品种、进群和配种季节、首配日龄对后备母猪繁殖性能的影响

为探究品种、进群和配种季节、首配日龄对后备母猪繁殖性能的影响,本研究观察并记录了1 656头后备母猪的繁殖情况,分别按照品种、进群季节、配种季节、首配日龄将其分组,并进行组间统计分析。结果表明：①长白后备母猪的配种利用率（89.73%）极显著（P<0.01）高于大白后备母猪（75.00%）和长大二元杂后备母猪（80.57%）;长大二元杂后备母猪的窝均总仔数（11.36）极显著（P<0.01）高于大白后备母猪（10.35）,显著（P<0.05）高于长白后备母猪（10.74）;②春季和冬季进群的长大二元杂后备母猪配种利用率（100.00%、100.00%）极显著（P<0.01）高于夏季（71.89%）和秋季（51.47%）,同时夏季也极显著（P<0.01）高于秋季;秋季配种的长大二元杂后备母猪受胎分娩率（86.21%）分别显著（P<0.05）和极显著（P<0.01）低于春季（94.07%）和冬季（97.42%）;③长大二元杂后备母猪首配日龄在211~230 d组的窝均活仔数（9.30）显著（P<0.05）低于231~250 d（10.15）和251~270 d（10.36）组,并且极显著（P<0.01）低于271~290 d（10.48）组;211~230 d组的窝均合格仔数（8.96）显著（P<0.05）低于231~250 d（9.82）组,极显著（P<0.01）低于251~270 d（10.04）和271~290 d（10.21）组。综合试验结果,长白后备母猪的配种利用率较好,长大二元杂后备母猪的产仔性能较好。长大二元杂后备母猪在春、冬季节进群时配种利用率较好,在秋季配种时受胎分娩率较差;且其首配日龄在211~230 d时产仔性能较低,在211~290 d时产仔性能较高。     

饲粮中添加柠檬酸对母猪产程和抗氧化能力的影响

试验旨在研究妊娠后期饲粮中添加柠檬酸(citric acid,CA)对母猪背膘厚、产仔数、平均产仔间隔、产程、抗氧化能力和血钙的影响。选择体况相近、妊娠90 d的健康二元(长×大)母猪30头,按背膘厚度和预产期相近原则随机分为2组,每组15头母猪。对照组母猪饲喂基础饲粮,处理组母猪饲喂基础饲粮+10 g/kg CA。试验时间为妊娠90 d至分娩当天。结果显示:与对照组相比,处理组母猪平均产仔间隔显著缩短(P0.05),母猪分娩产程有缩短趋势(0.05≤P0.10);处理组母猪血清中总抗氧化能力显著提高(P0.05)、丙二醛含量显著降低(P0.05),总超氧化物歧化酶、谷胱甘肽过氧化物酶、过氧化氢酶活性和血钙浓度有提高的趋势(0.05≤P0.10)。研究表明,CA能够提高妊娠母猪的抗氧化能力和血钙浓度,缩短平均产仔间隔和产程。     

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。     

分娩与断奶背膘厚度对猪繁殖性能的影响研究

为研究母猪分娩与断奶时背膘厚度对繁殖性能的影响,使用A超测定母猪分娩及断奶时的背膘厚度,根据分娩时背膘厚度将试验动物分为1组（X＜10 mm）、2 组（10 mm≤X≤14 mm）、3 组（X＞14 mm）,根据断奶时背膘厚度将试验动物分为A组（X＜7 mm）、B组（7 mm≤X＜10 mm）、C组（10 mm≤X＜13 mm）、D组（13 mm≤X＜16 mm）、E组（X≥16 mm）,又根据母猪哺乳期间损失的背膘厚度分为Ⅰ组（X＜3 mm）、Ⅱ组（3 mm≤X≤6 mm）、Ⅲ组（X＞6 mm）,用方差分析比较各组繁殖表现,并建立了发情间隔对背膘厚度的回归方程。结果表明,分娩时产死胎母猪的比例2组是10.5%,在3组中最小;断奶后平均发情间隔C组显著低于其他各组(P＜0.05);哺乳期间背膘损失最大的Ⅲ组母猪平均发情间隔为8 d,显著高于Ⅰ组、Ⅱ组(P＜0.05)。表明分娩与断奶背膘厚对母猪繁殖性能有显著影响,膘情适中的母猪有最好的繁殖表现,并建立了回归方程Y=31.787－6.169X +0.440X²－0.009X³,用于预测母猪发情配种日期。     

