牛羊胎儿过大综合征的研究进展

牛、羊的胚胎在囊胚阶段之前,暴露 于各种特殊环境,妊娠后能导致过大胎儿的 产出,并有可能伴随出现胎儿多个器官功能 的缺陷,此称为胎儿过大综合征。最近几年, 全世界范围内在实施胚胎移植、克隆等这些 需要对胚胎进行多种体外操作的项目中,已 有相当数量的过大或畸形胎牛、胎羊出生。 对于某项具体的胚胎工程项目而言,胎儿过 大综合征发生率从0%～100%,这就极大地 限制了胚胎体外生产、核移植等繁育新技术 在畜牧业上的大规模应用。文章从该综合征 的临床表现、产生的原因、发生时间及导致其 发生的分子机制等几个方面,简要综述了近 几年国外有关胎儿过大综合征的研究与报 道。     

母体日粮低能量对后代肉仔鸡生长性能、胴体品质和肉质的影响

本文旨在研究母体日粮低能量对后代肉仔鸡生长性能、胴体品质及肉质的影响.试验选用低脂系肉种鸡120羽,随机分成2组,每组60个重复,每个重复1羽,即单笼饲养.在肉种鸡产蛋期产蛋率达到5%进行试验处理,试验分试验组和对照组,试验组代谢能量为对照组的80%孵化后的肉仔鸡按照母体不同能量处理各挑选健康仔鸡,在相同的试验条件下进行饲养,试验期为56 d.结果表明:1)与对照组相比,母体日粮低能量有降低1日龄肉仔鸡体重的趋势,对全期日增重和料重比影响不显著(P＞0.05);2)与对照组相比,母体日粮低能量对后代肉仔鸡胸肌和腿肌的水分、脂肪和蛋白质含量,胸肌率和腹脂率均无显著影响(P＞0.05),但显著增加腿肌率(P＜0.05);3)与对照组相比,母体日粮低能量对后代肉仔鸡胸肌和腿肌的pH、红度、黄度、滴水损失和蒸煮损失均无显著影响(P＞0.05),但pH、红度和黄度值有升高趋势,滴水损失和蒸煮损失有降低趋势,胸肌和腿肌剪切力显著降低(P＜0.05);4)与对照组相比,母体日粮低能量显著提高后代肉仔鸡胸肌和腿肌肌纤维密度(P＜0.05),显著降低后代肉仔鸡胸肌和腿肌肌纤维直径(P＜0.05).本试验的研究结果表明:母体日粮低能量对后代肉仔鸡的胴体品质及肉质能产生一定的影响.     

Assessment of reproduction and growth performance of offspring derived from somatic cell cloned pigs

Since cloned pig was successfully produced, a new opportunity for porcine breeding industry to conserve genetic resources has been opened. However, there has been no report to investigate whether both somatic cell nuclear transfer (SCNT) pigs and their offspring have the characteristics of the donor breed. In this study, we compared the reproductive and growth performance of American Large White boars cloned by SCNT with the donor boar, and analyzed the test parameters, including semen quality, re‐service rate, rate of parturition, and average daily gain. The results showed that these cloned boars and the donor boar had no significant differences in the tests (P > 0.05) and the growth performance of their offspring was similar to the naturally bred American Large White pigs. In summary, the reproductive and growth performance of cloned pigs are similar to the donor pig and within the normal range. This suggests that pigs cloned by SCNT have the potential to be used in reproduction and breeding.     

