母猪卧向行为学的观察

本文通过2个试验对母猪在分娩圈和分娩栏中的卧向行为进行了观察,试验一中, 选择10头大白(Yorkshire)经产母猪作为观察对象,试验二中分别选择10头大白(Yorkshire) 经产母猪和10头长白(Landrace)经产母猪作为观察对象。观察采用瞬时记录方法,每周观察 三次,隔日观察,每天上午、下午各观察一次,每次3 h,每次观察间隔5 min。观察中发现,母猪 卧向以向外为主。分娩栏(四周是栏杆)中的母猪以选择卧向外(向北)为主,其次是卧向内(向 南),卧向左和卧向右最少且差异不显著,上栏前和下栏后差异不显著。分娩圈(四周是墙壁)中 母猪以选择卧向外为主,卧向内最少,卧向左和卧向右差异不显著。长白母猪比大白母猪选择 卧向外的多,妊娠阶段比哺乳阶段选择卧向外的多。     

中草药验方对乏情母猪繁殖性能的影响

试验选择由卵巢机能失调、子宫炎、阴道炎为主要原因引起的乏情母猪,通过中草药制剂和西药促性腺激素进行催情治疗的效果比较。证实了中草药验方对乏情母猪具有较好的提高繁殖性能的作用。     

丁酸梭菌对哺乳母猪繁殖性能、免疫和抗氧化功能的影响

本试验旨在研究丁酸梭菌对哺乳母猪免疫和抗氧化的影响,选取健康经产长白母猪32头(胎次和预产期相近),随机分为4组,每组8个重复,每个重复1头.对照组饲喂基础日粮,试验组分别在基础日粮基础上添加250、500、1000 mg/kg丁酸梭菌.预试期7 d,试验期为28 d(产前7 d至21 d断奶).结果 表明:哺乳第1天...     

Dietary fiber in a low-protein diet during gestation affects nitrogen excretion in primiparous gilts,with possible influences from the gut microbiota

We investigated the effects of dietary fiber (DF) supplementation in normal or low crude protein (CP) diets on reproductive performance and nitrogen (N) utilization in primiparous gilts. In total, 77 Landrace × Yorkshire pregnant gilts were randomly allocated to four dietary treatments in a 2 × 2 factorial design. The groups comprised 1) equal intake of normal CP (12.82% and 0.61% total lysine), 2) low CP (LP) (10.53% and 0.61% total lysine), and 3) with or 4) without DF supplementation (cellulose, inulin, and pectin in a 34:10:1 ratio). A low-protein diet during gestation significantly reduced daily weight gain from days 91 to 110 of pregnancy (−162.5 g/d, P = 0.004). From N balance trials conducted at days 35 to 38, 65 to 68, and 95 to 98 of pregnancy, DF addition increased fecal N excretion at days 65 to 68 (+24.1%) and 95 to 98 (+13.8%) of pregnancy (P < 0.05) but reduced urinary N excretion (P < 0.05), resulting in greater N retention at each gestational stage. DF increased fecal microbial protein levels and excretion during gestation. An LP diet also reduced urinary N excretion at different gestational stages. An in vitro fermentation trial on culture media with nonprotein N urea and ammonium bicarbonate (NH₄HCO₃) as the only N sources revealed that microbiota derived from feces of gestating gilts fed the high DF diet exhibited a greater capacity to convert nonprotein N to microbial protein. Microbial fecal diversity, as measured by 16S rRNA sequencing, revealed significant changes from DF but not CP diets. Gilts fed an LP diet had a higher number of stillbirths (+0.83 per litter, P = 0.046) and a lower piglet birth weight (1.52 vs. 1.37 kg, P = 0.006), regardless of DF levels. Collectively, DF supplementation to gestation diets shifted N excretion from urine to feces in the form of microbial protein, suggesting that the microbiota had a putative role in controlling N utilization from DF. Additionally, a low-protein diet during gestation negatively affected the litter performance of gilts.     

Free-range system and supplementation of 25-hydroxicholecalciferol increases the performance and serum vitamin levels in mixed-parity sows

Improvements in sow productivity have raised questions regarding dietary vitamin D recommendations. The present study aimed to evaluate the effects of the housing system with access to sunlight exposure and supplementation of 25-hydroxicholecalciferol on performance and serum levels of 25(OH)D₃ in sows during gestation and lactation. Sows were distributed in an experimental design with two housing systems: gestation crates or gestation free-range system with external area for sunlight exposure; and two diets: 0 or 50 μg of 25-hydroxicholecalciferol kg⁻¹. The use of 25-hydroxicholecalciferol tended (P = 0.052) to improve total born and influenced (P = 0.046) on number of born alive. Litter weight at birth was also increased (P = 0.01) by 25-hydroxicholecalciferol supplementation; 25-hydroxicholecalciferol supplementation and housing system (free-range with sunlight exposure) tended to increase weaning weight (P = 0.07) and litter daily gain (P = 0.051) during lactation. Exposure to sunlight and 25-hydroxicholecalciferol supplementation increased 25(OH)D₃ serum levels when compared with control treatment during gestation (136.95 vs. 113.92 ng mL⁻¹; P = 0.035) and lactation (120.29 vs. 88.93 ng mL⁻¹; P = 0.026). In conclusion, the association of 25-hydroxicholecalciferol supplementation with exposure to sunlight during gestation improved significantly 25(OH)D₃ serum levels and consequently performance traits in gestation and lactation.     

