Improvement Of Production Traits Research Articles

Microbial Community Structure and Metabolism of Xinjiang Fine-Wool Sheep based on High-Throughput Sequencing Technology.

It turns out that the more than trillion microorganisms living in the host's digestive tract are crucial for maintaining nutrient intake, environmental suitability, and physiological mechanism. Xinjiang fine-wool sheep is an exclusive breed for wool in China, which has excellent stress tolerance. In this study, we collected feces and blood samples of 20 Xinjiang fine-wool sheep under the same genetic characteristics, the Fine-Wool Sheep (FWS) group and the Control Fine-Wool Sheep (CFWS) group were set up according to the differs in phenotypic characteristics of their wool. By 16S rRNA amplicon sequence, ITS1 region amplicons and Targeted Metabolomics, we analyzed the microbial community structure of fecal microorganisms and Short Chain Fatty Acids (SCFAs) in serum of the Xinjiang fine-wool sheep. Fecal microbial sequencing showed that the bacterial composition and structure were similar between the two groups, whereas there were significant differences in the composition and structure of the fungal community. It was also found that the abundant of Neocallimastigomycota in the intestinal fungal community of FWS was higher. In addition, the results of the serum SCFAs content analysis showed that butyric acid was significantly differences than those two groups. Correlation analysis between SCFAs and bacteria found that butyric acid metabolism had positively correlated (P < 0.05) with Ruminococcus and UCG-005. Overall, our data provide more supplement about the gut microbes community composition and structure of the Xinjiang fine-wool sheep. These results might be useful for improving gut health of sheep and taking nutritional control measure to improve production traits of animals in future.

Efficiency of Recycled Plastic Bedding Material and Gender in Improvement of Productive Traits, Physiological, and Immunological Parameters of Hybrid Broiler Chickens

Litter management is important for poultry housing husbandry and affects chicken performance. The present study evaluated the effect of bedding material and gender on the productive, physiological, and immunological performance of a new hybrid chicken (WINZY Line 105) under cold stress for 56 days of age. A total of 540 one-day-old broiler chicks were divided into two groups. The groups, including 270 males (M) and 270 females (F) were further divided into two sub-groups, including sawdust litter (SL) and plastic slatted floor (PSF), three replicates, and 45 chickens each. Broiler chickens were raised during the winter with an average temperature of 10oC for 56 days. Productive, physiological, and immunological performance parameters were measured. The obtained results indicated that M reared on PSF (M x PSF) recorded the highest values in body weight (BW), body weight gain (BWG), carcass characteristics, and the best values in feed conversion compared with other interaction groups during all experimental periods. In addition, F reared on PSF had higher BW, carcass, and thigh percentages, low feed intake (FI), and best feed conversion compared to females reared on SL. The M reared on PSF had the highest hepatic enzymes except AST which was higher in F reared on PSF than other treatments. However, renal function biomarkers (Creatine, Uric acid, Urea) were higher in both M and F that were reared on SL than those reared on PSF. Moreover, there was a significant interaction detected for antibody titters against avian influenza (H5) and Newcastle disease at 21 days of age suggesting that the highest values observed for M reared on PSF (M x PSF) compared with other interaction groups during the experimental period, and it was higher in F that reared on PSF than F reared on SL at 21 days of age. It can be concluded that plastic slatted floors could be an alternative to substitute wood shavings to raise broiler chickens since it was efficient from the perspective of environmental conditions and production rates.

Advancing Yak Breeding in China: Harnessing Genetic Resources and Marker-Assisted Selection for Improved Production Traits

Advancing Yak Breeding in China: Harnessing Genetic Resources and Marker-Assisted Selection for Improved Production Traits

Development of selection strategies for genetic improvement in production traits of Mecheri sheep based on a Bayesian multi trait evaluation

