铬对肉仔鸡生长性能、免疫功能和胴体品质的影响

用21日龄Arbor Acress(AA)肉公鸡336只,研究饲粮中添加铬对肉仔鸡生长性能、免疫功能和胴体品质的影响。将试验鸡只共分为8个处理组,分别添加源于氯化铬的铬2．0、4．0、6．0、8.0、10．0、12．0和14．0mg/kg。结果表明:饲粮中添加2．0mg/kg铬显著提高了肉仔鸡胸腺重(P<0．10),降低了腹脂率(P<0．10),4．0、6．0mg/kg铬显著提高了全净膛率(P< 0．10),各试验组显著提高了T淋巴细胞转化率(P<0．10);饲粮中添加铬对其余指标则无显著影响(P>0．10)。     

白耳黄鸡生产性能和肉质性状的研究

对白耳黄鸡生长性能、屠宰性能、常规肉质、胸腿肌化学成分、肌肉组织学特性、胸肌氨基酸和脂肪酸含量等指标进行了研究。白耳黄鸡公母鸡的屠宰率、胸肌率、腿肌率、蛋白质含量、氨基酸总量、腹脂率、人体必需氨基酸含量、必需脂肪酸含量等分别为89.23/90.18%,16.65/18.09%,22.37/21.91%,23.64/25.30%,206.29/218.8mg/g,1.64/2.39%,92.78/96.75mg/g,30.69/29.52%。结果表明,白耳黄鸡的各指标都表现优良,其具有屠宰性能好,肉质优良,必需氨基酸和脂肪酸含量高,腹脂率低等特点,是一个值得推广的地方优良品种。     

半胱胺对肉仔鸡生产性能和胴体品质的影响

选择324只AA肉仔鸡随机分成6组,基础日粮中分别添加0、40、60、80、100、120mg/kg的半胱胺饲喂7周,结果表明:①日粮中添加60mg/kg半胱胺显著提高了3周末肉仔鸡的增重8.41%(P<0.05)和胸肌率13.6%(P<0.05)。②日粮中添加100mg/kg半胱胺显著提高了4～7周龄肉仔鸡的增重5.62%(P<0.05),降低料肉比12.97%(P<0.05),提高其屠宰率和胸肌率分别为4.1%(P<0.05)和12.4%(P<0.01),显著降低了肉仔鸡的腹脂率31.6%(P<0.05)。③日粮中添加60mg/kg半胱胺是改善1～3周龄肉仔鸡生产性能和胴体品质的最适剂量,100mg/kg半胱胺是改善生长全期肉仔鸡生产性能和胴体品质的最适添加剂量。     

单色光对蛋白高度、哈氏单位和蛋黄颜色的影响

180只海兰褐蛋鸡分别饲养在蓝、绿、红和白等不同光环境中,试验期为19～45周龄,光照强度为15lx,光照时间为16h。试验结果显示,绿光组蛋白高度最高((7.13±0.04)mm),与白光和蓝光组差异显著(P<0.05);绿光和红光组哈氏单位显著大于白光和蓝光组(P<0.05);白光组蛋黄颜色值(4.6±0.15)最大,与其它组之间差异极显著(P<0.01),但绿光组蛋黄颜色值与周龄间相关系数(r)极显著(P<0.01)。结果表明单色光可影响蛋品质,其中绿光组蛋品质最好。     

猪肉品质营养调控的研究进展

此文从能量、脂肪、蛋白质与氨基酸、维生素、矿物元素及其它一些添加剂等几个方面对猪肉品质营养调控的研究进展进行综述,并提出今后值得关注的几个研究方向。     

穴播条件下株行距对紫花苜蓿种子产量和质量的影响

在甘肃省酒泉市研究了穴播条件下不同株、行距处理对紫花苜蓿种子生产性能的影响，结果表明：在产种第一年（2004年）行距和株距对种子产量和产量构成因素均产生了显著的影响（P〈0．05），随着行距从60cm递增至100cm，种子产量也随之从1240kg／hm^2下降到982kg／hm^2，而各株距处理的种子产量则从15cm的1426kg／hm^2依次递减至60cm的807kg／hm^2；行距60cm和株距15cm组合的产量最高，为1833kg／hm^2，100cm行距和株距60cm组合的产量最低，为753kg／hm^2。株行距的增加显著降低了枝条密度，但结荚花序数／枝条和荚果数／结荚花序却显著提高。品种间种子产量的差异不显著。品种间的结荚花序数／枝条、种子重量、正常种苗率、发芽势和硬实率存在显著的差异（P〈0．05）。     

