影响断奶仔猪采食量的主要因素

断奶仔猪采食量不仅影响断奶后早期生长发育,且对整个生长期的生产性能也具有关键性作用。断奶前补饲,断奶后日粮的物理形态、气味与味道,饲料消化率,以及饮水、光照、饲养密度都对其采食量具有重要的影响。可采取针对性措施来降低断奶应激,提高采食量,进而提高养猪生产效益。1饲料形态引起断奶仔猪应激的一个重要因素,就是仔猪从吸吮液态饲料转变为采食固态干饲料,并且还需学习分别采食和饮水。所以,改变饲料形态,采用湿料和糊状料,是提高断奶仔猪采食量及生长性能的一个有效办法。采食量可提高9.5%~11.0%。2断奶前补饲在哺乳后期对仔猪给…     

仔猪断奶后为什么生长缓慢

美国和英国科学家研究证明,仔猪在断奶后头7天里采食量不能满足维持需要.美国试验人员研究21日龄断奶仔猪发现,在断奶后第一天,只进食维持需要量的10%,第三天接近维持需要,第一周生长速度从断奶前的250克/天下降到57克/天.采食量的降低是由于仔猪     

哺乳仔猪断奶时乳糖需求的研究进展

断奶时期的营养和生活环境改变会导致仔猪生理出现显著变化。仔猪断奶后通常表现出采食量低、饲料转化效率差、生长速度放慢和肠道紊乱发生率高等。     

哺乳期和断奶后颗粒直径对哺乳仔猪和断奶仔猪采食量的影响

正断奶对于仔猪来说是一种应激,伴随着断奶后几天较低的养分摄入(Bruininx等,2002)、较低和变异的生长速度,甚至失重(Pajor等,1991)。断奶后较低的采食量与受损的肠道结构和功能相关,从而增加对肠道病原体的易感性,导致消化混乱的发生(e.g.,Van Beers-Schreurs,1996)。一些研究已经证明,哺乳期教槽料的摄入与断奶早期采食量和生长性能正相关(Bruininx等,2002;Kuller     

乳清粉在断奶仔猪饲料中应用的研究进展

仔猪断奶后从吮吸口感好、易消化的液体母乳突然转到采食以复杂碳水化合物和植物蛋白为基础的干料，应激十分强烈（Miller等1984），生长受阻。仔猪在断奶后前7天或前10天的低采食量被认为是导致仔猪断奶后生长受阻的主要原因（Meade等1965），     

酵母核酸对断奶仔猪生产性能的影响

已有研究证实,断奶仔猪对核苷酸的需要量很高,但核苷酸以及合成核苷酸的前体物摄人量却很低.添加酵母核酸能够增加断奶仔猪采食量,改善消化吸收,提高生长速度,但酵母核酸对处于夏季热应激情况下断奶仔猪生产性能的影响还未见报道.     

两种诱食剂饲喂断奶仔猪试验

乳猪早期断奶,通过诱食提前乳猪的采食时间、提高采食量尤为重要,仔猪断奶后可以由饲料中获得充足全面的营养,取得较好的生产成绩,已在生产中广泛应用.本试验旨在比较top#98和奶猪香在减少仔猪断奶应激、增加断奶仔猪的采食量、提高断奶仔猪生产成绩方面的作用,为今后生产提供科学依据.     

仔猪采食量的影响因素分析

断奶对仔猪是一大应激,仔猪断奶后的健康及生长与刚断奶仔猪的采食量息息相关。文章分析动物因素、神经递质和激素、饲料营养、环境因素和哺乳期补饲对采食量的影响,对减少仔猪断奶应激和提高养猪经济效益具有积极作用。     

液体开食料可以缓和断奶应激

满足断奶前仔猪的营养需求是一项挑战性工作。一种新的方法是,通过安装在每个产床内的内的自动化饲喂系统来饲喂液态开食料。试验结果表明,这一方法可以增加仔猪的采食量,提高其生长速度。     

仔猪断奶技术

1 断奶前母猪减料。仔猪断奶前的5～6d，每1d适当减少母猪精饲料的供给量，以减少母猪泌乳量，促使仔猪多吃饲料。减少精料喂量还可防止母猪发生乳房炎。2 仔猪断奶日龄必须适宜。以仔猪35～42日龄，体重达5kg以上，日采食量达150g以上断奶为宜。3 避免应激因素影响。仔猪进行免疫注射、割骟时应暂缓断奶，因为这些因素会加重断奶应激。体弱的仔猪应待体重和采食量达到断奶要求时，再行断奶。4 实行逐渐断奶法。为避免仔猪断奶后，因环境和营养方式变化而产生不适，要实行逐渐断奶法断奶。具体步骤为：第1d仔猪哺乳5～6次，吃完奶即与母猪分…     

Correlation between age at neutering and age at onset of hyperadrenocorticism in ferrets

OBJECTIVE: To determine prevalence of hyperadrenocorticism in ferrets in The Netherlands and evaluate age, sex, and age at neutering in affected ferrets. DESIGN: Prevalence survey and retrospective study. ANIMALS: 50 ferrets with hyperadrenocorticism and 1,267 ferrets without hyperadrenocorticism. PROCEDURE: A questionnaire was sent to 1,400 members of a ferret-owners organization in The Netherlands; 492 (35%) owners returned the questionnaire, providing usable data on 1,274 ferrets. Seven of these ferrets developed hyperadrenocorticism during the survey period; medical records for these ferrets and 43 ferrets with confirmed hyperadrenocorticism were reviewed. Hyperadrenocorticism was confirmed by histologic examination of an excised adrenal gland (92% of ferrets) or clinical improvement after excision. RESULTS: Prevalence of hyperadrenocorticism in the survey population was 0.55%. Sex was not associated with prevalence of disease. Median time interval between neutering and diagnosis of hyperadrenocorticism was 3.5 years. A significant linear correlation between age at neutering and age at time of diagnosis was detected. CONCLUSIONS AND CLINICAL RELEVANCE: Age at neutering may be associated with age at development of hyperadrenocorticism in ferrets.     

