摘要：
Genomic breed composition (GBC) of an individual animal refers to the partition of its genome according to the inheritance from its ancestors or ancestral breeds. For crossbred or composite animals, knowing their GBC is useful to estimate heterosis, to characterize their actual inheritance from foundation breeds, and to make management decisions for crossbreeding programs. Various statistical approaches have been proposed to estimate GBC in animals, but the interpretations of estimates have varied with these methods. In the present study, we proposed a causality interpretation of GBC based on path analysis. We applied this method to estimating GBC in two composite breeds of beef cattle, namely Brangus and Beefmaster. Three SNP panels were used to estimate GBC: a 10K SNP panel consisting of 10,226 common SNPs across three GeneSeek Genomic Profiler (GGP) bovine SNP arrays (GGP 30K, GGP 40K, and GGP 50K), and two subsets (1K and 5K) of uniformly distributed SNPs. The path analysis decomposed the relationships between the ancestors and the composite animals into direct and indirect path effects, and GBC was measured by the relative ratio of the coefficients of direct (D-GBC) and combined (C-GBC) effects from each ancestral breed to the progeny, respectively. Estimated GBC varied only slightly between different genotyping platforms and between the three SNP panels. In the Brangus cattle, because the two ancestral breeds had a very distant relationship, the estimated D-GBC and C-GBC were comparable to each other in the path analysis, and they corresponded roughly to the estimated GBC from the linear regression and the admixture model. In the Beefmaster, however, the strong relationship in allelic frequencies between Hereford and Shorthorn imposed a challenge for the linear regression and the admixture model to estimated GBC reliably. Instead, D-GBC by the path analysis included only direct ancestral effects, and it was robust to bias due to high genomic correlations between reference (ancestral) breeds.
关键词：
Antioxidant system;Laying hens;Selenium;Trace elements
摘要：
The purpose of this study was to investigate the interactions between different selenium (Se) compounds including sodium selenite (SS), selenium-enriched yeast (SY), and nano-selenium (NS) and various essential trace elements involved in the antioxidant systems, and to evaluate the effects on laying performance and egg quality. A total of 288 21-week-old Hyline Sophie hens were allotted to four dietary treatments: (1) basal diet without Se supplementation; (2) basal diet supplemented with 0.3 mg/kg Se of SS; (3) basal diet supplemented with 0.3 mg/kg Se of SY; (4) basal diet supplemented with 0.3 mg/kg Se of NS. Each treatment had eight replicates with nine hens per replicate. The trial lasted for 35 days. Results demonstrated that NS supplementation decreased the egg production (EP) and increased the feed conversion rate (FCR) and eggshell thickness and that SY changed the egg shape index (p < 0.05). Supplementation with three Se compounds significantly increased serum Se concentration and glutathione peroxidase (GSH-Px) activity in all treatment groups, as well as total superoxide dismutase (T-SOD) activity in the SY and NS groups. Yolk iron (Fe) and copper (Cu) concentrations in the NS group were also increased with Se supplementation. While the serum zinc (Zn) concentration decreased in the NS and SY groups, as well as the yolk manganese (Mn) concentration in the SY group. And the total antioxidant capability (T-AOC) of yolk with 3 days of storage in the SY and NS groups, malondialdehyde (MDA) value in the NS group, and the T-SOD activity and MDA value of yolk with 10 days of storage in the SY group also decreased. Thus, the source of Se compounds may influence the balance between Se and other trace elements including Zn, Mn, Fe, and Cu, which is important for proper antioxidant defense in blood and egg yolk of laying hens.
