母猪繁殖性能影响因素分析

正目前,母猪繁殖障碍在规模化猪场普遍存在,以妊娠母猪流产、死胎、木乃伊胎、产弱仔、少仔、公猪不育和母猪不孕等为特征,发病率呈逐年上升之势,已成为严重危害养猪业和影响养猪经济效益的重要原因。目前,母猪繁殖障碍在规模化猪场普遍存在,以妊娠母猪流产、死胎、木乃伊胎、产弱仔、少仔、公猪不育和母猪不孕等为特征,发病率呈逐年上升之势,已成为严重危害养猪业和影响养猪经济效益的重要原因。影响母猪繁殖性能的原因错综复杂且种类繁多,本文对影响母猪繁殖性能的各方面因素进行综述性分析,以期为提高猪场母猪繁殖性能提供参考。     

影响母猪繁殖性能的因素探析

母猪的繁殖性能对增加猪场产能、提高猪场经济效益和保障猪肉市场稳定供应至关重要。在生产中母猪的繁殖性能受多种因素影响,本文从品种、饲养管理、营养摄入和环境等方面详细阐释了影响母猪繁殖性能的因素,并提出了相应的解决措施,以期对提高母猪繁殖性能、提高猪场效益起到积极的借鉴作用。     

影响母猪繁殖性能的因素分析

影响母猪繁殖性能的因素现已得到了广泛的研究,其中一些成果对生产具有重要的指导意义。笔者主要针对影响母猪繁殖性能的因素进行分析,以期在生产实践中得以应用,提高母猪的生产效益。     

影响母猪繁殖性能的因素分析

我国是世界上最大的猪肉生产国和消费国,猪在我们的生产生活中有着极其重要的作用,对优质安全猪肉的需求不断增加,很大程度上促进了我国生猪养殖产业的发展.生猪养殖行业的健康稳定发展,对于我国农业的整体发展和人民群众的生活都至关重要.     

母猪繁殖性能影响因素及建议

母猪繁殖性能直接决定了养猪业的生产效益,提高母猪有效的繁殖性能可显著提升猪场经济效益。母猪的繁殖性能由多因素影响制约,文中着重探究母猪非遗传力因素对母猪繁殖性能的影响进行分析与建议,如胎次、非生产天数、背膘厚、季节、生物安全5个因素,以期给广大猪场在提高母猪繁殖性能上提供可行性的参考。     

影响母猪繁殖性能的主要因素分析

母猪繁殖性能是决定生产经济效益的重要因素，只有准确掌握了母猪的繁殖性能状况，才能进一步提高其繁殖潜力。本文采用单因素各处理重复数不等的方差分析方法，对156头英系大约克夏母猪的繁殖成绩进行了统计分析，综合比较分析了不同胎次、季节、与配公猪品种影响下的母猪繁殖性能。     

营养因素对母猪繁殖性能的影响

营养因素是影响母猪繁殖性能的众多因素中一个十分重要的因素,本文在此综述了能量水平、L-精氨酸、粗纤维、维生素和矿物质元素等对母猪繁殖性能的影响,以期为养猪业者的生产实践提供参考。     

规模化商品场繁殖母猪的性能分析

<正> 一、前言人们对猪的育种目标,过去主要选择生产(育肥和胴体)性状.现在则同时考虑选择繁殖性状.对于商品猪场来说,繁殖性状的优劣更显得重要,不仅直接影响母猪的繁殖生产能力,而且也影响猪场的经济效益.现阶段北京市规模化商品猪场的繁殖母猪群体规模为100至900头不等,使用品种主要有北京黑猪(B)、北京花猪、长白猪(L)、杜洛克猪(D)、大约克猪(Y)以及长×北京黑猪(LB)、杜×北京黑猪(DB)、长×北京花猪、大×北京花猪等杂优猪.北京市海淀区永丰乡第一养猪场是北京市最大的商品猪场之一,年饲养繁殖母猪900头,上市肉猪1.4万头.从1989年投产以来主要饲养北京黑猪及其杂优猪,从1991年起又饲养北京花猪及其杂优猪.本文     