超额储备后备母猪的运作模式——非洲猪瘟背景下集团化养猪企业的盈利之道

集团猪场代表行业最高技术、管理及现代化水平,迅速发展。特别是2018年非洲猪瘟疫情在我国暴发后,在高风险、高回报的行业背景下,集团化养猪企业凭借资金、人才、技术、硬件设施等优势,采取超额储备种猪的运作模式,进而迅速扩张。超额储备的本质是利用资金充足、场区数量、生物安全等优势,通过统一使用长白或大白公猪配种,育肥场用作种猪场等方式超额储备后备母猪。个别场区清场后可以迅速引种补栏,多余后备母猪、妊娠母猪正常出售回收资金。这种模式可有效降低风险、保证足够盈利,同时在非洲猪瘟疫情的背景下有效整合农业资源、利用商业资金反哺养猪业,指引养猪行业走向。     

胚胎移植方法和受体母猪因素对克隆猪生产效率的影响

【目的】建立高效的胚胎移植技术体系,以提高克隆猪的生产效率。【方法】比较不同移植方法和不同受体母猪状况的胚胎移植分娩率和克隆猪的出生效率,利用体外发育能力相似的不同品种和发育阶段的克隆胚胎混合移植确定最佳的受体母猪发情同期时间。【结果】克隆胚胎经由输卵管伞移植比输卵管打孔移植具有更高的移植分娩率和克隆猪效率（2.2% 和0.4%,P＜0.01）,而胚胎移植后辅助人工授精会降低克隆效率（0.6% 和 2.2%,P＜0.01）。利用经产母猪作为移植受体比青年猪受体具有更高的克隆效率（3.0%和0.8%,P＜0.01）和平均窝产仔数（（5.5±0.7）头和（2.7±0.3）头,P＜0.05）。受体母猪发情时间比胚胎激活时间晚12-36 h组的克隆效率分别为显著（P＜0.05）和极显著（P＜0.01）,高于晚0 h和早12-24 h 组的克隆效率（2.0%、0.5%和0%）。最佳的受体母猪发情时间为晚于克隆胚胎激活后24 h,克隆效率达3.0%。【结论】选择自然发情时间晚于克隆胚激活后24 h的经产母猪为受体,通过输卵管伞端移植胚胎,能够获得较高的克隆效率,是猪克隆胚胎移植的较理想方法。     

三种地板类型对母猪肢蹄健康的影响

为探索饲养母猪适宜的地板类型,跟踪分析3 600头母猪在3种地板模式下肢蹄部健康状况的影响。结果表明:使用新型复合材料开放式地板的母猪肢蹄健康状态最好,母猪肢蹄部病变比例为17.87%;半开放式混凝土地板加三合土地板次之,母猪肢蹄部病变为23.67%;限位饲养全混凝土地板较差,母猪肢蹄部病变为30.44%。试验数据说明,利用全漏缝新材料复合地板在自由采食饲养管理方式作用下,能够改善母猪肢蹄部健康状况的新思路、新方法是有效的、可行的。     

Barium selenate as a slow-release selenium preparation to pigs

Pregnant sows were injected subcutaneously (s.c.) or intramuscularly (i.m.) with a barium selenate suspension (0.5–1.0 mg Se/kg body weight (b.w.)) and together with control animals fed a commercial diet. No response to the injection was seen either in blood selenium levels or in glutathione peroxidase (GSH-Px) activity in the sows. There was, however, a significant difference in these parameters between piglets born from treated dams and control animals. This status was maintained during the nursing period. In another experiment pigs (20 kg b.w.) on a Se-deficient diet were injected s.c. and i.m. with barium selenate (2.5 mg Se/kg b.w.). The treated groups maintained their blood levels of selenium and GSH-Px activity, although the selenium values in the group treated intramuscularly started to decline after 4 weeks. Organ samples from both groups were equal with regard to selenium at the time of slaughter while the control group showed a rapid decline both in blood selenium levels and GHS-Px activity.     

猪卵泡形成中后期卵母细胞发育和闭锁变化的超微结构研究

本文采用了电镜观察猪卵泡形成中后期卵母细胞(OC)的超微结构,其结果有两种变化:一是进行性变化,其核在排出第一极体以前,都处于生发泡阶段。细胞质内含大量脂滴(Li),线粒体(Mi)和内质网(ER)囊泡集群分布于近皮质区;随OC 的增大,皮质颗粒(CGs)的直径、分布密度都增加,但膜距减少。微绒毛(MV)数量、直径和长度逐渐变少、变粗、变短,极少见到高尔基复合体(Go)。颗粒细胞(GC)逐渐老化。二是闭锁变化,其核膜皱折,染色质浓缩,Mi 互相融合并出现空泡。ER 囊扩大融合,Li 减少,核蛋白体和糖元颗粒不清,卵膜皱缩,与透明带间出现大的裂隙。GC 质中出现空泡,核膜破裂。GC 数量减少,严重的完全消失。统计分析表明,卵泡直径5mm 时其闭锁率最高。