppies of 413 litters born during a 14-month period. PROCEDURE: For each puppy, pedigree was determined, and litter in which it was born was registered. Overall mortality and mortality per specific cause of death were analyzed by use of a model that included an additive genetic effect, common-litter effect, within-litter effect, and regression of mortality on inbreeding coefficient. Relative importance of the effects was determined from estimates of the variance in mortality explained by each factor. RESULTS: 22% of the puppies died before reaching 7 weeks old. Stillbirth was the most frequent cause of death, followed by infection. Most observed differences were attributable to within-litter factors, which explained 67% of the variance in death attributable to infection and < or = 96% of the variance in death attributable to asphyxia. Common-litter factors were more important than additive genetic factors. Variance attributed to common-litter factors ranged from 2% for cheiloschisis, palatoschisis, or cheilopalatoschisis to 30% for death attributable to infection, and variance attributed to additive genetic factors ranged from 0% for asphyxia to 14% for euthanatized because of white color. Inbreeding coefficient had a significant effect on death attributable to infection, which increased 0.26% for each percentage increase of inbreeding. CONCLUSIONS AND CLINICAL RELEVANCE: Additive genetic factors have less impact on preweaning mortality than common-litter factors, which in turn have less impact than within-litter factors. Mortality attributable to infection increases significantly with increases in inbreeding.     

Neonatal-piglet weight variation and its relation to pre-weaning mortality and weight gain on commercial farms

To determine the effect of within-litter neonatal-weight variation on pre-weaning mortality and weight gain, we analyzed piglet survival and weight gain within 400 litters from 10 commercial farms. Neonatal-weight variation (independent of mean neonatal weight, litter size and sow parity) was associated with pre-weaning survival and weaning-weight variation-but not with mean weaning weight. Neonatal piglets with weights well below the range of most of the litter (low-birth-weight piglets) had an increased risk of dying and were unable to obtain normal weight gains by weaning if they survived. These piglets experienced lower survival and poorer weight gain in larger litters. These piglets also tended to have lower survival but normal (albeit low) weaning weights if they survived in litters from middle-aged and old sows. High neonatal-weight variation resulted in lower survival and more variable weaning weights. Small piglets had a greater risk for poor survival and weight gain compared to their heavier litter-mates (a disadvantage that was exacerbated in large litters).     

初配日龄对美系大白母猪繁殖性能的影响

研究旨在揭示不同初配日龄对美系大白种猪产仔数、初生窝重、初生仔猪平均个体重、初生仔猪均匀度、校正21日龄窝重及母猪使用寿命的影响程度及变化规律,挖掘大白母猪的适宜初配日龄,以期为更好地利用初配日龄来辅助种猪选育及现场生产实践工作提供理论依据。选取华东某国家核心育种场717头母猪的2167条繁殖数据及23710条后裔信息数据,初配日龄划分为220 d及以下、221~240 d、241~260 d、260 d以上4个阶段进行单因素方差分析。结果表明,不同初配日龄对美系大白母猪产仔数、初生窝重及校正21日龄窝重影响不显著,对初生仔猪平均个体重、初生仔猪均匀度和母猪使用寿命有显著影响。初配日龄越小,初生仔猪平均个体重越大、均匀度越好、母猪使用寿命越长。因此,美系大白种猪适宜的初配日龄为210~240 d阶段。     

Neonatal survival in swine: effects of low birth weight and clinical disease

Data were collected for 3,636 full-term pigs born in a commercial swine herd to determine the effects of birth weight and clinical disease on survival during the first 3 weeks of life. Logistic regression models were constructed for 7-day survival for all live-born pigs, and for 21-day survival for pigs surviving the first week of life. Estimates of birth weight and disease effects were adjusted simultaneously for other risk factors including litter size, parity, and within-litter variation in birth weight. The 7-day survival model indicated that survival odds improved significantly with increasing birth weight. Maximal survival, relative to pigs weighing less than 601 g at birth, was evident in pigs weighing greater than 2 kg at birth (odds ratio [OR] = 349). Diarrhea (OR = 2.7) and splayed limbs (splay leg; OR = 37.3) significantly (P less than 0.05) reduced 7-day survival. Models of 21-day survival indicated a smaller, but still significant, effect of birth weight on survival. Adjusted survival odds for pigs in the heaviest weight group (greater than 2 kg) were 20.1 times higher than pigs weighing less than 801 g. Diarrhea (OR = 2.7) and lameness (OR = 2.6, 2 limbs) significantly (P less than 0.05) decreased 21-day survival.     

Timing and causes of piglet mortality in alternative and conventional farrowing systems

The causes and timing of piglet mortality were studied in different farrowing systems. In the first experiment 198 litters were recorded in three systems, two of which allowed the sows to move freely, and the third restricted them in conventional crates. More piglets were weaned from the conventional crates than from the open systems and they grew more quickly. More than half the liveborn mortality occurred during the first four days after parturition. In the open systems, 17 per cent and 14 per cent of the piglets born alive were crushed, compared with only 8 per cent in the crates. In the second experiment, 29 sows and litters were studied in detail in a communal pen system during the first seven days of lactation. Three-quarters of the liveborn mortality was due to crushing. The total number of piglets dying per litter, including stillbirths, was significantly associated with the total litter size and the sow's parity. The percentage liveborn mortality was significantly associated with the parity and body length of the sows and with the within-litter variation in the birth weight of the piglets. Individual birth weight was closely associated with percentage survival. Only 28 per cent of piglets weighing less than 1.1 kg at birth survived to seven days.