影响母猪繁殖的因素

母猪繁殖障碍包括：母猪不发情或发情屡配不孕．流产,产死胎、弱仔、畸形儿等。影响母猪繁殖的障碍性疾病可分为2类：一类是传染性疾病,如蓝耳病、伪狂犬、细小病毒、乙型脑炎等;另一类是非传染性疾病,该类疾病的发病原因比较复杂,主要有管理不善引起的．也有因自然条件、气候、气温等因素引起的。有单一原因引起的,也有2个或2个以上的原因引起的。     

影响母猪繁殖的因素

在养猪业飞速发展的今天 ,母猪的繁殖问题已成为当今养猪业的一大难题。在近几年的临床工作中发现 ,越来越多的母猪出现繁殖障碍 ,多表现为产死胎、流产或产下的仔猪在两月龄内不断死亡。繁殖障碍严重威胁着养猪业的健康发展。1　营养缺乏1 .1　维生素缺乏　在现实养猪业中 ,大多数养殖户担心母猪过肥而减少营养物质的投入 ,尤其是怀孕期间饲料配方不合理 ,忽视了怀孕期维生素的补充 ,特别是 VA、VE 等。种公猪缺乏 VA 可导致精子活力降低。母猪缺乏 VA 可导致流产、死胎或产畸形胎儿。 VE又名生育酚 ,对家畜的繁殖影响更大。 VE缺乏公…     

Faecal pH throughout the reproductive cycle of sows in commercial pig herds

Despite the importance of swine intestinal health, there are no easy-to-use and cost-efficient methods to evaluate it under field conditions for sows. To provide some indication about intestinal health, pH of faeces could be used but reference values for the currently high-performing commercial sow breeds are missing. In response, faecal pH of healthy sows from three different herds (herd A: 230 sows, herd B: 350 sows, herd C: 500 sows) was measured throughout the reproductive cycle. Within each herd, 10 sows were selected and rectal faeces samples were collected at different time points during the reproductive cycle: day 90 of gestation, day 1, 7, 14 and 21 of lactation, 7 days post-weaning and day 30 of the next gestation. In addition, data on sow body condition (back fat), feed composition and coarseness of the feed were collected. For individual pH measurements, the pH ranged from 6.30 to 7.93. However, for all herds together, the average faecal pH value of the sows throughout the reproductive cycle ranged from 6.89 to 7.15. Also, the variations due to sow and time of sampling during the reproductive cycle were low with coefficients of variation of less than 5%. The results from the pairwise comparisons of the statistical model showed that in the last stages of lactation (i.e., at day 21), significantly lower average pH values (p ≤ .05) are expected when compared to earlier stages of lactation (days 3 or 7), or at day 7 post-weaning or compared to day 30 of the next gestation. Bearing its limitations, our study provided reference faecal pH values from high-performing commercial sows under field conditions and as such they could be used directly in the field. Yet, further research is needed to provide more information on the factors affecting pH values throughout the reproductive cycle of the sow.     

Some observations on reproductive performance in selected commercial beef herds

Abstract

Extract

Although the opinion has been expressed (Andrews, 1971 Andrews, E. D. 1971. Cobalt deficiency in sheep and cattle. N.Z. Dept. Agric. Bull., : 180–180.  [Google Scholar]) that cobalt deficiency among cattle has virtually disappeared in New Zealand and that specimens for laboratory examination are rarely required, 15 to 20% of the liver samples submitted by veterinarians to the Animal Health Reference Laboratory for vitamin B₁₂ assay are from cattle. Diagnostic criteria for cobalt (vitamin B₁₂) deficiency cy have long been established for sheep but not for cattle In view of the continuing requests for vitamin B₁₂ analyses on bovine livers, it was desirable to establish normal values for clinically normal cattle so that results of routine diagnostic analyses could be more readily interpreted.     