Periconceptional undernutrition increases quantity and quality of oocyte population,but not cognitive or emotional response of 60‐day‐old lambs

Maternal periconceptional undernutrition is associated with altered development and increased risks of adverse outcomes in the offspring. The aim of this work was to determine the effect of periconceptional undernutrition on behavioural and reproductive aspects of the offspring. Fifty ewes were synchronized in oestrus (day 0) and allocated to two groups (n = 25) to be fed diets that provided 1.5 (C) or 0.5 (L) times the requirements for maintenance until day 15. Ewes were mated and fed the control diet from day 16 until lambing. Two months after lambing, 26 lambs were exposed to tests to determine their cognitive/emotional responses. Six ewe lambs were euthanized and in vitro oocyte maturation and fertilization procedures performed. The experimental diets produced no changes of mean live weight (LW) of C ewes, L ewes presenting a reduction in their initial LW with significant differences at day 15, in comparison with C ewes (p < 0.05). L ewes experienced a significant reduction in their body condition (BC) in comparison with C ewes (p < 0.05). Fourteen days after the onset of the experimental diets, mean LW and BC of L ewes was significantly lower than those of C ewes (p < 0.05). Undernourished ewes presented a trend to a reduction of prolificacy and fecundity (p < 0.10) in comparison with C ewes. Emotional and cognitive test revealed a similar response between groups. Ewe lambs from the undernourished ewes presented a population of oocytes 1.7 times higher than ovaries from control ewe lambs (66.0 ± 0.73 vs. 113.7 ± 15.6 oocytes; p < 0.05) and had more oocytes in the ‘good’ (p < 0.05) and ‘healthy’ (p < 0.05) categories. In conclusion, a low plane of nutrition around conception significantly increases quantity and quality of the oocyte population of 60‐day‐old female descendants. Modifications of the cognitive and emotional responses of the progeny have not been evidenced.     

Melatonin supplement induced the hair follicle development in offspring rex rabbits

Previous studies have shown that the administration of melatonin (MT) to early post-natal fur-bearing animals increases the numbers of hair follicles (HFs). In this study, the effect of maternal MT supplementation on the HF development in offspring was investigated. To explore the potential underlying mechanisms, the expression of the melatonin receptor 1A (MTNR1A) gene was determined in the offspring. The Rex rabbit was the animal model, and 79 same-day-pregnancy females were randomly assigned to either a control (n = 39) or MT treatment (n = 40) group, and 10 mg MT microcapsules was implanted at the base of the neck of rabbits in the treatment group. Skin, lung, liver, muscle, kidney, heart and duodenum samples were collected from the newborn rabbits. The results showed that MT improved fur quality in the offspring rabbits by reducing the diameter of primary and secondary HFs, and increasing the HF population. MT did not affect the reproductive performance of female rabbits, and it did affect the blood levels of thyroid-stimulating hormone, prolactin and MT. In the offspring rabbits, MT significantly stimulated MTNR1A gene expression in the skin and heart (p < .01), whereas MTNR1A gene expression was significantly suppressed in the liver and kidney (p < .05). These results revealed that maternal MT supplementation increased HF density, reduced hairiness and improved the fur quality in Rex rabbit offspring. Maternal MT supply may modulate the responses of HFs in the offspring by upregulating the expression of MTNR1A in the skin. In this study, implantation of low-dose MT did not affect the reproductive performance of female rabbits or on the growth of their offspring.     

引进肉用绵羊品种的杂交利用研究进展

文章综述了从国外引进优良肉用绵羊品种对国内不同地方绵羊品种杂交改良方面的研究应用情况,重点介绍了萨福克羊、杜泊羊、无角陶赛特羊、美利奴羊、特克塞尔羊等优良绵羊品种与我国不同地方绵羊品种杂交,其杂交后代在生长发育性能、产肉性能、胴体品质等方面的表现,旨在总结中国肉用绵羊的杂交改良工作,为推动中国肉用绵羊杂交改良,提高地方绵羊的生长性能和肉用性能,扩大我国肉羊的生产规模,促进我国畜牧业的健康发展和动物性肉食结构平衡提供借鉴。     

‘砀山酥梨’与‘苹果梨’杂交后代果实性状遗传趋势的研究

以‘酥梨’与‘苹果梨’杂交后代群体为试材,测量果心大小、单果重、可溶性固形物等7个指标,分析其分布规律,以期为梨遗传育种提供参考依据。结果表明：杂交后代单果重普遍较小,在100~120g区间分布最多,总体呈正态分布趋势。果形指数在0.98~1.04和1.07~1.19为集中分布区,果形与母本‘酥梨’相近。杂交后代果形指数、单果重、可溶性固形物含量、果心大小总体呈正态分布趋势,属数量遗传性状。果皮颜色以传统梨的黄色为主,占总数的59.42%,倾向于母本的果实颜色。后代果柄出现肉质化,果实的脱萼率为38.65%。     

