猪流行性腹泻病毒及其卵黄抗体研究进展

猪流行性腹泻病毒是引起仔猪病毒性腹泻甚至死亡的关键诱因,而安全高效的抗猪流行性腹泻病毒卵黄抗体具有降低仔猪腹泻率、死亡率等优点已应用于生猪养殖。本文总结了近年来猪流行性腹泻病毒的致病机理及其卵黄抗体的制备与应用效果的研究进展,为卵黄抗体在防治猪流行性腹泻上的应用提供理论基础和技术指导。     

Extenders modify the seminal plasma ability to minimize freeze‐thaw damage on ram sperm

Seminal plasma (SP) proteins interact with sperm plasma membrane (PM) modulating its functionality. It has been shown that SP proteins can reverse the damage caused by freeze‐thaw; however in these studies, SP has been added to washed sperm (i.e., cells depleted from homologous SP and extender). The aim of the current study was to assess whether the egg yolk‐based extender (EY) modifies SP ability to ameliorate sperm parameters in frozen‐thawed ram spermatozoa. Ejaculates were diluted in EY or soybean lecithin‐based extender (SL) and evaluated before and after freezing to measure the cell damage according to the extender. Even when all classical parameters decreased after freezing, as expected (p < .05), there was no effect of the extender. SP treatment was applied after freeze‐thaw. Sperm were incubated with SP (20% v/v) in the presence of either EY or SL, and sperm parameters were assessed after thawing compared with the same treatments after Percoll sperm selection (washed). Treatments with 20% SP improved sperm total and progressive motility compared with controls regardless of washing and extender (p < .05); however, washed sperm showed higher percentage of total sperm motility compared with those unwashed (p < .05). Moreover, treatment with 20% SP showed significantly higher percentages of PM integrity, sperm with intact acrosomes, integrity of chromatin and non‐capacitated sperm in samples diluted with EY when washed before treatment compared with the other conditions (p < .05). It was concluded that the presence of the extenders and particularly egg yolk alters the SP capacity to reduce the cryodamage.     

罗曼褐父母代产蛋前期产蛋规律的分析

对1249只健康的23周龄的罗曼褐父母代种母鸡的产蛋情况进行观察,试验期67 d(至32周龄),目的在于了解产蛋前期,蛋用种鸡产蛋性能的变化规律。试验结果表明,随鸡群日龄的增大蛋壳颜色逐渐变浅,产蛋率和种蛋合格率逐渐上升,鸡群的死淘率在开始人工授精的前2周最高,双黄蛋率随产蛋率的上升而逐渐减小,双黄蛋平均重随产蛋率上升逐渐增大,到产蛋率达最高峰时开始变小,软壳蛋率和破蛋率随鸡群日龄的增大而逐渐减小,总蛋重及种蛋平均重随鸡群日龄的增大而逐渐增大。     

Genetic parameters for strongyle and Nematodirus faecal egg counts in lambs and their relationships with performance traits

Genetic resistance to the gastro-intestinal parasites of lambs can contribute to sustainable systems of parasite control with associated benefits for health and welfare. This study reports estimates of the genetic parameters of strongyle egg counts (FEC), Nematodirus egg counts (NEM), faecal consistency scores (FCS) and their associations with growth and ultrasonic measurements of muscle (UMD) and fat (UFD) depths in lambs. The lambs were the progeny of 45 Bluefaced Leicester sires from Scottish Blackface and Hardy Speckled Face dams. Faecal samples were taken from lambs at 10, 14, 18, 22 and 26 weeks of age, giving 1024 to 3055 records per trait. Live weight was recorded for all lambs at 16 weeks and live weight, UMD and UFD were recorded in female lambs at 28 weeks. Mean FEC and NEM were significantly higher for twin versus single reared lambs, for male castrate versus female lambs and for the offspring of Scottish Blackface versus Hardy Speckled Face ewes. Heritability estimates for FEC were low (0.04 ± 0.02 to 0.20 ± 0.08) and showed a non-significant trend to increase with age. The phenotypic correlations between measures of FEC at different ages were low (0.06 to 0.34) but genetic correlations were not significantly different from one in most cases. Heritability estimates of NEM ranged from 0.05 ± 0.03 to 0.09 ± 0.05 and genetic correlations among counts at different ages were not significantly different from zero. FEC and NEM were strongly correlated genetically (0.62 to 0.93) and estimates of the genetic correlations between FEC and NEM with live weights (− 0.36 to 0.23), UMD (− 0.35 to 0.25) and UFD (0.08 to 0.55) were variable in sign, though not significantly different from zero. Heritability estimates for faecal consistency scores (FCS) were 0.06 ±0.03 to 0.11 ± 0.04, with strong genetic correlations between successive measures. FCS was not significantly correlated with FEC or lamb performance traits. It is concluded that selection for reduced strongyle egg counts in lambs at around 5–6 months of age will give favourable correlated responses in NEM in lambs, with limited correlated response in lamb performance or faecal consistency scores.     