摘要：
全基因组关联分析(genome-wide association study,GWAS)是近几年逐渐发展起来研究复杂性状的方法,并且在人类疾病和动植物复杂性状研究中得到广泛应用。文章主要综述了GWAS方法及近几年GWAS在畜禽重要经济性状的研究进展,主要目的是通过GWAS为畜禽复杂性状遗传机理的研究提供参考依据,为动物分子育种研究奠定基础。
作者机构：
[Jiang, Juan; He, Jun; Ma, Haiming; Zeng, Qinghua] Hunan Agr Univ, Coll Anim Sci & Technol, Changsha, Hunan, Peoples R China.;[Bauck, Stewart; Tait, Richard G., Jr.; Li, Hao; Wu, Xiao-Lin] Neogen GeneSeek, Biostat & Bioinformat, Lincoln, NE 68504 USA.;[Gianola, Daniel; Wu, Xiao-Lin; Rosa, Guilherme J. M.] Univ Wisconsin, Dept Anim Sci, Madison, WI 53715 USA.;[Zeng, Qinghua] Ningxiang Pig Farm Dalong Livestock Technol Co Lt, Ningxiang, Hunan, Peoples R China.
通讯机构：
[Wu, Xiao-Lin] N;[Wu, Xiao-Lin] U;Neogen GeneSeek, Biostat & Bioinformat, Lincoln, NE 68504 USA.;Univ Wisconsin, Dept Anim Sci, Madison, WI 53715 USA.
摘要：
An important economic reason for the loss of local breeds is that they tend to be less productive, and hence having less market value than commercial breeds. Nevertheless, local breeds often have irreplaceable values, genetically and sociologically. In the breeding programs with local breeds, it is crucial to balance the selection for genetic gain and the maintaining of genetic diversity. These two objectives are often conflicting, and finding the optimal point of the trade-off has been a challenge for breeders. Genomic selection (GS) provides a revolutionary tool for the genetic improvement of farm animals. At the same time, it can increase inbreeding and produce a more rapid depletion of genetic variability of the selected traits in future generations. Optimum-contribution selection (OCS) represents an approach to maximize genetic gain while constraining inbreeding within a targeted range. In the present study, 515 Ningxiang pigs were genotyped with the Illumina Porcine SNP60 array or the GeneSeek Genomic Profiler Porcine 50K array. The Ningxiang pigs were found to be highly inbred at the genomic level. Average locus-wise inbreeding coefficients were 0.41 and 0.37 for the two SNP arrays used, whereas genomic inbreeding coefficients based on runs of homozygosity were 0.24 and 0.25, respectively. Simulated phenotypic data were used to assess the utility of genomic OCS (GOCS) in comparison with GS without inbreeding control. GOCS was conducted under two scenarios, selecting sires only (GOCS_S) or selecting sires and dams (GOCS_SD), while kinships were constrained on selected parents. The genetic gain for average daily body weight gain (ADG) per generation was between 18.99 and 20.55 g with GOCS_S, and between 23.20 and 28.92 with GOCS_SD, and it varied from 25.38 to 48.38 g under GS without controlling inbreeding. While the rate of genetic gain per generation obtained using GS was substantially larger than that obtained by the two scenarios of genomic OCS in the beginning generations of selection, the difference in the genetic gain of ADG between GS and GOCS reduced quickly in latter generations. At generation ten, the difference in the realized rates of genetic gain between GS and GOCS_SD diminished and ended up with even a slightly higher genetic gain with GOCS_SD, due to the rapid loss of genetic variance with GS and fixation of causative genes. The rate of inbreeding was mostly maintained below 5% per generation with genomic OCS, whereas it increased to between 10.5% and 15.3% per generation with GS. Therefore, genomic OCS appears to be a sustainable strategy for the genetic improvement of local breeds such as Ningxiang pigs, but keeping mind that a variety of GOCS methods exist and the optimal forms remain to be exploited further.