动物饲料中补加铬进入新纪元

印度的研究显示,铬可降低肉鸡腹脂的沉积;中国台湾的试验表明,铬可降低鸡蛋中胆固醇的水平;中国大陆的研究发现,铬提高了种蛋的孵化率。 在过去的几年里,动物营养学家对铬产生了极大的兴趣。许多人在谈到铬时就会联想到它是有毒的。然而,只有6价的铬才是有毒的。3价的铬是安全无毒的,可用作营养元素补加到动物饲     

Long-term outcome of gonadectomy performed at an early age or traditional age in dogs

OBJECTIVE: To determine long-term results and complications of gonadectomy performed at an early age (prepubertal) or at the traditional age in dogs. DESIGN: Cohort study. ANIMALS: 269 dogs from animal shelters. PROCEDURE: Dogs that underwent gonadectomy were allotted to 2 groups on the basis of estimated age at surgery (traditional age, > or =24 weeks old; prepubertal, < 24 weeks old). Adoptive owner information was obtained from shelter records, and telephone interviews were conducted with owners to determine physical or behavioral problems observed in the dogs since adoption. Follow-up information was obtained from attending veterinarians for dogs with complex problems or when owners were uncertain regarding the exact nature of their dog's problem. RESULTS: Prepubertal gonadectomy did not result in an increased incidence of behavioral problems or problems associated with any body system, compared with traditional-age gonadectomy, during a median follow-up period of 48 months after gonadectomy. Rate of retention in the original adoptive household was the same for dogs that underwent prepubertal gonadectomy as those that underwent traditional-age gonadectomy. Infectious diseases, however, were more common in dogs that underwent prepubertal gonadectomy. CONCLUSIONS AND CLINICAL IMPLICATIONS: With the exception of infectious diseases, prepubertal gonadectomy may be safely performed in dogs without concern for increased incidence of physical or behavioral problems during at least a 4-year period after gonadectomy.     

Long-term outcome of gonadectomy performed at an early age or traditional age in cats

OBJECTIVE: To determine long-term results and complications of gonadectomy performed at an early age (prepubertal) or at the traditional age in cats. DESIGN: Cohort study. ANIMALS: 263 cats from animal shelters. PROCEDURE: Cats that underwent gonadectomy were allotted to 2 groups on the basis of estimated age at surgery (traditional age, > or = 24 weeks old; prepubertal, < 24 weeks old). Adoptive owner information was obtained from shelter records, and telephone interviews were conducted with owners to determine physical or behavioral problems observed in the cats after adoption. Follow-up information was obtained from attending veterinarians for cats with complex problems or when owners were uncertain regarding the exact nature of their cat's problem. RESULTS: Compared with traditional-age gonadectomy, prepubertal gonadectomy did not result in an increased incidence of infectious disease, behavioral problems, or problems associated with any body system during a median follow-up period of 37 months. Additionally, the rate of retention in the original adoptive household was the same for cats that underwent prepubertal gonadectomy as those that underwent traditional-age gonadectomy. CONCLUSIONS AND CLINICAL RELEVANCE: Prepubertal gonadectomy may be performed safely in cats without concern for increased incidence of physical or behavioral problems for at least a 3-year period after gonadectomy.     

Joint longitudinal modeling of age of dam and age of animal for growth traits in beef cattle

Two methods to jointly model age of dam (AOD) and age of animal in random regression analyses of growth in Gelbvieh cattle were examined. The first method (M1) was analogous to the multiple-trait analysis and consisted of AOD as a nested class variable and a cubic polynomial regression on age nested within birth, weaning, and yearly weights. The second method (M2) used two-dimensional splines, with age knots at 150, 205, 270, 340, and 390 d. The AOD knots were placed at 725, 1,464, and 2,189 d. These selected knots were used to form a two-dimensional grid containing 15 knots, each representing a specific age and AOD combination. A data set containing Gelbvieh growth records was split along contemporary groups into two data sets. Data set 1 contained 316,078 records and was used for prediction by mixed-model equations. Data set 2 contained 164,167 records and was used for cross validation. In the complete data set, only 90 and 30% of animals with birth weight had records on weaning and yearling weights, respectively. Models were evaluated based on R2, average squared error (ASE), percent bias, and plots of solutions. The ASE for weights associated with birth weight, weaning weight, and yearling weight for M1 were 15, 505, and 703 kg2. With M2, large jumps in fixed-effect estimates were observed outside the two-dimensional grid. To eliminate this problem, weighted one-dimensional splines were used for extrapolation beyond the two-dimensional grid. For M2 with weighted spline extrapolation, the ASE were 15, 542, and 777 kg2 for birth weight, weaning weight, and yearling weight, respectively. Creation of optimal two-dimensional splines is difficult when data are clustered. Despite such difficulties, the two-dimensional spline was capable of jointly and continuously modeling AOD and age of animal.