Effect of different levels of bee pollen on performance and blood profile of New Zealand White bucks and growth performance of their offspring during summer and winter months

The effect of bee pollen on productive and reproductive performances of adult buck rabbits and their offspring was studied during winter and summer seasons. Forty New Zealand White bucks were equally divided among four groups feeding the same commercial diet and receiving a water solution containing, respectively, 0 (control), 100, 200 and 300 mg bee pollen/kg body weight, twice per week along two experimental periods. The experimental periods were listed for ten weeks both during winter (30–40 weeks of age) and summer seasons (56–66 weeks of age). During the trials body weight, body weight gain, total feed intake, semen quality, fertility and blood constituents were determined. Fertility was determined after natural mating with no treated females. For each season, 80 weaned rabbits obtained from the bucks of the control group were equally divided (20 per group) among 4 levels (0, 100, 200 and 300 mg/kg BW) of bee pollen, given as a water solution twice per week. The offspring sired by bucks given 100, 200 and 300 mg (20 for each group and season) were not administrated bee pollen. The effect of bee pollen on growth performance of rabbits was studied from 4 to 12 weeks of age. Bee pollen at 200 mg/kg BW significantly (p < 0.01) improved semen quality, increased fertility percentage, improved biochemical profiles of blood and helps outstanding of bucks during both seasons. The same concentration of bee pollen increased body weight gain and survival rate and reduced feed intake and feed conversion ratio of offspring up to 12 weeks of age.     

Aggression to a foal after 4 months of nursing

A 4-month-old male Arabian foal was examined because of a kicking trauma to the right frontal region. The foal had been kicked by its dam when it was seeking the udder the previous day. Radiographic inspection of head and neck showed no defect or bone fracture. Treatment consisting of intravenous administration of hypertonic solution, dexamethasone, and furosemide improved the clinical signs temporarily; however, second head trauma due to falling of the standing foal resulted in deterioration of clinical condition and finally death. At necropsy, epidural, subdural, and subarachnoid hemorrhages, a hematoma at cerebrocerebellar fissure and cerebellar herniation were observed. Continuous assessment of foal rejection-related signs in susceptible mares should be considered until foal weaning.     

Nutritional value and physiological effects of soya-free diets fed to rats during growth and reproduction

The objective of the study was to assess the effects of substitution milk and egg for soya products in breeding diets for rats, with concomitant decrease of the dietary protein level and supplementation with amino acids. Soya-containing (S) and two soya-free (NS and NSA) diets were evaluated as protein and energy sources, and their effects on reproductive performance during two cycles, and on the quality of the offspring were assessed. Organ weights were registered in females and blood parameters were determined in males. In the offspring males from S and NS groups, plasma LH, testosterone and prolactin levels were measured on the 22nd and the 60th day of life. The S diet contained more protein of smaller concentration of methionine and cystine and lower biological value than both NS and NSA diets and promoted similar post-weaning growth rate, similar body weight changes of dams during gestation and lactation and slightly lower mating efficiency. Within each reproductive cycle, the number and individual and total body weight of newborn and weanling pups did not differ but in two cycles mean number of neonates per litter and mean litter weight were significantly lower on S than on NSA diet. Plasma concentration of hormones did not differ in 22-day-old offspring males while in the older ones LH and prolactin levels were higher in animals fed on S than on NS diet. It is concluded that replacing soya protein by milk and egg protein with concomitant lowering dietary protein level and amino acid supplementation does not impair the growth rate and tends to improve reproductive performance. Feeding soya-free vs. soya-containing diets differentiates hormonal status of young males.     

