Responses in carcass lean pH at 24 hours post-mortem in lines of Large White pigs selected for growth rate on a fixed ration over a set time

A restricted maximum likelihood analysis applied to an animal model showed no significant differences (P > 0.05) in pH value of the longissimus dorsi measured at 24 h post-mortem (pH24) between high and low lines of Large White pigs selected over 4 years for post-weaning growth rate on restricted feeding. Genetic and phenotypic correlations between pH24 and production and carcass traits were estimated using all performance testing records combined with the pH24 measurements (5.05–7.02) on slaughtered animals. The estimate of heritability for pH24 was moderate (0.29 ± 0.18). Genetic correlations between pH24 and production or carcass composition traits, except for ultrasonic backfat (UBF), were not significantly different from zero. UBF had a moderate, positive genetic correlation with pH24 (0.24 ± 0.33). These estimates of genetic correlations affirmed that selection for increased growth rate on restricted feeding is likely to result in limited changes in pH24 and pork quality since the selection does not put a high emphasis on reduced fatness.     

Physiological responses of transported goats treated with ascorbic acid during the hot-dry season

The aim of the present study was to determine the physiological responses of transported Red Sokoto goats (RSG) treated with ascorbic acid (AA). Ten RSG treated orally with ascorbic acid served as experimental subjects, while seven goats treated with sterile water served as the control. The goats were transported for 8 h. The ambient temperature and relative humidity during the study period fluctuated between 21 and 38°C and 51 and 91%, respectively, which indicated that the season was thermally stressful and did not favor transportation of goats. The rectal temperature obtained in the control goats was significantly higher (P < 0.01) than the value in the experimental goats after transportation. There was a significant decrease (P < 0.05) in eosinophil counts and an increase (P < 0.01) in neutrophil counts and neutrophil : lymphocyte ratio recorded in the control goats after transportation, which suggested that the control goats were physically and emotionally stressed. The control goats lost 11.9% of their initial liveweight, while the experimental goats lost only 1.04% after transportation. Multiple stresses, including extreme meteorological factors, acted upon the transported goats and impaired their homeostatic mechanism. In conclusion, AA administration in goats reduced the adverse effects of road transportation stress.     

恒河猴血液细胞、生化和凝血功能正常参考指标的测定

测定分析人工饲养及在非麻醉(清醒)状态下108只健康成年恒河猴的血常规、血液生化及血小板和凝血功能正常值,并分析各项检测数据的性别差异。血常规测定值17项,其中,雌猴较雄猴极显著高(P<0·01)的项目为红细胞分布宽度(RDW)。血液生化测定值17项,其中,雌猴比雄猴显著低(P<0·05)的项目有丙氨酸转氨酶(ALT),显著高(P<0·05)的项目有碱性磷酸酶(ALP)。血小板和凝血功能测定值9项,其中,雌猴比雄猴明显高(P<0·05)的项目为活化部分凝血活酶时间(APTT),极显著高(P<0.01)的项目为凝血酶时间(TT)。建立了人工饲养条件下健康成年恒河猴的血常规、血液生化、血小板和凝血功能正常参考值指标,丰富和完善了恒河猴动物实验和疾病诊断中血液分析的基础知识。     

低能饲粮添加植酸酶对仔猪养分利用率、血清理化指标及生长性能的影响

选用24头长白×荣昌杂交仔猪进行2×2因子的代谢试验,试验设2个有效磷水平(0.36%和0.26%)、2个植酸酶添加水平(0、750FTU/kg),共4个处理组,每个处理组设6个重复仔猪起始均重16.9kg,饲粮DE12.8MJ/kg,试验期2周。结果表明:饲粮添加植酸酶,仔猪平均日增重(ADG)、增重/kgW0.75(GPW)、F/G、增重/代谢能(GPM)、蛋白质物质价值(BV)、净蛋白效率比(PER)、钙消化率(CD)、钙沉积率(CR)、磷消化率(PD)和磷沉积率(PR)分别提高10.6%、7.2%、7.9%、7.7%、11.6%、6.7%、4.3%、4.9%、19.6%(P<0.01)、21.3%(P<0.01),每千克增重的饲粮成本(CPG)降低6.6%;植酸酶对仔猪血清理化指标无显著影响,但血清磷浓度趋于升高,血清钙、血清尿素氮浓度趋于降低。降低饲粮有效磷,ADG、GPW、F/G、GPM、BV、PER、PD和PR分别降低3.8%、3.3%、3.2%、4.6%、9.6%、3.2%、7.7%、6.9%,CD、CR和CPG分别增加11.1%、11.6%、3.0%(P>0.05)。     

