钙蛋白酶系统在动物营养中的应用

钙蛋白酶(Calpain)系统包括钙蛋白酶、钙蛋白酶抑制蛋白(Calpastatin)和钙蛋白酶激活蛋白(CalpainActivator)。研究表明,钙蛋白酶系统通过参与肌原纤维蛋白的降解过程从而影响肌肉生长及肉的嫩化。胞内Calpain活性受多种因素的调节,包括钙需要量、自溶裂解、磷脂的作用、钙蛋白酶抑制蛋白和激活蛋白等,然而对于体内钙蛋白酶的活性如何调控的争议仍然存在。     

Identification of polymorphisms and association analysis with meat quality traits in the porcine KIAA1717 and HUMMLC2B genes

Skeletal muscle genes are potential candidates for production and meat quality. Screening a subtracted cDNA library constructed with mRNA obtained from longissimus dorsi muscles of F1 hybrids Landrace × Yorkshire and their female parents Yorkshire, we isolated two partial sequences coding for the H3-K4-specific methyltransferase (KIAA1717) and skeletal muscle myosin regulatory light chain (HUMMLC2B) genes. Database search revealed KIAA1717 and HUMMLC2B encoded proteins with SET domain and EF-hand calcium binding motif, respectively. In the present work we identified their partial polymorphisms and two SNPs, one (C1354T) at the 3′ untranslated region (UTR) of KIAA1717 and one (A345G) at the SINE (PRE-1) element of HUMMLC2B, both created/disrupted a restriction site for endonuclease Msp I. The selected pigs were genotyped at the KIAA1717 C1354T and HUMMLC2B A345G sites by means of a PCR-RFLP protocol. Significant associations were observed for the KIAA1717 C1354T polymorphic site with meat marbling (longissimus doris (p < 0.05), biceps femoris (p < 0.01)) and intramuscular fat (p < 0.01). HUMMLC2B A345G were significantly associated with meat pH (longissimus doris (p < 0.05), biceps femoris (p < 0.01)), drip loss (p < 0.01), water holding capacity (p < 0.01) and meat color value (longissimus doris (p < 0.01), biceps femoris (p < 0.05)). Further studies are needed to confirm these preliminary results.     

氮硅添加对高寒草甸生物量和多样性的影响——以青藏高原为例

草地施肥多集中于添加氮肥与磷肥,很少涉及硅肥。硅作为对植物有益的一种元素,能提高植物对环境的抗性,促进植物的生长。本研究以青藏高原高寒草甸为研究对象,通过添加不同组合的氮肥和硅肥,研究群落地上生物量和生物多样性的变化。结果表明,氮肥和硅肥的添加均能提高群落的地上生物量,然而硅肥提高群落地上生物量的幅度远低于氮肥;在添加氮肥导致群落物种多样性下降的同时,添加硅肥可以缓解群落多样性下降的趋势;硅肥的生物学功能在群落水平上存在着最佳浓度效应。同时,我们推测硅肥在维持群落中杂草的存活率上发挥着积极的作用,并通过比较不同硅肥处理时,杂草生物量所占群落生物量比重的变化,支持了上述推测。     

Substrate use and postural behavior in free‐ranging snub‐nosed monkeys (Rhinopithecus bieti) in Yunnan

Extant colobines represent a predominantly arboreal primate radiation, but there are outliers such as some species of snub‐nosed monkeys (Rhinopithecus spp.) that utilize both arboreal and terrestrial substrates. We quantified the degree of terrestriality and the distribution of individuals across canopy levels, the extrinsic and intrinsic determinants and constraints of strata association as well as use of postures in relation to behavior and food sources in a wild population of Yunnan snub‐nosed monkeys (Rhinopithecus bieti) in the Samage Forest, China. The subjects spent 80.5% of the observation time in the trees and 19.5% on the ground. Ground use occurred most frequently in the context of travelling (61%) and less often in the context of feeding and resting (30% combined). Adult males frequented the ground significantly more often than other age‐sex classes. Age‐sex differences were also apparent in substrate preferences, which likely reflect body weight constraints. Adult males were significantly more associated with solid substrates and less with terminal branches than adult females and juveniles. Juveniles were seen more often on unstable ground (i.e. on thin and oblique branches) and in the upper canopy. Substrate use also varied with behavior: feeding was much more common in the upper stratum, outer canopy, on highly inclined and thin branches, as compared to resting. Severe weather also influenced canopy use in that tree crowns were used less often during periods of snowfall. The most frequently exhibited resting and feeding postures was sitting. Standing and suspensory postures were most often used in the context of feeding on lichens.     

