加系大白母猪不同阶段背膘厚对繁殖性能的影响研究

母猪背膘厚是母猪体况的一个重要指标,与母猪的繁殖性能密切相关。为了系统地分析母猪各个阶段不同背膘厚对其繁殖性能及下一胎繁殖性能的影响,利用超声波对加系大白后备母猪和经产母猪的配种背膘厚、妊娠30 d背膘厚、临产背膘厚和断奶背膘厚进行测定统计,并根据背膘厚把繁殖各个阶段的母猪细分为4组,分析不同阶段母猪的背膘厚对产仔性能及配种分娩率等繁殖性能的影响。结果表明,大白后备母猪配种背膘厚和妊娠30 d背膘厚均在21～26 mm时,产死胎数和产死胎的母猪比例都最低,产活仔数达到最高;经产母猪配种时背膘厚在13～16 mm时,产死胎数和产死胎的母猪比例达到最低,分娩率和产活仔数达到最高;经产母猪妊娠30 d背膘厚在17～26 mm时,分娩率、产活仔数和初生窝重较高;初产母猪和经产母猪产前背膘厚为23～30 mm组的产仔数和产活仔数都显著低于8～14 mm组(P0.05);初产母猪和经产母猪背膘损失在1～4 mm时发情间隔最短,断奶后7 d内发情率最高;初产母猪断奶背膘厚在17～20 mm时,断奶至再配种间隔最短,7 d内发情率和下一胎的配种分娩率最高;经产母猪断奶背膘厚在13～16 mm时,断奶至再配种间隔最短,7 d内发情率和下一胎的配种分娩率最高。表明母猪背膘厚对其产仔性能和断奶发情率有显著影响,配种时和妊娠前期背膘较厚和妊娠后期膘情适中的母猪繁殖性能最强。因此,应针对不同繁殖阶段的母猪采用合理的营养控制方案来调控母猪背膘,从而提高母猪利用率,使其达到最佳生产性能。     

母猪断奶再配间隔的影响因素分析

<正>母猪断奶后再次配种间隔天数是影响母猪繁殖效率的重要因素之一。为了探究影响母猪断奶再配间隔的因素,本文收集了国内某猪场某年的繁殖数据,通过对这些繁殖数据的整理分析,发现母猪品种、分娩胎次、断奶月份、分娩总仔数、哺乳天数皆对其断奶再配间隔有极显著影响。     

断奶至配种间隔时间对杜洛克母猪繁殖性能影响

本试验以杜洛克母猪678窝次的生产繁殖成绩为研究对象,分析断奶至配种间隔时间对母猪繁殖性能影响。结果表明,71.53%的杜洛克母猪在断奶后0-7天发情配种,平均间隔时间为4.64天,平均分娩胎次为3.54胎,产活仔数、总产仔数、断奶仔猪数、21日龄断奶窝重、哺乳成活率都与最高组未形成显著差异。杜洛克母猪繁殖性状间的相关性分析表明,偏相关系数有正有负,相关强度有大有小。其中,断奶至配种间隔天数与其他指标相关性不显著。     

分娩胎次及季节对台系杜洛克母猪繁殖性能影响研究

统计分析了不同胎次及产仔季节对台系杜洛克母猪繁殖性能的影响。结果表明,分娩胎次对台系杜洛克母猪的怀孕天数、健仔数、产活仔数、总产仔数、初生窝重、21日龄断奶总仔猪数、21日龄断奶窝重影响显著或极显著,对配种情期、死胎数、死仔数、寄入仔猪数、寄出仔猪数、21日龄断奶公仔数、21日龄断奶母仔数、哺乳成活率影响不显著。产仔季节对杜洛克母猪的产仔胎次、怀孕天数、健仔数、死胎数、产活仔数、死仔数、总产仔数、寄入仔猪数、初生窝重、21日龄断奶公仔数、21日龄断奶母仔数、21日龄断奶总仔猪数、21日龄断奶窝重影响显著或极显著,对配种情期、木乃伊数、寄出仔猪数、哺乳成活率影响不显著。     

