Effects of size of ingestively masticated fragments of plant tissues on kinetics of digestion of NDF

Ingestively masticated fragments were collected and sized via sieving. Different sizes of esophageal masticate and ruminal digesta fragments, and ground fragments of larger masticated pieces were incubated in vitro, and undigested NDF remaining at intervals of up to 168 h of incubation was determined. The ruminal age-dependent time delay (tau) for onset of digestion of NDF was positively correlated (P < 0.004) with the mean sieve aperture estimated to retain 50% of the fragments between successive sieve apertures (MRA). Degradation rate of potentially degradable NDF (PDF) and level of indigestible NDF were not related (P > 0.10) to MRA of masticated and ground fragments. Estimates of tau were positively related to MRA, with slopes of bermudagrass < corn silage < ruminal fragments of corn silage. It was concluded that fragment size-, and consequently, ruminal age-dependent onset of PDF degradation of a mixture of different fragment sizes results in an age-dependent rate of degradation of the more rapidly degrading of two subentities of PDF. Models are proposed that assume a tau before onset of simultaneous degradation of PDF from two pools characterized as having gamma-modeled age-dependency and age-constant rates. The ruminal age-dependent pool seems to be associated with the faster-degrading pool, and its rate parameter increases with range in MRA in the population of fragments. Conceptually, the ruminal age-dependent rate parameter for PDF degradation seems to represent a composite of several effects: 1) effects of the size-dependent tau; 2) range in MRA of the population of ingestively masticated fragments; and 3) subentities of PDF that degrade via more rapid age-dependent rates compared with subentities of PDF that degrade via age-constant rates. The estimated fractional rates of ruminative comminution of ingestively masticated fragments (0.060 to 0.075/h) were of a magnitude similar to the mean fractional rates of PDF digestion (0.030 to 0.085/h), which implies that ruminative comminution may be first-limiting to fractional rate of PDF digestion. The in vivo roles of ingestive and ruminative mastication of fragments on PDF degradation must be considered in any kinetic system for estimating PDF digestion in the rumen. These results and others in the literature suggest that the rate of surface area exposure rather than intrinsic chemical attributes of PDF may be first-limiting to degradation rate of PDF in vivo.     

Parasites of the stomach in donkeys of the highveld of Zimbabwe

Fourteen donkeys from a communal area of the Zimbabwean highveld were examined for stomach parasites during July and November of 1986 and January and April of 1987. All 14 animals were infected. Habronema muscae occurred in 12, Draschia megastoma in 11, H. majus in 9, Trichostrongylus axei in 9, Gasterophilus intestinalis in 14 and G. nasalis in 1 donkey. The lowest level of infection was in January for the helminths and in April for Gasterophilus larvae. The peak burdens of parasites were in July for Habronema spp. and in November for D. megastoma and Gasterophilus larvae. Infections with spirurid worms and Gasterophilus develop mainly from the middle of the rainy season to the beginning of the dry season (January to May/June). G. intestinalis seems to have an annual cycle.     

Lack of mutagenicity of fasciolicides

Six fasciolicides, bithionol, bromofenofos, DS-6, nitroxynil, oxyclozanide and tribromsalan, were tested for mutagenicity in the Salmonella reverse mutation test using S. typhimurium tester strains TA100, TA98, TA1535, TA1537 and TA1538 and the micronucleus test in mice. None of the fasciolicides increased the number of revertant colonies in any tester strain in the presence and absence of S9 mix, nor did they induce a significant increase of the micronuclei in erythrocytes. Taking the high correlation between mutagenicity and carcinogenicity into consideration, these results suggest that the fasciolicides tested in this investigation are devoid of carcinogenic action.     

