甜菜碱对1至21日龄肉鸭体脂重分配的作用效果及机理

通过饲养、屠宰试验和有关指标分析,探讨了甜菜碱对21 日龄肉鸭体脂重分配的作用效果及其对脂肪代谢的作用机理。276 只1 日龄樱桃谷肉鸭分成对照组和甜菜碱组两个处理,每个处理138只,每组设3 个重复,每个重复组46 只肉鸭,公母各半。基础饲粮相同(甲硫氨酸和总含硫氨基酸含量分别为0.30% 和0.66% ),对照组饲喂不含甜菜碱的日粮,甜菜碱组饲喂含800 m g/kg 甜菜碱的日粮。肉鸭饲喂到21 日龄时称重、屠宰。结果表明,甜菜碱对21 日龄肉鸭体脂具有显著的重分配作用,它分别降低了鸭的腹脂率、皮脂厚和肝脏粗脂肪含量,提高了鸭胸肌中粗脂肪含量和肌间脂肪的厚度。肝脏、肌肉、腹脂和血清样品分析结果揭示,甜菜碱似通过降低脂肪生成酶的活性(P< 0.01),来提高脂肪分解酶的活力,促进肉碱的合成,加强肝脏、尤其是肌肉组织中长链脂肪酸的β-氧化作用,从而发挥着重新分配肉鸭体脂肪的作用。     

Cloning and Expression of CMKLR1 Gene and Its Correlation with Intramuscular Fat in Goat (Capra hirus)

In order to enrich basic date in goat (Capra hirus) CMKLR1 gene and investigate the correlation between CMKLR1 gene expression and intramuscular fat (IMF) content in muscles, the CMKLR1 gene was cloned from the goat of subcutaneous adipose tissue by RT-PCR, characterized by bioinformatics methods. The expression profiles of CMKLR1 gene of goat in various tissues were constructed liver was benchmark, the GAPDH (GenBank accession No.: AJ431207.1) as a reference gene.Then, the correlation between CMKLR1 mRNA expression and IMF content in muscles was analyzed. The results showed that the CMKLR1 gene CDS of goat (GenBank accession No.: KT165374) was 1 089 bp. Real-time PCR indicated that CMKLR1 was widely expressed in various tissues, including heart, liver, spleen, lung, kidney, adipose, longissimus dorsi, biceps femoris and triceps brachii, and was the highest in lung (P< 0.05). Similar expression variation trend of CMKLR1 was observed between the muscles from 1 to 3 and 24 months old goat, and was the highest in biceps femoris. Reversely, in 8 to 10 months old CMKLR1 was the highest in triceps brachii. The IMF of longissimus dorsi from 24 months old was the highest. Correlation analysis demonstrated that different correlations were observed between expression of CMKLR1 mRNA and IMF content in longissimus dorsi, biceps femoris, and triceps brachii in goat. The CMKLR1 gene did not participate in the deposition of IMF in goats. The research built the theoretical basis for further studies about the CMKLR1 gene.     

西宁奶牛场荷斯坦奶牛乳脂率测定

对西宁奶牛场３２７头中国荷斯坦泌乳奶牛的乳汁进行乳脂率测定。结果：乳脂率平均值为３．４９％，变动范围１．２％～６．８％；乳脂率在２．７％以下的牛３１头，占全群牛的９．５％，２．８％～３．２％的牛６７头，占２０．５％，３．３％～３．９％的牛１６３头，占４９．８％，４％以上的牛６６头，占２０．２％；不同胎次、产奶量及不同泌乳期乳脂率有一定的变化。     

甜菜碱对猪不同阶段脂肪和蛋白质代谢的影响

对断奶仔猪、生长猪和肥育猪分别饲喂添加甜菜碱800、1000、1750mg/kg的饲粮，分别进行为期36、62、40d的饲养试验，并进行屠宰取样和分析测定。结果表明甜菜碱使断奶仔猪、生长猪、肥育猪的日增重分别提高8.71%(P<0.05)、13.20%(P<0.01)、13.32%(P<0.01);胴体脂肪率分别降低12.97%(P<0.01)、19.62%(P<0.01)、12.49%(P<0.01)；瘦肉率分别提高4.08%(P<0.05)、7.15%(P<0.05)、3.31%(P<0.05);肝脏中游离肉碱含量分别增加8.98%(P<0.05)、21.36%(P<0.05)、30.18%(P<0.01);血清中生长激素(GH)水平分别增高46.15%(P<0.01)、102.11%(P<0.01)、58.33%(P<0.05)；胰岛素样生长因子-1(IGF-1)水平分别增高38.74%(P<0.05)、44.74%(P<0.01)、47.95%(P<0.01)。生长猪和肥育猪皮下脂肪组织中苹果酸脱氢酶(MDH)的活性分别上升13.60%(P<0.05)和14.59%(P<0.01)，断奶仔猪有提高趋势，但差异不显著(P>0.05)。     