断奶-发情间隔对母猪繁殖性能的影响

为探讨断奶-发情间隔对母猪繁殖性能的影响,提高母猪年生产力,对海南罗牛山万头种猪场2012年8月1日至2013年7月31日全部母猪（161头初产母猪、555头经产母猪）的生产数据进行统计分析。结果表明：1）在良好的饲养管理条件下,初产母猪下一胎的分娩率96.27%和产仔数12.59头均优于经产母猪的90.09%和11.87头,产房良好的饲养管理完全可以克服二胎母猪综合征,提高二胎母猪繁殖性能;2）77.02%初产母猪与77.12%经产母猪集中在断奶后第4、5、6天发情,该阶段发情配种的母猪与其他阶段相比,返情率较低,分娩率最高,产仔情况也最好;3）对经产母猪而言,断奶-发情间隔天数为1~2 d、7~12 d时,降低下一胎的分娩率和产仔数。     

饲养模式对母猪繁殖性能的影响

为了研究不同饲养模式对母猪繁殖性能的影响,试验整理了河南省某公司群养模式下母猪5 625窝和限位栏饲养模式下母猪5 086窝的繁殖记录(包括杜洛克猪、大白猪、长白猪),采用独立样本t检验的方法对不同饲养模式下初产及经产母猪繁殖性能进行了研究。结果表明:在产仔数方面,相比于限位栏饲养模式,经产母猪在群养模式下总产仔数提高了0.63头、产活仔数提高了0.64头、健仔数提高了0.79头、畸形数降低了0.01头(P0.01)。在生长性能方面,相比于限位栏饲养模式,初产母猪在群养模式下所产仔猪平均初生重提高了0.11 kg、断奶仔猪数提高了0.55头、平均断奶重提高了0.46 kg(P0.01);经产母猪在群养模式下所产仔猪初生窝重提高了3.44 kg、平均初生重提高了0.18 kg、断奶仔猪数提高了0.61头、平均断奶重提高了0.59 kg(P0.01)。在杜洛克、长白、大白三个品种之间,初产及经产母猪的产仔数、活仔数、断奶仔猪数、断奶重等各项繁殖相关参数多在群养模式下升高,显现出了一致性。在发情及平均使用胎次方面,群养模式下母猪断奶后再发情间隔缩短了0.77 d(P0.01),年均胎次增多了0.27胎(P0.05)。说明群养模式下,母猪整体繁殖性能及利用率优于限位栏饲养模式,杜洛克、长白、大白初产及经产母猪的繁殖相关参数表现出了相似的变化趋势,且群养模式下母猪初情和初配日龄均有所提前,生产周期更短。     

胎次、配种月份和分娩月份对杜洛克母猪繁殖性能的影响

通过对杜洛克母猪分娩胎次、配种月份和分娩月份产仔数、仔猪初生重等数据进行统计分析,研究影响杜洛克母猪繁殖性能的因素,用以指导实际生产提高养猪场经济效益.通过分析,母猪生产胎次对繁殖性能的影响主要表现在:以3胎母猪产活仔数和健仔数最高、1胎最低,死仔数以2胎最低、7胎最高,且差异均极显著(P<0.01).配种月份的影响主...     

母猪断奶-发情间隔天数对下一胎繁殖性能的影响

本文对巴西一个猪场的15600胎的断奶-发情间隔天数与繁殖成绩的关系进行了母猪统计分析。统计数据包括了母猪断奶-发情间隔天数在21d之内、哺乳天数在13-26d、1-8胎的所有成绩。统计发现，平均断奶-发情间隔天数为4．8d，有6．1％的母猪断奶-发情间隔天数为2d之内。不论初产母猪还是经产母猪，断奶-发情间隔天数在3-5d的母猪返情率最低。在断奶后第二天发情的初产母猪及断奶当天发情的经产母猪返情率最高，分娩率最低。所有母猪，凡断奶-发情间隔天数在0-2d，6-8d，9-12d，13-18d，下一胎的分娩率显著低于（P〈0．05）断奶-发情间隔天数为3-5d的母猪。对初产母猪，断奶-发情间隔天数在6-8d，9-12d，下一胎的产仔数最低。对经产母猪，断奶-发情间隔天数由0-2d增加到3-5d，其下一胎的产仔数显著增加，当断奶-发情间隔天数增加到6-8d时，下一胎的产仔数明显降低，但断奶-发情间隔天数在9-21d时又增加。结论：断奶-发情间隔天数在0-2d和6-12d对下一胎繁殖成绩有不利影响。     