妊娠期背膘厚对母猪产程及繁殖性能的影响

为优化母猪繁殖效率,探究妊娠期不同背膘厚对母猪繁殖性能和分娩产程的影响,本研究以广西某公司2 969头大白母猪和1 787头长白母猪为试验群体,收集2017年1月至2017年10月妊娠期3个阶段(妊娠30、80和107 d)背膘厚与分娩接产记录数据,分析背膘厚与分娩产程、总产仔数、产活仔数和初生窝重等性状的关系。研究结果表明,大白母猪分娩产程时间显著短于长白母猪(P<0.05),大白母猪总产仔数、产活仔数和初生窝重显著优于长白母猪(P<0.05)。在妊娠30 d时,背膘厚在18～20 mm组的大白母猪总产仔数和产活仔数最高,且初生窝重最大;背膘厚在18～20 mm组的长白母猪总产仔数和产活仔数最高。在妊娠80 d时,背膘厚≥20 mm组的大白母猪总产仔数和产活仔数最高,且初生窝重最大、产程最短;背膘厚在16～18 mm组的长白母猪总产仔数和产活仔数最高,且初生窝重较高、母猪产程较短。在妊娠107 d时,背膘厚在14～16 mm组的大白母猪总产仔数和产活仔数最高,且初生窝重最大,但母猪产程与其他组差异不显著(P>0.05);背膘厚≥20 mm组的长白母猪总产仔数和产活仔数最高,且初生窝重较大。妊娠期背膘厚减少1～2 mm的大白母猪,其总产仔数和产活仔数最高,初生窝重较小,产程较长。而背膘厚减少>2 mm的长白母猪,其总产仔数和产活仔数最高,初生窝重较大,产程较短。上述试验结果说明,在母猪妊娠期间,合适的背膘厚可有效提高母猪繁殖性能和母猪分娩期间的福利水平。养殖场可以根据营养配方和猪群品种建立背膘数据库,通过精准饲喂将母猪背膘厚调整至最佳范围,同时合理控制妊娠期背膘变化。     

猪饲养管理中应注意的几个问题

1母猪产仔时间如果母猪在晚上产仔，给管理带来很多不便。使用氯前列烯醇钠可以达到控制分娩时间的目的，但是注射时间、注射部位是关键的问题。前列烯醇钠一般采用肌肉注射，注射时间却没有具体说明。但是实践证明，前列烯醇，注射时间掌握在下午6点钟，注射部位选择皮下注射效果好，98％母猪可以在注射后第2天分娩，一般注射后20小时产仔。母猪阴部注射，用量1毫升（这个部位可以减少用量），见效快。     

妊娠期背膘厚对母猪产程及繁殖性能的影响

为优化母猪繁殖效率,探究妊娠期不同背膘厚对母猪繁殖性能和分娩产程的影响,本研究以广西某公司2 969头大白母猪和1 787头长白母猪为试验群体,收集2017年1月至2017年10月妊娠期3个阶段(妊娠30、80和107 d)背膘厚与分娩接产记录数据,分析背膘厚与分娩产程、总产仔数、产活仔数和初生窝重等性状的关系。研究结果表明,大白母猪分娩产程时间显著短于长白母猪(P0.05),大白母猪总产仔数、产活仔数和初生窝重显著优于长白母猪(P0.05)。在妊娠30 d时,背膘厚在18～20 mm组的大白母猪总产仔数和产活仔数最高,且初生窝重最大;背膘厚在18～20 mm组的长白母猪总产仔数和产活仔数最高。在妊娠80 d时,背膘厚≥20 mm组的大白母猪总产仔数和产活仔数最高,且初生窝重最大、产程最短;背膘厚在16～18 mm组的长白母猪总产仔数和产活仔数最高,且初生窝重较高、母猪产程较短。在妊娠107 d时,背膘厚在14～16 mm组的大白母猪总产仔数和产活仔数最高,且初生窝重最大,但母猪产程与其他组差异不显著(P0.05);背膘厚≥20 mm组的长白母猪总产仔数和产活仔数最高,且初生窝重较大。妊娠期背膘厚减少1～2 mm的大白母猪,其总产仔数和产活仔数最高,初生窝重较小,产程较长。而背膘厚减少2 mm的长白母猪,其总产仔数和产活仔数最高,初生窝重较大,产程较短。上述试验结果说明,在母猪妊娠期间,合适的背膘厚可有效提高母猪繁殖性能和母猪分娩期间的福利水平。养殖场可以根据营养配方和猪群品种建立背膘数据库,通过精准饲喂将母猪背膘厚调整至最佳范围,同时合理控制妊娠期背膘变化。     

