Finding best exotic breed proportion in crossbred lactating sheep kept under farmers’ conditions in Ethiopia determined by use of nested Legendre polynomials with limited data

ABSTRACT

The present study was conducted to estimate milk production performance and fit lactation curves for groups of ewes of Local and of Awassi crosses, with a variable blood level, reared under farmer’s environment. The Weigh-Suckle-Weigh method plus hand milking was used to estimate milk yield for ewes. A total of 466 observations from 115 ewes were used. Estimated least-squares adjusted means for the milk production over 120 days were 0.56?kg day^?1 (Local), 0.67 (<30% Awassi), 0.86 (30–50% Awassi), and 0.96 (>50% Awassi). Groups with 30–50% Awassi and >50% Awassi ewes produced significantly (p?<?0.05) more milk than Local ewes. Significant differences were observed between <30% Awassi and >50% Awassi crossbred groups. The best crosses (>50% Awassi) produced over 70% more milk than the local ewes which demonstrates the potential that exists in increasing milk production through the initiated crossbreeding programme with sheep in Ethiopia.     

非洲猪瘟与典型猪瘟的诊断与防控

2018年8月,我国首例非洲猪瘟疫情在辽宁省沈阳市被确诊,该病的确诊以及原先存在的典型猪瘟必然会对我国养猪业健康发展造成冲击和影响。对非洲猪瘟和典型猪瘟的病原学、流行病学、诊断技术和防控4个方面进行了综述,以期为非洲猪瘟和典型猪瘟的有效综合防控提供参考。     

Reproductive parameters of the chub mackerel <Emphasis Type="Italic">Scomber japonicus</Emphasis> estimated from human chorionic gonadotropin-induced final oocyte maturation and ovulation in captivity

ABSTRACT:   Final oocyte maturation and ovulation of captive chub mackerel Scomber japonicus with fully yolk-accumulated oocytes were induced by a single injection of human chorionic gonadotropin. Reproductive parameters, including spawning frequency and batch fecundity, which are required to estimate spawning biomass in pelagic fish by the daily egg production method, were analyzed. Germinal vesicle migration (GVM) occurred at 18–24 h post-injection, and the hydration and ovulation of oocytes were completed at 30 and 36 h post-injection, respectively. The results of the maturation process suggest that fish with GVM-stage ovaries captured in the daytime from the field are capable of spawning on the night following their capture. The oocytes used in the oocyte size-frequency distribution method for batch fecundity estimates should be at late GVM and more advanced stages. The results of sequential artificial insemination showed that the quality of ovulated eggs held in the ovarian lumen rapidly deteriorated as time progressed after ovulation. This indicates that the fertilization window for the ovulated eggs of chub mackerel lasts only a few hours, and spawning behavior should be performed within a few hours after ovulation in the wild population.     

Monophyly and infrageneric variation of Corispermum L.(Chenopodiaceae),evidence from sequence data psbB-psbH,rbcL and ITS

Corispermum is one of the most problematic taxonomic genera in Chenopodiaceae.To understand the phylogeny and infrageneric variation of Corispermum,we sequenced the nuclear ribosomal ITS region and two chloroplast DNA regions(rbcL and psbB-psbH) of 22 species and three varieties of Corispermum and the related genus Agriophyllum.Several representative species of Salsola,Suaeda,Chenopodium,Kalidium and Camphorosma served as outgroups.Our phylogenetic trees confirm that the tribe Corispermeae is monophyletic,Corispermum and Agriophyllum have a close relationship.Corispermum is demonstrated to be monophyletic,and contains at least four clades which,consequently,are served as the foundation of the infrageneric sectional variation of Corispermum,in terms of a combination of molecular data and morphological characters.The evolution of morphological characters for fruit wing and apex,two important characters in generic classification,is consistent with the sectional division of Corispermum,especially to the East Asian and Chinese taxa.     