The progression of genetic selection techniques to enhance farm animal performance traits is guided by the present level of genetic variation and maternal impact in each trait, as well as the genetic association between traits. This study was conducted on a population of Mecheri sheep maintained from 1980 to 2018 at Mecheri Sheep Research Station, Pottaneri, India, to determine variance and covariance components, as well as genetic parameters for various production performance traits. A total of 2616 lambs, produced by 1044 dams and 226 sires, were examined in the study and the production traits of Mecheri sheep assessed include birth weight (BW), weaning weight (WW), six-month weight (SMW), nine-month weight (NMW), and yearling weight (YW). The Bayesian approach, using the Gibbs sampler, analyzed six animal models with different combinations of additive direct and maternal additive effects. Direct genetics, maternal genetics, and residual effects models were the major contributors to total phenotypic variation for all the production traits studied. Direct heritability estimates of birth weight, WW, SMW, NMW, and YW were 0.25, 0.20, 0.12, 0.14, and 0.13, respectively. The maternal heritability estimated for BW, WW, SMW, NMW, and YW were 0.17, 0.10, 0.12, 0.14, and 0.14, respectively. The maternal effects had a major impact on the pre-weaning production traits. The genetic correlations estimated between different pairs of production traits studied ranged from 0.19 to 0.93. The body weight at birth exhibited a higher genetic relationship with weaning weight than post-weaning growth characteristics, and the genetic correlation between weaning weight and post-weaning attributes was moderate to high (0.52 to 0.72). Based on the additive genetic variance in weaning weight and the correlation estimates of weaning weight with post-weaning traits, weaning weight was proposed as a selection criterion for improving growth traits in Mecheri sheep.

Marker-assisted and Genomic Selection of Beef Cattle

This article provides an overview of modern genetic technologies for improving production traits and predicting breeding value in beef cattle. In particular, in marker-assisted selection the most promising is the selectionby desirable genotypes in the genes of myostatin (MSTN), calpain (CAPN), calpastatin (CAST), growth hormone (GH), leptin (LEP), thyroglobulin (TG), fatty acid binding protein (FABP), retinoic acid C-receptor (RORC), diacyl-glycerol acyltransferase (DGATI), sterol-Co desaturase (SCD). A modern and much more advanced approach is the Single Step Genomic Best Linear Unbiased Predictions (ssGBLUP) method, which calculates a Genomic Estimated Breeding Value (GEBV) using DNA chip genotyping, phenotype and pedigree data. Genome-wide association studies (GWAS), based on the use of genetic markers distributed throughout the genome and in non-equilibrium linkage with at least one of the quantitative traits, are currently recognised as more informative for finding new genes for beef cattle productivity. New genes associated with live weight at different stages of ontogenesis, average daily live weight gain, residual feed intake, carcass weight and flesh content have been identified. Most of the identified genes control cell division, lipid and carbohydrate metabolism. The accumulated data on full-genome association studies and exome sequencing led to new methods of genetic analysis – gene ontology and gene networks. The use of gene networks provided the first detailed understanding of the genetic basis for the formation of complex phenotypic traits based on the complex interaction of regulatory networks of «major» and «peripheral» genes controlling the development of a particular trait.

Perspectives in Genome-Editing Techniques for Livestock.

Genome editing of farm animals has undeniable practical applications. It helps to improve production traits, enhances the economic value of livestock, and increases disease resistance. Gene-modified animals are also used for biomedical research and drug production and demonstrate the potential to be used as xenograft donors for humans. The recent discovery of site-specific nucleases that allow precision genome editing of a single-cell embryo (or embryonic stem cells) and the development of new embryological delivery manipulations have revolutionized the transgenesis field. These relatively new approaches have already proven to be efficient and reliable for genome engineering and have wide potential for use in agriculture. A number of advanced methodologies have been tested in laboratory models and might be considered for application in livestock animals. At the same time, these methods must meet the requirements of safety, efficiency and availability of their application for a wide range of farm animals. This review aims at covering a brief history of livestock animal genome engineering and outlines possible future directions to design optimal and cost-effective tools for transgenesis in farm species.

Research progress on the regulation of production traits by gastrointestinal microbiota in dairy cows.