Management of equine ataxia caused by cervical vertebral stenotic myelopathy: A European perspective 2010–2015

The diagnosis and therapy of cervical vertebral stenotic myelopathy (CVSM) are challenging and have been most frequently described in racehorses. We aimed to analyse CVSM cases presented for diagnostic work‐up and treatment in a nonracing horse population. We hypothesised that our diagnostic work‐up protocol including clinical/orthopaedic/neurological/radiographic and myelographic examinations may provide practical reference points for in vivo diagnosis/prognosis and adequate CVSM management. Medical records from 2010 to 2015 were reviewed retrospectively. Cases were included if our standardised work‐up protocol was followed, there was no evidence of any infectious diseases causing the neurological signs, and native cervical radiographs and myelograms confirmed CVSM. Age/breed/sex/type of performance/degree of neurological deficits and number/sites/quality/therapy of stenosis were recorded. Sixty‐two horses met the inclusion criteria. The majority of the horses were aged 5–10 years (44%) or >10 years (35%); nine horses (15%) were 1–4 years and four <1 year (6%) old. Forty‐six horses were Warmbloods (73%), 10 ponies (16%) and six of other breeds (11%). Males were more affected (69%) than females (31%). Sixty‐one percent were pleasure‐horses, 26% were sport‐horses and no information was available for 13%. Most cases presented with mild–moderate neurological signs (grade 2/5 = 18%, grade 2–3/5 = 31%). On myelograms, 23 horses (37%) had single‐level, 22 (35%) had double‐level, and eight (13%) triple‐level stenosis, while nine cases (15%) did not have stenosis. Fifty horses (55%) showed dynamic and 41 (45%) static stenosis. Dynamic stenosis was more common (46%) than static (29%) stenosis and/or combined stenosis (25%). Stenoses were more frequently observed in the mid‐to‐caudal vertebrae. Static stenoses tended to be located more caudally. Based on our protocol, 15% of horses were subjected to euthanasia without therapy, 62% treated conservatively and 23% underwent cervical ventral interbody fusion. In conclusion, our diagnostic work‐up protocol provided practical reference points for in vivo diagnosis/prognosis and adequate management of CVSM in a nonracing horse population.     

Effect of Royal Jelly on behavioural patterns,feather quality,egg quality and some haematological parameters in laying hens at the late stage of production

The aim was to elucidate the impact of Royal Jelly (RJ) on behavioural patterns, feather cover, egg quality and some blood haematological indices in laying hens (58–64 weeks of age). A total of 108 Tetra Brown laying hens were used in the current trial. The birds were divided into three equal groups (36 birds each). The pure RJ was prepared for immediate injection subcutaneously, as follows: the first treated group (RJ₁:100 mg/kg); the second treated group (RJ₂:200 mg/kg); the control group. The eating and drinking activities in the RJ₂ group were significantly (p = .009 and .015 respectively) higher than the control and RJ₁ groups. Furthermore, the aggressive pecks, feather pecks and threating behaviour in the RJ₂ group were significantly (p = .005, .001 and .039 respectively) lower than the control and RJ₁ groups. Both RJ‐treated groups had the best feather cover on the neck and abdomen regions (p = .010 and .001 respectively; Figure  1 ). Both RJ‐treated groups had a significantly higher eggshell ratio (p = .019) and shell thickness (p = .001) in comparison with the control group. The albumen height, Haugh units and yolk index in both RJ‐treated groups were significantly greater than those recorded in the control group (p = .026, .001 and .022 respectively). The erythrocyte and total leucocyte counts in the RJ₂ group were significantly higher than those reported in the control and RJ₁ groups (p = .029 and .013 respectively); however, the heterophil/lymphocyte (H/L) ratio and heterophil % in both RJ‐treated groups were significantly the lowest (p = .001 and .039). In conclusion, birds in the RJ₂ group had superior feather cover, welfare and behavioural indices, probably due to the impact of active flavonoids components of RJ on laying hen performance. Furthermore, the RJ‐treated groups had significantly improved egg quality parameters and some blood haematological indices.