种犬公母搭配饲养的益处

在种犬饲养过程中,大家都比较重视种犬的科学饲喂、散放运动和卫生疾病等方面的情况,却很少有人从种犬的性别搭配方面来思考种犬饲养方面的问题.其实,在实际工作中种犬的公母搭配饲养对种犬饲养工作是大有益处的.     

维生素A和β-胡萝卜素在反刍动物中的应用

文中简要介绍了维生素A和β-胡萝卜素的营养生理功能,重点综述了维生素A和β-胡萝卜素对反刍动物繁殖、免疫和生产性能的影响。     

Changes in growth performance, digestive enzyme activities and nutrient digestibility of cherry valley ducks in response to aflatoxin B1 levels

The objective of this study was to investigate toxic effects of aflatoxin B1(AFB₁) on growth performance, organs, hepatic enzyme activities, apparent digestibility of nutrients and digestive enzyme activities in ducks. Ninety 1-day-old Cherry Valley commercial ducks were designed to three treatment groups with three replicates of ten birds each. Group I (control) was fed conventional feed free of AFB₁, group II or III was fed the diets containing 20 μg/kg or 40 μg/kg AFB₁-contaminated rice respectively. The feeding trial lasted 6 weeks. The results were that decreased body weight gain and feed intake, increased feed to gain ratio and selected organ weights (liver, kidney and pancreas) were observed in AFB₁-treated groups. The activities of serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were significantly increased in AFB₁-contamined groups. The apparent digestibility of crude protein (CP) was significantly lower while activities of digestive enzyme from duodenum contents including protease, chymotrypsin, trypsin and amylase were increased in AFB₁-treated group. These results indicated that AFB₁ of feed could decrease growth performance and apparent digestibility of nutrients, change digestive enzyme activities of duodenum contents in duck.     

孔雀组织滴虫病的诊治

2007年9月份,沈阳市郊区某珍禽饲养场30日龄雏孔雀暴发组织滴虫病,该场起初误诊断为球虫病,曾用敌菌净、球威、氯苯胍治疗,但仍不     

Mitochondrial dysfunction influences apoptosis and autophagy in porcine parthenotes developing in vitro

Mitochondria are important regulators of both apoptosis and autophagy. One of the triggers for mitochondrial-mediated apoptosis is the production of reactive oxygen species (ROS), which include hydrogen peroxide, superoxide, hydroxyl radical, nitric oxide and peroxynitrite. Recently, several studies have indicated that ROS may also be involved in the induction of autophagy. In the present study, we used H(2)O(2) to induce mitochondrial stress, examined apoptotic- and autophagic-related gene expression and observed LC3 protein (autophagosome presence marker) expression in porcine parthenotes developing in vitro. In porcine four-cell parthenotes cultured for 5 days in NCSU37 medium containing 0.4% BSA, the developmental rate and mitochondrial distribution did not differ from that of the group supplemented with 100 μM H(2)O(2) but was significantly decreased in the group supplemented with 500 μM H(2)O(2) (P<0.05). Transmission electron microscopy (TEM) indicated that whereas normal shaped mitochondria were observed in blastocysts from the control group, abnormal mitochondria (mitophagy) and autophagic vacuoles were observed in blastocysts from the group that received 500 μM H(2)O(2). Furthermore, addition of H(2)O(2) (100 μM and 500 μM) decreased cell numbers (P<0.05) and increased both apoptosis (P<0.05) and LC3 protein expression in the blastocysts. Real-time RT-PCR showed that H(2)O(2) significantly decreased mRNA expression of anti-apoptotic gene Bcl-xL but increased pro-apoptotic genes, Caspase 3 (Casp3) and Bak, and autophagy-related genes, microtubule-associated protein 1 light chain 3 (Map1lc3b) and lysosomal-associated membrane protein 2 (Lamp2). However, the addition of H(2)O(2) had no effect on mRNA expression levels in nuclear DNA-encoded mitochondrial-related genes, cytochrome oxidase (Cox) 5a, Cox5b and Cox6b1, in blastocysts. These results suggest that H(2)O(2) leads to mitochondrial dysfunction that results in apoptosis and autophagy, which is possibly related to porcine early embryo development.