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91.
Masahiro Osada Hitomi Iwabuchi Toru Aoki Kika Sasaki Hitoshi Ushijima Takeyuki Ozawa 《Animal Science Journal》2019,90(4):597-603
Artificial insemination using sex‐sorted semen is employed to efficiently increase the number of female dairy calves born. Previous studies have determined that using sex‐sorted semen is beneficial to improve the management, but the mechanism by which it increases cattle numbers through objective indices of breeding remains unclear. This study focused on a Brown Swiss cattle herd in which frozen female sex‐sorted semen was systematically employed to increase the number of cattle. We analyzed the correlation between the increase in the number of cattle and the screening accuracy of sex‐sorted semen, measuring indices such as pregnancy rate and birth rate of female calves. Study revealed that: (1) production cost for female calves is influenced by the pregnancy rate, rate of female calves, and using sex‐sorted semen is less expensive than using nonsorted semen; (2) improvements in screening accuracy nearly doubled the number of cows and tripled the number of heifers in 5 years; and (3) use of sex‐sorted semen improved milk quality. The pregnancy rate was lower when sex‐sorted semen was used, but the birth rate of heifers was improved. Results suggest that artificial insemination using sex‐sorted semen is beneficial because it economically produces offspring to increase the herd. 相似文献
92.
近几年来,南宁的许多中华蜜蜂(以下简称中蜂)养殖场经常出现麻色蜜蜂和黄色蜜蜂混同一起的种群(简称双色群),引起中蜂养殖者的高度关注。笔者在南宁市吴圩镇(广西国有七坡林场)定地养殖中蜂十余年,每年都有少量双色蜂种群出现,为此对双色中华蜜蜂进行了详细观察、记录、验证,认为双色蜂不是一个独立品种,是外来黄色蜂种与本地麻色蜂种杂交的结果。 相似文献
93.
本文利用天然食品资源乌贡糙米为原料配合大豆、麦仁和蛋白糖生产乌贡糙米粉,通过乌贡糙米粉的生产工艺达到营养互补,方便食用,是老人、儿童、体弱病人的食疗、休闲食品。 相似文献
94.
去苞叶对玉米子粒脱水过程的影响 总被引:1,自引:1,他引:0
95.
Michelle Wen San Lim Kar Mem Tan Lye Yee Chew Kin Weng Kong 《Journal Of Aquatic Food Product Technology》2018,27(4):446-463
Two-level full factorial design was employed to identify the extraction parameters that can improve the derivation of fucoxanthin content (FC), total carotenoid content (TCC), and antioxidant from two brown seaweeds, Sargassum siliquosum (SS) and Sargassum polycystum (SP). These parameters included temperature (A: 4–45°C), time (B: 30–1,440 min), and solvent-to-solid ratio (C: 10–50 ml/g). Antioxidant activities were determined as trolox equivalent antioxidant capacity (TEAC), 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activity, and ferric-reducing antioxidant power (FRAP). Results showed that all three factors were significant (p < 0.05) in providing higher FC in both species. These factors were also significant in obtaining higher TCC in SS; whereas in SP, TCC was only affected by solvent-to-solid ratio. Only temperature was found to contribute significantly to a higher TEAC in both species. However, none of the factors improved DPPH for SS, except temperature and time for SP. For SS, only time was significant in obtaining higher FRAP; whereas temperature and time were significant for SP. Hence, results indicate that a simple modification in the extraction temperature, time, and solvent-to-solid ratio will be able to improve the derivation of fucoxanthin, carotenoids, and antioxidant activities. 相似文献
96.
洛川近地层夜间气温逆温特征及空气扰动防霜可行性分析 总被引:1,自引:1,他引:0
为了更加有效地在洛川开展苹果花期霜冻预防技术试验与推广,笔者利用洛川县苹果园梯度观测塔观测的温度、风速数据,采用数理统计方法,分析了洛川近地层夜间气温逆温特征。结果表明:洛川春季辐射降温时,逆温持续时间长、温差大、风速小,具备开展空气扰动防霜的基本条件。洛川逆温出现时间与日出日落时间密切相关,日落后逆温形成,日出后逆温消失。逆温的平均强度为0.7~0.8℃,在冬季最大值出现在午夜,春季(4—5 月)最大值出现在凌晨。春季出现辐射霜冻时,近地层平均逆温强度在2℃以上,最大值可达4℃。逆温的出现受天气影响,当夜间为阴天或有降水时,逆温不会形成。风速对逆温的形成及强度影响极大,当春季夜间风速大于2.5 m/s时,逆温基本上也不存在。 相似文献
97.
