Performance and effects of small ruminal boluses for the electronic identification of fattening lambs

Two types of electronic boluses were evaluated in two experiments using intensively reared lambs. In Experiment 1, 148 lambs were assigned to three treatments defined by bolus type and lamb's age: mini (M, 5.2 g) applied as early as possible; small (S, 20.0 g) applied after weaning; and control (C), without bolus. Application of the M and S boluses required lambs older than 8 and 46 days, respectively. No differences in total mortality (6.8%), milk and concentrate intakes, and final live weight (LW) were observed between bolus types at the end of fattening (11 weeks). Total retention rates of boluses were 59.0% and 100% for the M and S boluses, respectively. Abattoir retrieval was 100%. Conventional ear tag loss rate in the same period was 2.1%. In Experiment 2, we used 94 lambs in three treatments, 2 of them applied with M boluses at: M1, 1 week before weaning; M2, 1 week after weaning; and C, without bolus. Bolus retention rate (43.5%) of M boluses was not affected by weaning. Ear tag loss rate was 3.2%. In conclusion, application age of M boluses was earlier than 8 days of age but their retention rates need to be improved. The S boluses are feasible to use as a permanent identification system in lambs older than 7 weeks. For earlier tagging, boluses as small as M but with greater weight and specific gravity should be developed.     

Effects of small ruminal boluses used for electronic identification of lambs on the growth and development of the reticulorumen

Fifty-four male lambs were used to study the effects of two types of small electronic boluses on the dimensions and epithelial characteristics of their reticulorumen. Newborn lambs were assigned according to bolus type and age of application to the following treatments: 1) control (C, n = 21), without bolus; 2) mini (M, n = 21), identified with a 9.3 x 37.4-mm, 5.2-g bolus during the first week after birth; and 3) small (S, n = 12), identified with a 15.0 x 39.1-mm, 20-g bolus after weaning at wk 5, when lambs weighed more than 12 kg. After weaning, lambs were given ad libitum access to concentrate and barley straw. Six lambs were euthanized at the start of the experiment to measure initial reticulorumen characteristics. Ten lambs (five from M and five from C treatments) were slaughtered at weaning and 24 (eight per treatment) were slaughtered when they reached 24 kg. After bolus recovery, the reticulorumen was emptied and filled with polyurethane foam to obtain reticulorumen casts. Weight of the emptied reticulorumen and volume of the casts were measured. Four representative lambs from each treatment were also slaughtered at 24 kg, and their reticulorumen used to evaluate papillae size, number of dead cells, and degree of keratinization of both the reticulum wall and the rumen wall epithelia. Weight at weaning (13.8 kg), age at the end of fattening (65 d), and mortality rate (4%) did not differ among treatments. Retention rate for M and S boluses was 82.4 and 100%, respectively. Fresh weight and volume of the reticulorumen did not differ among treatments at weaning (130 g and 1,679 mL) or at the end of the fattening period (640 g and 5,931 mL). Lambs in the M treatment had greater (P < 0.05) rumen papillae size and lower (P < 0.10) keratinization than C lambs; values in the S lambs were intermediate between M and C lambs. Neither the M nor S type of bolus affected dimensions of the reticulorumen, but the earlier presence of M boluses induced a greater papillae size, with no negative effects on health and fattening performances of young lambs.     

The nitrogen retention of early weaned lambs

At 30-to-60-day-old lambs reared without mothers 23 different feed mixtures were tested in N-balance experiments. The following results were achieved: The concentration of digestible crude protein and energy as well as the relation between them (PEQ) have no significant influence on the lambs' nitrogen retention. The energy intake and the intake of digestible crude protein have an intensive, significant influence on nitrogen retention. Rising energy and N-intake within the limits on which the investigation is based increased nitrogen retention. Of the protein feedstuffs tested, a 6 ... 7% higher nitrogen retention was realised from soybean oil meal as the sole source of proteins with 35% retained nitrogen related to the nitrogen intake in comparison to the combinations soybean oil meal/dried skim milk resp. fish meal. Increasing dried yeast portions (greater than 5%--20%) in the feed mixture diminished nitrogen retention. On the basis of the existing results the following recommendations for the use of the tested protein feedstuffs in rearing feed for lambs can be formulated: Soybean oil meal can be used as the sole source of protein in rearing lambs. The use of up to 5% dried yeast in the rearing feed as protein source and for vitaminisation is possible; 20% however diminish nitrogen retention. Because of the positive effect on feed intake it appears suitable to use fishmeal in the rearing feed for lambs.     

