Reproductive Biotechnology: Prospects and Applications in the Herd Management of Sows*

Biotechnological procedures are valuable tools for an efficient reproductive management in a commercial pig production. Artificial insemination, puberty induction, estrus synchronization, early pregnancy diagnosis and induction of parturition are routinely used since years already and have significant impact for the herd management of sows. Embryo transfer (ET) can also be efficiently applied. But surgical procedures are required for the recovery and transfer of embryos. ET related biotechniques such as cryopreservation of ova and embryos, in vitro production of embryos, cloning and gene transfer are still at an experimental stage but will most likely gain significance shortly.     

蛋鸡日粮阴离子适宜含量及其当量比研究

本试验研究了在蛋鸡日粮中添加不同量氯离子和碳酸氢根离子对蛋鸡血清阴离子组成、产蛋率、饲料转化率和蛋壳品质的影响。结果表明,在日粮添加0.121％氯离子(日根氯离子总量为0.212％)和0.145％碳酸氢根离子(日粮碳酸氢根离子总量为0.276％)时,蛋鸡血清阴离子含量及其当量比正常,产蛋率和饲料转化率达到最大(P<0.01),蛋壳品质极显著地提高(P<0.01)。蛋鸡日粮氯离子和碳酸氢根离子最佳水平分别为0.212％和0.276t％,其适宜当量比为1.32:1。     

大约克母猪排卵规律的研究

通过对大约克母猪在发情不同时间分批屠宰测定表明，大约克母猪排卵时间是在发情开始后４８小时左右至７２小时之前这一范围。并采用杜洛克和大约克公猪分别在母猪发情的不同阶段先后配种，从所产仔猪的遗传特征鉴别结果判断，排卵大多集中在发情３６小时后至６０小时左右范围内，与屠宰测定基本一致。据上试验结果，确定掌握适配期为母猪发情开始后３６－４８小时期间第一次配种，间隔１２－２４小时内复配一次。经两年配种实践取得良好效果，情期受胎率分别达到９１．２７％（２０９／２２９）和９３．３６％（２６７／８６）。     

籽粒苋草粉对生长肥育猪饲养效果试验

为了寻找配合料中籽粒苋草粉的最佳用量，通过不同含量籽粒苋草粉配合料对生长肥猪的饲养对比试验，初步筛选出含有１０％籽粒苋草粉配合料的最佳配方。     

采食水平对东北民猪代谢热量的影响

以哈白猪为对照，研究２０℃条件下，低（Ｌ，７５０ｇ／ｄ），中（Ｍ１０５０ｇ／ｄ）高（Ｈ，１３００ｇ／ｄ）三种采食水平（饲料ＭＥ含量为１２．３７ＫＪ／ｋｇＣＰ：１６％）对体重２０～２５ｋｇ的民猪产热量的影响，研究结果表明，随采食水平提高，产热量有逐渐增加的趋势，但产不显著（Ｐ〉０．０５），三种采食水平下，民猪和哈白猪的产热量分别为３３．５，３４．５，３５．９和３１．９，３３．８，３４．９ＫＪ／ｋｇ＾     

ARTERIOGRAPHIC ANATOMY OF THE ABDOMINAL AORTA IN THE GOAT, DOG, PIG, AND RABBIT

Arteriographic anatomy of the major branches of the abdominal aorta of rabbits, dogs, pigs, and goats was investigated. The origin and location of the celiac, cranial mesenteric, right renal, left renal, caudal mesenteric, and external iliac arteries were demonstrated, and their placement was described in relation to the iliac bifurcation and lumbar vertebral bodies.     

Airway management under general anaesthesia in pigs using the LMA-ProSeal: a pilot study

OBJECTIVE: Evaluation of the LMA-ProSeal for positive pressure ventilation (PPV) in the pig. STUDY DESIGN: Prospective observational study. ANIMALS: Twelve German country pigs, weighing 25-62 kg. METHOD: Lungs of pigs were mechanically ventilated under general anaesthesia using the LMA-ProSeal. The ease of insertion, number of attempts and total time until placement of the LMA-ProSeal and gastric tube were recorded. Bronchoscopy was performed to determine the position of the LMA-ProSeal and to detect signs of aspiration. Ventilation variables and the leak airway pressure (P(leak)) were measured. An arterial blood gas sample was taken to determine the adequacy of ventilation. RESULTS: The airway was secured in all pigs within 39 +/- 19 seconds (27-51). Different sizes of LMA-ProSeal were used; up to 30 kg: size 3, up to 43 kg: size 4; and above 43 kg: size 5. In all but one animal the P-LMA and gastric tube were inserted at the first attempt. In nine animals gastric fluid was drained through the gastric tube. There was no evidence of aspiration in any animal. The mean [+/-SD (95%CI)]P(leak) was 28.8 +/- 7.5 cm H(2)O (24.06-33.60) and normal ventilation was achieved in all animals. CONCLUSIONS: The results of this study indicate that the airway of pigs weighing 25-62 kg can be secured safely and reliably with the sizes 3, 4 and 5 LMA-ProSeal. CLINICAL RELEVANCE: Endotracheal intubation in pigs can be difficult so there is a risk of hypoxemia in the apnoeic animal. With the LMA-ProSeal the airway can be secured rapidly, safely and reliably. Use of the Standard-LMA under PPV can be associated with gas leakage into the stomach and the subsequent risk of gastric distension and regurgitation. Both the ability to drain the stomach and the high P(leak) of the LMA-ProSeal could contribute to improved protection against aspiration under PPV.     