The composition and abundance of microorganisms in the gastrointestinal tract of cows are complex and extensive, and they play a crucial role in regulating nutrient digestion, absorption, maintaining digestive tract stability, and promoting the production and health of the host. The fermentation carried out by these microorganisms in the gastrointestinal tract is fundamental to the health and productivity of cows. Rumen microorganisms produce the majority of enzymes required to break down feed substrates, such as cellulose, protein, lipids, and other plant materials, through fermentation. This process provides energy metabolism substrates that satisfy approximately 70% of the host's energy requirements for physiological activities. Gut microorganisms primarily decompose cellulose that is difficult to digest in the rumen, thereby providing heat and energy to the hosts. Additionally, they have an impact on host health and productivity through their role in immune function. Understanding the composition and function of the cow gut microbiota can help regulate dairy cattle breeding traits and improve their health status. As a result, it has become a popular research topic in dairy cattle breeding. This article provides a review of the composition, structure, physiological characteristics, and physiological effects of the cow gut microbiota, serving as a theoretical foundation for future studies that aim to utilize the gut microbiota for dairy cattle breeding or improving production traits. It may also serve as a reference for research on gut microbiota of other ruminants.

High‐throughput genotyping in estimating genetic resources and detecting pathogens in aquaculture

High‐throughput genotyping in estimating genetic resources and detecting pathogens in aquaculture

Impact of environmental disturbances on estimated genetic parameters and breeding values for growth traits in pigs

Due to the diversification of farming systems and climate change, farm animals are exposed to environmental disturbances to which they respond differently depending on their robustness. Disturbances such as heat stress or sanitary challenges (not always recorded, especially when they are of short duration and low intensity) have a transitory impact on animals, resulting in changes in phenotypes of production (feed intake, BW, etc.). The aim of this study was to evaluate the impact of such unknown disturbances on the estimated genetic parameters and breeding values (BV) for production traits. A population of 6 120 individuals over five generations divided into eight batches of 10 pens was generated, each individual underwent an ≃100-day test period. A longitudinal phenotype mimicking piglet weight during the fattening period was simulated for each individual in two situations: disturbed and non-disturbed. The disturbed phenotype was modified according to the robustness of the animal and the intensity and duration of the disturbance that the animal was subjected to. Various sets of simulations (1 000 replicates per set) were considered depending on the type of disturbance (at the level of the batch, pen, or individual), the genetic correlation (negative, neutral, or positive) between the two components of the robustness (resistance and resilience), the genetic correlation (negative, neutral, or positive) between growth and the components of robustness, and the heritability of the components of robustness (weak or moderate). An animal model was used to estimate the genetic parameters and BV for two production traits: the BW at 100 days of age (BW100) and average daily gain (ADG). The estimated heritability of the production traits was lower in the disturbed situation compared to the non-disturbed one (reduction of 0.08 and 0.05 points respectively for BW100 and ADG). The correlations between estimated breeding values of the observed phenotypes (EBV) and BV for production traits in absence of disturbance were lower in the disturbed situation (reduction of 0.04 and 0.06 points for BW100 and ADG respectively) while the partial correlation between EBV and BV for robustness was not significantly different from 0 in the two situations. These results suggest that selection in a well-controlled environment with random disturbances of low intensities does not allow to improve animal robustness while it is less effective for improving production traits than selection under no environmental disturbances.

The impact of genetic relationship between training and validation populations on genomic prediction accuracy in Atlantic salmon

The potential of genomic selection (GS) to improve production traits has been widely demonstrated in many aquaculture species. Atlantic salmon breeding programmes typically consist of sibling testing schemes, where traits that cannot be measured on the selection candidates are measured on the candidates’ siblings. While annual testing on close relatives is effective, it is expensive due to high genotyping and phenotyping costs. Accurate prediction of breeding values in distant relatives could significantly reduce the cost of GS. This study aimed to evaluate the impact of decreasing the genomic relationship between the training and validation populations on the accuracy of genomic prediction for two key traits; body weight and resistance to sea lice; and to assess the interaction of genetic relationship with SNP density. Phenotype and genotype data from two year classes of a commercial breeding population of Atlantic salmon were used. The accuracy of genomic predictions were close to zero when the prediction was performed across year class, albeit this may reflect a lack of genetic correlation between the same traits measured in the different year classes. Within a year class, systematically reducing the relatedness between the training and validation populations resulted in decreasing accuracy of genomic prediction; when the training and validation populations were set up to contain no relatives with genomic relationships > 0.3, the accuracies decreased by 44% for sea lice count and by 53% for body weight. Less related training and validation populations also tended to result in highly biased predictions. No clear interaction between decreasing SNP density and relatedness between training and validation population was found. These results confirm the importance of close genetic relationships between training and selection populations in salmon breeding programmes, and suggests that prediction across generations using existing approaches would severely compromise the efficacy of GS.