犊牛羔羊早期培育的特种饲料对策

犊牛、羔羊幼龄阶段的生长发育与成年后的生产性能有直接的关系,幼畜的早期培育是现代养殖业的成功技术对策。该文综述了我国犊牛、羔羊早期断奶所使用的代乳品的研究进展,主要从代乳品原料的特殊加工工艺、代乳品中营养参数的研究、特种饲料应用效果等方面的研究结果进行论述。代乳品可以使羔羊10日龄断奶,犊牛出生后5d断奶。     

Mortality in early born, housed lambs in south-west England

During a 2 year study of diseases in lambs in three early lambing (housed) flocks a total of 428 of 4413 (9.7%) lambs died. All these lambs were examined at post mortem by one investigator who used a routine procedure. Results were stored on a database (dBase III Plus) and analysed using Epiinfo. The peak rate of death occured in lambs less than 1 week old. Over 50% of deaths took place in this period. A small proportion of lambs (approximately 10 out of 1000) died during the prenatal period. Fatalities included chlamydial and mycotic abortions, but in the majority of cases there was no specific abortive agent, lambs were either freshly dead or mummified. Partum deaths (23.3–45.1 per 1000) were categorised into those due to the lambing process, lambs born dead and congenital defects. The most frequent abnormality observed was subcapsular liver rupture (9.3–20.9 per 1000) with up to 60% of affected lambs also having signs of malpresentation (subcutaneous oedema of the neck). Early postpartum deaths (12.9–31.5 per 1000) were primarily associated with starvation.     

Puberty and early sexual development in Libyan fat-tailed ram lambs

Puberty and early sexual development were studied in 143 Libyan fat-tailed ram lambs, equally representing Brownhead and Blackhead strains of this breed. The two strains did not differ in any of the measured parameters in a consistent way, yet the Brownhead lambs tended to be slightly heavier and to have a slightly larger testis diameter than Blackheads. At the commencement of the observations when the lambs were 69 days old, 25.2% had fully descended testes at a significantly higher (P less than 0.01) mean (SD) body weight (24.1 +/- 4.1 kg) than those with partly descended (69.2%, 15.7 +/- 6.3 kg) or with non-descended testes (5.6%, 19.5 +/- 3.2 kg). Testes development followed a triphasic pattern with an initial and a final phase of slow growth and a middle phase of fast growth, commencing at a weight of 24.5 kg and an age of 85 days and lasting until the weight of 36-43 kg and age of 180-200 days in both strains. The separation of penile adhesions commenced at a mean body weight and age of 33.6 +/- 3.7 kg and 125.5 +/- 27.4 days respectively and was completed at a mean weight and age of 38.3 +/- 4.2 kg and 153.4 +/- 29.9 days. Only four lambs failed to show complete penile separation. Age had little influence on testis descent or on penile development. Puberty was assessed in 71 lambs using sperm recovery following electroejaculation as an end point. Most of these lambs (92.9%) reached puberty at a mean (SD) age of 171.5 (39.9) days, mean body weight of 39.9 (9.3) kg, mean testis diameter of 4.1 (0.4) cm and mean horn length of 21.4 (3.7) cm. Puberal lambs were significantly superior to non-puberal lambs (P less than 0.01) in all these counts except for age which was similar in both categories. Direct testicular observation showed a strong correlation between testis diameter, testis weight, body weight, sperm concentration/g testis weight and to testis histology. Age was poorly correlated to testis weight, histology or sperm concentration. It is concluded that the body weight is a major determinant of puberty in this breed. It is also considered that the two strains of the breed are remarkably similar in the studied aspects of puberty and sexual development.     