Molecular Cloning and Expression of IL2 cDNA from the Tibet Pig

Interleukin-2 is a vital cytokine secreted by activated T lymphocytes, and plays important role in the regulation of cellular and humoral immunity of animals. In our experiment, IL2 cDNA of the Tibet Pig was first cloned by RT-PCR from ConA-stimulated lymphocytes in the blood and subcloned into pMD-18 T vector, which then was identified with endonuclease restriction. The sequencing result showed that Tibet pig IL-2 (TPIL-2) cDNA was 503 bp long (ORF was 465 bp) (Genbank accession number: AY 294018). The recombinant prokaryotic and eukaryotic expression plasmids of the cDNA were then constructed to analyse the ability to stimulate the proliferation of porcine lymphocytes in vitro. The recombinant porcine IL-2 expressed in the prokaryotic cells was found to be of 43 kDa molecular mass, which was consistent with a 17.4 kDa protein deduced from the IL-2 cDNA sequence (glutathione S-transferase molecular mass is 26 kDa); the recombinant protein in eukaryotic cells was confirmed by use of specific rabbit anti-porcine IL-2 serum in an ELISA. The bioactivity of TPIL-2 was detected through MTT colorimetry by stimulating the proliferation of pig ConA-stimulated blasts in vitro. The results indicate that the TPIL-2 significantly promoted the proliferation of ConA-stimulated blasts of pig. This confirms that IL-2 cDNA of the Tibet pig was successfully cloned and expressed in prokaryotic and eukaryotic cells, which lays the foundation for the the preparation of specific recombinant IL-2 protein and development of novel immune adjuvants to raise the immunity of pigs against various infectious pathogens and increase the immunoprotective efficacy of vaccines.     

Osteochondrosis and arthrosis in pigs. 3. A comparison of the incidence in young animals of the Norwegian Landrace and Yorkshire breeds

An investigation concerning the occurrence of osteochondrosis and arthrosis in 2 materials totalling 63 pigs of the Landrace breed and 63 of the Yorkshire breed is described. The animals were bred under the same conditions of feeding and housing. The differences should therefore mainly be of genetic origin. Both breeds were highly improved, Landrace the most. In general, Yorkshire pigs showed a lower incidence and a less marked degree of osteochondrosis and arthrosis than Landrace pigs. Statistically significant differences (P < 0.01) were demonstrated in the distal epiphyseal plate of the ulna, in the intervertebral joints of the lumbar region and in the medial condyle of the femur in 1 of the materials. The Landrace pigs had longer bodies, broader hindquarters, shorter femurs, and the stifle had a different shape as compared with Yorkshire pigs. There thus seemed to be a connection between exterior features, joint and bone shape and the occurrence of joint lesions. Differences among litters within breed were also demonstrated.     

地方猪种对纤维饲料利用的研究——Ⅱ.消化道形态与大肠内容物重量的变化

以三元杂种猪为对照,研究了东北民猪在3种NDF水平(0、10、20％)下消化道形态及后肠内容物鲜重的变化。试验从活重30千克开始,80千克结束时,每组在最后一次给食后的2、4、8、12或16小时随机屠宰2头。电击晕死后立即开膛取出内脏,分为胃、小肠、盲肠和结肠4段进行测量。结果表明猪对饲粮纤维含量的增加从胃肠道形态上发生明显的适应性变化,消化道长度、鲜重增加,尤其结肠长度增加明显,胃、小肠和结肠的鲜重显著地高于基础饲粮组。民猪胃重和结肠鲜重及长度的增加比对照杂种猪明显,消化道总鲜重及其占空体重的比例显著地高于对照杂种猪。随NDF水平的提高,大肠内容物鲜重明显增加,其中民猪更为突出,后肠是吸收水分的主要场所。