胎次对杜洛克、长白和大白母猪繁殖性能的影响

为了研究胎次对杜洛克、长白和大白母猪繁殖性能的影响,根据江苏省某国家级生猪核心育种场2009-2011年出生的繁殖母猪资料,分别选取128头杜洛克、681头长白和610头大白母猪共7280窝生产数据,统计分析不同胎次母猪的总产仔数、产活仔数、断奶仔猪数、初生窝重及校正21日龄窝重。此外,依据胎次将母猪分为3个繁殖阶段（1～2胎、3～6胎及7～8胎）来探究品种差异对母猪繁殖性能的影响。结果表明：胎次对母猪繁殖性能有显著影响（P<0.05）,母猪1～4胎的总产仔数、产活仔数、断奶仔猪数及初生窝重随胎次呈增加趋势,第4胎达到高峰,且显著高于其他胎次（P<0.05）;3～6胎繁殖性能较好,7胎之后出现迅速下降趋势;除在第4胎略有下降外,其他胎次的校正21日龄窝重随胎次递增。品种对母猪繁殖性能的影响显著（P<0.05）,长白和大白母猪的繁殖性能均极显著高于杜洛克母猪（P<0.01）;长白母猪的产活仔数和校正21日龄窝重显著高于大白母猪（P<0.05）,2个品种其他繁殖性能无显著差异（P＞0.05）。综上所述,杜洛克、长白和大白母猪的最佳繁殖胎次为3～6胎,长白猪的繁殖性能总体上优于大白猪,就本试验所在的育种场而言,长白猪可能更适合作为二元母猪生产中的母本。     

胎次和配种季节对长白、大白母猪繁殖性能的影响

为了分析不同胎次、配种季节对母猪繁殖性能的影响,笔者对江西省赣州市某猪场2015年长白母猪、大白母猪的繁殖记录进行统计分析,并按胎次及配种季节进行分组,分析其在不同胎次、配种季节条件下的繁殖性能差异。结果表明:长白母猪和大白母猪3~5胎繁殖性能较好,第1胎的初生均重、断奶均重最低;长白母猪第3胎窝产活仔数最高,显著高于1,2,6,7,8胎(P0.05);大白母猪第4胎窝产活仔数最高,显著高于第1,2胎(P0.05);长白母猪夏季配种窝产仔数、窝产活仔数最高,初生均重、断奶均重春季配种最高;大白母猪不同季节配种窝产仔数差异不显著(P0.05),夏季、秋季配种产活仔数显著高于冬季(P0.05)。说明不同胎次、配种季节对长白、大白母猪繁殖性能有较大影响。     

Consequences of variation in weaning-to-estrus interval on reproductive performance of swine females

Frequency distribution of females according to weaning-to-estrus interval (WEI) was evaluated in a database containing 15,600 breeding records of one Brazilian farm. The consequences of WEI duration on the reproductive performance was evaluated, emphasising on the effect of very short WEI (0 to 2 days). Only females with WEI up to 21 days, lactation length of 13 to 26 days and parity 1 to 8 were included in the analyses. The average WEI was 4.8 days and the percentage of females showing estrus within 2 days after weaning was 6.1%. In both primiparous (PO 1) and multiparous females (PO > 1) those with WEI of 3–5 days showed the lowest return to estrus rate. The highest RER and the lowest FR were observed when estrus occurred on the day after weaning, for primiparous sows, and on the day of weaning, for multiparous sows. In both parity classes, WEI of 0–2, 6–8, 9–12 and 13–18 days resulted in FR lower (P < 0.05) than those observed for WEI of 3–5 days. In PO 1 females, the lowest subsequent litter size (SLS) was observed in those with WEI of 6–8 and 9–12 days (P < 0.05). In PO > 1 females SLS increased significantly from WEI 0–2 to WEI 3–5 days, it decreased in females with WEI of 6–8 days and increased again in females with WEI of 9 to 21 days. A negative effect of WEI on reproductive performance is clear in females with very short WEI (0–2 days) and in those with WEI of 6–12 days.     