Effects of early human handling on the pain sensitivity of young lambs

Objective Pain sensitivity of lambs changes over the first weeks of life. However, the effects of early treatments such as human handling on pain sensitivity are unknown for this species. This study investigated the effects of regular early gentle human handling on the pain sensitivity of lambs, indicated by their behavioural responses to tail docking. Study design Prospective part‐blinded experimental study. Animals Twenty‐nine singleton Coopworth lambs (females n = 14, males n = 15). Methods Starting at one day of age, lambs were either handled twice daily for 2 weeks (Handled), were kept in the presence of lambs who were being handled but were not handled themselves (Presence), or were exposed to a human only during routine feeding and care (Control). At 3 weeks of age, all lambs were tail docked using rubber rings. Changes in behaviour due to docking were calculated and change data were analyzed using two‐way anova with treatment and test pen as main factors. Results All lambs showed significant increases in the frequency and duration of behaviours indicative of pain, including ‘abnormal’ behaviours, and decreases in the frequency and duration of ‘normal’ behaviours after docking. Handled lambs showed a smaller increase in the time spent lying abnormally after docking than did Control lambs (mean transformed change in proportion of 30 minutes spent ± SE: Control 0.55 ± 0.04; Handled 0.38 ± 0.03; Presence 0.48 ± 0.03; C versus H t = 3.45, p = 0.007). Conclusions and clinical relevance These results provide some evidence that handling early in life may reduce subsequent pain sensitivity in lambs. While the behavioural effects of handling on pain behaviour were subtle, the results suggest, at the very least, that early handling does not increase pain sensitivity in lambs and suggests there is still flexibility postnatally in the pain processing system of a precocial species.     

Histopathology of the early phase during experimental Corynebacterium pseudotuberculosis infection in lambs.

Histological responses during experimental Corynebacterium pseudotuberculosis infection in lambs were investigated in parotid lymph nodes for ten days following inoculation. Lambs were infected by the subcutaneous route into the right eyelid with a virulent strain of C. pseudotuberculosis. Multiple microscopic acute abscesses, predominantly infiltrated with polymorphonuclear (PMN) leucocytes, were seen in the right parotid lymph node on the 1st day post-inoculation (PI). This massive PMN infiltration coincided with a peripheral blood granulocytosis. On day 3 PI, an influx of histiocytes was observed, while the microabscesses became confluent. From day 3 to day 10 PI, these lesions became enlarged and transformed into typical pyogranulomas with a central necrosis and a peripheral mantle of mononuclear cells composed of macrophages, epithelioid cells and lymphocytes; these histological changes were associated with a bacterial dissemination limited to the superficial lymph nodes. A lymphoid hyperplasia with prominent germinal centers was observed in the draining lymph nodes from day 3 PI. These results illustrate the dual role of granulomatous lesions in chronic bacterial infections: although they limit bacterial dissemination, the granulomas do not impair the persistence of infectious organisms in the host, leading to focal tissue damage.     

Subcutaneous electronic identification in cattle: a field study

The use of injectable transponders in cattle for identification purposes, for up to 30 months, was investigated. Passive electronic transponders, encapsulated in either polymer or glass, were injected subcutaneously into either the ear base or the earlobe of 652 calves in three populations. The animals were clinically examined weekly, and transponder signalling was checked immediately before and after injection, after two weeks and after about eight months. About 10 per cent of animals in one population were also checked after 20 and 30 months. No severe clinical or visible pathological changes were observed, and the calves' welfare was not apparently affected by the procedure. None of the transponders migrated from their injection sites. Eight months after injection, a signal was detected from 98.2 per cent of transponders injected in the ear base and from 90.5 per cent of those in the earlobe. At 20 and 30 months after injection, 10.4 per cent and 2.6 per cent of transponders, respectively, had ceased to signal. Thus, most transponders in the calves' ear base demonstrated functionality for up to 30 months.     

口感化及颗粒化开食料对早期断奶羔羊生长和胃肠道发育的影响

分析探讨口感化及颗粒化开食料对早期断奶羔羊生长和胃肠道发育的影响。选取新生健康的双羔湖羊公羔42只,随机分为两组,分别饲喂颗粒化和口感化开食料,试验期42 d。两组羔羊21日龄之前的采食量、体重和绝对生长的变化趋势相似。21日龄以后,口感化开食料组羔羊的采食量、体重、绝对生长和相对生长均明显高于颗粒化开食料组,42日龄体重、后两周的采食量及15～21日龄的相对生长率在两组间有显著差异(P < 0.05)。口感化开食料还显著提高(P < 0.05)了羔羊42日龄时的育肥指数、体长指数、胸围指数、管围指数和断奶前的瘤胃质量和瘤胃/胴体。以上结果表明,与颗粒化开食料相比,口感化开食料更有利于羔羊早期断奶前后的瘤胃发育、采食量提高、体重和体尺的发育,但对其他胃室及肠道发育没有影响。     