乙烯利、多效唑及修剪处理对盆播早熟禾的影响

为寻求减少草坪修剪次数以节约人力、物力的可行措施,本研究采用乙烯利和多效唑两种生长延缓剂对盆播早熟禾进行分别处理,并同时设修剪试验进行对照研究。结果是:在本试验所采取的剂量范围内,乙烯利使盆播早熟禾叶片枯死脱落,再生叶片窄小挺立,节间伸长和整株早衰;多效唑具有延缓盆播早熟禾生长的功能,且随着用量加大,延缓生长作用增强,多效唑还有使叶片变窄变小、绿色加深和更加鲜柔的作用。在本试验所选择的留茬高度和修剪频率条件下,修剪促进盆播早熟禾的生长,并抑制其分蘖和草皮层发育。与修剪试验对比,多效唑处理确可减少修剪次数。     

更新观念创新服务

饲料工业在我国是一个新兴的产业,是涉及农业、化工、轻工、机械、医药、商业、电子等多学科、多部门综合性的产业,依附于种植业,服务于养殖业的农用工业,在国民经济中,是一个腾飞的朝阳工业。北京饲料工业是从20世纪70年代开始崛起,特别是改革开放以来,在市委、市政府的高度重     

宁南黄土丘陵区坡耕地土壤侵蚀对土地生产力影响研究

坡耕地土壤侵蚀对土地生产力的影响表现在多方面 .该文运用模拟侵蚀方法 ,对宁夏西吉县黄土丘陵区坡耕地表层土壤发生不同程度侵蚀后 ,表土养分流失、作物产量和生物量下降的状况进行了定量测试分析 .结果显示 :①耕作层 (0～ 2 0cm)土壤肥力指标有机质、全N、碱解N、全P分别比下层土壤 (2 0～ 6 0cm)高 14 2 % ,12 0 % ,37 3%和 9 2 % ,且流失土壤的养分富集现象明显 .②种植春小麦和豌豆的坡耕地 ,每流失 1cm表土 ,产量分别下降 1 9%～ 3 1%和 2 0 %～ 2 6 % ,而马铃薯和胡麻产量分别降低 0 9%～ 1 0 %和 0 9%～ 1 5 % .③发生强度和剧烈侵蚀的坡耕地 ,每年农作物产量下降幅度为 0 35 %～ 1 76 %和 1 0 7%～ 3 36 % .     

影响老瓜头泌蜜量主导因素的研究

老瓜头自然分布于沙漠地带。在老瓜头开花期,天气变化无常。我们研究了对老瓜头泌蜜量起关键影响作用的气象因子。根据当地气候的变化规律进行预测预报,指导养蜂者正确选择场地,以夺取老瓜头蜜高产。     

Pastoralists’ perceptions of feed scarcity and livestock poisoning in southern rangelands, Ethiopia

A survey was conducted between April and July 2007 to generate information on dry season feeding management and livestock poisoning in the southern rangelands of Ethiopia. A total of 119 pastoralists were interviewed using a semi-structured questionnaire. Moreover, additional information was obtained through informal discussions. The study revealed that pastoralists have rich knowledge of natural resource management and utilization and employ various strategies such as migration, collection of grasses and pods, and cutting branches to overcome feed scarcity during dry/drought periods. Migration of livestock and people to areas with better grazing is the widely used strategy. However, the implementation of this strategy is diminishing as a result of changes such as bush encroachment, expansion of settlements, and crop cultivation in dry-season grazing lands. The respondents also indicated the presence of poisonous plants in the rangeland, and about 20 such plants were identified by the respondents. Various species and classes of livestock are reported to be affected by toxic plants particularly in the dry and early rainy seasons when feed is in short supply. A more extensive survey is required to document all poisonous plants in the rangelands and to identify the major toxic principles in the different species. Future development interventions should consider the prevailing constraints and potentials of the rangelands with active participation of the pastoralists.