有机锌锰对蛋鸡种蛋中锌锰含量及子代胫骨发育的影响

试验旨在研究蛋鸡母体添加有机锌和有机锰对种蛋中锌锰含量及后代雏鸡骨骼发育的影响。选取23周龄、体重相近的健康海兰褐祖代种母鸡576只,随机分为3组,每组12个重复,每个重复16只鸡。对照组饲粮添加80 mg/kg的无机锌锰(来源:ZnSO4、MnSO4),等量添加组饲粮用40 mg/kg的有机锌锰(来源:氨基酸锌、锰)替换对照组饲粮等量的无机锌和无机锰,额外添加组饲粮在对照组饲粮的基础上添加40 mg/kg有机锌、锰,试验第8、24周测定种蛋中锌锰含量,试验第31周所产种蛋入孵。检测1日龄雏鸡的胫骨发育情况。结果表明:种鸡饲粮中添加有机锌锰显著提高了蛋黄和胫骨中的锰沉积量(P<0.05);试验第23周,等量添加组雏鸡的胫骨长度显著高于对照组和额外添加组(P<0.05);试验第31周,等量添加组雏鸡的胫骨重显著低于对照组(P<0.05)。因此,种鸡饲粮等量添加有机和无机锌锰能促进锰在蛋黄和后代胫骨中的沉积,促进骨骼发育。     

不同水平母源硒对黎城大青羊后代公羔睾丸发育的影响

试验通过在妊娠期和哺乳期的母羊日粮中添加不同水平酵母硒,研究不同水平母源硒对后代公羔睾丸发育的影响。结果表明:对照组羔羊的睾丸重量、长度和周径均为最低,而0.5 mg/kg组羔羊最高,随后随着日粮硒含量的增加,睾丸重量、长度和周径逐渐降低。H-E染色的结果表明,0.5mg/kg组睾丸的曲精细管管壁最厚,生精细胞数量最多,而2.0 mg/kg与4.0 mg/kg组羔羊睾丸的曲精细管管壁较薄,生精细胞数量相对较少,而且生精细胞之间有较大空隙。试验说明母体中的硒元素可以通过胎盘与乳汁转移给后代,影响后代公羔的睾丸发育。适宜的母源硒可以促进后代公羔的睾丸发育,而较高的硒添加量会对后代睾丸的发育造成不良影响。     

硒对母猪氧化应激及其后代抗氧化能力的营养调控研究

硒作为的重要微量元素之一,可以通过胎盘和乳组织进行转移。仔猪可以从乳汁中获取硒源,提高硒含量,进而提高仔猪的初生重。同时,硒也能够调节母猪妊娠期间代谢速度,控制妊娠期自由基产生,进而提高胎盘输送营养功能。文章从母猪氧化应激体系角度来解析硒对母猪妊娠期氧化应激的调控机制、硒对哺乳母猪生产性能的调控作用。     

Perinatal maternal feeding with an energy dense diet and/or micronutrient mixture drives offspring fat distribution depending on the sex and growth stage

Maternal nutrition during pregnancy and lactation influences offspring development and health. Novel studies have described the effects on next generation obesity‐related features depending on maternal macro‐ and micro‐nutrient perinatal feeding. We hypothesized that the maternal obesogenic diet during pregnancy and lactation programs an obese phenotype, while maternal micronutrient supplementation at these stages could partially prevent these features. Thus, the aim was to assess the influence of a perinatal maternal feeding with an obesogenic diet enriched in fat and sucrose and a micronutrient supplementation during pregnancy and lactation on offspring growth and obese phenotypical features during life course. Female Wistar rats were assigned to four dietary groups during pregnancy and lactation: control, control supplemented with micronutrients (choline, betaine, folic acid and vitamin B₁₂), high‐fat sucrose (HFS) and HFS supplemented. At weaning, the offspring were transferred to a chow diet, and weight and fat mass were measured at weeks 3, 12 and 20. At birth, both male and female offspring from mothers fed the obesogenic diet showed lower body weight (?5 and ?6%, respectively), while only female offspring weight decreased by maternal micronutrient supplementation (?5%). During lactation, maternal HFS diet was associated with increased body weight, while micronutrient supplementation protected against body weight gain. Whole body fat mass content increased at weeks 3, 12 and 20 (from 16 to 65%) due to maternal HFS diet. Maternal micronutrient supplementation decreased offspring fat mass content at week 3 (?8%). Male offspring showed higher adiposity than females at weeks 12 and 20. In conclusion, maternal HFS feeding during pregnancy and lactation was associated with a low offspring weight at birth and obese phenotypical features during adult life in a sex‐ and time‐dependent manner. Furthermore, maternal methyl donor supplementation protected against body weight gain in male offspring during lactation and in female offspring also during juvenile period.     