在放牧干扰下冷蒿种群脯氨酸含量的变化

对放牧干扰下土壤含水量、冷蒿体内含水量、脯氨酸含量变化进行的研究结果表明随着放牧强度的增加土壤含水量降低,冷蒿叶片、根中含水量呈下降趋势。在生长初期,随着放牧强度的增加冷蒿叶片内脯氨酸含量迅速积累;生长盛期脯氨酸含量虽随牧压有所增加,但增加的幅度较小;生长末期脯氨酸含量较高,而且随着牧压的增加略有下降。地下部分,脯氨酸含量在牧压梯度间变化较小。相关分析表明,在生长初期和盛期,冷蒿叶片、根的含水量与土壤含水量呈正相关,生长末期不相关。冷蒿脯氨酸含量与植物的含水量呈负相关,在生长初期和末期呈显著负相关,而生长盛期相关不显著;与此不同,在生长初期冷蒿体内脯氨酸含量与土壤含水量呈负相关,在生长末期二者负相关性不显著,这说明随着放牧干扰强度的增加土壤含水量降低,导致冷蒿体内水分胁迫增加,致使脯氨酸开始逐渐积累。而生长末期的降温和群落中植物种间竞争减少,使脯氨酸的积累速度也相应放慢。在放牧干扰下,脯氨酸大量积累,对冷蒿的生存和生长起到了重要的作用,是冷蒿种群耐啃食、耐践踏、逐渐取代禾本科植物而成为退化草原的优势植物的生理基础之一。     

Effect of rate of induction of carbon dioxide anaesthesia on the time of onset of unconsciousness and convulsions

The effect of different rates of induction of carbon dioxide anaesthesia on the time to loss of consciousness was investigated in broilers and hens. In experiment 1, 24 and 17 broilers, respectively, were exposed to 45 per cent carbon dioxide within 8 or 18 seconds (accession time). In experiment 2, 18 to 20 broilers and hens were exposed to either 35, 45, 55 or 65 per cent carbon dioxide within 8 seconds. The results indicated that, in general, the rate of accession is more critical than the final concentration of carbon dioxide; however, in 35 per cent carbon dioxide an exposure time of longer than 5 minutes is required to kill the birds. The time to sustained eye closure, time to onset of clonic and tonic convulsions and the duration of convulsive episodes were shorter in broilers than in hens. It is suggested that under commercial situations a final concentration of 55 per cent carbon dioxide would be suitable for killing broilers and hens.     

Diagnostic value of cytology of bronchoalveolar fluid for lung diseases of sheep

Bronchoalveolar lavage fluid was collected postmortem from the lungs of 113 sheep, and total and differential cell counts were analysed in relation to the presence of gross and microscopic lung pathology. The diffuse lung diseases, maedi and adenomatosis, were both characterised by an increase in overall cellularity and by increases in the percentages of lymphocytes and neutrophils, respectively. Focal parasitic lung disease was characterised by an increase in the percentage of eosinophils and mast cells. Consolidated lung lesions were characterised by a slight increase in cellularity but no change in the differential cell profile. In regions of parasitised and consolidated lungs without lesions the differential cell profile was consistent with focal lung pathology, although the slight increase in cellularity observed in the consolidated regions was not observed in the regions without lesions. A decision tree was developed to facilitate the interpretation and indicate the likely predictive capacity of the differential cytology of the fluid.     

C-reactive protein in monitoring and evaluation of effects of therapy of the MMA syndrome of sows

The elevated concentration of CRP in sows at the early stage of the MMA reflected the inflammation in the reproductive tract and in the mammary gland. Monitoring the level of CRP during the first days after parturition may be used to diagnose early stages of the MMA and to start therapy. In the treated MMA sows the level of CRP steadily decreased, and by the end of the experiment it had returned to the normal level. In the non-treated MMA sows CRP persisted at a high level and at day 10 of the experiment it was 13 times higher than in the treated animals and 16 times higher than in controls. Measurements of serum CRP are valuable in monitoring the health status of sows after parturition and should be introduced as the diagnostic method of the MMA syndrome in sows. The determination of the concentration of serum CRP during the first two days after parturition should be used for diagnosis of the early stages of MMA syndrome in sows and to start therapy when clinical symptoms of MMA are still absent.     

