Morphological study of Socorro Island Merino sheep and its crosses with hair breeds

Tropical Animal Health and Production - A study was conducted with the objective to characterize the morphology of Socorro Island Merino sheep. A total of 67 sheep, 62 females, 26 purebred and 36...     

荷兰奶业产业链管理及质量控制

在第四届中国国际奶业展览会及高层论坛上,韩国、日本、德国、荷兰奶业交流专场吸引了众多中外奶业界同仁。国外专家关于本国奶牛养殖业、乳品加工业的精彩报告,使与会代表对各国的奶业发展现状和趋势有了全面而深入地了解。本刊编辑部,对各位国外专家的发言进行了整理,现分韩国篇、日本篇、德国篇、荷兰篇四个部分予以刊登,以飨读者,希望对中国建设现代奶业有所借鉴。     

Remote Sensing of Spatial and Temporal Vegetation Patterns in Two Grazing Systems

One constraint that range scientists must face in grazing studies is the lack of accurate and repeatable techniques for discriminating grazing effects from both temporal variability and spatial heterogeneity of vegetation. Both forms of variability contribute to inconsistent grazing system effects on vegetation response and forage production in semiarid ecosystems. Remote sensing may be an efficient tool for detecting differences in spatial and temporal patterns of grazing impact on vegetation. The purpose of this study was to evaluate the spectral data derived from satellite images as a tool for comparing grazing system impacts on spatial and temporal vegetation patterns. We evaluated the effect of two grazing systems, “Continuous” (C) and “Two-Paddocks Rest-Rotation” (TPRR), on vegetation cover from 1996 to 2006 in a semiarid ecosystem of Argentina. We compared grazing effects on vegetation cover using two indices derived from the Normalized Difference of Vegetation Index (NDVI) data from Landsat Thematic Mapper images. We observed a slight advantage in NDVI improvement for the TPRR over the C. Even though, in both grazing systems, an upward vegetation trend occurred only in areas located far from the watering points, TPRR showed higher relative vegetation cover near the watering point than C. We consider this methodology an important step for monitoring vegetation changes and making management decisions in livestock systems of semiarid regions because grazing system impacts may be compared for both spatial and temporal vegetation patterns. However, we think that the key next step is to develop procedures that discriminate between forage and nonforage components.     

日粮中蛋白质和纤维水平对仔猪生产性能和健康状况的影响

为了研究日粮的蛋白质和纤维水平对仔猪生产性能和健康状况的互作,特选择96头35日龄的仔猪（体重为9.11±0.60kg）,分32个栏饲养,每栏3头,分成4个日粮处理组,饲喂期21d。在设定的2×2因子处理中,4种日粮以大米、奶制品和大豆粕为基础配制,日粮蛋白质设两个水平（15.4%与19.4%,风干基）,纤维也设两个水平[低水平纤维（LF）为含5.3%中性洗涤纤维,高水平纤维（HF）为含7.15%中性洗涤纤维,风干基]。高水平纤维日粮组在基础日粮中添加了40g/kg的小麦麸和20g/kg的甜菜浆。每周测定动物生产性能,试验第1天和最后一天收集粪样进行微生物学分析,并且按1（液态）到4（硬实）的评分体系对粪便进行评分。在试验最后1d,每栏选1头猪采集血液,分析急性期反应蛋白（acute-phase protein）和主要急性期反应蛋白（major acute-phase prot）（即Pig-MAP）的含量,随后进行屠宰,对消化道（包括内容物）进行称重,并进行结肠组织学分析。饲喂高水平纤维日粮的仔猪具有较大的平均日增重（390g与457g,P≤0.001）和大肠重量（以占体重比例衡量为4.4%与5.4%,P≤0.05）。这与较高的短链脂肪酸浓度（尤其是乙酸和丁酸）、较少的大肠杆菌数量（每克粪便含7.77与6.86logcfu,P≤0.05）和较高乳酸杆菌与肠道细菌比（0.76与1.37,P≤0.05）是相符的。虽然日粮蛋白质水平没有改变猪的生产性能,但是20%的蛋白质水平提高（P≤0.05）了小肠（6.5与7.7）和大肠（3.8与4.3）的相对重量（占体重的百分比）。在大肠内,含20%蛋白质的日粮使仔猪杯状细胞数量增加（4.6/100与5.4/100μm;P≤0.05）,并使肠上皮内淋巴细胞数量减少（1.8/100与1.3/100μm;P≤0.05）。在健康状况方面,提高日粮纤维水平所产生的效果与日粮中的蛋白质含量有关。在含16%蛋白质的日粮中增加纤维水平可降低粪便评分值、增加抗生素治疗次数,然而在?     