Production and related variables in bovine leukaemia virus-infected cows

A newly developed milk dot blot test was used to detect anti-bovine leukaemia virus (BLV) antibody in milk samples from 2079 lactating adult cows from among 61 herds. The milk dot blot test was highly repeatable; the concordance rate, compared with the agar gel immunodiffusion test performed on serum, was 83.5%. All herds contained BLV-positive cows; the prevalence rate was 36%. BLV-positive cows tended to come from larger herds and were older and more often later in lactation. Fourteen production and related variables (herd size, age, days open, days in milk, milk somatic cell count, milk, fat, and protein produced in the current lactation, projected production of milk, fat, and protein, and breed class average deviations for milk, fat, and protein) were compared between BLV-positive and BLV-negative cows. Although somatic cell count, milk produced, and projected production of milk and protein were related significantly to BLV status using simple tests of association, once the variables herd size, age and days in milk were controlled, these differences were removed. Further analyses using logistic (outcome: individual cow BLV status) and least-squares regression (outcome:herd proportion of BLV-positive cows) failed to show an association between any of the measured production or related variables and BLV-positivity. We concluded that the effect of BLV on production and related variables in dairy cows was below the sensitivity of our analytical techniques or was non-existent.Abbreviations ABCA herd average breed class average for milk, fat, and protein production - AVGAGE average age of the herd - ADIM herd average for days in milk - AGID agar gel immunodiffusion - AVGSCC herd average milk somatic cell count - BCA breed class average, a milk, fat and protein production index calculated by comparing a cow's actual 305-day lactation production to the corresponding BCA standard for the same breed, age, and month of calving - BLV bovine leukaemia virus - CALVINT calving interval - COWAGE cow age - DBCA breed class average deviation for milk, fat, and protein production, the difference between an individual cow's BCA and the herd average - DIM days in milk - HS herd size corresponding to the number of lactating cows in a herd - LACT actual amount of milk, fat, and protein produced in a cow's lactation - ODHIC Ontario Dairy Herd Improvement Corporation - PCTPOS percentage of herd that is BLV-positive - PROJ projected 305-day production for milk, fat, and protein by fitting to a standard lactation curve adjusted for days in milk and age at calving - RHBCA rolling herd average for breed class average for milk, fat, and protein production, the average for all cows that completed a lactation (cows must have completed a 305-day lactation) during the previous 12 months - SCC milk somatic cell count     

Development of a New Foxtail Millet Germplasm with Super Early Maturity and High Iron Content

Super Early Maturation No.2 is a new foxtail millet germplasm developed by using the targeted-character-gene-bank-breeding method. It has several outstanding characteristics. (1) Super early maturity. It can normally mature in Bashang, Hebei Province, China, where the altitude is around 1 400 meters, and it needs 1650°C of effective accumulated temperature in the growing period. (2) Millet is rich in iron. The iron content of the millet of Super Early Maturation No.2 is 54.10 mg kg⁻¹, which is 62.0% higher than the average iron content of the foxtail millet varieties in China. (3) High crude fat content. Its crude fat content is 6.24%, which is 54.1% higher than the average content of foxtail millet varieties in China. (4) High crude protein content. The average of the crude protein content of all the foxtail millet varieties in China is 12.71%, only 5% varieties surpass 14%, however, the crude protein content of Super Early Maturation No.2 is 14.36%, which is rare in improved varieties of foxtail millet in China. (5) Overall characteristics are good.     

The fat content of milk from dairy cattle infected with bovine leukosis virus

Two groups of cows infected with the bovine leukosis virus (BLV) were kept on two different diets and the fat content of their milk was assayed. The results were compared with those obtained from two comparable groups of BLV-free cows. The cows in each group were of similar ages, those in the groups on the poorer diet being 1–4 months post partum, while those on the richer diet were 5–7 months post partum. The mean percentage of fat in the milk from uninfected cows on the poorer diet was 2.94 while that from the similar infected cattle was 3.06. Uninfected cows on the richer diet produced milk containing 3.39% fat, while those that were infected produced milk containing 3.30% fat. No statistical differences in milk fat production were observed between the BLV seropositive and seronegative cows.     

饲料蛋白质组分对泌乳奶牛乳脂率和乳蛋白的影响

本试验研究采用粗蛋白质相同而蛋白质组分水平不同的四种日粮(日粮粗蛋白质中瘤胃未降解蛋白质(RUP)比例由35.9%逐步提高到40.9%,其他营养成分基本保持一致),选择32头处于中产水平的荷斯坦奶牛,根据产奶量、胎次和泌乳日龄按配对法随机分为四组,研究了不同蛋白质组分水平的日粮对奶牛乳脂率、乳蛋白率和乳蛋白质产量的影响规律。结果表明,粗蛋白质相同而蛋白质组分水平不同的日粮对奶牛乳脂率、乳蛋白率和乳蛋白产量没有显著的影响(P>0.05),但乳脂率有下降的趋势,乳蛋白产量有增加的趋势。     

脂肪细胞膜免疫的研究进展

综述了脂肪细胞膜免疫的研究进展.为今后进一步深入研究脂肪细胞膜免疫与动物的体脂过量沉积之间的关系提供了重要的参考价值.