Haplotype analysis of β-actin gene for its association with sperm quality and boar fertility

β‐actin (ACTB) was examined as a direct functional candidate gene for the possible association with sperm concentration, motility (MOT), semen volume per ejaculate, plasma droplet rate, abnormal sperm rate (ASR) and the fertility traits, non‐return rate and number of piglets born alive (NBA). Three polymorphisms in intron 3 (T>C) and one polymorphism in exon 4 (T>C) of porcine ACTB gene were identified by comparative sequencing of animals of the breeds Pietrain and Hampshire. Association analysis revealed that haplotypes affected the variation of the traits MOT, ASR and NBA. The beneficial haplotypes may provide considerable improvement of sperm quality and fertility in the tested commercial boar population.     

Effects of Cage Location and Tier Level with Respect to Light Intensity in Semiconfined Housing on Egg Production and Quality During the Late Laying Period

This experiment was conducted to determine the effects of cage location and tier level with respect to light intensity on egg production and egg quality of hens housed in a semiconfined facility. Hens (ISA Brown, n = 225) at 75 wk of age were placed into 3-tier cages as top (T), middle (M), and bottom (B) tiers located in cages illuminated artificially (EI), by window (FW), or between corridors (C) for 2 mo. Light intensity was measured monthly for each cage at 5 cm from feeders every 6 h. Egg production was recorded daily and egg quality was assessed biweekly. Light intensity was the greatest for cages in the FW group (151.9, 119.8, and 89.8 lx for tiers T, M, and B, respectively), followed by EI (52.6, 54.5, and 51.0 lx for tiers T, M, and B, respectively), and C (44.5, 23.4, and 4.7 lx for tiers T, M, and B, respectively). Hens at location EI had greater egg production than hens at FW and C. Egg production for hens at tier T was also greater than for hens at tiers M and B. Egg production for hens at EI and C decreased quadratically, whereas that for hens at FW decreased linearly from tiers T to B. Cage location, but not tier level, affected egg weight. Hens at EI and FW produced heavier eggs than hens at C. Shape index, yolk color, and yolk index were independent of cage location and tier level. Hens at EI and FW produced eggs with thinner and weaker shells than hens at C. Moreover, eggshell strength increased linearly from tier T to B. Both albumen index and Haugh unit were the greatest for hens at FW, followed by EI and C. Their responses to cage location varied with tier levels. In conclusion, variation in light intensity in multitier cage systems in semiconfined laying hen houses may be a contributing factor for depressed laying performance and egg quality.     

甜樱桃不同品种贮藏性的研究

通过试验,在常规栽培管理条件下,采用自行研制的甜樱桃专用保鲜剂和专用保鲜袋,预冷48h,于0±0.5℃下冷藏,拉宾斯、雷尼、巨红表现为最耐贮藏,红灯、佳红、红艳较耐贮藏,萨米脱和斯坦勒最不耐贮藏。     

短日照处理天数对一品红开花和观赏品质的影响

 短日照处理不同天数后转到自然长日照下, 研究短日照处理对促成栽培的‘千禧’和‘早生天鹅绒’一品红生长开花的影响。结果表明短日照处理天数对其发育进程、苞片着色和观赏品质有显著影响。苞片转色后结束短日照处理, 节数与连续短日照相似, 但开花显著延迟; 现蕾时结束短日照处理, 开花时间、冠幅与连续短日照相似; 过渡性叶片面积在短日照处理至现蕾后13～14 d才与连续短日照相似。一品红对短日照处理天数的反应存在品种差异。现蕾前结束短日照处理导致一品红过渡性叶片的节间和花梗伸长、苞片着色变差, 出现开花逆转现象。为了保证观赏品质, 短日照处理要持续到现蕾以后。