不同类型黑麦草营养价值评估

文章旨在通过体内外试验评估不同类型黑麦草的营养价值。试验选择平均体重为（66.87±2.34）kg的绵羊12头,随机分成3组,每组4个重复,每个重复1头。3组绵羊分别饲喂新鲜、青贮和晒干黑麦草。经过14?d的饲养试验后收集粪便和牧草样品进行后续分析。结果：晒干黑麦草的干物质、有机物和无氮浸出物含量均表现最高（P＜0.05）。新鲜黑麦草粗蛋白质和半纤维素含量较青贮黑麦草分别显著提高42.10%和10.82%（P＜0.05）。青贮黑麦草粗脂肪、粗纤维、中性洗涤纤维和酸性洗涤纤维含量显著高于其他两种类型的黑麦草（P＜0.05）。新鲜、青贮和晒干黑麦草的粗蛋白质、粗脂肪和粗纤维表观消化率无显著差异（P＞0.05）。晒干黑麦草干物质表观消化率较新鲜和青贮黑麦草显著提高6.34%和6.21%（P＜0.05）,同时晒干黑麦草有机物表观消化率较新鲜黑麦草显著提高6.65%（P＜0.05）,无氮浸出物表观消化率较青贮黑麦草显著提高15.44%（P＜0.05）。当体外代谢能值以MJ/kg有机物表示时,新鲜和青贮黑麦草代谢能值较晒干黑麦草分别显著提高21.34%和22.41%（P＜0.05）,而当体外代谢能值以MJ/kg干物质表示时,新鲜黑麦草能值最高,青贮黑麦草能值次之,晒干黑麦草能值最低（P＜0.05）。结论：新鲜、晒干和青贮黑麦草在不同营养成分上各有优势,但3种牧草主要营养物质的表观消化率和代谢能值无显著差异。因此,无论是新鲜、晒干还是青贮黑麦草都可以作为反刍动物粗饲料的良好来源。 [关键词]黑麦草;青贮;营养价值;消化     

气味丰容对几种蛇类行为影响实验

2010年3月～11月,在成都动物园两爬馆饲养展出蛇类中选取了缅甸蟒、缅甸白蟒、加州王蛇和三色乳蛇等进行了不同气味丰容实验并对气味丰容前后蛇类自主活动行为进行观察比较。其中对缅甸白蟒和缅甸蟒均采用了兔子血、茶叶包进行气味丰容;对加州王蛇和三色乳蛇均采用了小白鼠、茶叶包进行气味丰容。实验结果表明,通过不定期采用不同气味对蛇类进行丰容刺激,可以显著改善蛇类的自主活动情况,从而提高蛇类的观赏展示效果,也有利于改善蛇类的健康状况。气味丰容方案可以在其他蛇类的饲养展出中进行推广应用。     

Effects of application in spring of urea fertiliser on aspects of reproductive performance of pasture-fed dairy cows

AIMS: To assess if raising concentrations of crude protein (CP) in pasture in spring by the frequent application of urea fertiliser would affect ovarian follicular dynamics, luteal function, onset of oestrus and reproductive performance of dairy cows under farming conditions in New Zealand. METHODS: Spring-calved dairy cows were grazed for 101 days in paddocks that were either not fertilised (Control; n=20) during the course of the study, or were fertilised with 40-50 kg nitrogen (N)/ha every 4-6 weeks (High-N; n=20). Similar generous pasture allowances were offered to both groups. Concentrations of CP in pasture, urea in serum and progesterone in milk were measured. Ovarian follicular and luteal dynamics were determined using ultrasonography. Oestrous behaviour and the number, time and outcome of inseminations were also recorded. RESULTS: Mean concentrations of CP in pasture and urea in serum was higher in the High-N than the Control group (25.2 vs 21.6 and 8.3 vs 5.4 mmol/L for CP and urea, respectively; p<0.001). Intervals between calving and first oestrus, first insemination and conception, the time of first emergence of a dominant follicle, milk progesterone concentration, and the diameter of the corpus luteum (CL) in the first luteal phase did not differ significantly between groups. The interval from calving to first ovulation tended (p=0.10) to be lower and the diameter of the dominant follicle of the oestrous cycle at which cows conceived was greater (p=0.02) in Control than High-N cows. CONCLUSIONS: The use of large amounts of urea fertiliser during spring and the consequent increases in concentrations of CP in pasture and urea in serum did not negatively affect any of the parameters of reproductive performance of pasture-fed dairy cows that were assessed in this study.     