大豆黄酮对母鸡蛋品质及后代仔鸡肉品质的影响

本文旨在研究添喂大豆黄酮对母鸡蛋品质及后代仔鸡肉品质的影响.试验选取产蛋后期肉种鸡480只,随机分为2组,每组设8个重复.试验组在基础日粮中添喂10 mg/kg的大豆黄酮,第5周后收集种蛋,每组随机取30枚做蛋品质分析,剩余种蛋按正常程序孵化,出雏后饲养至63日龄,宰杀取肌肉做肉品质分析.结果表明母鸡饲喂大豆黄酮后,蛋壳厚度和蛋壳比重分别增加了0.03 mm(P ＜ 0.01)和0.45%(P ＜ 0.05);蛋白的Haugh单位增加了4(P ＜ 0.05);入孵蛋出雏率和受精蛋出雏率分别降低了11.5%和8.3%(P ＜ 0.05).添喂大豆黄酮对后代仔鸡生长无显著影响,但显著降低了雌仔鸡肌肉比重和肌肉的蒸煮损失率(P ＜ 0.05),显著降低雄仔鸡肌肉的滴水损失率(P ＜ 0.05);显著增加胸肌黄度(P ＜ 0.05);但对腿肌的快慢肌纤维比例、纤维密度以及快慢肌纤维的横截面积均无显著影响(P ＞ 0.05).以上结果提示10 mg/kg剂量的大豆黄酮应慎用于种蛋禽上,而在商品蛋禽上则具有良好的应用前景.     

氟对不同世代大鼠大脑皮质细胞凋亡的影响

为研究氟中毒能否引起世代蓄积而对不同世代动物大脑造成损伤,试验采用离乳Wistar大鼠16只,随机分为2组,对照组饲喂大鼠标准饲料,饮自来水;高氟组饲喂大鼠正常饲料,饮含氟化钠（NaF）100 mg/L的去离子水。饲喂3个月,生产子二代和子三代大鼠,仔鼠饲喂采用与其母鼠相同的处理。取0、10、20、30、60、90日龄的不同世代大鼠,分别宰杀,取大脑,制成单细胞悬液,采用流式细胞仪检查其细胞凋亡情况。结果显示,与对照组相比,不同日龄高氟组二代、三代大鼠大脑皮质细胞凋亡率升高。与二代大鼠相比,不同日龄氟中毒三代大鼠大脑皮质细胞凋亡程度增高,10、20、60、90日龄时差异显著（P<0.05）。提示,氟中毒可以引起世代蓄积,接触氟环境时间越长,其动物子代大脑损伤越严重。     

