Tag-SNP selection using Bayesian genomewide association study for growth traits in Hereford and Braford cattle

The aim of this study was to perform a Bayesian genomewide association study (GWAS) to identify genomic regions associated with growth traits in Hereford and Braford cattle, and to select Tag-SNPs to represent these regions in low-density panels useful for genomic predictions. In addition, we propose candidate genes through functional enrichment analysis associated with growth traits using Medical Subject Headings (MeSH). Phenotypic data from 126,290 animals and genotypes for 131 sires and 3,545 animals were used. The Tag-SNPs were selected with BayesB (π = 0.995) method to compose low-density panels. The number of Tag-single nucleotide polymorphism (SNP) ranged between 79 and 103 SNP for the growth traits at weaning and between 78 and 100 SNP for the yearling growth traits. The average proportion of variance explained by Tag-SNP with BayesA was 0.29, 0.23, 0.32 and 0.19 for birthweight (BW), weaning weight (WW205), yearling weight (YW550) and postweaning gain (PWG345), respectively. For Tag-SNP with BayesA method accuracy values ranged from 0.13 to 0.30 for k-means and from 0.30 to 0.65 for random clustering of animals to compose reference and validation groups. Although genomic prediction accuracies were higher with the full marker panel, predictions with low-density panels retained on average 76% of the accuracy obtained with BayesB with full markers for growth traits. The MeSH analysis was able to translate genomic information providing biological meanings of more specific gene products related to the growth traits. The proposed Tag-SNP panels may be useful for future fine mapping studies and for lower-cost commercial genomic prediction applications.     

Ultrasonographic cervical evaluation: A tool to select ewes for non-surgical embryo recovery

This study assessed the cervical ultrasonography mapping as a tool to select donor ewes for non-surgical embryo recovery (NSER). Lacaune ewes had their cervix evaluated by ultrasonography 12 hr after induced oestrus onset (Trial 1, n = 24) or 30 min before NSER (Trial 2, n = 17). Cervical rings were longitudinally evaluated and classified by their degree of misalignment on ultrasonography (DMUS) into: DMUS-1—cervix rectilinear, DMUS-2—intermediate and DMUS-3—highly asymmetrical. For predicting cervical transposing, only DMUS-1 and DMUS-2 were considered suitable. Similar ranking was attributed to degree of misalignment on the cervical map (DMCM 1–3), established immediately before NSER, which was performed at days 6 to 7 after oestrus. In Trial 1, cervical retraction for NSER was not possible only in three ewes classified as DMUS-3 (3/14, 21.4%). No difference (p > .05) was observed in the cervical transposing rates between ewes with different DMUS (ranged from 80% to 100%). In Trial 2, DMUS-1 and DMUS-2 reached 100% of transposing, and the only DMUS-3 ewe has not been transposed. In Trial 1, the prediction performance for successful cervical transposing showed low sensitivity (45%) and no specificity due to a high incidence of false negatives (52%). However, in Trial 2, sensitivity and specificity were both 100%. The DMCM and DMUS were uncorrelated, probably due to cervical stretching required to perform NSER. In conclusion, cervical ultrasound assessment immediately before NSER was more efficient to predict the cervical transposing than at induced oestrus, allowing the classification and selection of ewes eligible for NSER.     

Effects of crude protein and lactose levels in diets on growth performance,intestinal morphology,and expression of genes related to intestinal integrity and immune system in weaned piglets

