Cellular composition of granulomatous lesions in gut-associated lymphoid tissues of goats during the first year after experimental infection with Mycobacterium avium subsp. paratuberculosis

Mycobacterium avium subsp. paratuberculosis (MAP) causes lesions in naturally and experimentally infected ruminants which greatly differ in severity, cellular composition and number of mycobacteria. Morphologically distinct lesions are already found during the clinically inapparent phase of infection. The complex local host response and number of MAP were characterized at the initial sites of lesions, organized gut-associated lymphoid tissue, in experimentally infected goats. Tissues were collected at 3, 6, 9 and 12 month post-inoculation (mpi) from goat kids that had orally received 10 times 10 mg of bacterial wet mass of MAP (JII-1961). The cellular composition of lesions in Peyer's patches in the jejunum and next to the ileocecal valve was evaluated in 21 MAP-inoculated goats, where lesions were compared with unaltered tissue of six control goats. CD68⁺, CD4⁺, CD8⁺, γδ T lymphocytes, B lymphocytes and plasma cells, MHC class II⁺ and CD25⁺ cells were demonstrated by immunohistochemistry in serial cryostat sections.At 3 mpi, extensive granulomatous infiltrates predominated, consisting of numerous epitheloid cells admixed with many CD4 and γδ T lymphocytes. Only single MAP were detected. This indicates a strong cellular immune reaction able to control MAP infection. γδ T lymphocytes were markedly increased in this type of lesion which may reflect their important role early in the pathogenesis of paratuberculosis. At 9 and 12 mpi, divergent lesions were observed which may reflect different outcomes of host–pathogen interactions. In five goats, minimal granulomatous lesions were surrounded by extensive lymphoplasmacytic infiltrates and no MAP were detected by immunohistochemistry. This was interpreted as effective host response that was able to eliminate MAP locally. In three goats, decreased numbers of lymphocytes, but extensive granulomatous infiltrates with numerous epitheloid cells containing increased numbers of mycobacteria were seen. This shift of the immune response resulted in uncontrolled mycobacterial multiplication. Focal and multifocal circumscribed granulomatous infiltrates of mainly epitheloid cells may represent sites of new infection, since they were observed in goats at all times after inoculation. Their presence in goats with minimal granulomatous lesions surrounded by extensive lymphoplasmacytic infiltrates may indicate that despite the local clearance, the infection may be perpetuated.The complex cellular immune reactions postulated for the pathogenesis of paratuberculosis were demonstrated at the local sites of infection. These early host–pathogen interactions are most likely essential for the eventual outcome of the MAP infection.     

Effects of social and climatic factors on birth sex ratio in Macaca mulatta in Mount Taihangshan area

Sex allocation theory predicts the optimal investment to male and female offspring. However, a biased sex ratio requires explanations as to why the deviation occurs. Rhesus macaque (Macaca mulatta) is the most widely distributed nonhuman primate species and the Taihangshan macaque (Macaca mulatta tcheliensis) occupies the northern limit of all rhesus macaque natural populations worldwide. We observed one macaque troop (Wangwu‐1 [WW‐1]) inhabiting Taihangshan Macaque National Nature Reserve and recorded all birth events and the sex of newborn macaques from 2004 to 2013. Our aim was to apply the Trivers–Willard hypothesis to this free‐ranging rhesus macaque troop, and to understand the relationship between climatic parameters (precipitation and temperature) and birth sex ratio. We found that the total newborn macaques showed a female‐biased sex ratio at birth in the WW‐1 troop, but there were no significant biased birth sex ratios in all matriarchs and in high‐ranking and middle‐ranking matrilineal units. However, the low‐ranking macaque matrilineal unit was significantly female‐biased. Moreover, we found that the annual precipitation of the previous year was positively associated with the birth sex ratio, and there was an interactive effect of troop size and current winter temperature on the birth sex ratio. The underlying mechanisms for the effects of social and climatic factors on birth sex ratio could be complex, and we discuss several plausible explanations.     

