共查询到19条相似文献，搜索用时 156 毫秒
1.
20世纪80年代末到90年代初,肉羊产业快速兴起,而肥羔肉和优质小羊肉的生产成为肉羊业的发展趋势.肉羊的工厂化、集约化生产客观上要求母羊快速繁殖,通过品种引进、杂交改良、人工授精、同期发情、胚胎移植等繁殖新技术的应用大大提高了母羊的繁殖力,肉羊多胎率日益增加[1],这就要求羔羊必须实施早期断奶.采用营养全面、易于吸收的羔羊代乳粉既可以促进幼畜胃和肠道等消化器官的发育[2],同时对母羊的多胎多产和羔羊成活率的提高都具有重要的意义[1].本文综述了代乳粉对早期断奶羔羊生长发育的影响,从而为早期断奶羔羊的快速健康成长提供可靠的保障[3]. 相似文献
2.
3.
4.
5.
肉羊育肥生产实质是在短的时间内，以最低的生产成本获得量多质好的羊肉。根据绵羊屠宰年龄不同，通常将羊肉分成大羊肉和羔羊肉两种。大羊肉指周岁以上脱换过门齿以后的羊肉；羔羊肉指生后不满周岁，还是乳齿的羊肉，其生后4－6个月屠宰的羔羊。
随着冷藏技术的进步，交通运输的发展，以及人民生活水平的不断提高，我国对羊肉的需求量不断增加，而且，我国即将加入WTO，经济将与国际接轨，目前又正在进行西部大开发战略的实施，牧区的羊肉生产也是一个重要的开发项目之一。近年来，肉羊价格稳定，利润较高，羊肉市场前景广阔，加速肉羊生产是时代的需求。下面将羊肉生产的新技术介绍如下：
一、肉羊品种要良种化。我国在短期内应以绵羊、山羊品种资源为基础，引进国外优秀肉羊品种，开展广泛的经济杂交，其关键是筛选和确定适于我国不同地区的最佳杂交组合，并逐步建立相应的杂交繁殖体系。以长远观点看，应培育专门化的肉羊新品种(系)。 相似文献
6.
7.
现代羊肉生产以"优质、高效、生态、有机"为主要内涵,目的是顺应经济社会的发展需要,实现羊肉业的可持续发展。现代肉羊生产的本质要求是,实现从传统放牧饲养向现代工厂化饲养的转变,从粗放经营向集约化经营的转变,进而实现集良种繁育—杂交利用—羔羊育肥—屠宰加工—产品销售于一体的产业化。本文论述的重点有两个,一是从研究肉羊的生产指标体系入手,试图形成现代肉羊的顶层设计,使肉羊的发展更加科学,更加合理,更加高效;二是用现代装备技 相似文献
8.
近年来,世界养羊业呈现出向肉用发展的趋势,我国的肉羊产业也得到了快速发展。在羊肉生产中,尤以二元或三元杂交的6月龄左右、体重在15～16公斤的羔羊肉最受欢迎,瘦肉多、膻味小,特别是胆固醇低。因此,肉用羔羊的生产是我国将来羊肉生产的主要方向。本文就我国华北平原农区肉羔杂交生产的主要技术措施和应注意的问题谈一点看法。 杂交是肉羊生产中提高肉羊生产性能的一个主要手段,亲本选择是保证杂交效果的基础,采用的杂交方式是杂交优势发挥的重要技术保证。 相似文献
9.
10.
11.
Quigley JD Carson AF Polo J 《Veterinary therapeutics : research in applied veterinary medicine》2002,3(3):262-269
Newborn lambs (n = 45) at the Agricultural Research Institute of Northern Ireland were fed either 50 grams of commercial lamb milk replacer or 50 grams of commercial colostrum replacer (bovine origin) in 200 ml of water four times during the first 24 hours of life or were given ad libitum access to the ewe. Total plasma protein at 24 hours of age was highest in lambs allowed to suckle the ewe (76.9 g/L). However, by 14 days of age, there were no differences in plasma protein levels among the three treatments. Bovine IgG was measured in lambs fed colostrum replacer and ovine IgG was measured in other lambs. Mean plasma IgG concentrations at 24 hours of age were 0.7 (milk replacer), 18.0 (colostrum replacer), and 26.6 (dam's milk) g/L. Bovine IgG administered orally to newborn lambs was adequately absorbed, and circulating IgG concentrations were sufficiently maintained throughout this study. 相似文献
12.
Bundza A Sugden EA Nielsen K Hartin KE 《The Canadian veterinary journal. La revue veterinaire canadienne》1982,23(3):102-105
Thirty-four hysterectomy derived, crossbred lambs were fed a commercial, lamb milk replacer, containing added copper from birth. Twenty-five lambs died, four were killed and five survived. At necropsy, generalized icterus, enlarged kidneys and enlarged or small livers were found. 相似文献
13.