妊娠后期营养水平对初产母猪繁殖性能及血液生化指标的影响

为研究妊娠后期营养水平对初产母猪体况、繁殖性能及血液生化指标的影响,本试验选用背膘厚及体重相近的初产杂交母猪36头,按体况和配种时间随机分为3组（Ⅰ、Ⅱ、Ⅲ组）,每组6个重复,每个重复2头母猪,饲喂营养水平依次为维持需要的1.5、2.0和2.5倍的日粮,母猪妊娠81 d时开始试验至母猪分娩结束,试验期33 d。结果显示,分娩时Ⅰ组母猪背膘厚显著低于Ⅲ组（P<0.05）,断奶时各组背膘厚度差异不显著（P>0.05）;Ⅰ组母猪泌乳期背膘损失显著低于Ⅲ组（P<0.05）;Ⅲ组母猪分娩后体重、分娩前体重均显著高于Ⅰ组（P<0.05）,各组母猪妊娠81 d体重及泌乳期失重等差异均不显著（P>0.05）。试验组间窝产仔数、窝产活仔数、断奶个体重及母猪断奶-发情间隔均无显著差异（P>0.05）;Ⅲ组仔猪初生均重、断奶窝重、泌乳期窝增重均显著高于Ⅰ组（P<0.05）。随营养水平升高,Ⅱ、Ⅲ组雌激素水平显著高于Ⅰ组（P<0.05）;各组催乳素和孕酮水平差异不显著（P>0.05）;Ⅰ组甘油三酯水平显著低于Ⅱ、Ⅲ组（P<0.05）;各组尿素氮和葡萄糖含量随营养水平的升高逐渐增大,且差异显著（P<0.05）;Ⅲ组胰岛素含量显著高于I组（P<0.05）;各组总蛋白含量无显著差异（P>0.05）。结果提示,母猪妊娠后期饲喂营养水平为2.0倍维持需要的日粮时可使后备母猪分娩时体况达到标准水平,而饲喂营养水平为2.5倍维持需要的日粮可使母猪产仔性能得到提高。     

不同屠宰体重对苏山猪屠宰性能、胴体性状和肉品质的影响

试验旨在探讨不同屠宰体重对苏山猪屠宰性能、胴体性状和肉品质的影响,从而确定苏山猪最佳屠宰体重。选用60头30 kg左右的苏山猪,公母各半,随机分成A、B、C组,每组20头,平均体重分别达到90、100、110 kg时,每组选取3头公猪、3头母猪进行屠宰性能、胴体性状和肉品质测定。结果表明：随着苏山猪屠宰体重的增加,各组屠宰性能存在较大差异,A组瘦肉率为63.18%,显著高于B、C组（P<0.05）;C组板油重、肩部最厚处背膘厚、倒数第3~4肋骨处背膘厚显著高于A组（P<0.05）;3个处理组屠宰率、皮率、骨率以及脂肪率等指标无显著差异（P>0.05）;3个处理组背最长肌水分、粗蛋白质、粗脂肪无显著差异（P>0.05）,但A组的粗灰分显著高于B、C组（P<0.05）;B组肌肉L^*值为43.50,显著高于C组（P<0.05）,C组pH_{1 h}和pH_{24 h}分别为6.40和5.83,显著（P<0.05）或极显著（P<0.01）高于A、B组。随屠宰体重增长肌肉内饱和脂肪酸和单不饱和脂肪酸呈上升趋势,多不饱和脂肪酸呈下降趋势,其中C组饱和脂肪酸显著高于A组（P<0.05）;A组总氨基酸、必需氨基酸和鲜味氨基酸均高于B、C组,但差异均未达到显著水平（P>0.05）。因此,综合考虑,苏山猪的最佳屠宰体重为90 kg左右。     