To evaluate the effects of crude protein (CP) and lactose (LAC) for weaned piglets on performance, intestinal morphology, and expression of genes related to intestinal integrity and immune system, 144 piglets with initial weight 7.17 ± 0.97 kg were allotted in a randomized design, in a 2 × 3 factorial arrangement (20.0% and 24.0% CP and 8.0%, 12.0%, and 16.0% LAC) with eight replicates. Piglets fed 20.0% CP had greater weight gain and feed intake. Including 12.0% LAC in the 20.0% CP diet provided higher villous height in the duodenum than 8.0% LAC, and 12.0% or 16.0% LAC in the 24.0% CP diet resulted in higher villous height in the jejunum and ileum, and higher villi/crypt ratio in the ileum than 8.0% LAC. No effects of CP and LAC on interleukin‐1β and tumor necrosis factor‐α mRNA were observed. The 16.0% LAC diet provided higher gene expression of transforming‐β1 growth factor. Feeding 20.0% CP resulted in better performance than 24.0% CP. The 12.0% LAC diet promoted greater genetic expression of occludin and zonula occludens. Including 12.0% LAC in the diet may improve intestinal epithelial morphology and integrity, and these improvements are more evident when piglets are fed diets with 24.0% CP.     

The Effects of Refrigeration Temperature and Storage Time on Apoptotic Markers in Equine Semen

Evaluation of the damage caused by the sperm preservation process is crucial to improving fertilization rates. The objective of this study was to evaluate the effects of refrigeration temperature (5°C and 15°C) and storage time (0, 12, 24, 48, and 72 hours) on apoptotic markers in equine semen. Membrane phosphatidylserine translocation index, caspase activation index, and DNA fragmentation index were analyzed using epifluorescence microscopy. Analysis of variance was used for statistical analysis, and Tukey test was used to compare means. The significance level was set at P < .05. The results demonstrated that for transport duration shorter than 24 hours, semen quality was maintained when stored at either 5°C or 15°C. A storage temperature of 5°C should be used when it is necessary to transport semen for longer than 24 hours. There was a significant decrease in semen quality after 48 hours of refrigeration.     

Effect of Storage Time and Temperature of Equine Epididymis on the Viability,Motion Parameters,and Freezability of Epididymal Sperm

The recovery of sperm from the epididymal cauda may be the last chance to obtain genetic material when sudden death or serious injuries occur in valuable stallions. However, the lack of technical knowledge regarding the storage and transportation of the epididymis often prevents the preservation of the sperm. Therefore, the aim of this study was to compare sperm parameters of sperm obtained immediately after orchiectomy with sperm recovered from epididymal cauda at different times after storage at 5°C and at room temperature (RT). For that, 48 stallions of different breeds were used. In group 1 (control group), eight stallions were used, and the harvest of the epididymal sperm was performed immediately after orchiectomy. In group 2, 40 stallions were used, which were divided into five groups according to the storage time of the epididymis after orchiectomy (6, 12, 18, 24, or 30 hours), making a total of eight stallions per group. One epididymis of each stallion was stored at 5°C, and the contralateral epididymis was stored at RT, both for the same period. The sperm parameters of total motility, progressive motility, progressive linear velocity, curvilinear velocity, percentage of rapid sperm, and plasma membrane integrity were evaluated in all the groups after sperm recovery, resuspension in a sperm freezing diluent, and thawing. In conclusion, the storage of the testis-epididymis complex at 5°C provided better preservation of epididymal sperm than the storage at RT, and regardless of the temperature, the progressive motility is the sperm parameter that is most sensitive to storage time.     

Variation in seed protein digestion of different pea (Pisum sativum L.) genotypes by cecectomized broiler chickens: 2. Relation between in vivo protein digestibility and pea seed characteristics, and identification of resistant pea polypeptides

