杂交狼尾草饲喂怀孕早期母猪的效果试验

此试验设4个组,即对照组和试验Ⅰ、Ⅱ、Ⅲ组,对照组喂基础饲粮(含粗纤维3.94%),试验Ⅰ组、试验Ⅱ组、试验Ⅲ组分别用杂交狼尾草2、4、6kg/d(按10%折合成干物质)等量替代部分配合饲料,3个试验组饲粮中粗纤维含量分别为6.37%、8.81%和11.24%,进行怀孕早期母猪(妊娠期前60天)的饲养试验,设6次重复,参试长大母猪140头次。结果表明,试验Ⅰ组、试验Ⅱ组和试验Ⅲ组的分娩率、窝产仔数和窝产活仔数与对照组相比均有不同程度的提高,分娩率提高2.07～3.54个百分点,窝产仔数增加0.76～1.49头,窝产活仔数增加0.88～1.71头,以试验Ⅲ组效果最好。     

EM制剂对母猪繁殖性能的效果研究

采用配对设计 ,将 2 0头繁殖母猪随机分为试验组和对照组 ,试验组从空怀至分娩用EM发酵饲料替代 2 0 %的基础日粮 ,对照组始终喂基础日粮。结果表明 :产仔数、产活仔数、初生窝重试验组比对照组分别提高 2 5 .2 5 %、2 9.79%、2 8.99% ,差异极显著 (P <0 .0 1) ;初生重、2 0日龄窝重、断奶重、断奶窝重和断奶仔猪数试验组比对照组分别提高8.91%、4 .76 %、18.0 0 %、12 .79% ,但差异不显著 (P >0 .0 5 )。     

妊娠母猪的精细管理及其调控

母猪饲养包括空怀、配种、妊娠、哺乳、离乳相互紧密关联的不同生理阶段,其中妊娠阶段时间最长,约占整个繁殖周期75%左右,妊娠期的饲养管     

以母猪胎盘效率为指标的产仔数选择效果研究

本文通过对长大二元杂母猪胎盘效率与总产仔数、产活仔数等的相关关系分析,进行了基于高低胎盘效率的产仔数选择效果研究.结果表明①按胎盘效率分组,胎盘效率高(6.70)、中(5.30)和低(5.00)的长大二元杂母猪,其窝均产仔数分别为12.68±2.76、10.58±2.33和9.12±2.80;窝产活仔数相应分别为10.70±2.76、10.08±2.70和8.88±2.03;三个组的胎盘效率差异均极显著(P＜0.01).②用杜洛克公猪的精液作人工授精后,长大二元杂母猪高胎盘效率组(6.12±0.40)的总产仔数(12.75±0.45对10.78±0.52)、活产仔数(12.20±0.23对10.20±0.58)均极显著高于低胎盘效率组(5.13±0.37)(P＜0.01).     

以母猪胎盘效率为指标的产仔数选择效果研究

本文通过对长大二元杂母猪胎盘效率与总产仔数、产活仔数等的相关关系分析,进行了基于高低胎盘效率的产仔数选择效果研究。结果表明:①按胎盘效率分组,胎盘效率高(6.70)、中(5.30)和低(5.00)的长大二元杂母猪,其窝均产仔数分别为12.68±2.76、10.58±2.33和9.12±2.80;窝产活仔数相应分别为10.70±2.76、10.08±2.70和8.88±2.03;三个组的胎盘效率差异均极显著(P<0.01)。②用杜洛克公猪的精液作人工授精后,长大二元杂母猪高胎盘效率组(6.12±0.40)的总产仔数(12.75±0.45对10.78±0.52)、活产仔数(12.20±0.23对10.20±0.58)均极显著高于低胎盘效率组(5.13±0.37)(P<0.01)。     