定时输精对经产母猪繁殖性能及生殖激素的影响

试验旨在建立高效的经产母猪定时输精（timed artificial insemination,TAI）技术,研究了定时输精对经产母猪繁殖性能、断奶-分娩间隔、不同胎次母猪产仔性能及断奶后7 d内血清生殖激素水平的影响。选取309头2~8胎次二元（长×大）经产母猪,随机分为对照组和试验组,对照组母猪进行常规人工授精（artificial insemination,AI）,试验组母猪进行断奶后24 h注射PMSG 1 000 IU,间隔72 h注射GnRH 100 μg,在注射GnRH后24和40 h各输精1次的定时输精技术。通过统计两组母猪的断奶1周内发情率、受胎率、分娩率、窝均产仔数等,判断定时输精对经产母猪繁殖性能的影响;通过对断奶时间和分娩时间的统计,检测定时输精对经产母猪断奶-分娩间隔的影响;用放射免疫（RIA）方法检测2~4胎次母猪断奶1周内血清E₂、LH、FSH和P₄的含量,研究定时输精对母猪生殖激素的影响。结果显示,试验组母猪发情率显著高于对照组（P<0.05）,但两组间受胎率、分娩率差异不显著（P>0.05）,窝均产仔数、窝均合格仔数和繁殖效率有增加的趋势,但差异不显著（P>0.05）;定时输精显著缩短了母猪的断奶-分娩间隔（P<0.05）。在胎次方面,3~4胎母猪使用定时输精的效果较好,其发情率、受胎率和分娩率均显著高于对照组（P<0.05）。在生殖激素方面,试验组E₂水平在注射PMSG后迅速上升,且在定时输精处理后66~96 h内持续高于对照组（P<0.05）,试验组P₄水平在断奶后至配种前显著低于对照组（P<0.05）,但配种后快速升高,并高于对照组;LH和FSH的含量在两组间无显著差异。综上,定时输精可有效提高经产母猪的断奶发情率,并减少其非生产天数,可显著提高3~4胎母猪的繁殖性能。     

Multiple oxytocin application increases the predictability of prostaglandin induced farrowing in swine

In a large Croatian commercial unit, 1204 of parity 2-7 late pregnant sows were from January till Mai 2002 randomly assigned to four farrowing groups and treated as follows: Group one (n = 302 sows) received a single perivulvar injection of 175 g cloprostenol at day 113 of pregnancy. The remaining animals have received a treatment as group one and were additionally treated with 10 IU of oxytocin intramuscularly 6 hours after prostaglandin application (Group two, n = 311), or with 10 IU of oxytocin 6 and 12 hours later (Group three, n = 291), or 10 IU of oxytocin 6, 12 and 18 hours later (Group four, n = 300). Onset of farrowing, duration of parturition, total born litter size and stillbirth rate were evaluated. Except total born litter size, combined oxytocin + cloprostenol treated sows revealed significantly (p < 0.01) better results as the only with cloprostenol treated ones. Multiple oxytocin application increased the predictability of farrowing. The application of multiple oxytocin injections following prostaglandin partusinduction are recommended for batch farrowing of sows in large production units.     

饲粮添加吡咯喹啉醌对围产期母猪繁殖性能和抗氧化功能的影响

本试验旨在比较吡咯喹啉醌(PQQ)与维生素E和有机硒对围产期母猪繁殖性能和抗氧化功能的影响。选用40头体重和背膘厚接近且妊娠90 d的第3胎大约克母猪,随机分为2组,每组20头。对照组在基础饲粮中添加60 mg/kg维生素E和0.20 mg/kg有机硒,试验组在基础饲粮中添加1 mg/kg PQQ。试验期为妊娠第90天至分娩后第7天。结果表明:与对照组相比,饲粮添加PQQ对母猪产程、产仔数、产活仔数及仔猪初生窝重、仔猪平均初生重以及产后7 d仔猪平均日增重均无显著影响(P0.05),但数值上有所升高;饲粮添加PQQ显著提高了初生仔猪和母猪血清总超氧化物歧化酶、谷胱甘肽过氧化物酶活性及还原型谷胱甘肽含量(P0.05),显著降低了血清丙二醛含量(P0.05),对血清过氧化氢酶活性、总抗氧化能力及氧化型谷胱甘肽含量均无显著影响(P0.05)。综合得出,围产期饲粮中添加PQQ较维生素E和有机硒对母猪繁殖性能无显著影响,能显著增强围产期母猪及初生仔猪的血清抗氧化功能。     