饲粮中添加鹅脱氧胆汁酸对种鸡脂代谢、生产性能及子代肌肉发育的影响

本研究探讨了饲粮中添加鹅脱氧胆汁酸(CDCA)对种鸡脂代谢、生产性能及子代肌肉发育的影响。试验选用14周龄矮脚黄种鸡80只,随机分为5个组,每组16个重复,每个重复1只鸡。对照组饲喂基础饲粮,试验组在基础饲粮中分别添加10、50、100和500 mg/kg的CDCA,试验期4周。在试验最后1周收集种蛋进行孵化,出雏后的子代根据种鸡分组情况分为5组,饲养期12周。结果表明:1)饲粮中添加CDCA对种鸡的体重、产蛋率和蛋品质均无显著影响(P0.05);与对照组相比,饲粮中添加100 mg/kg的CDCA能够显著增加种鸡血清中甘油三酯(TG)含量(P0.05),显著降低血清中极低密度脂蛋白(VLDL)含量(P0.05);与对照组相比,饲粮中添加100 mg/kg的CDCA能够显著降低试验第14天和第28天种鸡蛋内总胆汁酸(TBA)含量(P0.05),显著增加蛋内胆固醇(TC)和低密度脂蛋白胆固醇(LDL-C)含量(P0.05)。2)与对照组相比,饲粮中添加50 mg/kg的CDCA能够显著增加子代腓肠肌肌纤维密度和子代公鸡肝脏率(P0.05),饲粮中添加100 mg/kg的CDCA能够显著降低子代母鸡的平均日增重、子代公鸡腓肠肌总蛋白沉积量和子代母鸡腓肠肌中乳酸脱氢酶(LDH)活性(P0.05),饲粮中添加500 mg/kg的CDCA能够显著降低子代母鸡腓肠肌琥珀酸脱氢酶(SDH)活性和子代公鸡腓肠肌LDH活性(P0.05)。由此可见,饲粮中添加CDCA对种鸡的生产性能无显著影响,但会影响种鸡的脂代谢以及蛋内沉积特别是TBA的沉积,进而对子代肌肉发育产生抑制作用,因此CDCA在种鸡饲粮中的应用应注意添加剂量以及使用时间。     

Supplementing organic-complexed or inorganic Co,Cu, Mn,and Zn to beef cows during gestation: postweaning responses of offspring reared as replacement heifers or feeder cattle

One hundred and ninety nonlactating, pregnant beef cows (¾ Bos taurus and ¼ Bos indicus; 138 multiparous and 52 primiparous) were assigned to this experiment at 117 ± 2.2 d of gestation (day 0). Cows were ranked by parity, pregnancy type (artificial insemination = 102, natural service = 88), body weight (BW) and body condition score, and assigned to receive a supplement containing: (1) sulfate sources of Cu, Co, Mn, and Zn (INR; n = 95) or (2) an organic complexed source of Cu, Mn, Co, and Zn (AAC; Availa4; Zinpro Corporation, Eden Prairie, MN; n = 95). The INR and AAC provided the same daily amount of Cu, Co, Mn, and Zn, based on 7 g of the AAC source. From day 0 to calving, cows were maintained in a single pasture and segregated 3 times weekly into 1 of 24 individual feeding pens to receive treatments. Calves were weaned on day 367 (200 ± 2 d of age), managed as a single group for a 45-d preconditioning period (days 367 to 412), and transferred to a single oat (Avena sativa L.) pasture on day 412. Heifer calves were moved to an adjacent oat pasture on day 437, where they remained until day 620. Heifer puberty status was verified weekly (days 437 to 619) based on plasma progesterone concentrations. Steer calves were shipped to a commercial feedlot on day 493, where they were managed as a single group until slaughter (day 724). Plasma cortisol concentration was greater (P = 0.05) in AAC calves at weaning but tended to be less (P = 0.10) on day 370 compared with INR calves. Mean plasma haptoglobin concentration was greater (P = 0.03) in INR vs. AAC calves during preconditioning, and no treatment effects were noted (P = 0.76) for preconditioning average daily gain (ADG). Puberty attainment was hastened in AAC heifers during the experiment (treatment × day; P < 0.01), despite similar (P = 0.39) ADG between treatments from days 412 to 620. Expression of myogenin mRNA in the longissimus muscle was greater (P = 0.05) in INR vs. AAC heifers on day 584. No treatment effects were detected (P ≥ 0.24) for steer ADG from day 412 until slaughter, nor for carcass quality traits. Hepatic mRNA expression of metallothionein 1A was greater (P = 0.02) in INR vs. AAC steers on day 586. In summary, supplementing Co, Cu, Zn, and Mn as organic complexed instead of sulfate sources to beef cows during the last 5 mo of gestation did not improve performance and physiological responses of the steer progeny until slaughter, but hastened puberty attainment in the female progeny reared as replacement heifers.