Effect of Calcium Source in Supplemental Diets on the Growth Performance and Carcass Characteristics of the Giant African Land Snails (Archachatina marginata) in the Western Highlands of Cameroon

To contribute to the diversification of protein sources, the conservation and preservation of the Giant African Land Snails (Archachatina marginata), a study was carried out between March and July 2019 at the Helvy Farms-WVED Cameroon located at Station Bamenda to investigate the effect of three calcium sources on their growth performance and carcass characteristics. 180 juvenile snails aged 4 months initially weighing between 24.2 and 28.5 g, shell length ranging between 40.25 - 48.35 mm, and shell diameter of between 14.08 - 18.44 mm were randomly allotted to 3 treatments containing each a different calcium source (crushed snail shell, eggshell and agricultural limestone) and a control treatment constituted of natural plant feeding materials of the snail. There were 45 snails per treatment, constituted of three replicates with 15 snails per replicate. Each replicate was housed in well-constructed surface trench pens equipped with drinking and feeding troughs. The basal diet made up of feedstuffs like pawpaw leaves and watermelons was provided ad libitum. The initial weights of the snails were recorded at the start of the experiment followed by weekly weight measurements, while the snail length and width were measured with a digital caliper of 0.05 mm accuracy. The snails were monitored for a period of 21 weeks and data was collected for 20 weeks after a 1 week adaptation period. The results showed that the weight gain (g) of snails for diets containing calcium sources in the supplemental diets were all significantly higher (P < 0.05) than the corresponding values recorded for the control diet with natural plant material. It was observed that the shell length (0.34 ± 0.02), shell width (0.16 ± 0.02), weight gain (13.13 ± 0.03) and feed conversion efficiency (1.977 ± 0.11) were highest in snails fed snail shell diet as calcium source compared with snails from other treatments. These values were however not significantly higher than corresponding values for the other two supplemental diets containing eggshell or agricultural limestone. It can be deduced that the snail shell is an important calcium source for growing snails and can be adopted and used in the diets of snails. This will amount to some good methods of recycling in snail production.

Detection of Quantitative Trait Loci Associated with Several Internal Organ Traits and Teat Number Trait in a Pig Population

Quantitative trait loci （QTL） were detected for 8 internal organ traits, 3 carcass length traits, and teat number trait in 214 pigs in a resource population that included 180 F2 individuals. A total of 39 microsatellite markers were examined on SSC4, SSC6, SSC7, SSC8, and SSC13. The genetic traits included heart weight （HW）, lung weight （LW）, liver and gallbladder weight （LGW）, spleen weight （SPW）, stomach weight （STW）, small intestine weight （S1W）, large intestine weight （LIW）, kidney weight （KW）, carcass length to the first cervical vertebra （CL1）, carcass length to the first thoracic vertebra （CL2）, rib numbers （RNS）, and teat numbers （TNS）. Results indicated that, 3 highly significant QTL （P≤0.01 at chromosome-wise level） for HW （at 30 cM on SSC6）, RNS （at 115 cM on SSC7）, TNS （at 110 cM on SSC7）, and 6 significant QTL （P≤0.05 at chromosome-wise level） for LW （at 119 cM on SSC13）, LGW （at 94 cM on SSC6）, SPW （at 106 cM on SSC8）, SIW （0 cM on SSC4）, LIW （170 cM on SSC 4）, and TNS （at 95 cM on SSC6） were detected. The phenotypic variances for which these QTL were accounted ranged from 0.04 % to 14.06 %. Most of these QTL had not been previously reported.

黑线姬鼠胴体重长指标的研究

采用体重与体长的比值作为胴体重长指标KWL',对贵州省余庆县2003～2004年捕获的326只黑线姬鼠(其中,雌鼠160只,雄鼠166只)进行分析研究,结果表明:黑线姬鼠胴体重长指标在1.31～3.25,平均为2.09±0.38, 雌雄鼠胴体重长指标之间无显著差异;不同年龄组之间胴体重长指标差异极显著,且随着种群内年龄的增长,胴体重长指标逐渐增加;不同生境胴体重长指标差异显著;不同月份之间胴体重长指标具有一定差异,在4～5月和8～9月出现2个高峰期,其季节变化趋势为春季最高,夏季较高,秋季较低,冬季最低.黑线姬鼠胴体重长指标与种群繁殖密切相关.