Environmental Impacts and Their Association With Performance and Excretion Traits in Growing Pigs.

The selection of pigs for improved production traits has been, for a long time, the major driver of pig breeding. More recently, because of the increasing concern with the environment, new selection criteria have been explored, such as nitrogen (N) excretion. However, many studies indicate that life cycle assessment (LCA) provides much better indicators of environmental impacts than excretion. Therefore, the objective of this study was to investigate, using a modeling approach, the relationships between production traits and LCA impacts of individual growing pigs calculated at the farm gate for 1 kg of body weight gain. Performances of pigs were simulated for 2-phase (2P) and precision feeding (PR), using the InraPorc population model (on 1,000 pigs). Nitrogen excretion was positively correlated with feed conversion ratio (FCR; r = +0.96), climate change (CC; r = +0.96), acidification potential (AC; r = +0.97), eutrophication potential (EU; r = +0.97), and land occupation (LO; r = +0.96), whatever the feeding program. However, FCR appeared to be a better indicator of LCA impacts, with very high and positive correlations (r > +0.99) with CC, AC, EU, and LO for both feeding programs. The CC, AC, and EU impacts of pig production for PR feeding were 1.3, 10, and 7.5% lower than for 2P, respectively, but the correlations within each outcome were very similar among feeding programs. It was concluded that the use of FCR as a selection criterion in pig breeding seems to be a promising approach to associate improved performance and low environmental impact of pig fattening.

Sustainable Food Production: The Contribution of Genome Editing in Livestock

The growing demand for animal source foods to feed people has been pushing the livestock industry to increase productivity, a tendency that will continue throughout this century. The challenge for the coming years is to increase the food supply to ensure equity in access to high quality food, while maintaining global sustainability including combating climate change, avoiding deforestation, and conserving biodiversity, as well as ensuring animal health and welfare. The question is, how do we produce more with less? Classical methods to enhance livestock productivity based on the improvement of animal health, nutrition, genetics, reproductive technologies and management have made important contributions; however, this is not going to be enough and thus disruptive approaches are required. Genome editing with CRISPR may be a powerful contributor to global livestock transformation. This article is focused on the scope and perspectives for the application of this technology, which includes improving production traits, enhancing animal welfare through adaptation and resilience, conferring resistance to infectious diseases, and suppressing pests and invasive species that threaten livestock. The main advantages and concerns that should be overcome by science, policy and people are discussed with the aim that this technology can make a real contribution to our collective future. This review is part of the special issue “Genome Editing in Animal Systems to Support Sustainable Farming and Pest Control”.

281 Can We Developmentally Program the Epigenome to Improve Traits Relevant to Production in Cattle?

Abstract While sequence variation can be informative to associate regions of the genome with specific traits and improve genetic selection, the epigenome may provide a more powerful tool to manage cattle. Identifying practices that are producer friendly and effectively control epigenetic function within animals is crucial to translating developmental programming to a production setting. Initial studies of developmental programming investigated how environmental or nutritional stresses during fetal and peri-natal development impacted performance of animals later in life. These studies demonstrated changes in methylation, alterations in transcript abundance, and negative impacts on physiology, but they also suggested that we may be able to beneficially impact the epigenome and developmentally program animals to excel in their niche in the production system. Maternal nutritional status during the third trimester influenced date of conception of female progeny in several studies but failed to do so in other studies. Transcriptomic analyses provided evidence that nutritional treatments alter mRNA abundance in brain, liver, muscle, and ovary, but does not conclusively demonstrate that this is due to functional changes in the epigenome. If developmental programming is to be applied in production systems, responses must be consistent and beneficial. Reducing nutrient intake in heifers during peri-pubertal development increased number of primordial follicles in the ovaries and reproductive longevity. While nutritional programming of the ovarian reserve in peri-pubertal heifers appears to occur consistently across locations and studies, it does not ensure that subsequent environmental stressors will not induce changes in the ovarian reserve that will negate beneficial effects. These studies demonstrate that it is possible to developmentally program the epigenome in cattle in ways that will improve production traits; however, there remains a need for studies to improve the consistency of response and to determine best practices that fit into production systems. USDA is an equal opportunity provider and employer.