不同采收年限和月份对大丰95橡胶树产胶量的影响

为探讨不同采收年限和月份对大丰95橡胶树产胶量的影响,采用统收统测的方式对13个5~18 a中低割龄的大丰95无性系树位的5~12月份干胶产量进行测定分析。结果表明,不同割龄和不同采割月份的大丰95月株产干胶量和月公顷产干胶量差异均明显,其中,8个采割期中,株产干胶量和公顷产干胶量由高到低的月份均依次为11、7、6、8、9、10、12、5月。13个割龄中,11 a的年株产干胶量最高,达4.90 kg,16 a的年公顷产干胶量最高,达1 807.97 kg,18 a的年株产干胶量和年公顷产干胶量均最低,分别为2.59、373.82 kg,最高值与最低值间差异达极显著水平(P0.01)。13个割龄的月公顷产干胶量和年公顷产干胶量与月株产干胶量和年株产干胶量均呈极显著正相关(P0.01),而所有割龄与年株产干胶量和年公顷产干胶量的正相关均不显著。综上可见,大丰95中低割龄橡胶树的干胶产量显著受采收月份影响,而随采收年限变化则不明显。     

Reproductive biology of a pride of lions on Karongwe Game Reserve,South Africa

The reproductive biology of a pride of lions (Panthera leo) was studied on the 8500 ha Karongwe Game Reserve from 1999 to 2005. Over this period, the pride consisted of between four and 11 lions with a paired coalition of adult males during the first three years and a single adult male for the next three years. We recorded shorter than normal interbirth intervals, high birth rates of 1.3 cubs/lioness/year, very high cub survival rates, and subadults leaving the pride at young ages. This translated into substantially faster growth rates than are typical in large lion populations in ecologically similar circumstances such as Kruger National Park, but are similar to those of lions in Serengeti National Park. These demographic characteristics were probably induced initially by a lack of intense intraspecific competition and high prey availability, but population stability was maintained through the removal of young subadults by management. Interestingly, variability in conception rates between lionesses resulted in lower growth rates than have been found in other similar reintroduced lion populations. These demographic traits characterize many of the small reintroduced lion populations, and call for appropriate management to avoid the consequences of high predator densities.     

性别控制液应用于母牛配种的试验报告

本试验表明,使用性别控制液后配种,母牛的产母犊率可以达到70％。     

非遗传因素对多胎细毛羊初生重和断奶重的影响

本研究旨在分析影响多胎细毛羊出生重和断奶重的因素,为优质多产细毛羊的选育奠定基础.利用SPSS19.0软件对多胎细毛羊羔羊的初生重和断奶重进行了描述性统计分析,并利用SAS9.2软件的GLM(最小二乘方差分析)程序对新疆科创畜牧繁育中心2009-2019年多胎细毛羊1 567条产羔记录分析出生年份、出生月份、性别和母羊...     

影响海南黑山羊初生重的非遗传因素初探

研究出生年份、出生类型、出生季节和出生性别等非遗传因素对海南黑山羊初生重的影响。初步结果表明,海南黑山羊母羊胎产羔数为1～3羔的比例分别为58.7%、38.9%、2.4%;公羔与母羔之比为0.98∶1;羔羊初生重逐年提高;出生年份、出生类型和出生性别对羔羊初生重都有极显著的影响(p<0.01);出生季节对羔羊的初生重无显著的影响(p>0.05)。分析的4个非遗传因素的两两互作作用中,只有出生季节与出生类型的互作作用对羔羊的出生重无显著的影响(p>0.05),其余的对羔羊初生重都有极显著的影响(p<0.01);3因素和4因素互作作用对羔羊初生重都有极显著的影响(p<0.01)。     

肉牛难产主要因素分析

难产(dystocia)是母畜分娩时胎儿娩出缓慢或难以娩出,需要助产帮助胎儿娩出的过程。难产既会导致母牛出现生殖道疾病而影响其后的发情和繁殖,也会危及犊牛和母牛的生命,严重损害养牛经济效益。引起肉牛难产的因素很多,有遗传因素和非遗传因素,包括母牛因素、胎儿因素、公牛因素、营养因素与环境因素等。犊牛出生重、母体骨盆结构和妊娠时长是3个最主要的因素。多种因素的交叉互作,使难产成为极其复杂的生理与病理现象。国际牛业发达国家非常重视母牛繁殖与生产环节,开展了大量卓有成效的研究与分析。在对几十年来有关肉牛繁殖与生产方面的报道较为细致分析基础上,文章重点对普通肉牛繁殖与生产过程中出现的主要难产问题进行综述,供国内同行借鉴。