摘要：
<jats:p>The intestinal microbiome plays a crucial role in promoting intestinal health, and perturbations to its constitution may result in chronic intestinal inflammation and lead to colorectal cancer (CRC).<jats:italic>α</jats:italic>-Ketoglutarate is an important intermediary in the NF-<jats:italic>κ</jats:italic>B-mediated inflammatory pathway that maintains intestinal homeostasis and prevents initiation of intestinal inflammation, a known precursor to carcinoma development. The objective of this study was to assess the potential protective effects of<jats:italic>α</jats:italic>-ketoglutarate intervention against CRC development, which may arise due to its known anti-inflammatory and antitumour effects. CRC was induced in C57BL/6 mice using azoxymethane (AOM) and dextran sulfate sodium (DSS). Tumour frequency, histological rating, and colonic microbiota were assessed in colonic samples. The findings demonstrated that<jats:italic>α</jats:italic>-ketoglutarate offered significant protection against CRC development in mice. Furthermore,<jats:italic>α</jats:italic>-ketoglutarate also exhibited immunomodulatory effects mediated via downregulation of interleukin (IL)-6, IL-22, tumour necrosis factor (TNF)-<jats:italic>α</jats:italic>, and IL-1<jats:italic>β</jats:italic>cytokines. Finally, intervention with<jats:italic>α</jats:italic>-ketoglutarate tended to minimise the frequency of opportunistic pathogens (<jats:italic>Escherichia</jats:italic>and<jats:italic>Enterococcus</jats:italic>) while increasing the populations of<jats:italic>Akkermansia, Butyricicoccus</jats:italic>,<jats:italic>Clostridium,</jats:italic>and<jats:italic>Ruminococcus</jats:italic>. Taken together, our findings show that dietary<jats:italic>α</jats:italic>-ketoglutarate intervention may protect against inflammation-related CRC.</jats:p>
摘要：
Heat stress is a non-specific physiological response of the body when exposed to high ambient temperatures, which can break the balance of body redox and result in oxidative stress that affects growth performance as well as the health of poultry species. Polyphenols have attracted much attention in recent years due to their antioxidant ability and thus, can be an effective attenuator of heat stress. In this paper, the potential mechanisms underlying the inhibitory effect of polyphenols on heat stress in poultry has been reviewed to provide a reference and ideas for future studies related to polyphenols and poultry production.
摘要：
<jats:title>Abstract</jats:title><jats:p>This study investigated the effect of dietary resveratrol supplementation on growth performance, rectal temperature, and serum parameters of yellow‐feather broilers under heat stress. A total of 480 yellow‐feather broilers (28‐day‐old) were randomly allotted to five groups with six replicates. A thermoneutral group (<jats:styled-content style="fixed-case">TN</jats:styled-content>) (24±2°C) received a basal diet and another four heat‐stressed groups (37±2°C for 8hr/day and 24±2°C for the remaining time) were fed the basal diet or basal diet with 200, 350, and 500mg/kg resveratrol for 14 consecutive days. The results revealed that resveratrol supplementation improved average daily gain (<jats:italic>p</jats:italic>=<jats:italic></jats:italic>0.001), and decreased (<jats:italic>p</jats:italic><0.05) rectal temperature from d 3 when compared with heat‐stressed group without resveratrol. In addition, supplementation with resveratrol at 350 or 500mg/kg lowered (<jats:italic>p</jats:italic><0.05) the contents of corticosterone, adrenocorticotropic hormone, cholesterol, triglycerides, uric acid, malonaldehyde, and activities of aspartate aminotransferase, alanine aminotransferase, and lactate dehydrogenase, increased (<jats:italic>p</jats:italic><0.05) the levels of triiodothyronine, the ratio of triiodothyronine to thyroxine, total protein, glutathione, and activities of alkaline phosphatase, total superoxide dismutase, catalase, and glutathione peroxidase, though with few fluctuation. In conclusion, supplementation with resveratrol can improve the growth performance by positively regulating serum metabolic parameters and alleviating tissue oxidant damage of broilers under heat stress.</jats:p>
摘要：