Correlation of cell-mediated immunity against porcine reproductive and respiratory syndrome virus with protection against reproductive failure in sows during outbreaks of porcine reproductive and respiratory syndrome in commercial herds

OBJECTIVE: To determine whether cell-mediated immunity against porcine reproductive and respiratory syndrome (PRRS) virus is correlated with protection against reproductive failure in sows during clinical outbreaks of PRRS in commercial herds. DESIGN: Outbreak investigation in 4 swine breeding herds. ANIMALS: 97 sows. PROCEDURES: On each farm, blood samples were collected from sows with clinical signs (abortion or increased fetal death; case sows) and from clinically normal sows (control sows). The intensity of the cell-mediated immune (CMI) response was determined by use of an interferon-gamma enzyme-linked immunospot (ELISPOT) assay. Multiple logistic regression analyses and t tests were used to compare ELISPOT assay values between case and control sows. Multiple linear regression was used to investigate associations between cell-mediated immunity and the magnitude of clinical signs. RESULTS: In 2 farms, case sows had lower ELISPOT assay values than control sows. A negative association between the intensity of the CMI response and the number of pigs born dead per litter was detected on 1 farm. In 1 farm, no association was detected between the intensity of the CMI response and protection against reproductive failure. CONCLUSIONS AND CLINICAL RELEVANCE: Evidence that a strong CMI response was correlated with protection against clinical PRRS was detected in 3 of 4 farms. However, farms and sows within farms varied considerably in their immune responsiveness and in the degree to which they were protected clinically. Increasing cell-mediated immunity within infected herds has the potential to decrease clinical reproductive disease, but only if the sources of intra- and interfarm variation in the intensity of cell-mediated immunity to PRRS virus can be identified.     

Factors affecting length of productive life in Swedish commercial sows

The objective of this study was to investigate factors that might influence the length of productive life in Swedish crossbred (Landrace x Yorkshire) sows. The data set consisted of 20,310 sows farrowing between 2001 and 2004 in 21 commercial piglet-producing herds. Productive life (PL) was defined as the number of days between first farrowing and removal or termination of data collection. In addition to the overall risk analysis of PL, another 4 longevity traits were analyzed (competing risk analyses): reproductive disorder-determined length of PL (RPL), udder problem-determined length of PL (UPL), lameness-determined length of PL (LPL), and mortality-determined length of PL (MPL). Analyses were performed by using survival analysis, applying a Weibull model with 6 time-dependent and 1 time-independent variable (age at first farrowing). The factor with the largest contribution to the likelihood function for PL was days after farrowing, followed by parity, the herd x year combination, the total number of piglets born, days between weaning and next farrowing, farrowing month, and age at first farrowing. For all 4 competing risk traits, the factors contributing most to the likelihood function were days after farrowing, the herd x year combination, and parity, with a varied order between traits. The hazard for removal was greatest 30 to 40 d after farrowing (after weaning) for PL, UPL, and LPL (P < 0.001). However, for MPL the hazard was greatest just after farrowing (0 to 10 d), and for RPL the hazard peaked at 70 to 100 d after farrowing. The hazard for removal was, compared with parity 1, less in parities 2 to 7 and greater from parity 8 for PL (P < 0.001). The hazard was greatest in parity 1 (P < 0.01) for RPL, UPL, and LPL, whereas for MPL the hazard increased with greater parity number and was markedly greater from parity 9 (P < 0.001). Sows with litters of 9 piglets or less had a greater hazard for removal than sows with litters of 12 to 13 piglets (P < 0.001). Intervals between 120 and 122 d from weaning to the next farrowing showed the lowest hazard for removal (P < 0.001). The influence of farrowing month displayed no clear pattern for PL. Sows of 14 mo or older at their first farrowing had a 20% greater hazard for removal than younger sows (P < 0.001). The hazard for removal was greater for smaller litters in all parities but was more accentuated in greater parities. Overall, days after farrowing was the main risk factor for sow removal. Removal hazard was greatest shortly after weaning, and this peak increased with greater parity number.     