Effect of Lactation Diet Fat Level on Sow and Litter Performance

The primary objective of this study was to determine the effects of supplemental dietary fat during lactation on sow BW, sow backfat thickness, sow feed consumption, litter size, and pig growth rate. Dietary treatments included 0, 3, 6, and 9% supplemental low acid yellow fat in a traditional corn-soybean meal basal lactation diet. A total of 160 Landrace and crossbred sows (approximately 40 per treatment) were included in the study. Sows fed 3 and 6% supplemental fat had greater (P<0.10) average backfat thickness at weaning. Sow weight change and feed consumption were inconsistent among dietary fat levels. Dietary fat level during lactation did not affect number of pigs born alive or number of stillborns. However, the 9% fat level was associated with more mummified pigs at birth. Number of pigs weaned was greater for the 0% supplemental fat than for the 9% fat level. The largest average pig weights at 21 (5.8±0.29 kg) and 28 (7.48±0.38) d of age were those from sows fed the 3% added fat diet. Sows with ≤25.4 mm backfat at farrowing had more pigs born alive (P<0.05), had less backfat at 21 and 28 d of lactation (P<0.05), and consumed more feed during wk 2 and 3 of lactation. Of all sows fed the control diet, sows with >25.4 mm backfat at farrowing consistently had heavier pigs throughout the lactation phase (P<0.05). Backfat loss during lactation was lower (P<0.05) for sows with ≤25.4 mm at farrowing within all dietary treatments. Consistent significant differences were not observed in sow weight loss or feed consumption between low and high backfat sows for each dietary treatment. Sow backfat loss during lactation is dependent on body condition at farrowing, in that, fatter sows at farrowing have greater backfat loss during lactation. Sows with ≤25.4 mm of backfat at farrowing responded to added dietary fat treatments and produced heavier pigs throughout the lactation period.     

母猪妊娠末期背膘厚度对产仔性能和胎盘脂质氧化代谢的影响

本试验旨在探讨母猪妊娠末期背膘厚度对产仔性能和胎盘脂质氧化代谢的影响,以探索母猪妊娠期脂肪沉积与繁殖性能的关系。本试验度量了846头经产大白母猪妊娠第109天时的背膘厚度,并分为3组,背膘厚度≤18 mm的为第1组(母猪192头),背膘厚度为19~22 mm的为第2组(母猪265头),背膘厚度≥23 mm的为第3组(母猪389头)。记录母猪分娩后的产仔性能,测定胎盘组织中脂质、氧化产物水平及抗氧化酶活性。结果表明:1)尽管母猪妊娠末期背膘厚度对总产仔数、产活仔数及木乃伊数无显著影响(P0.05),但显著影响了死胎数、初生窝重、初生头重和胎盘效率(P0.05)。其中,第2组的初生头重、初生窝重及胎盘效率显著高于其他2组(P0.05);第2组的死胎数显著低于第1组(P0.05),与第3组差异不显著(P0.05)。值得注意的是,母猪妊娠末期背膘厚度显著影响每窝初生重≤0.9 kg的仔猪数和每窝初生重≤1.0 kg的仔猪数(P0.05),第3组的每窝初生重≤0.9 kg的仔猪数和每窝初生重≤1.0 kg的仔猪数均显著高于其他2组(P0.05)。2)在第3组的胎盘组织中,不仅甘油三酯(TG)、低密度脂蛋白胆固醇(LDL-C)及游离脂肪酸(FFA)的水平显著高于其他2组(P0.05),而且丙二醛(MDA)和活性氧(ROS)水平也显著高于其他2组(P0.05),同时超氧化物歧化酶(SOD)活性显著低于其他2组(P0.05)。3)妊娠末期母猪胎盘组织中ROS水平与总产仔数、初生窝重及胎盘效率呈显著负相关(P0.05),而MDA水平与总产仔数呈显著负相关(P0.05)。由此可知,母猪妊娠末期背膘厚度与产仔性能密切相关。妊娠末期维持背膘厚度在19~22 mm,母猪可获得较高的产仔性能;背膘厚度≤18 mm时,会增加死胎数;而背膘厚度≥23 mm时,会引起胎盘组织中脂质过度沉积,从而加剧胎盘氧化应激的发生。     