Eight pea genotypes characterized for their major protein fractions were used to investigate the effect of seed protein composition variability on protein digestibility in poultry. These genotypes of various pea types, were also variable in other seed components. They showed variations in their carbohydrate (insoluble fibre compounds, soluble fibre, soluble carbohydrates) and trypsin inhibitor (TI) contents. To exclude the effect of tannins and of particle size, the seeds were dehulled and micro-ground. They were incorporated as the only protein source in isoproteinaceous diets with similar metabolisable energy content and fed to cecectomized chickens. The average amino acid digestibility (apparent and true) and endogenous amino acid excretion were related with pea diet characteristics (protein composition, carbohydrate composition and TI activity). This allowed to precise which of the diet characteristics affect protein digestibility and endogenous excretion. Average apparent digestibility of amino acids was negatively correlated with insoluble fibre components (R = − 0.71 to − 0.72; p < 0.05) and TI activity (R = − 0.93; p < 0.001). Average endogenous losses of amino acids were positively correlated with soluble carbohydrate content (R = 0.77; p < 0.05) and TI activity (R = 0.84; p < 0.01). Average true digestibility of amino acids was positively correlated with the PA2 albumin level (R = 0.71; p < 0.05), and negatively with the legumin level (R = − 0.72; p < 0.05). Resistant peptides extracted from chicken excreta were analysed through electrophoresis and identified by immunodetection. Intensity of detected resistant peptides showed variation among genotypes. However, for the 8 pea genotypes, the pea proteins, which persisted at the end of the digestive tract, were mainly albumin PA1b and lectin. Other minor peptides were also detected: vicilin, albumin PA2 and legumin peptides which migrated at the same level as β-subunits.     

Effectiveness of 1-MCP treatments on ‘Bartlett’ pears as influenced by the cooling method and the bin material

Wooden bin-stored ‘Bartlett’ pears (Pyrus communis L.) were hydrocooled (HC) or forced-air cooled (FAC) and immediately treated or not with 1-methylcyclopropene (1-MCP) for 24 h. 1-MCP gas concentrations used were 0, 0.3 or 0.6 μL L^?1 (called 0, 0.3 and 0.6, respectively). Fruit were subsequently kept at 20 °C for 20 d or stored at ?0.5 °C and 95% RH for 60, 90, 120 or 150 d. After cold storage, fruit were kept at 20 °C for up to 16 d for further ripening. In another experiment, pears stored in wooden bins (W) or plastic bins (P) were all hydrocooled, treated or not with 0.5 μL L^?1 1-MCP (called 0.5 and 0, respectively), stored at ?0.5 °C and 95% RH for 0, 30, 60, 90 or 120 d, and transferred to 20 °C for further ripening. In FAC pears, increasing 1-MCP concentrations usually resulted in delayed increases in ethylene production and lower ethylene production rates, as well as delayed softening. In contrast, HC-0.3 pear firmness did not differ from that of HC-0 fruit after cold storage. Generally, HC-0.3 pears displayed higher ethylene production and lower firmness values than FAC-0.3 pears after a 7-d exposure to 20 °C, regardless the length of cold storage. FAC-0.6 pears always showed lower ethylene production rates and higher flesh firmness values than HC-0.6 fruit. Soluble solids concentration was not consistently affected by 1-MCP. FAC-0.3 and HC-0.6 fruit showed higher titratable acidity values than HC-0 fruit after 0, 60, 120 and 150 d of cold storage plus 7 d at 20 °C. Effectiveness of 1-MCP treatments on HC pears was influenced by the bin material; P-0.5 pears were firmer than W-0.5 pears after 7 d at 20 °C, regardless the length of the cold storage. HC-0.5 fruit exposed to ?0.5 °C for 90 d reached eating quality (firmness ≤23 N) by day 7 if placed in W, and by day 21 when stored in P. Results and previous evidence suggest that wet wooden bin material may represent a major though unpredictable source of 1-MCP sorption that could bind a significant percentage of the 1-MCP applied. When used at relatively low doses 1-MCP partial removal by wet wooden bins can compromise the application effectiveness for controlling ethylene action.     

Comparison of two versions of larval development test to detect anthelmintic resistance in Haemonchus contortus

Larval development (LDT) and micro-agar larval development tests (MALDT) were used to compare the reliability and sensitivity of two methods for detecting anthelmintic resistance in Haemonchus contortus. The tests were conducted using three resistant and four susceptible isolates of H. contortus. Both versions of the tests provided comparable results with regard to the characterization of benzimidazole and levamisole susceptibility but neither test was sufficiently sensitive to discrimination between an ivermectin (IVM) susceptible and an IVM resistant isolate. Each test has its own merits with the LDT having the advantage of being less time-consuming.