AIM: To examine the effects in vitro of bovine milk and milk products and soymilk on the motility of sheathed and exsheathed L3 Ostertagia circumcincta (also known as Teladorsagia circumcincta) as a measure of larval viability and infectivity. METHODS: L3 were exsheathed in 0.2% sodium hypochlorite, resuspended in Hank's Balanced Salt Solution (HBSS) pH 7.4 and incubated with test solutions at 37 degrees C for up to 48 h. The motility of 50 larvae from each incubate was assessed at selected times using a McMaster slide. Larvae were considered immotile only if straight and not moving. Fresh bovine milk, homogenised milk (3.3% fat), low-fat milk (0.2% fat) and lamb milk replacer were diluted with HBSS pH 7.4 to concentrations from 1.6-100%, and incubated with exsheathed L3 for 1, 24 or 48 h. Bovine whey protein was tested in concentrations of 5-15% at pH 2.5-6.5, casein at 5 or 7.5%, and skim milk powder from 5-15% at pH 5.5 or 6.5, all for 2, 4 or 24 h. Soymilk was tested in concentrations of 1.6-100% for 1, 2, 24 or 48 h. HBSS was used as the control solution. Sheathed L3 were incubated in HBSS pH 7.4, 50% homogenised milk in HBSS, or 50% soymilk in HBSS. Each solution was incubated for 1,2, 24 or 48 h. RESULTS: The motility of exsheathed L3 was reduced by fresh bovine milk, homogenised milk, low-fat milk, lamb milk replacer, whey, casein and skim milk solutions, but not by soymilk. The mean percentage (and SE) immotile at 48 h were: fresh milk 38% (SE 20); homogenised milk 65% (SE 7); low-fat milk 57% (SE 5); lamb milk replacer 43% (SE 7); and soymilk 7% (SE 0.5). Larval immotility increased in whey protein solutions from 5-15%, from pH 2.5-6.5 and from 2 to 24 h (all p<0.001); in skim milk from 5-15% (p<0.001), and was greater at pH 6.5 than at pH 5.5 (p<0.001); in casein from 5-7.5% (p<0.001), but was no different at pH 5.5 and 6.5. The motility of sheathed L3 was reduced at 24 h (p=0.009) and 48 h (p<0.001) by 50% homogenised milk, but not by 50% soymilk or HBSS. CONCLUSIONS: Bovine milk proteins, or components associated with the proteins, reduced the motility of both sheathed and exsheathed L3 O. circumcincta. Soymilk had no effect on nematode motility. Lower larval motility may reduce worm establishment and be a contributing factor to the smaller burdens of gastrointestinal nematodes in milk-fed animals compared with animals after weaning. 相似文献
14.
This study examined the time course of rumen metabolic development in the absence of solid feed consumption and the effect of delayed solid feed consumption on sheep rumen development. Twenty-seven lambs consumed milk replacer until slaughter at nine ages from 1 to 84 d (milk group). Three additional lambs consumed milk replacer from 1 to 48 d. From 49 d until slaughter at 84 d, these lambs were weaned onto solid feed (fed group). At slaughter, rumen contents were removed for VFA analysis and rumen epithelium was preserved for morphological examination. Rumen epithelial cells were isolated and incubated in media containing 2.5 mM U-[14C]-glucose or 10 mM 1-[14C]-butyrate. Rumen VFA concentrations did not change with age in lambs given milk replacer. At 84 d of age, intraruminal VFA concentrations were elevated in lambs consuming solid feed compared to 84-d-old lambs given milk replacer (P < .05). The number of ruminal papillae per square centimeter decreased (P < .05) while papillae length and width did not change significantly with age in rumen epithelium from lambs given milk replacer. At 84 d of age, rumen epithelium from lambs in the fed group had fewer and larger papillae/per square centimeter than rumen epithelium from lambs given milk replacer (P < .05). Rates of glucose and butyrate oxidation and acetoacetate and lactate production by rumen cells isolated from lambs given milk replacer did not change with age. Beta-hydroxybutyrate (BHBA) production was undetectable before 42 d of age in lambs given milk replacer and increased to levels found in conventionally raised adults by 84 d. At 84 d there were no differences in rates of glucose and butyrate oxidation or acetoacetate and lactate production by rumen cells between the two treatment groups. Thus, the change in substrate oxidation from glucose to butyrate, indicative of rumen metabolic maturation, does not occur in the absence of solid feed consumption. However, the development of rumen ketogenesis, as evidenced by increased BHBA production, does occur in the absence of solid feed consumption. Delaying the initiation of solid feed consumption results in rumen morphological development but does not stimulate rumen metabolic development. Increased intraruminal VFA concentrations, earlier exposure to VFA, or a longer period of exposure to VFA may be required to induce the genes responsible for rumen metabolic development. 相似文献
15.
The hill-sheep farming industry in Great Britain, in which the ewe flocks are dependent on grazed pastures throughout the year, is described briefly. Research work on the relationships between nutrition and the various components of hill-sheep production (principally ovulation rate, lamb birth weight, milk production and lamb growth rate) has provided an understanding of the biological reasons for current low levels of output, and has led to the development of a new system of management. This is based on the provision of improved nutrition, from higher quality pasture, at the two stages in the annual cycle when sheep production is most responsive to changes in nutrition, i.e. during lactation and in the pre-mating/mating period. In large field-scale tests of the new management system increases of 130 to 290% in the weight of weaned lamb produced have been achieved as a result of combined increases in output per ewe and in ewe numbers. 相似文献
16.