Reproductive Performance of Purebred Swedish Landrace and Swedish Yorkshire Sows: I. Seasonal Variation and Parity Influence

The objective of this retrospective study was to investigate the causes of variation in the reproductive performance of purebred Swedish Landrace (L) and Swedish Yorkshire (Y) sows. Data analysed comprised farrowings from 1994 through 1997 from 19 Swedish nucleus herds and included 20 275 litters from 6989 purebred sows (3598 L and 3491 Y). The main traits analysed were litter size, weaning-to-first-service interval (WSI), farrowing rate, remating rate and age at first farrowing. Analysis of variance was used for the statistical analysis of quantitative data. Logistic regression analysis was applied for binary data using the GLIMMIX macro in the SAS program. Factors included in the analyses were breed of sow, breed of boar, parity number, herd-year combination within breed, mating type (natural mating or artificial insemination), lactation length and month of the year. L sows, compared with Y sows, produced larger litters [11.61 vs 11.54 total born/litter (ns) and 10.94 vs 10.58 born alive/litter (P<0.001)] and had a longer WSI (5.5 vs 5.4 days, P<0.001), a higher farrowing rate (82.8 vs 80.9% units, P<0.05) and a lower remating rate (6.2 vs 8.8% units, P<0.001). On average, L sows were younger at first farrowing than Y sows (355.6 vs 368.6 days, P<0.001). The seasonal influence on WSI was greater for primiparous sows than for multiparous sows. Primiparous sows weaned from June to October had a longer WSI than those weaned from January to May or in November (P<0.05). Mating in August resulted in the lowest farrowing rate and the highest remating rate. The seasonal influence on farrowing rate and WSI was more pronounced in Y sows than in L sows. However, season had no significant influence on litter size in either L or Y sows.     

Evidence that oxidative stress is higher in replacement gilts than in multiparous sows

The recent success obtained in term of increasing the litter size of sows has not correlated with a reduction of replacement rate. There is thus an increased economic demand for gilts with optimal reproductive potential and longevity. Unfortunately, replacement gilts are known to be more susceptible to diseases and less productive than multiparous sows. Interestingly, reproductive performance, resistance to diseases and longevity could all be largely affected by oxidative stress. To investigate whether oxidative stress conditions could account for the poor longevity of gilts, three distinct groups of conventional Yorkshire × Landrace sows were formed based on their similar age and parity (gilts, second parity sows as well as fourth to fifth parity sows). All animals were slaughtered during the post‐ovulatory period, and blood as well as tissue samples were collected. Biomarkers of oxidative damage to proteins (carbonyls) and DNA (8‐OHdG) were analysed in samples. Specific mRNA expression of major antioxidants such as glutathione peroxidases 1, 3 and 4 (GPx1, GPx3, GPx4) as well as superoxide dismutases 1 and 2 (Sod1, Sod2) were monitored in liver and kidney samples by quantitative RT‐PCR. Specific enzymatic activities of both GPx and SOD were measured by spectrophotometric assays. The plasma concentration of protein carbonyls was significantly different between the three groups with the highest concentration being observed in gilts (p ≤ 0.001). The mRNA expression levels of GPx1 and GPx4 were also significantly increased in the liver of gilts when compared to multiparous sows (p ≤ 0.05). SOD2 enzymatic activity was found to be higher in the liver of gilts than multiparous sows (p ≤ 0.05). Taken together, these results indicate that replacement gilts sustain significantly higher oxidative conditions than multiparous sows. Current findings may contribute to the design of nutritional regimens that will increase the productivity of gilts by counteracting oxidative stress.     