空怀母猪饲喂金霉素对繁殖性能的影响研究

对21－25天断奶的120头空怀母猪饲喂15％的金霉素250mg/kg至配种，结果表明，饲喂金霉素的A组120头母猪与对照B组的120头母猪比较，断奶至再配种时间间隔不明显，但情期受胎率提高4．1％，产仔率提高5．8％；窝产活仔数提高0．25头，金霉素提高母猪繁殖性能效果明显。     

EM发酵饲料对母猪产仔性能的影响

将 2 0头繁殖母猪随机分为试验组和对照组 ,试验组从空怀至分娩用EM发酵饲料替代 2 0 %的基础日粮 ,对照组始终喂基础日粮。结果产仔数、产活仔数、初生窝重 ,试验组比对照组分别提高 2 5 2 5 %、2 9 78%、2 8 99% ,差异极显著 (P <0 0 1)初生重提高 2 5 6% ,差异不显著 (P >0 0 5 )。     

提高母猪繁殖力的技术措施

提高母猪繁殖力关键是提高母猪年产仔窝数和母猪窝产活仔数。 1 提高母猪年产仔窝数 1.1 缩短母猪的哺乳期 首先实行仔猪早期断奶。试验证明,仔猪28d断奶与35d断奶相比,28d断奶对母猪断奶后的发情时间和断奶后仔猪发育无不良影响,对于个别窝仔猪开料 早,发育较好的仔猪可采取23～24日龄断奶的办法。其次是实行分批断奶。对于体质瘦弱的母猪和后备猪实行提前断奶,保证这些母猪断奶后及时发情配种。     

不同施肥处理的杂交狼尾草打浆后饲喂育肥猪效果研究

试验设计4个处理3个重复,开展不同施肥处理的杂交狼尾草打浆后饲喂育肥猪效果研究.4个处理为:处理Ⅰ(CK)只饲喂肥育猪的基础日粮,处理Ⅱ为基础日粮+浇灌沼液的牧草浆0.25kg/头.d,处理Ⅲ为基础日粮+浇灌沼液的牧草浆0.5kg/头.d,处理Ⅳ为基础日粮+浇灌沼液并加施尿素的牧草浆0.5kg/头.d.结果表明,处理Ⅱ、Ⅲ、Ⅳ平均日增重分别比处理Ⅰ提高了22.4g,40.4g和48.4g,料肉比分别比处理Ⅰ降低了4.62%、3.96%和7.26%,每头猪效益分别比处理Ⅰ提高了26.0元、34.3元和44.6元,猪肉氨基酸含量也比处理Ⅰ有不同程度的提高,尤其以添加增施尿素的牧草浆后,肥育猪的日增重、料肉比和经济效益都最好.     

不同施肥处理的杂交狼尾草打浆后饲喂育肥猪效果研究

试验设计4个处理3个重复,开展不同施肥处理的杂交狼尾草打浆后饲喂育肥猪效果研究。4个处理为：处理Ⅰ（CK）只饲喂肥育猪的基础日粮,处理Ⅱ为基础日粮＋浇灌沼液的牧草浆0.25kg/头.d,处理Ⅲ为基础日粮＋浇灌沼液的牧草浆0.5kg/头.d,处理Ⅳ为基础日粮＋浇灌沼液并加施尿素的牧草浆0.5kg/头.d。结果表明,处理Ⅱ、Ⅲ、Ⅳ平均日增重分别比处理Ⅰ提高了22.4g,40.4g和48.4g,料肉比分别比处理Ⅰ降低了4.62%、3.96%和7.26%,每头猪效益分别比处理Ⅰ提高了26.0元、34.3元和44.6元,猪肉氨基酸含量也比处理Ⅰ有不同程度的提高,尤其以添加增施尿素的牧草浆后,肥育猪的日增重、料肉比和经济效益都最好。     

Compensatory feeding during early gestation for sows with a high weight loss after a summer lactation increased piglet birth weight but reduced litter size