AIM: To examine the effects in vitro of bovine milk and milk products and soymilk on the motility of sheathed and ex- sheathed L3 Ostertagia circumcincta (also known as Teladorsagia circumcincta) as a measure of larval viability and infectivity. METHODS: L3 were exsheathed in 0.2% sodium hypochlorite, resuspended in Hank’s Balanced Salt Solution (HBSS) pH 7.4 and incubated with test solutions at 37°C for up to 48 h. The motility of 50 larvae from each incubate was assessed at selected times using a McMaster slide. Larvae were considered immotile only if straight and not moving. Fresh bovine milk, homogenised milk (3.3% fat), low-fat milk (0.2% fat) and lamb milk replacer were diluted with HBSS pH 7.4 to concentrations from 1.6–100%, and incubated with exsheathed L3 for 1, 24 or 48 h. Bovine whey protein was tested in concentrations of 5–15% at pH 2.5–6.5, casein at 5 or 7.5%, and skim milk powder from 5–15% at pH 5.5 or 6.5, all for 2, 4 or 24 h. Soymilk was tested in concentrations of 1.6–100% for 1, 2, 24 or 48 h. HBSS was used as the control solution. Sheathed L3 were incubated in HBSS pH 7.4, 50% homogenised milk in HBSS, or 50% soymilk in HBSS. Each solution was incubated for 1, 2, 24 or 48 h. RESULTS: The motility of exsheathed L3 was reduced by fresh bovine milk, homogenised milk, low-fat milk, lamb milk replacer, whey, casein and skim milk solutions, but not by soymilk. The mean percentage (and SE) immotile at 48 h were: fresh milk 38% (SE 20); homogenised milk 65% (SE 7); low-fat milk 57% (SE 5); lamb milk replacer 43% (SE 7); and soymilk 7% (SE 0.5). Larval immotility increased in whey protein solutions from 5–15%, from pH 2.5–6.5 and from 2 to 24 h (all p<0.001); in skim milk from 5–15% (p<0.001), and was greater at pH 6.5 than at pH 5.5 (p<0.001); in casein from 5–7.5% (p<0.001), but was no different at pH 5.5 and 6.5. The motility of sheathed L3 was reduced at 24 h (p=0.009) and 48 h (p<0.001) by 50% homogenised milk, but not by 50% soymilk or HBSS. CONCLUSIONS: Bovine milk proteins, or components associated with the proteins, reduced the motility of both sheathed and exsheathed L3 O. circumcincta. Soymilk had no effect on nematode motility. Lower larval motility may reduce worm establishment and be a contributing factor to the smaller burdens of gastrointestinal nematodes in milk-fed animals compared with animals after weaning. 相似文献
17.
Constable PD Ahmed AF Misk NA 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2005,19(1):97-102
Abomasal ulceration occurs commonly in suckling calves, and the cause for the high prevalence of abomasal ulceration is unknown. We hypothesized that diet may play a role in the etiopathogenesis of abomasal ulceration. Six male dairy calves with an abomasal body cannula suckled fresh Holstein cow's milk, all milk-protein milk replacer, or combined milk- and soy-protein milk replacer twice daily at 12% of body weight/d. Abomasal luminal pH was measured every second for 24 hours by using a miniature glass pH electrode. Mean 24-hour abomasal luminal pH for all milk-protein milk replacer (3.22) and combined milk- and soy-protein milk replacer (3.27) were similar but significantly (P < .05) higher than that for cow's milk (2.77; standard error = 0.08). Both milk-replacer formulations failed to clot after the addition of chymosin, whereas cow's milk clotted within 2 minutes. The in vitro titration curve of cow's milk and all milk-protein milk replacer were similar, but different to that of combined milk- and soy-protein milk replacer. The osmolalities of all milk-protein milk replacer (375 mOsm/kg) and combined milk- and soy-protein milk replacer (410 mOsm/kg) were greater than that of cow's milk (278 mOsm/kg). The slightly lower mean abomasal luminal pH in calves suckling cow's milk, compared to milk replacer, was probably due to clotting of cow's milk, with extrusion of low pH whey, and a slower rate of abomasal emptying caused by the hyperosmolality of milk replacer. Examination of our results suggests that suckling cow's milk may increase the prevalence of abomasal ulceration by decreasing mean luminal pH, although this remains to be determined. 相似文献
18.
羔羊早期断奶是利用羔羊代乳料代替母乳,人为缩短母乳哺乳时间。通过实施早期断奶,可促进羔羊生长,提高母羊生产力,获得更高的生产效益。文章就羔羊早期断奶时间、羔羊代乳料的研究现状、早期断奶应注意的问题几方面进行综述,以期为日后羔羊早期断奶技术的研究和生产实践提供参考。 相似文献