An assessment of reproductive and lifetime performances of Kagoshima Berkshire gilts and sows

We investigated the reproductive and lifetime performances of Kagoshima Berkshire gilts and sows. We examined 20 605 parity records of 4419 pigs for 2008 to 2012 on a farrow‐to‐finish commercial farm. The mean parity (± SD) of all animals was 3.0 ± 2.1. For farrowing performance, the highest numbers of total pigs born and pigs born alive were found in sows with parities 5 and 6 and with parity 3–6, respectively (P < 0.05). Regarding weaning and mating performance, sows with parity 2 had the lowest preweaning mortality (P < 0.05). The longest weaning‐to‐first‐mating interval was found in parity 1 pigs, and the interval decreased as parity increased (P < 0.05). Parities 0 and 1 pigs had the lowest farrowing rate and those with parity 4 had the highest farrowing rate (P < 0.05). The mean parity at culling, total number of pigs born alive in a lifetime, and nonproductive days in a lifetime were 5.5 ± 2.93, 49.2 ± 24.72 pigs, and 132.1 ± 83.34 days, respectively. These animals had a lower litter size and fertility that the F₁ crossbred sows mainly used in Japan, but a similar tendency for performance by parity.     

Lactation feed disappearance and weaning to estrus interval for sows fed spray-dried plasma

Four experiments involving 265, 410, 894, and 554 sows (Exp. 1 to 4, respectively) were conducted to determine the effect of spray-dried plasma (SDP) at 0 or 0.25% (Exp. 1 and 2) and 0 or 0.50% (Exp. 3 and 4) in lactation diets on average daily feed disappearance (FD), sum of sow BW, fetal and placental loss from d 110 gestation to weaning (SWL), litter size at weaning, litter weight at weaning, and average days from weaning to first estrus (WEI). Experiments 1, 3, and 4 were conducted during summer months, and Exp. 2 was conducted during fall to winter months. Experiment 1 used only parity 1 and parity 2 sows and Exp. 4 used only mature (>2 parities) sows, whereas Exp. 2 and 3 used all parity groups. Sows fed SDP in Exp. 1 had increased (P < 0.01) FD and a tendency for reduced (P = 0.06) SWL and WEI (P = 0.06). Sows fed SDP in Exp. 2 had a tendency for increased (P = 0.09) sow BW at weaning and reduced (P = 0.09) SWL, whereas other variables were not different between diets. Parity 1 and 2 sows fed SDP in Exp. 3 had increased (P < 0.01) FD, but mature sows fed SDP had reduced (P = 0.02) FD. Pig survival and litter size at weaning for all parity groups was not different between diets. The WEI for parity 1 sows fed SDP was reduced (P = 0.02) and tended to be reduced (P = 0.10) for mature sows fed SDP, but was not different between diets for parity 2 sows. More parity 1 sows fed SDP were detected (P = 0.01) in estrus 4 to 6 d after weaning, and fewer were detected (P < 0.01) in estrus 6 d after weaning compared with control parity 1 sows. In Exp. 4, FD was reduced (P < 0.01) for mature sows fed SDP; however, litter weight and average pig BW at weaning was increased (P < 0.01) with more (P < 0.01) marketable pigs (pig BW > 3.6 kg) weaned per litter. Relatively low dietary levels of SDP (0.25 to 0.50%) fed to parity 1 sows farrowed during summer months increased lactation FD and reduced WEI. Mature sows fed SDP during summer months consumed less lactation feed without compromising WEI, but had an increased litter weight, average pig BW, and number of marketable pigs at weaning.     