Factors affecting reproductive performance in dromedary camel herds in Saudi Arabia

A survey of 7122 dromedary camels in 115 herds in Saudi Arabia was used to estimate the effects of herd size (HZ; <?25 vs. 25–49 vs. 50–100 vs. >?100 camels), herder/camels ratio (H/C; 1:<?25 vs. 1:25–50 vs. 1:>?50), manager experience (ME; <?5 vs. 5–10 vs. >?10 years), male/females ratio (M/F), housing system (HS; free vs. closed vs. mixed), length of the breeding season (winter vs. winter and spring vs. fall, winter and spring), age at first mating (3 vs. >?3 years), and time of mating after parturition (≤?3 vs. >?3 months) and their interactions on the overall pregnancy rate. Barren females of these herds (n?=?886) were examined for the causes of infertility. Results showed that herds with H/C of 1:<?25 had higher overall pregnancy rate (95.29%) than herds with H/C of 1:25–50 (79.84%) and those with H/C of 1:>?50 (72.79%) (p?=?0.003). Herds having ME of >?10 years revealed greater overall pregnancy rate (94.89%) than herds with ME of 5–10 years (80.54%) and those with ME of <?5 years (72.5%) (p?=?0.001). There were significant interactions between H/C × HZ (p?=?0.003), H/C × HS (p?=?0.006), and ME × HS (p?=?0.02). The overall pregnancy rate did not significantly differ between herds bred females by age of 3 years and those bred females by age >?3 years and in females bred within 3 months after parturition and in those bred after 3 months. The mean calving interval was shorter (p?=?0.008) in camels mated within 3 months of parturition (15.25?±?2.8 months) than in those mated after that time (24.33?±?6.5 months). Clinical endometritis, ovarian hydrobursitis, and vaginal adhesions were the common clinical findings in barren females. Thus, efforts to reduce the age at first mating and the interval after calving, increase the number of herders/camels, and control reproductive disorders could improve the reproductive performance and quality of camel herds in Saudi Arabia.

     

Mortality, death interval, survivals, and herd factors for death in gilts and sows in commercial breeding herds

The objectives of this study were to measure death intervals and survival, to determine mortality rate and mortality risks, and to investigate the association of herd factors with mortality risk in individual female pigs. This study was conducted by obtaining female data with lifetime records of 65,621 females born between 1999 and 2002, and herd data with mean measurements of 5 yr from 2000 to 2004 in 105 herds. Annualized mortality rate was calculated as the number of dead females divided by the sum of life days in all gilts and sows, multiplied by 365 d. Mortality risk was calculated as the number of dead females divided by the number of surviving females at farrowing in each parity. Death interval in gilts was defined as the number of days from birth to death, and that in sows was the number of days from the last farrowing to death. A Cox proportional hazards model was used to obtain the survival probability by parity. Logistic regression analyses were used to investigate the association of herd factors with mortality risk in individual females in each parity. Of the 65,621 females, the mortality risk was 9.9%, and the annualized mortality rate was 3.9%. Of the 6,501 dead females, death intervals in gilts and sows were 294.7 and 55.0 d, respectively. In gilts, survival probability rapidly decreased at 33 and 50 wk of age, around the first mating and the first parturition. In contrast, survival probability in sows decreased at wk 1 after farrowing, and rapidly decreased at wk 20 and 21 after farrowing in all parity groups that were around a subsequent peripartum period. The percentages of death on wk 0, 1, and 2 after the last farrowing in all the dead sows were 6.5, 23.5, and 10.1%, respectively. Approximately 10% of deaths also occurred from wk 20 to 21 after the last farrowing. Death interval in parity > or =5 was the shortest among all parity groups (49.2 d; P < 0.05). Mortality risks in parities 0 and 1 were 1.44 and 1.83%, respectively. As parity increased from 2 to > or =5, mortality risk increased from 1.63 to 5.90%. Herd factors (greater herd mortality, less herd productivity, and smaller herd size) were associated with greater mortality risk in individual females in parity 0 to > or =5, parity 4 and > or =5, and parity 1 to 4, respectively (P < 0.05). In conclusion, females in peripartum periods, gilts, and high-parity sows are at a greater risk of dying. Increased care should be implemented for prefarrowing females and early-lactating sows.     