Halyomorpha halys (Stål) (Hemiptera: Pentatomidae) is an invasive species that has become an important orchard pest in the Mid-Atlantic region of the US. Adults and nymphs feed on tree fruit. Feeding injury from adults has been characterized but the injury from nymphs has not been examined systematically. Since the four plant-feeding instars of H. halys (second through fifth) differ substantially in size, it is plausible that the effects of their feeding on fruit injury and injury expression may differ among them. We compared feeding injury at harvest from young nymphs (second plus third instars), older nymphs (fourth plus fifth instars), and adults that were caged on ‘Smoothee Golden’ apples and ‘Redhaven’ peaches in early June (peach and apple), late July (peach), and late August (apple). Individual apples and peaches were caged at fruit set and assigned to the following treatments (n = 28/treatment): 1) control (no H. halys), 2) young nymphs or 3) adults early in the season, and 4) young nymphs, 5) older nymphs or 6) adults later in the season. Fruit in each treatment were exposed to 3–4 young nymphs, two older nymphs or 1–2 adults placed in the cages for 96 h and evaluated for external and internal feeding injury within 36 h after harvest. No injury was recorded from unexposed peaches or apples. The percentage of injured fruit and number of injuries per fruit varied significantly among the exposed treatments. Early season feeding by young nymphs yielded the least injury to peaches and apples. In apples, the highest percentage of injured fruit and number of injuries per fruit were caused by late season feeding by adults. In peaches, early season adult feeding produced the highest percentage of injured fruit and injuries per fruit. More internal than external injury was recorded on peach and no such difference was observed on apple. The implications of these findings on H. halys management in fruit orchards are discussed. 相似文献
98.
99.
The loss, fragmentation and degradation of native vegetation are major causes of loss of biodiversity globally. Extinction debt is the term used to describe the ongoing loss of species from fragmented landscapes long after the original loss and fragmentation of habitat. However, losses may also result from habitat changes that are unrelated to fragmentation, which reduce breeding success and recruitment. Many woodland birds have declined in fragmented landscapes in Australia, probably due to loss of small, isolated populations, though the ecological processes are poorly understood. We record the progressive regional loss of two ground-foraging, woodland birds, the Brown Treecreeper Climacteris picumnus and Hooded Robin Melanodryas cucullata, in northern New South Wales, over 30 years. This has happened despite most habitat loss occurring over 100 years ago, suggesting the payment of an extinction debt. Our observations suggest that several ecological processes, caused by habitat loss, fragmentation or degradation, and operating over different time scales, have led to both species’ declines. Female Brown Treecreepers disperse poorly among vegetation remnants, leaving only males in isolated populations, which then go extinct. In contrast, Hooded Robins suffer high nest predation in fragmented landscapes, producing too few recruits to replace adult mortality. Foraging by both species may also be affected by regrowth of ground vegetation and shrubs. We found little support for a major role played by drought, climate change or aggressive Noisy Miners Manorina melanocephala. We propose that both extinction debt in the classical sense and ongoing habitat change frequently contribute to species’ decline in modified landscapes. Management to arrest and reverse such declines needs to consider these multiple causes of decline. For instance, reconnecting isolated populations may be inadequate alone, and activities such as appropriate grazing, fires and the addition of woody debris may also be required. 相似文献
100.
十和田近等基因系糙米锌含量QTL定位 总被引:3,自引:0,他引:3
以十和田为轮回亲本,丽粳2号为供体亲本培育出糙米锌含量近等基因系群体BC5F6为材料,从遍布水稻12条染色体上的600对引物中筛选到一个与糙米锌含量有关的SSR标记RM4608.根据其在水稻染色体上的位置,结合PCR扩增结果又发现了与糙米锌含量有关的4个SSR标记(RM19491,RM19489,RM6119和RM19487).用MAPMAKER3.0软件做出了这5个标记的连锁群,最后采用混合线性模型定位法找到了糙米锌含量的QTL位点.QTL分析结果显示:该位点位于6号染色体上RM4608和RM6119标记之间,贡献率为5%,为新发现的与糙米锌含量有关的微效基因位点,暂命名为qZINC-6.同时与糙米铬和镁含量有关的QTL位点也被发现,其中糙米铬含量QTL位于标记RM19489和RM19491之间,贡献率为9%,是一个主效基因;糙米镁含量QTL位于标记RM4608-RM6119之间,是一个微效基因,贡献率为4%. 相似文献