A regional evaluation of injections of high levels of vitamin A on reproductive performance of sows

A regional study involving 443 litters from 182 sows was conducted at 5 cooperating experiment stations to determine the effects of an i.m. injection of vitamin A at weaning and breeding on subsequent litter size of sows. Sows were assigned to 1 of 3 treatments given at weaning and again at breeding: 1) a placebo i.m. injection (2 mL of corn oil), 2) i.m. injection with 250,000 IU of vitamin A (1 mL of vitamin A palmitate in oil), and 3) i.m. injection with 500,000 IU of vitamin A (2 mL of vitamin A palmitate in oil). Corn-soybean meal diets in gestation were formulated to contain 13% CP and 0.60% total Lys. Lactation diets were formulated to contain 17% CP and 0.90% Lys. A common vitamin-mineral premix that supplied 11,000 IU of vitamin A/kg of diet (as-fed) was used by all stations. As expected, station effects were noted for many response measures. Analysis of the data also revealed both treatment x station and treatment x parity interactions for litter size responses. The treatment x parity interactions were stronger than the treatment x station effects, and when the litter size response was separated into early parity sows (parity 1 and 2) and late-parity sows (parity 3 to 6), the treatment x station interactions were no longer present in either subgroup. For sows of parity 1 and 2, litter sizes were increased linearly (P 相似文献   

Interactions between the associations of parity, lactation length, and weaning-to-conception interval with subsequent litter size in swine herds using early weaning

Sixteen farms having an average lactation length between 14.9 and 18.9 days were selected based upon producers' willingness to keep records of production and lactation feed intake. Data contained 9162 subsequent litter-size records abstracted from computerized production information-system files and lactation feed-intake records. Two-way interactions between the associations of parity and lactation length, and parity and weaning-to-conception interval with subsequent litter size were found in the same statistical model. Subsequent litter size did not increase in parities 1 and 2 as lactation length increased – but subsequent litter size in sows of parities 3–6 increased. In only parity 1, sows with weaning-to-conception interval 6–12 days produced 0.5 fewer pigs at subsequent farrowing than those with weaning-to-conception interval 1–5 days. However, in multiparous sows, no difference in subsequent litter size was found between weaning-to-conception intervals 1–5 and 6–12 days.     

苏太猪不同胎次繁殖性能的比较分析

本试验对苏太母猪核心群不同胎次的繁殖性能进行比较,并对后备猪的初生重、35日龄断奶重、4月龄重和6月龄重等早期生产性能与后期繁殖性能之间的关系进行分析,旨在进一步了解苏太猪的繁殖性能,为苏太后备母猪的选种提供指导。结果表明,第1胎产仔数最少,成活率最低,第4胎成活率最高,至第3胎达较高水平并一直稳定保持至第6胎,第3胎的繁殖性能可以作为淘汰母猪的重要依据。后备猪35日龄断奶重与4月龄重、6月龄重都呈极显著正相关,4月龄重和6月龄重间也具有极显著正相关关系,苏太后备母猪早期生产性能与后期繁殖性能没有显著相关,选择35日龄断奶重小的母猪留种更加经济。     

Effects of genetic line and supplemental dietary fat on lactation performance of Duroc and Landrace sows.

A total of 124 Duroc and 99 Landrace primiparous and multiparous sows were assigned, within breed and contemporary group, to control (N) or 10% added fat (F) diets on d 105 of gestation based on parity and genetic line (control or selected for improved sow productivity), to determine the effects of genetic line and fat addition to the lactation diet on sow and litter performance. Weekly feed intake was not affected (P greater than .10) by genetic line for Duroc and Landrace sows but feed intake was reduced (P = .08) during wk 1 to 4 for Duroc sows and during wk 1 and 4 for Landrace sows (P less than .05) when they were fed diet F compared with diet N. Select (S)-line Duroc and Landrace sows lost more weight during lactation (P less than .01) than did control (C)-line sows. Select-line Landrace sows lost more backfat during lactation (P less than .05) than did C-line sows. Landrace sows lost less weight during lactation (P less than .05) when fed diet F than when fed diet N. The total number of pigs born, born alive, and alive at 21 d and at weaning were higher (P less than .01) for S-line Duroc sows, and litter size at 21 d and at weaning was higher (P less than .01) for S-line Landrace sows than for C-line litters within each breed. Pig survival from birth to weaning was increased (P = .07) for Duroc sows fed diet F but not for Landrace sows.(ABSTRACT TRUNCATED AT 250 WORDS)