含阿维菌素类药物长效注射剂的研究概况

概述了用亲水性或疏水性缓释材料制备的溶液型长效注射剂、用氢化蓖麻油或乙基纤维素等疏水性缓释材料制备的类似于胶体状态的长效注射剂和长效混悬注射剂等几种含阿维菌素类药物(AVMs)的长效注射剂.其中长效混悬注射剂包括AVMs以微粒状态或以载药微粒状态悬浮于制剂中的水悬或油悬注射剂;侧重概述了用AVMs/明胶微球制备的一种具有脉冲式释药的长效注射剂和用AVMs/氢化蓖麻油固体分散体制备的长效注射剂.同时对制剂的组成特点、缓释原理和缓释效果都作了综述和分析.     

三株牛支原体的致病性比较

为检测从内蒙古发病牛场分离到的3株牛支原体(HS2019、HSZ2019、HSS2019)的致病性,对其进行本动物回归试验,通过观察攻毒后的临床症状、病理变化,以及应用实时荧光定量PCR确定组织器官中支原体载量,分析3株支原体的毒力。结果显示,3株牛支原体回归牛体后均使试验牛出现体温升高、咳嗽、呼吸困难等临床症状,解剖可观察到试验牛肺部损伤以及肺脏与胸腔粘连的病理变化,其中HS2019株较其他两株引起的症状与病变更为明显,组织脏器中的载菌量最高。结果表明,这3株支原体均有致病性,其中HS2019株致病性最强,可作为今后疫苗研制的预备菌株。本研究既为国内疫苗的研制提供了菌株资源,也为今后牛支原体的免疫攻毒试验提供了评价标准。     

Lack of mutagenicity of fasciolicides

Six fasciolicides, bithionol, bromofenofos, DS-6, nitroxynil, oxyclozanide and tribromsalan, were tested for mutagenicity in theSalmonella reverse mutation test usingS.typhimurium tester strains TA100, TA98, TA153, TA1537 and TA1538 and the micronucleus test in mice. None of the fasciolicides increased the number of revertant colonies in any tester strain in the presence and absence of S9 mix, nor did they induce a significant increase of the micronuclei in erythrocytes. Taking the high correlation between mutagenicity and carcinogenicity into consideration, these results suggest that the fasciolicides tested in this investigation are devoid of carcinogenic action.     

一日龄大通牦牛和平原黄牛骨骼肌显微结构的比较

为了探讨1日龄大通牦牛骨骼肌组织学特点及对低氧的适应,以平原黄牛为对照,利用光镜和计算机图像分析系统测定骨骼肌肌纤维直径、表面积密度;通过透射电镜比较骨骼肌线粒体的面数密度、面积密度、体积密度、平均体积等结构参数。结果显示,1日龄大通牦牛骨骼肌肌纤维直径显著细于1日龄平原黄牛,表面积密度明显大于平原黄牛,差异极显著(P<0.01);1日龄大通牦牛骨骼肌细胞中线粒体平均体积小于1日龄平原黄牛,并具有极显著差异(P<0.01);而1日龄大通牦牛骨骼肌细胞中线粒体体积密度、面积密度、面数密度均大于1日龄平原黄牛,且差异极显著(P<0.01)。以上结果表明,大通牦牛通过增加骨骼肌线粒体面数密度、面积密度、体积密度,降低线粒体平均体积来提高其在低氧环境中对氧的利用,并且在长期进化中形成了肌纤维直径小,表面积密度大的组织学特点。     

Evaluation of moxidectin for the treatment of internal parasites of cattle

Two groups of eight yearling Hereford cattle were used to assess the efficacy of injectable moxidectin in removing internal parasites. At 0.2 mg/kg liveweight, moxidectin was effective in ridding all eight treated animals of internal parasites in the abomasum, small and large intestines. The difference in worm counts between treated and control animals was highly significant (P<0.001) for all worm species present in sufficient numbers for evaluation. No adverse side-effects were observed in the treated animals.     

Electron microscopy of bursa of Fabricius of chicks infected with a field strain of infectious bursal disease virus

Chicks were infected in the bursa with a field strain of infectious bursal disease virus. Inter- and intracellular edema, condensation and margination of nuclear chromatin, increased number of lysosomes in macrophages, and lymphocytolytic changes appeared earliest by 8 hours post infection. Inclusions containing spheroid to hexagonal virus particles were seen in the cytoplasm of the macrophages. Multiplying virus particles in crystalline arrays arranged either in single or in multiple clusters were seen in the cytoplasm of macrophages, lymphocytes and light stained reticular epithelial cells.     