1. Adipocyte fatty acid binding protein (A-FABP) plays a key role in fatty acid uptake and intracellular transport. The objective of the present study was to identify and characterise the A-FABP gene in Xupu goose.2. The full-length cDNA of goose A-FABP gene was cloned from the liver tissue using reverse transcription polymerase chain reaction (RT-PCR) and rapid amplification of cDNA ends (RACE). The distribution of the goose A-FABP in different tissues was determined by quantitative real-time PCR (qRT-PCR).3. The results showed that the full-length cDNA sequence of goose A-FABP was 657 bp, containing a 5'-UTR of 52 bp, a 3'-UTR of 206 bp and an open reading frame (ORF) of 399 bp, which encoded a polypeptide of 132 amino acids (AA).4. The AA sequence of goose A-FABP showed 76.52%, 75.00%, 93.18% and 99.24% identities with previously described homologues from humans (Homo sapiens), mouse (Mus musculus), chicken (Gallus gallus), and duck (Anas platyrhynchos), respectively, and phylogenetic analysis revealed a close relationship among them. The transcript of Xupu goose A-FABP was ubiquitously expressed in all tested tissues, and showed a high-level expression in abdominal fat, sebum and liver.5. A significant positive correlation was identified between A-FABP mRNA abundance in the three adipose tissues and liver weight, ratio of liver to body weight, TG content, and VLDL concentration in the plasma of Xupu goose. A significant negative correlation was observed between the mRNA level of A-FABP and HDL concentration in the plasma of Xupu goose.6. These findings provide a foundation for further research on the function and mechanism of A-FABP in the fat deposition process.
摘要：
Ruminant production, especially in the tropics and developing countries suffers a setback when compared with the temperate and developed countries, which is attributable to the kinds of available feed resources in the region of production. In the tropics, ruminants are restricted to grazing on low-quality forages, crop residues and agro-industrial by-products with very little or no concentrate diets, which adversely affect the animals in exhibiting their full production potential. Considering this fact, there is an increasing interest in improving the digestibility of these feed resources. In recent years, researchers have explored several methods to enhance the functions of rumen microflora, improve digestion and fermentation processes, as well as increase bioavailability and utilization of nutrients through feed supplementation. This review aims to explore the positive effects of supplementation of ruminant diets with probiotics or botanical extracts and their metabolites on the productivity of the animals. Moreover, the functions of these non-pathogenic and non-toxic live microorganisms (probiotics) and plant biologically active compounds (botanical extract) are explored because of the ban on non-therapeutic use of antibiotics as growth promoters coupled with the critical preference of consumers to high quality and safe animal products. It has been reported that these alternative supplemental products have a beneficial impact on both animal health and productivity, which is affecting stabilization of rumen environment, inhibition of pathogenic bacteria proliferation in gastro-intestinal tract, modulation of immune response, increase in fibre degradation and fermentation, nutrients availability and utilization, animal growth performance and milk production, among others. However, long-term in vivo studies are still required to determine the synergetic effects of these 2 safe supplemental products.
摘要：
Background: Our previous study suggested that short-term lysine restriction improved feed intake and gut microbiota in piglets. Thus, in this study, we further used proteomics technology to investigate the potential mechanism associated with long-term lysine restriction in pigs. In addition, blood biochemical parameters, meat quality, and muscle nutrient transporters were also evaluated in lysine restricted pigs. Results: The results showed that 131 proteins in the liver were markedly altered in response to dietary lysine restriction, with 54 being downregulated and 77 being upregulated, which mainly involved in neurodegenerative diseases, oxidative phosphorylation, and metabolic pathways. In addition, lysine restriction markedly reduced serum BUN, CHOL, and HDL abundances. Dietary lysine restriction enhanced meat color lightness and upregulated SLC7A2 expression. Conclusion: Lysine restriction affected meat quality, blood biochemical parameters, and liver global protein expressions. This study is the first attempt to evaluate the liver protein profile of lysine restricted pigs, and the current results may provide valuable information with respect to better understanding the host response to lysine restriction in pigs.