Sows mated in summer produce a greater proportion of born-light piglets (<1.1 kg) which contributes to increased carcass fatness in the progeny population. The reasons for the low birth weight of these piglets remain unclear, and there have been few successful mitigation strategies identified. We hypothesized that: 1) the low birth weight of progeny born to sows mated in summer may be associated with weight loss during the previous summer lactation; and 2) increasing early gestation feed allowance for the sows with high lactational weight loss in summer can help weight recovery and improve progeny birth weight. Sows were classified as having either low (av. 1%) or high (av. 7%) lactational weight loss in their summer lactation. All the sows with low lactational weight loss (LLStd) and half of the sows with high lactational weight loss received a standard gestation feeding regime (HLStd) (2.6 kg/d; day 0–30 gestation), whereas the rest of the sows with high lactational weight loss received a compensatory feed allowance (HLComp) (3.5 kg/d; day 0–30 gestation). A comparison of LLStd (n = 75) versus HLStd sows (n = 78) showed that this magnitude of weight loss over summer lactation did not affect the average piglet or litter birth weight, but such results may be influenced by the higher litter size (P = 0.030) observed in LLStd sows. A comparison of HLStd versus HLComp (n = 81) sows showed that the compensatory feeding increased (P = 0.021) weight gain of gestating sows by 6 kg, increased (P = 0.009) average piglet birth weight by 0.12 kg, tended to reduce (P = 0.054) the percentage of born-light piglets from 23.5% to 17.1% but reduced the litter size by 1.4 (P = 0.014). A subgroup of progeny stratified as born-light (0.8–1.1 kg) or -normal (1.3–1.7 kg) from each sow treatment were monitored for growth performance from weaning until 100 kg weight. The growth performance and carcass backfat of progeny were not affected by sow treatments. Born-light progeny had lower feed intake, lower growth rate, higher G:F, and higher carcass backfat than born-normal progeny (all P < 0.05). In summary, compensatory feeding from day 0 to 30 gestation in the sows with high weight loss during summer lactation reduced the percentage of born-light progeny at the cost of a lower litter size, which should improve growth rate and carcass leanness in the progeny population born to sows with high lactational weight loss.     

Effects of dietary glucose level during late gestation on litter performance and glucose concentration in sows

The effects of feeding glucose during the 5 days before parturition on litter performance and on glucose concentration in sows were studied. At day 100 of gestation, 130 multiparous sows were assigned to the treatments. Late gestating sows were fed 0 g, 150 g, 250 g, 350 g and 450 g of glucose a day, respectively. During lactation, all sows were given free access to the same lactation diet (without glucose). One day before parturition, blood samples were collected from 30 sows (6 sows per treatment) at 10 before and 20, 40, 60 and 80 min after the meal. The supply of additional dietary glucose increased piglet birth weight ( P  < 0.05). Feed intake in week 1 and week 1–4 of lactation was greatest in sows fed the 0% glucose diet, least by sows fed the 18% glucose diet, and intermediate by sows fed the 6, 10, 14% glucose diets ( P  < 0.05). Basal glucose concentration and time of maximum glucose concentration after glucose intake were not affected by dietary treatment in the last 5 days of gestation. The sows fed the 14 and 18% glucose diets had greater maximum increase in glucose concentration than sows fed diet without glucose ( P  < 0.05). In conclusion, feeding glucose to sows during 5 days before parturition increased birth weight of live-born piglet and decreased sows feed intake during lactation, but did not affect the performance of sows and piglets.     

复合有机铁对母猪繁殖性能及其抗氧化能力的影响

为研究复合有机铁对母猪繁殖性能、血液理化指标及抗氧化能力的影响,试验选用体重接近、胎次接近、预产期一致的健康“长×白”二元杂母猪30头,随机分为3组,每组10个重复,每个重复1头母猪,3个处理组分别在基础日粮中补充硫酸亚铁、甘氨酸亚铁、复合有机铁。结果显示:较硫酸亚铁组,复合有机铁组产程缩短23.57%、胎产健仔数增加14.00%、初生窝重增加14.14%(P < 0.05);母猪血红蛋白含量、红细胞数和红细胞压积分别提高19.88%、10.53%、8.33%(P < 0.05);母猪抗氧化酶活性和机体抗氧化能力提高47.33%(P < 0.05),丙二醛含量降低37.05%(P < 0.05)。综上所述,母猪日粮中额外补充复合有机铁源能提高母猪繁殖性能,改善血液理化指标,增强母猪抗氧化能力。     