猪O型口蹄疫免疫抗体检测方法的比较

试验采用口蹄疫O型间接血凝试验和O型口蹄疫抗体液相阻断ELISA 2种试验方法检测了60份血清中猪O型口蹄疫免疫抗体.研究结果显示,60份被检血清口蹄疫O型间接血凝试验检测合格率为93.3％,O型口蹄疫抗体液相阻断ELISA试验检测的合格率为73.3％,口蹄疫O型间接血凝试验检测合格率明显高于O型口蹄疫抗体液相阻断ELISA试验检测的合格率（相差20个百分点）;2种方法的总符合率为66.7％、＜25（＜2^6）的符合率为28.6％,≥2^5（≥2^6）的符合率为82.1％.2种方法检测出的整体免疫效果较好,平均合格率远高于农业部规定的70％.     

Investigation of serology for diagnosis of outbreaks of botulism in cattle

Serology has been used to diagnose retrospectively types C and D outbreaks of botulism in cattle in Australia and this study has investigated whether the approach would be applicable in England and Wales. Three hundred sera from routine surveillance submissions in England and Wales were used as a negative control population. Some stored sera were available from a small number of clinical cases of botulism and 125 samples were collected from cohort groups of clinical cases in four new outbreaks of botulism. Three of these outbreaks were identified as being caused by type D Clostridium botulinum toxin. Sera were tested by antibody ELISA in laboratories in Australia and Germany. There was no increase in the proportion of animals seropositive to type C or D antibody in the botulism-associated cattle. The proportion of samples which were seropositive to type D antibodies was <2% in both the negative control and outbreak populations. It was concluded that single time serology is unlikely to be helpful for retrospective diagnosis of outbreaks of type D botulism in England and Wales.     

两种绿头鸭肌肉营养成分分析及评价

本试验旨在研究两种绿头鸭（白羽绿头鸭和绿头鸭）肌肉营养组成和价值,为绿头鸭肉产品的开发利用提供基础数据和理论依据。选择白羽绿头鸭和绿头鸭60只（每个品种各30只,公母各半）,依照国家标准测定胸肌粗蛋白质、粗脂肪、胆固醇含量及氨基酸、脂肪酸、微量元素和维生素的组成和含量,并对胸肌进行氨基酸评价及脂肪酸营养价值评价。结果显示,白羽绿头鸭肌肉粗蛋白质含量显著低于绿头鸭（P<0.05）;两种绿头鸭肌肉中均检测到17种含量大于0.01%的氨基酸,其中白羽绿头鸭肌肉苏氨酸、组氨酸、丝氨酸和脯氨酸含量显著高于绿头鸭（P<0.05）,赖氨酸、谷氨酸和精氨酸含量显著低于绿头鸭（P<0.05）;检测到13种含量均大于0.01%的脂肪酸,其中白羽绿头鸭硬脂酸和油酸含量显著低于绿头鸭（P<0.05）;检测到9种矿物质元素（钠、镁、钾、钙、锰、铁、铜、锌和硒）,两种绿头鸭差异不显著（P>0.05）;检测到8种维生素,白羽绿头鸭肌肉维生素B₁含量显著高于绿头鸭（P<0.05）,维生素D和维生素E含量显著低于绿头鸭（P<0.05）。两种绿头鸭肌肉氨基酸比例接近世卫组织推荐的理想模式,富含人体所需的矿物质元素和维生素,具有广阔的开发利用前景。     

35个紫花苜蓿品种在内蒙古赤峰地区的生产性能评价

在内蒙古赤峰地区对引进国内外的35个紫花苜蓿（Medicago sativa）品种进行田间试验,比较了生长第2年的越冬率及不同茬次的株高、鲜草产量、干草产量、叶茎比等各项农艺性状指标的差异,并通过灰色关联分析综合评价不同苜蓿品种的生产性能。结果表明,在种植第2年,综合评价最优的参试品种是龙牧806,其次是飞马、肇东、龙牧801、公农1号等,这些苜蓿品种均为适宜在赤峰地区推广种植的优良品种,而肇东苜蓿、龙牧系列、公农1号与敖汉苜蓿越冬率相对较高,生产性能在综合评价中表现良好,其全面的特点更适合在赤峰市气候偏冷的北部旗县地区推广应用。