勺状亚侧耳菌丝培养特性的研究

研究了C源、N源、pH、温度和料水比及不同培养基对勺状亚侧耳(Hohenbuehelia petaloides)Hp.831菌丝生长的影响。试验结果表明,该菌丝生长的最适温度、pH、C源、N源和含水量分别为25～30℃、6～7、羧甲基纤维素钠、蛋白胨和60%～70%;马铃薯和松针的热水提取液可促进该菌菌丝生长;该菌菌丝在配方7培养料上长势最好,菌丝生长动态符合logistic方程:Y=109.6/(1 60.1131e-0.1894x)(y=菌丝生长长度mm,x=培养时间d)。     

不同光增方式和周期对蛋鸡蛋品质和血液生化指标的影响

研究光增方式和光照周期对蛋鸡蛋品质和血液生化指标的影响。将20周龄海兰褐商品蛋鸡320只,随机分为8组,每组4个重复,每个重复10只鸡。试验光照周期采用渐增和骤增2种,光周期设11L∶13D、13L∶11D、15L∶9D、17L∶7D4个水平。结果表明:①不同光增方式对蛋形指数和哈氏单位有显著影响(P<0.05),以渐增条件下较好。不同光增方式对血液生化指标没有显著影响(P>0.05)。②不同光照周期对蛋黄颜色有显著影响(P<0.05),以15L∶9D处理组蛋黄颜色最好。不同光照周期对血液生化指标有一定影响,以13L∶11D处理组较好。     

Physiological and anatomical changes in two rapeseed (Brassica napus L.) genotypes under drought stress conditions

Understanding the mechanisms of drought resistance in crop species is crucial for the selection and breeding of tolerant rapeseed (Brassica napus L.) varieties. The present study aimed to assess the physiological and anatomical responses of two rapeseed genotypes, P287 (drought-tolerant) and T88 (drought-sensitive) under three intensities of drought stress. All physiological and anatomical parameters related to drought acclimation were significantly altered in both genotypes under stress conditions. At the fourth-leaf stage, the relative water content, chlorophyll content, protein content, malondialdehyde content, and the activities of peroxidase and catalase in P287 were significantly higher than those in T88, particularly under severe drought conditions. After rehydration, all physiological indexes recovered rapidly, especially in P287. In addition, under drought stress, compared with T88, P287 had thicker palisade tissue, thinner spongy tissue, higher ratio of chloroplast length to chloroplast width, higher stomatal density and stomatal closure rate. Overall, the interaction between physiological and anatomical features improved the drought tolerance of P287 under drought stress conditions.     

不同锌水平对荷斯坦种公牛血液理化指标的影响

本文旨在研究不同水平的锌对荷斯坦种公牛血液理化指标的影响。试验选取30头荷斯坦种公牛,随机分为5组,单因子饲养试验设计,分别饲喂不同锌水平的日粮,A为对照组,饲喂基础日粮,B、C、D、E组锌的添加水平分别为50、80、110和200 mg/kg(按日粮干物质计),试验期为8个月。结果表明:(1)不同锌水平对荷斯坦种公牛血清中谷草转氨酶(GOT)和谷丙转氨酶(GPT)酶活性影响极显著(P<0.01),对碱性磷酸酶(AKP)和乳酸脱氢酶(LDH)活性无显著影响(P>0.05);(2)不同锌水平对荷斯坦种公牛血清中睾酮含量影响极显著(P<0.01),对血清锌影响不显著(P>0.0 5)。综合分析不同锌水平试验牛生理生化指标的变化得出,锌的适宜添加量为1 1 0 mg/kg日粮干物质。     

6-BA缓解黄瓜弱光胁迫的浓度研究

在温室条件下,研究喷施不同浓度6-苄氨基嘌呤(6-BA)对弱光条件下不同类型黄瓜气体交换参数和叶绿素荧光参数的影响。结果表明,华南型杂交组合‘07QP56’在10 μmol/L 6-BA处理条件下,欧洲迷你型杂交组合‘07QP51’在2,5 μmol/L 6-BA 处理时,可以较为明显地缓解由弱光导致的饱和光合速率(A_sat)、气孔导度(Gs)和蒸腾速率(Tr)降低的现象。同时,10 μmol/L 6-BA处理对缓解弱光下‘07QP56’的PSⅡ潜在活性(Fv/Fo)、原初光能转化效率(Fv/Fm)的降低也有一定的效果。‘07QP51’较‘07QP56’耐弱光,并且对高浓度6-BA处理也更为敏感。