不同粗纤维水平日粮对妊娠母猪生殖激素水平的影响

为研究不同粗纤维水平日粮对妊娠母猪生殖激素水平的影响,选用30头胎次、配种时间及体况均相近的经产PIC配套系父母代母猪,随机分成5组,妊娠期间分别饲喂含3%、5%、7%、9%和11%的苜蓿草粉粗纤维日粮,通过调节各组的饲喂量,使其所摄入的能量、蛋白、钙、磷等水平基本一致。3%为对照组,日粮中不另加粗纤维。研究结果显示:提高日粮中粗纤维水平会降低妊娠各阶段母猪雌二醇的浓度,但增加妊娠后期孕酮和催乳素的浓度,且当日粮中粗纤维含量达到9%时效果最佳。     

外源激素对紫穗狼尾草愈伤组织诱导及分化的影响

以紫穗狼尾草(Pennisetum alopecuroides)幼芽基部为外植体,研究了外源激素对其愈伤组织诱导及分化的影响,筛选适宜的激素种类及浓度配比,为狼尾草无性系抗性育种奠定基础。结果表明,2,4 D对愈伤组织诱导的作用最显著,生长素NAA和KT的作用相近,均以0.5~1.0 mg·L-1为宜;NAA对愈伤组织分化的作用较明显,以0.5~1.0 mg·L-1与3.0 mg·L-16 BA配合效果最佳,KT的作用不明显。最佳诱导培养基为MS+2,4 D 3.0 mg·L-1+NAA 1.0 mg·L-1 +KT 1.0 mg·L-1;最佳分化培养基为MS+NAA 0.5 mg·L-1 +6 BA 3.0 mg·L-1。     

Thermoregulatory and physiological responses of nonpregnant,mid-gestation,and late-gestation sows exposed to incrementally increasing dry bulb temperature

Gestating sows may be more susceptible to increasing dry bulb temperatures (T_DB) due to greater metabolic heat production and increased body mass, especially as gestation advances. However, there are few studies on the thermoregulatory and physiological responses of sows at differing gestation stages exposed to gradually increasing temperatures. The study objective was to determine the thermoregulatory and physiological responses of nonpregnant (n = 12; parity 3.27 ± 0.86), mid-gestation (59.7 ± 9.6 d pregnant, n = 12; parity 3.25 ± 0.83), and late-gestation (99.0 ± 4.8 d pregnant, n = 12; parity 3.33 ± 0.75) sows exposed to increasing T_DB. Prior to the experiment (5.0 ± 0.7 d), jugular catheters were placed in all sows. During the experiment, the T_DB was increased incrementally by 2.45 ± 0.43 °C every 60 min from 19.84 ± 2.15 to 35.54 ± 0.43 °C over 400 min, and relative humidity was recorded at 40.49 ± 18.57%. Respiration rate (RR), heart rate (HR), skin temperature, and vaginal temperature were measured, and blood samples were obtained via the jugular catheter every 20 min. Data were analyzed using PROC MIXED in SAS 9.4. RR increased at a lower T_DB (P < 0.01) in late-gestation sows compared with mid-gestation and nonpregnant sows, but no differences were detected between mid-gestation and nonpregnant sows. Overall, late-gestation sows had greater RR (P < 0.01; 23 ± 2 breaths per min [brpm]) compared with mid-gestation (16 ± 2 brpm) and nonpregnant (15 ± 2 brpm) sows. Late-gestation sows had an overall greater HR (P < 0.01; 84 ± 5 beats per min [bpm]) than mid-gestation (76 ± 5 bpm) and nonpregnant (69 ± 5 bpm) sows. Late-gestation sows had overall reduced bicarbonate and total carbon dioxide levels (P = 0.02; 23.89 ± 1.97 and 25.41 ± 2.07 mmol/L, respectively) compared with mid-gestation (27.03 ± 1.97 and 28.58 ± 2.07 mmol/L, respectively) and nonpregnant (26.08 ± 1.97 and 27.58 ± 2.07 mmol/L, respectively) sows. Moreover, late-gestation sows had overall greater nitric oxide levels (P < 0.01; 248.82 ± 34.54 µM) compared with mid-gestation (110.47 ± 34.54 µM) and nonpregnant (41.55 ± 34.54 µM) sows. In summary, late-gestation sows appear to be more sensitive to increasing T_DB as indicated by thermoregulatory and physiological responses when compared with mid-gestation or nonpregnant sows. The results from this study provide valuable information regarding thermoregulatory thresholds of sows at differing gestation stages.     