不同尸体材料上蝇类滋生及丝光绿蝇Lucilia sericata生长发育比较

为了探明不同动物尸体上蝇类滋生及生长发育的差异，放置不同尸体材料于杭州室外诱使蝇类滋生，同时在室内２４℃恒温下用以上尸体材料饲养丝光绿蝇。结果表明：在灵长类、猪、牛等动物材料上滋生的蝇类种类及各种类的大体数量没有明显差异；２４℃下在所有尸体材料上丝光绿蝇的发育历期没有显著差异；对幼虫及蛹体长多重比较，表明体长在灵长类、猪、牛、鱼等之间差异不显著。

绵羊IQCA1、PARS2及ANO7多态性与胴体性状的关联分析

旨在探究IQCA1、PARS2及ANO7多态性与胸椎数和胴体长的相关性,筛选提高绵羊胴体品质的重要分子标记。利用Sequenom MassARRAY^(■)SNP技术检测苏尼特羊和小尾寒羊2个绵羊群体与胴体性状相关候选基因IQCA1、PARS2及ANO7单核苷酸多态性(SNPs)位点,进行群体遗传学分析,并与表型性状进行关联分析。结果表明,IQCA1基因g.4692837G>A,PARS2基因g.30789785C>T、g.30789946T>A、g.30789995C>T、g.30790544T>C和ANO7基因g.535119G>A、g.535343T>C、g.541221C>T、g.541186T>C共计9个SNPs位点在小尾寒羊和苏尼特羊中均与胸椎数不显著相关(P>0.05)。SNPs与胴体长相关性分析结果表明,小尾寒羊群体中,IQCA1 g.4692837G>A,PARS2 g.30789785C>T、g.30789946T>A、g.30789995C>T、g.30790544T>C,ANO7 g.535119G>A、g.535343T>C、g.541221C>T、g.541186T>C位点均与胴体长不显著相关(P>0.05)。综上所述,在苏尼特羊群体中,IQCA1、PARS2与ANO7的SNPs位点与胸椎数性状均不显著相关。在小尾寒羊群体中,IQCA1、PARS2与ANO7的SNPs位点与胸椎数和胴体长性状也均不显著相关。

苜蓿干草颗粒长度对羔羊生产性能、消化和胴体特性的影响

本试验以36只平均体重为24kg、约3月龄的羔羊为研究对象,研究饲粮中苜蓿干草颗粒长度对其生长性能、消化、氮平衡和胴体特性的影响。将羔羊随机分配为3个日粮处理:9.5和14mm日粮组(苜蓿草加工成9.5和14mm颗粒长度,与浓缩料和全混合日粮混合)以及长苜蓿草日粮组[苜蓿草切碎长度为(17.8±2.4cm)],所有处理日粮的营养成分基本保持一致。所有羊羔在饲喂14周后屠宰。结果 :在9.5mm和14mm苜蓿干草日粮中,超过77%的苜蓿干草长度分布在> 6.4~16.3mm之间以及> 10.1~21mm之间。在较短颗粒长度(<3.8mm)所占比例中,9.5mm和14mm的颗粒长度之间没有显著差异(P <0.05)。羔羊采食9.5mm较14mm长度的苜蓿干草日粮有更高的末重、平均日增重和饲料转化率(P <0.05)。长苜蓿干草较9.5mm的苜蓿日粮酸性洗涤纤维、中性洗涤纤维表观消化率以及尿氮排泄量分别提高8.18%、11.46%和19.3%(P <0.05),而9.5mm的苜蓿日粮较其他两组氮沉积量分别提高8.01%和5.55%(P <0.05)。9.5mm的苜蓿日粮较其他两组热胴体重和胴体蛋白质含量分别提高3.56%、3.15%和4.89%和18.49%(P <0.05)。与长苜蓿干草组相比,9mm的苜蓿颗粒日粮可分离瘦肉和胴体粗脂肪含量提高6.28%和18.49%(P <0.05),但水分含量降低4.78%(P <0.05)。结论 :本研究条件下,在不改变羔羊干物质摄入量的基础上,降低全混合日粮中苜蓿草颗粒长度可以提高羔羊生长性能,且与较长切碎长度相比,羔羊育肥效率更高。