Factors influencing piglet pre-weaning mortality in 47 commercial swine herds in Thailand

The present study aims to determine the occurrence of piglet pre-weaning mortality in commercial swine herds in Thailand in relation to piglet, sow, and environmental factors. Data were collected from the database of the computerized recording system from 47 commercial swine herds in Thailand. The raw data were carefully scrutinized for accuracy. Litters with a lactation length < 16 days or >28 days were excluded. In total, 199,918 litters from 74,088 sows were included in the analyses. Piglet pre-weaning mortality at the individual sow level was calculated as piglet pre-weaning mortality (%) = (number of littermate pigs ? number of piglets at weaning) / number of littermate pigs. Litters were classified according to sow parity numbers (1, 2–5, and 6–9), average birth weight of the piglets (0.80–1.29, 1.30–1.79, 1.80–2.50 kg), number of littermate pigs (5–7, 8–10, 11–12, and 13–15 piglets), and size of the herd (small, medium, and large). Pearson correlations were conducted to analyze the associations between piglet pre-weaning mortality and reproductive parameters. Additionally, a general linear model procedure was performed to analyze the various factors influencing piglet pre-weaning mortality. On average, piglet pre-weaning mortality was 11.2% (median = 9.1%) and varied among herds from 4.8 to 19.2%. Among all the litters, 62.1, 18.1, and 19.8% of the litters had a piglet pre-weaning mortality rate of 0–10, 11–20, and greater than 20%, respectively. As the number of littermate pigs increased, piglet pre-weaning mortality also increased (r = 0.390, P < 0.001). Litters with 13–16 littermate pigs had a higher piglet pre-weaning mortality than litters with 5–7, 8–10, and 11–12 littermate pigs (20.8, 7.8, 7.2, and 11.2%, respectively; P < 0.001). Piglet pre-weaning mortality in large-sized herds was higher than that in small- and medium-sized herds (13.6, 10.6, and 11.2%, respectively; P < 0.001). Interestingly, in all categories of herd size, piglet pre-weaning mortality was increased almost two times when the number of littermates increased from 11–12 to 13–16 piglets. Furthermore, piglets with birth weights of 0.80–1.29 kg in large-sized herds had a higher risk of mortality than those in small- and medium-sized herds (15.3, 10.9, and 12.2%, respectively, P < 0.001). In conclusion, in commercial swine herds in the tropics, piglet pre-weaning mortality averaged 11.2% and varied among herds from 4.8 to 19.2%. The litters with 13–16 littermate pigs had piglet pre-weaning mortality of up to 20.8%. Piglets with low birth weight (0.80–1.29 kg) had a higher risk of pre-weaning mortality. Management strategies for reducing piglet pre-weaning mortality in tropical climates should be emphasized in litters with a high number of littermate pigs, low piglet birth weights, and large herd sizes.     

Swine herds achieve high performance by culling low lifetime efficiency sows in early parity

Sow lifetime performance and by-parity performance were analyzed using a 3 by 3 factorial design, comprising 3 herd productivity groups and 3 sow efficiency groups. Data was obtained from 101 Japanese herds, totaling 173,526 parity records of 34,929 sows, for the years 2001 to 2006. Sows were categorized into 3 groups based on the lower and upper 25th percentiles of the annualized lifetime pigs born alive: low lifetime efficiency sows (LE sows), intermediate lifetime efficiency sows or high lifetime efficiency sows. Herds were grouped on the basis of the upper and lower 25th percentiles of pigs weaned per mated female per year, averaged over 6 years: high-, intermediate- or low-performing herds. Mixed-effects models were used for comparisons. LE sows in high-performing herds had 57.8 fewer lifetime nonproductive days and 0.5 earlier parity at removal than those in low-performing herds (P<0.05). The number of pigs born alive of LE sows continuously decreased from parity 1 to 5, whereas those of high lifetime efficiency sows gradually increased from parity 1 to 4 before decreasing up to parity ≥ 6 (P<0.05). In conclusion, the LE sows have a performance pattern of decreasing number of pigs born alive across parity. The present study also indicates that high-performing herds culled potential LE sows earlier than the other herds.