饲粮中添加苹果渣对妊娠母猪粪便及繁殖性能的影响

本试验旨在研究饲粮中添加苹果渣对妊娠母猪粪便和繁殖性能的影响。选用胎次、体况相近,健康状况良好的妊娠母猪(长白×大约克)80头,随机分为2组(对照组和试验组),每组40个重复,每个重复1头母猪。对照组和试验组母猪在妊娠第1~89天分别饲喂妊娠母猪饲粮A(不含苹果渣)和妊娠母猪饲粮B(含10%苹果渣),在妊娠第90天至分娩当天分别饲喂哺乳母猪饲粮A(不含苹果渣)和哺乳母猪饲粮B(含5%苹果渣)。试验自妊娠开始,试验期为1个妊娠周期。结果表明：1)饲粮中添加苹果渣后,母猪排便通畅,粪量增加,粪色深黑,粪形呈筒状,可堆积成形,这说明苹果渣的添加缓解了妊娠母猪便秘的发生;2)饲粮中添加苹果渣对产仔数、产活仔数、初生窝重、初生个体均重的影响不显著( P>0.05),但极显著降低了母猪的便秘发生率( P<0.01),试验组比对照组降低35%。由此可见,饲粮中添加苹果渣可极显著降低妊娠母猪的便秘发生率,但对其繁殖性能没有显著影响。     

不同苜蓿草粉水平对初产母猪生产和繁殖性能的影响

为了探讨初产母猪的后备期、妊娠期饲粮中不同比例的苜蓿草粉,对其生长性能和繁殖性能的影响,试验选用640头日龄110 d、体重45 kg左右的健康后备母猪(长×大),采用单因子完全随机设计,分为4个处理,分别为:对照组(0%草粉组)、5%草粉组、10%草粉组、15%草粉组,每个处理4个重复,每个重复40头猪。妊娠期选取增重和发情较好的5%草粉组后备期母猪,发情配种后分为对照Ⅰ组(0%草粉组)、10%草粉组、15%草粉组、20%草粉组,后备期对照组母猪继续作为妊娠期的对照组,共5个处理,每个处理4个重复,每个重复3头猪。结果表明:1)在后备期45~70 kg阶段,试验组的采食量均低于对照组,随着苜蓿草粉用量的增加,采食量依次下降;5%草粉组的日增重显著高于、料重比显著低于10%和15%草粉组(P<0.05),但与对照组无显著差异;3个试验组中,只有5%草粉组的增重成本低于对照组,且使用苜蓿草粉愈多,成本愈高。在后备期70~130 kg阶段,无论是采食量还是日增重,3个试验组均低于对照组,随着草粉用量增加,采食量和日增重均依次下降,其中10%和15%草粉组显著低于对照组(P<0.05),但与5%草粉组差异不显著;3个试验组的料重比和增重成本均高于对照组,且有随着苜蓿草粉用量增加而依次增加的趋势,其中15%草粉组显著高于对照组(P<0.05)。添加5%的苜蓿草粉对母猪发情率有改善,但各组之间差异不显著。2)在妊娠期阶段,草粉组的背膘增厚显著高于对照组和对照Ⅰ组(P<0.05);对照Ⅰ组和10%、15%、20%苜蓿草粉组的初生活仔率均显著高于对照组,初生窝重分别比对照组提高了14.88%、6.89%、12.31%、24.48%,弱仔率分别降低了53.44%、36.39%、87.37%、62.78%,尽管均未达到显著差异程度,但说明后备期饲粮中使用苜蓿草粉对妊娠期母猪产仔数及仔猪健康有良好的后续效应,后备期用5%苜蓿草粉妊娠期使用20%苜蓿草粉效果最佳。综合得出,后备期添加5%的苜蓿草粉不会影响后备母猪生长但会提高发情率,后备期添加5%草粉妊娠期不添加时,母猪的繁殖效果也得到改善;妊娠期添加20%的苜蓿草粉产活仔率和初生窝重最佳。     