Comparison of three methods of feeding sows in gestation and the subsequent effects on lactation performance

A total of 684 sows from breeding groups over 6 wk was used to compare three methods of feeding during gestation on gestation and lactation performance. Control gilts and sows were fed according to body condition based on a scale of 1 to 5 (1 = thin, 5 = fat). Sows were visually assessed for body condition at breeding and were assigned a daily feed allowance to achieve a BCS of 3 at farrowing. Treatment 2 used feeding levels based on backfat thickness (measured between d 0 and 5 after breeding) and weight at weaning for sows or service for gilts. Feed allowance was calculated to achieve a target backfat of 19 mm at farrowing, and remained constant from d 0 to 101 of gestation. Feed allowances were based on modeled calculations of energy and nutrient requirements to achieve target sow maternal weight and backfat gains. Treatment 3 was identical to Treatment 2, except that feeding pattern was altered for thin sows and gilts (<15 mm at service) in an attempt to reach 19 mm by d 36 of gestation. Sows were weighed at the previous weaning, and gilts were weighed at service, with both weighed again between d 112 and 114 of gestation. Backfat was measured between d 0 and 5, and again between d 108 and 113 of gestation. At farrowing, sows on Treatments 2 and 3 had 19 and 19.1 mm of backfat, respectively, whereas control sows tended to have greater (P < 0.07) backfat (20 mm). On average, sows targeted to gain 6 to 9 mm of backfat failed to reach target gains regardless of feeding method. Feeding sows in gestation based on backfat (Treatments 2 and 3) resulted in a numerically higher proportion of sows in the target backfat range of 17 to 21 mm (40.2, 53.3, and 52.6% for control and Treatments 2 and 3, respectively) at farrowing and a numerically lower percentage of fat sows (>21 mm), but no difference in the percentage of thin sows (<17 mm) compared with feeding based on body condition. In conjunction with this observation, sows fed based on BCS were fed higher (P < 0.05) feeding levels in gestation than were sows fed based on backfat depth. Gestation feeding method had no effect on performance during lactation. Feed intake in lactation was lower (P < 0.05) for high backfat sows (>21 mm) at farrowing compared with sows with <21 mm. The high proportion of sows in the optimal backfat category demonstrates that feeding based on backfat and BW has potential for facilitating more precise feeding during gestation.     

羟甲基丁酸钙盐对妊娠后期-哺乳期母猪繁殖性能、乳成分及仔猪生长性能的影响

文章旨在评估日粮中添加羟甲基丁酸钙盐对妊娠后期到哺乳期母猪繁殖性能、乳成分及仔猪生长性能的影响.试验选择32头胎次接近的二元母猪,随机分为2组,每组4个重复,每个重复4头猪.对照组母猪在妊娠后期和哺乳期饲喂基础日粮,处理组母猪在妊娠和哺乳期饲喂基础日粮+8?mg/kg羟甲基丁酸钙,试验从分娩前6?d到仔猪21?d断奶....     

Effect of dosage of cloprostenol on induction of farrowing and body temperature of sows

In an experiment involving 161 farrowings, cloprostenol was injected on day 112 or 113 of gestation at the recommended dosage (175 μg) or a lower dosage (125 μg). Cloprostenol treatment did not result in abnormally high body temperatures of sows at parturition. Farrowing began within 29 hours of injection in 94% and 88% of the sows treated with 175 μg and 125 μg cloprostenol respectively, as compared to 15% of saline-injected controls. The duration of farrowing and number stillborn were not affected by treatment. Sows farrowing within 19 hours of treatment tended to have a large number of piglets and a higher body temperature postpartum.