Gaining Acceptance of Novel Plant Breeding Technologies.

Ensuring the sustainability of agriculture under climate change has led to a surge in alternative strategies for crop improvement. Advances in integrated crop breeding, social acceptance, and farm-level adoption are crucial to address future challenges to food security. Societal acceptance can be slow when consumers do not see the need for innovation or immediate benefits. We consider how best to address the issue of social licence and harmonised governance for novel gene technologies in plant breeding. In addition, we highlight optimised breeding strategies that will enable long-term genetic gains to be achieved. Promoted by harmonised global policy change, innovative plant breeding can realise high and sustainable productivity together with enhanced nutritional traits.

Turkey production and health: current challenges

Several factors and problems are influencing turkey production and health. These include intense global competition between producing countries, permanent changes in social, political and consumer perceptions regarding food safety, animal welfare and environmental protection. Several human foodborne infections are linked to poultry and poultry products, causing a serious challenge because it is difficult to control. Moreover, contamination of the turkey meat and product with antibiotic-resistant bacteria is a constant public health hazard. The loss of consumer confidence and trust in turkey meat product safety and quality will also be a major concern. The current and future turkey health concepts should cover the control of diseases in birds and the relationship between bird’s health, welfare and environmental protection. Additionally, infectious turkey diseases' emergence and re-emergence will remain an important and never-ending challenge. Only a few authorized pharmaceutical veterinary products are available to treat turkeys. The development of efficient vaccines and natural antimicrobials against bacterial infections will reduce antibiotic use and reduce resistant bacteria's development. Genetic selective breeding to improve production traits and health is a long-standing goal of the turkey industry. Furthermore, rearing technology, management, and feeding will help maintain the birds healthy and comfortable. Finally, all other partners involved in the production chain, including farmers, veterinarians, stockholders, need to collaborate to meet the consumer expectations for high quality and safe products

Efficient CRISPR/Cas9-mediated gene editing in Guangdong small-ear spotted pig cells using an optimized electrotransfection method.

Guangdong Small-ear Spotted (GDSS) pigs are a pig breed native to China that possesses unfortunate disadvantages, such as slow growth rate, low lean-meat percentage, and reduced feed utilization. In contrast to traditional genetic breeding methods with long cycle time and high cost, CRISPR/Cas9-mediated gene editing for the modification of the pig genome can quickly improve production traits, and therefore this technique exhibits important potential in the genetic improvement and resource development of GDSS pigs. In the present study, we aimed to establish an efficient CRISPR/Cas9-mediated gene-editing system for GDSS pig cells by optimizing the electrotransfection parameters, and to realize efficient CRISPR/Cas9-mediated gene editing of GDSS pig cells. After optimization of electrotransfection parameters for the transfection of GDSS pig cells, we demonstrated that a voltage of 150V and a single pulse with a pulse duration of 20ms were the optimal electrotransfection parameters for gene editing in these cells. In addition, our study generated GDSS pig single-cell colonies with biallelic mutations in the myostatin (MSTN) gene and insulin-like growth factor 2 (IGF2) intron-3 locus, which play an important role in pig muscle growth and muscle development. The single-cell colonies showed no foreign gene integration or off-target effects, and maintained normal cell morphology and viability. These gene-edited, single-cell colonies can in the future be used as donor cells to generate MSTN- and IGF2-edited GDSS pigs using somatic cell nuclear transfer (SCNT). This study establishes the foundation for genetic improvement and resource development of GDSS pigs using CRISPR/Cas9-mediated gene editing combined with SCNT.

Effect of Season, Parity and Stage of Lactation on Productive Performance of Sahiwal Cattle

The study was conducted to understand the effect of season, parity and stage of lactation on productive performance of Sahiwal cattle. The data of productive traits of 133 Sahiwal cattle from 2016 to 2018 maintained at the Livestock Research Center, Karnal, Haryana, were used for this study. The production data were analyzed using least-square procedures based on season, parity and stage of lactation. Results indicated that the parity had significant (p less than 0.05) influence on monthly milk yield (MMY) whereas, the stage of lactation had highly significant (P less than 0.01) influence on monthly milk yield (MMY) and test day milk yield (TDMY). However, there was no significant effect of season on different productive performance traits in Sahiwal cattle. The phenotypic parameter estimates indicated that the parity and stage of lactation of cattle can be used as a selection tool for improvement of productive traits considering its high positive phenotypic correlations with succeeding productive traits in Sahiwal cows.