口感化及颗粒化开食料对早期断奶羔羊生长和胃肠道发育的影响

分析探讨口感化及颗粒化开食料对早期断奶羔羊生长和胃肠道发育的影响.选取新生健康的双羔湖羊公羔42只,随机分为两组,分别饲喂颗粒化和口感化开食料,试验期42 d.两组羔羊21日龄之前的采食量、体重和绝对生长的变化趋势相似.21日龄以后,口感化开食料组羔羊的采食量、体重、绝对生长和相对生长均明显高于颗粒化开食料组,42日龄体重、后两周的采食量及15～21日龄的相对生长率在两组间有显著差异(P<0.05).口感化开食料还显著提高(P<0.05)了羔羊42日龄时的育肥指数、体长指数、胸围指数、管围指数和断奶前的瘤胃质量和瘤胃/胴体.以上结果表明,与颗粒化开食料相比,口感化开食料更有利于羔羊早期断奶前后的瘤胃发育、采食量提高、体重和体尺的发育,但对其他胃室及肠道发育没有影响.     

代乳品营养水平对高寒牧区羔羊生长的影响

为探讨代乳品营养水平对高寒牧区早期断奶羔羊的饲喂效果,选取30只10日龄的甘肃高山细毛羊羔羊,分为5组,其中对照组(E)羔羊由母羊自由哺乳,并放牧;试验组羔羊10日龄断奶,分为A、B、C、D 4组,代乳品消化能、粗蛋白含量相应为18.5 MJ/kg2、3.0%,20.0 MJ/kg、25.0%,21.5 MJ/kg、27.0%,23.0MJ/kg、29.0%,试验期至90日龄。结果表明,50及70日龄时,对照组羔羊体质量高于试验组;90日龄时,C、D组羔羊体质量显著高于A组(P0.05),E组高于A、B、C组(P0.05),而D组与E组差异不显著(P0.05);E组瘤胃指数显著低于B、C、D组(P0.05),肾脏指数、肝脏指数显著低于各试验组(P0.05)。上述结果显示,高寒牧区羔羊10日龄断奶时,采食消化能23.00 MJ/kg、粗蛋白含量29.0%代乳品的体质量与未断奶羔羊无显著差异,生长发育情况优于其他低能低蛋白质的早期断奶羔羊,早期断奶羔羊的胃肠道和肝肾发育程度高于未断奶羔羊。     

提高羔羊成活率的关键技术措施

近年来，随着人们膳食结构的改变，牛羊肉特别是羊肉越来越受到人们的青睐，养羊业得到了迅速发展，羔羊成活率关系羊场的成败，如何提高羔羊成活率成为广大养羊专业户关心的话题，笔者根据几年的实践总结以下几点，叙述如下：１科学安排配种时间羔羊在１４～２５℃比较适合活动和生长，２～５月份产羔温度适宜，青草也开始萌发，利于羔羊的生长；在７～８月份产羔温度较高，羔羊易患胃肠炎；９～１１月份产羔，天气寒冷时，羔羊虽已强壮起来，但应种黑麦等补饲草，因此２～３月份、８～９月份尽量少安排配种。因此春季（２～５月份）和秋季…     

饲喂代乳粉对羔羊生长性能和血清生化指标的影响

试验旨在研究代乳粉对早期断奶羔羊生长性能及血清生化指标的影响。将18只新生陶赛特(♂)×小尾寒羊(♀)杂交F1羔羊随机分为试验组和对照组,每组9只羔羊,试验组饲喂代乳粉,对照组随母羊哺乳。在羔羊20、40、60、80、90日龄测定体重及体尺,并在50、90日龄采集血液样品分析血清生化指标。结果表明:饲喂代乳粉组羔羊体增重显著高于母羊哺乳组(P<0.05),试验组羔羊增重比母羊哺乳组高26.47%;体高、体长及胸围差异不显著(P>0.05);50日龄时,饲喂代乳粉组羔羊白蛋白和白/球蛋白比显著低于母羊哺乳组(P<0.05),而50和90日龄时,饲喂代乳粉组碱性磷酸酶活性显著高于母羊哺乳组(P<0.05)。结论:饲喂代乳粉可提高早期断奶羔羊的生长性能,促进其生长发育。