Identification of serum stress biomarkers in pigs housed at different stocking densities

Eight Duroc×(Landrace×Large White) male pigs housed at a stocking rate of 0.50m(2)/pig were subjected to a higher stocking rate of 0.25m(2)/pig (higher density, HD) for two 4-day periods over 26 days. Using biochemical and proteomic techniques serum and plasma samples were examined to identify potential biomarkers for monitoring stress due to HD housing. HD housed pigs showed significant differences (P<0.001) in total cholesterol and low density lipoprotein-associated cholesterol, as well as in concentrations of the pig-major acute phase protein (Pig-MAP) (P=0.002). No differences were observed in serum cortisol or other acute phase proteins such as haptoglobin, C-reactive protein or apolipoprotein A-I. HD-individuals also showed an imbalance in redox homeostasis, detected as an increase in the level of oxidized proteins measured as the total plasma carbonyl protein content (P<0.001) with a compensatory increase in the activity of the antioxidant enzyme glutathione peroxidase (P=0.012). Comparison of the serum proteome yielded a new potential stress biomarker, identified as actin by mass spectrometry. Cluster analysis of the results indicated that individuals segregated into two groups, with different response patterns, suggesting that the stress response depended on individual susceptibility.     

Culture system and long-term storage of culture media in the in vitro production of bovine embryos

The optimum culture system for in vitro matured and fertilised oocytes still remains to be clarified. Culture media (CM) for mammalian embryos are routinely prepared fresh for use and preserved under refrigeration during one or two weeks. The purposes of this work were (1) to compare the efficiency of a synthetic oviduct fluid (SOF) with two different bovine serum albumin (BSA) concentrations (3 and 8 g/L) for the in vitro production of bovine blastocysts, (2) to test the effect of timing on adding fetal calf serum (FCS) to the SOF, and (3) to evaluate the effects on bovine embryo development of freezing and lyophilisation as procedures for preserving the SOF. Supplementation of SOF with 3 g/L BSA increased Day-7 blastocyst expansion rates (18.3 ± 1.6 vs. 14.4 ± 0.7; P < 0.05), although no differences in hatching rates were found. Addition of FCS to SOFaa (SOF with amino acids) medium supplemented with sodium citrate (SOFaaci) at 48 and at 72 h post-insemination (PI) allowed obtaining higher Day-6 embryo development rates than when FCS was added at 18 or 96 h PI (Day-6 morulae + blastocyst rate: 30.0 ± 1.1, 40.8 ± 1.1, 43.9 ± 2.3 and 39.3 ± 0.5 for FCS addition at 18, 48, 72 and 96 h, respectively). Hatching rates were significantly improved when serum was added at 72 h PI. Finally, both refrigeration and lyophilisation appeared as useful cryopreservation procedures for SOFaaci, although a significant loss of its ability to support embryo development, compared to the control fresh culture medium, was observed.     