Effectiveness of body measurement traits for improving production traits in Duroc pigs

デュロック種2,835頭の記録を用いて，体型形質（体長，体高，前幅，胸幅，後幅，胸深，胸囲，前肢および後肢管囲，前肢および後肢つなぎ，ボディマス指数，体密度）および産肉形質（検定開始時および検定終了時日齢，一日平均増体重（DG），背脂肪厚（BF），ロース芯面積（LMA）および筋肉内脂肪含量（IMF））の遺伝的パラメーターを推定した．体型形質の遺伝率は後幅の0.24から後肢管囲の0.44と，中程度以上の値が推定された．DG, BF, LMAおよびIMFとの遺伝相関の推定値の絶対値が最も大きい体型形質は，それぞれ胸囲（0.42），胸囲（0.68），前肢つなぎ（－0.28），胸幅（0.38）で，産肉形質改良の指標となる可能性が示唆された．また，前肢および後肢管囲とBF, 前肢つなぎとLMAで負，前肢つなぎとDGで正の遺伝相関が推定された．

The state of the beef cattle industry in the Kurgan region

The agro-industrial complex of the country faces a strategically important task, which as to increase the production of meat, including beef. This problem has been trying to solve by creating a specialized beef cattle industry. The impetus for the development of beef cattle in the Kurgan region was the departmental target program of the Department of agriculture and processing industry of the Kurgan region “Development of beef cattle for 2011–2015”. Implementation of the Program has allowed to increase the number of beef cattle from 2010 to 2015 from 2089 to 6531 heads including cows from 666 up to 2898 heads. In subsequent years there was also a positive trend. For the development of the beef cattle industry in the Kurgan region at present there are all conditions: natural forage lands, the possibility of using low-cost intensive grazing technology, resources of breeding stock in dairy herds for the formation of new beef farms, forage grain. The results of the analysis of the state and prospects of development of this industry in the Kurgan region have been presented in the article. A positive trend has been revealed. In order to preserve the positive trends in the development of beef cattle industry of the Kurgan region it is planned to continue the annual increase of livestock, improvement of productive traits, including live weight, milk capacity and reproductive ability of cows, and improved forage base and optimization of feeding rations according to sex and age of groups.

Genetic relationship between koi herpesvirus disease resistance and production traits inferred from sibling performance in Amur mirror carp

Koi herpesvirus disease (KHVD) is currently the most serious threat to global carp farming. Prevention is a sensible strategy for tackling this disease and improved genetic resistance of carp strains is a desirable breeding goal. To study the potential for multitrait selection, the objective of the current study was to estimate the genetic correlations between KHVD resistance and production traits in Amur mirror carp. A total of 1500 fingerlings from four factorial crosses of five dams and ten sires were challenged with Koi herpesvirus (KHV). Juvenile growth-related traits were collected on the same individuals before the challenge test. Production traits were measured on siblings of the challenged population at different life stages (yearling to market size). The estimated heritability for resistance to KHVD was 0.43 ± 0.08 on the observed scale and 0.72 ± 0.13 on the underlying liability scale. Most genetic correlations between KHVD resistance and important production traits were insignificant, showing that selection for improved production traits would not increase susceptibility to KHV and vice versa. However, resistance to KHVD was negatively correlated with Fulton's condition factor (FC) after the second overwintering and relative head length (RHL), relative body height (RBH) and relative body width (RBW) from the second growing season to the market size, with a more prolonged body shape of Amur mirror carp (genes from Amur wild scaly carp, Cyprinus rubrofuscus) being associated with higher KHVD resistance. Intermediate favorable genetic correlations between KHVD resistance and log-log residuals of headless carcass yield (0.37 ± 0.14) and fillet yield (0.44 ± 0.13) at market size suggested that selection for improved yields of edible body parts might indirectly lead to a slight improvement in KHVD resistance and vice versa.