Effects of different gestation housing types on reproductive performance of sows

This study evaluated the effects of different gestation housing types on reproductive performance of sows. A total of 60 sows (218 ± 24 kg body weight) with mixed parity were used. During gestation, 28 sows were housed in groups with electronic sow feeders (space allowance = 1.26 m²/sow) and 32 sows were housed in individual stalls (space allowance = 1.20 m²/sow). Sows from both housing types were moved to farrowing crates on day 109 of gestation and stayed until weaning (18 days post‐farrowing). Typical corn‐soybean meal diets were provided to sows during gestation and lactation. Measurements were reproductive performance of sows at farrowing as well as performance of sows and their litter during lactation. Similar total numbers of piglets born at farrowing were observed for sows gestated in both housing types. However, group‐housed gestation sows had more mummies (0.321 vs. 0.064; P < 0.05) and stillbirths (0.893 vs. 0.469; P = 0.073) at farrowing than individual‐housed gestation sows. Consequently, individual‐housing type had higher percentage of piglets born alive (95.5 vs. 90.4%; P < 0.05) than the group‐housing type. Therefore, improved reproductive performance of sows from individual gestating housing was confirmed in this study.     

Effects of dietary resveratrol supplementation during gestation and lactation of sows on milk composition of sows and fat metabolism of sucking piglets

The purpose of this article was to investigate the effects of dietary resveratrol supplementation during gestation and lactation of sows on the milk composition of sows and the fat metabolism of sucking piglets. Forty sows were allotted to two experimental treatment groups that included the following: (a) control sows (CON treatment, n = 20) fed with a corn–soybean meal control diet and (b) treatment sows (RES treatment, n = 20) fed with a control diet with addition of 300 mg/kg resveratrol. The results showed that the content of lactose in the colostrum was increased (p < 0.05) and the content of fat in 21‐day milk was increased (p < 0.05) by dietary resveratrol supplementation. In the RES treatment group, the concentrations of high‐density lipoprotein‐cholesterol (HDL‐C), low‐density lipoprotein‐cholesterol (LDL‐C), lipase activity and insulin (INS) in plasma of sucking piglets were increased (p < 0.05). In the adipose tissue, the enzyme activities of hormone‐sensitive lipase (HSL), acetyl‐CoA carboxylase (ACC) and lipoprotein lipase (LPL) increased significantly by RES treatment (p < 0.05), and the mRNA levels of acetyl coenzyme A‐alpha (ACCα), LPL, fatty acid transport protein (FATP1) and CCAAT–enhancer‐binding protein gene (C/EBPα) were higher in the RES treatment group (p < 0.05). In conclusion, resveratrol supplementation on gestational and lactating sows improved the content of lactose in the colostrum and the content of fat in milk at day 21 of lactation. In addition, resveratrol supplementation on sows increased HDL and LDL in the plasma of piglets. In piglet adipose tissue, the enzyme activity and mRNA level related to lipolysis, fatty acid uptake from circulating triacylglycerols and lipogenesis are partially improved by resveratrol supplementation on sows. These aspects affect fat metabolism in piglets.