Genetic association between different criteria to define sexual precocious heifers with growth,carcass, reproductive and feed efficiency indicator traits in Nellore cattle using genomic information

The aim of this study was to estimate genetic parameters for different precocious calving criteria and their relationship with reproductive, growth, carcass and feed efficiency in Nellore cattle using the single‐step genomic BLUP. The reproductive traits used were probability of precocious calving (PPC) at 24 (PPC24), 26 (PPC26), 28 (PPC28) and 30 (PPC30) months of age, stayability (STAY) and scrotal circumference at 455 days of age (SC455). Growth traits such as weights at 240 (W240) and 455 (W455) days of age and adult weight (AW) were used. Rib eye area (REA), subcutaneous fat thickness (SFT), rump fat thickness (RFT) and residual feed intake (RFI) were included in the analyses. The estimation of genetic parameters was performed using a bi‐trait threshold model including genomic information in a single‐step approach. Heritability for PPC traits was moderate to high (0.29–0.56) with highest estimates for PPC24 (0.56) and PPC26 (0.50). Genetic correlation estimates between PPC and STAY weakened as a function of calving age. Correlation with SC455, growth and carcass traits were low (0.25–0.31; ?0.22 to 0.04; ?0.09 to 0.18, respectively), the same occurs with RFI (?0.09 to 0.08), this suggests independence between female sexual precocity and feed efficiency traits. The results of this study encourage the use of PPC traits in Nellore cattle because the selection for such trait would not have a negative impact on reproductive, growth, carcass and feed efficiency indicator traits. Stayability for sexual precocious heifers (PPC24 and PPC26) must be redefined to avoid incorrectly phenotype assignment.     

A comparison of the uterine proteome of mares in oestrus and dioestrus

Proteomic analysis of mare uterine flush fluid provides a minimally invasive technique for studying protein changes associated with the oestrous cycle. The aim of this study was to identify differentially abundant proteins in the uterine flush fluid of mares in oestrus and dioestrus. In this study, uterine flush fluid samples were collected from eight reproductively healthy mares in either oestrus (n = 5) or dioestrus (n = 3). Proteomic analysis was performed using liquid chromatography‐tandem mass spectrometry. Of 172 proteins identified, six proteins (immunoglobulin lambda‐like polypeptide 1, haemoglobin subunit alpha, alpha‐1B‐glycoprotein, serotransferrin, apolipoprotein A‐1, and haemoglobin subunit beta) were significantly more abundant in oestrus. These proteins may contribute to the endometrial defence system through roles in inflammation, immunity or antimicrobial activity. In other species, some of these proteins have been described as immunoglobulins, negative acute phase proteins or defence agents against micro‐organisms. During dioestrus, immunoglobulin alpha‐1 chain C region‐related, complement factor I, CD 109 antigen and uterocalin, were significantly more abundant. Research in other species suggests that these four proteins contribute to the immune response through proposed immunoregulatory characteristics, complement system involvement or roles in B cell–T cell interactions. In conclusion, ten differentially abundant proteins were identified in the uterine flush fluid of mares in oestrus and dioestrus. Targeted studies on these proteins could elucidate their role in uterine defence mechanisms during the oestrous cycle in the mare.     

Quantitative and descriptive histological aspects of jaguar (Panthera onca Linnaeus, 1758) ear skin as a step towards formation of biobanks

Skin of mammals vulnerable to extinction, such as the jaguar, is used as a source of material in conservation strategies. The composition of skin is not uniform among species, and the ability to distinguish similarities in skin morphology in animal groups is fundamental in the application of skin tissue for use in biobanks. The aim of our study was to evaluate the structure, composition and capacity for culture of ear skin from the yellow and black jaguars. Both qualitative and quantitative methods were used, focusing on skin thickness, cell quantification and distribution, collagen density, proliferative activity and viability. Histomorphometrical study of the skin showed a total thickness of 273.2 and 274.6 µm for the yellow and black jaguars, respectively. Melanocytes and fibroblasts were, respectively, 9.7 and 23.0 for the yellow jaguar and 11.3 and 26.8 for the black jaguar. A collagen density of 67.0% and 49.0% was observed for yellow and black jaguars, respectively. Both animals presented a proliferative activity varying between 1.20 and 1.30. All tissues could promote cellular detachment, reaching subconfluence in 10–15 days. This kind of information from histomorphometrical features and cell cultures can be essential for a more targeted application of ear skin cryopreservation in this species, as such information will enable understanding the action of substances on tissues during the conservation process.