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91.
山毛豆草粉颗粒料对肉兔的饲用价值评定 总被引:1,自引:0,他引:1
为探讨山毛豆(Tephrosia candida)草粉对肉兔的饲用价值,将60只新西兰青年肉兔分为5组,分别添加0%(对照),10%,20%,30%和40%的山毛豆草粉制成全价颗粒饲料,饲喂90 d后测定各组饲料的营养成分及肉兔采食量、日增重、料重比和屠宰性能.结果表明:山毛豆营养生长期粗蛋白含量为17.77%,肉兔对山毛豆中粗蛋白的消化率为78.09%,山毛豆的可消化总养分为56.18%.与对照组相比,添加20%草粉日增重达到20.80 g·d-1(P<0.01);料重比为4.45∶ 1(P<0.05);屠宰率为57.78%(P<0.01);单位kg增重平均最低饲料成本差异显著(P<0.05).因此,添加20%山毛豆草粉制成全价颗粒饲料可显著提高肉兔的生产性能和养殖效益. 相似文献
92.
作者约翰·瓦德斯沃思(John Wadsworth)先生是Intermark的总经理。他以英国国内研究为依托,在世界人造板领域从事研究和咨询工作已经有27年之久,在业界享有极高的威望。现将英国《国际木质人造板》2010年第3期杂志上约翰·瓦德斯沃思(JohnWadsworth)先生撰写的2009年度世界中密度纤维板生产能力调查这篇文童翻译成中文,以飨读者。文章以截止2009年12月欧洲和北美地区中密度纤维板生产能力一览表为依据,详细阐述了中密度纤维板市场的过去、现在和将来。 相似文献
93.
甘肃省干旱半干旱地区降水的研究 总被引:1,自引:1,他引:1
本文通过对甘肃省降水资料的具体分析,指出了在干旱、半干旱地区降水的主要特征,如暴雨的特殊性、固体降水与海拔关系、降水量与海拔关系、降水量与作物产量关系等,并对如何提高降水利用率,发展农业生产等问题进行了探讨。 相似文献
94.
体外培育赤眼蜂研究进展 总被引:2,自引:0,他引:2
体外培育赤眼蜂的国内外研究已达到相当平:随着人工饲料配方的优化,选用的人工卵壳材料更适合于赤眼蜂的寄生与发,以及人工卵卡机的研制成功和性能不断改进,产业化体外培育赤眼蜂已成为可能。体外培育赤眼蜂的品质管理问题是实现产业化体外培育赤眼蜂的关键。然而,国内外对体外培育赤眼蜂的品质管理研究涉及甚少,有待进一步研究。本文指出应开展体外培育赤眼蜂生物学特性、行为学特性和分子生物学特性的研究,并应用于品质管理,建立体外培育赤眼蜂的品质管理体系,促进实现体外培育赤眼蜂产业化的进程,从而满足农业生产上对赤眼蜂种群的大量需要。另外,人工卵滞育贮存法的突破有助于实现体外培育赤眼蜂的产业化,也应加强研究,最后,本文对体外培育赤眼蜂的应用前景进行了展望。 相似文献
95.
畜以猪为主,肉以猪肉为主是渭北旱塬畜牧业资源及生产配置的基本格局,这种格局既不利于区位资源优势的充分发挥形成畜产优势,促进畜牧业发展;也不利于食物结构的改善和消费水平提高。为此本文从渭北畜牧业资源配置、生产配置现状问题出发,运用模糊数学、系统工程等原理,通过定性定量分析,提出了该区畜牧业资源及生产配置的战略思想。 相似文献
96.
Retrospective analysis of trends and production factors associated with sow mortality on swine-breeding farms in USA 总被引:2,自引:0,他引:2
Koketsu Y 《Preventive veterinary medicine》2000,46(4):249-256
Of the 825 pig farms in USA that mailed in their electronic file containing production records, 604 farms were used to observe breeding-female mortality risk and related factors (herd size, lactation length, parity and season). Multiple regression was used to determine factors associated with annual mortality risk. Analyses of variance were used for comparisons of mortality risks among parity and season groups. Average annual mortality risks during the 1997 period was 5.68%. Average breeding-female inventories and average lactation length on USA farms were 733 and 18.3 days, respectively. Higher annual breeding-female mortality risk was associated with larger herd size, greater parity at farrowing and shorter lactation length (P<0.02). For example, as herd size increases by 500 females, mortality risk increases by 0.44%. Older parity was associated with higher mortality risks. Summer season was also associated with higher mortality risk. Using five-years’ records on 270 farms, annual mortality risk in 1997 was higher than those of 1993 and 1994, while average breeding-female inventory increased and lactation length decreased. It is recommended that producers, especially in large herds, pay more attention to breeding females. 相似文献
97.
A Weibull mixed survival model was used to study the effect of a change in the housing system on length of productive life (LPL) in dairy cows. The data set included records on 71,469 Swiss Brown cows in 1674 farms in eastern and central Switzerland. About 36% of the records were right-censored. The observation period lasted from January 1, 1988 to May 1, 2001. During this period, 517 farms changed their housing conditions from a tie-stall barn to a loose housing system. Besides a random time-dependent effect of herd–year–season, the model included fixed effects of housing system, lactation number and stage of lactation, within herd and parity production level (all time-dependent), and age at first calving (time-independent). All effects had a significant effect on LPL at a level of p < 0.001. Cows in loose housing systems showed the lowest risk ratios of being culled (0.93) compared to the reference system tie-stall barn (1.00). The highest relative culling rate (1.09) was observed within the changing period from tie-stall barn to loose housing system. Within the first three lactations, the relative culling risk increased stepwise with lactation stage. The hazard slightly increased from first until lactation number 8 and higher. The relative culling rates were highest (2.22) for cows yielding less than 90% compared to herd-mates of the same lactation number, whereas the lowest risk ratios were estimated for animals yielding more than 110% compared to their reference group (0.64). When heifers were older than 3 years at first calving, there was a tendency towards a higher relative culling risk (1.06). 相似文献
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