bluuebunny/crossref_metadata_2025 huggingface dataset:
37 Genetic aspects of livestock adaptation
Authors: Riley David G
Published: December 2019

Livestock adaptation to less than favorable ambient has a genetic basis. Estimates of additive genetic variance and narrow sense heritability for % intramuscular fat in Hereford varied across United States geography quantifications evaluated in random regression analyses. Shedding and regrowth of winter coats of Angus cows in subtropical areas may indicate differential adaptation in cattle not adapted to the subtropics. Acquired adaptation to local conditions (multiple generations across more than 50 years) may was evidenced by performance of Florida Angus relative to prominent U.S. Angus in subtropical Florida; later sexual maturation may be a prominent component of such adaptation, and increasing milk production may be antagonistic to adaptation in natural conditions. Cattle temperament may be indicative of adaptation and is highly heritable; however, results from random regression analyses suggest that the additive genetic component appears to decrease in importance and the permanent environmental component of phenotype appears to become more important as calves age. Crossbreeding represents a proven strategy to improve adaptation almost immediately. Heterosis influences cattle body temperature maintenance, reproduction, survival, and, to a lesser extent, temperament in subtropical or other stressful environmental conditions (for example, in toxic fescue). Prenatal stress alters patterns of methylation (and likely other epigenetic mechanisms) and thereby encourages or inhibits gene expression to promote postnatal fitness. Brahman exposed to prenatal stress exhibited substantially different patterns of methylation across the genome in lymphocytes in both male and female calves; those patterns differed by sex. Female longevity may be the ultimate adaptation trait, as annual compliance to reproductive standards may be an appropriate assessment of a combination of attributes that represent adaptation. Longevity has documented heterotic influence; the additive genetic component is less well characterized but real. A simple, effective way to improve longevity may be to select bulls from aged, proven cows.
34 Reproductive management of beef females in tropical and sub-tropical environments
Authors: Oosthuizen Nicola , Fontes Pedro Levy Piza , Lamb G Cliff
Published: December 2019

Bos indicus and Bos taurus cattle diverged from an evolutionary standpoint more than 110,000 years ago. Since then, Bos indicus cattle have undergone genetic adaptations beyond the commonly discussed increased thermo-tolerance and parasite resistance. Several physiological differences exist between Bos indicus and Bos taurus cattle, and it is important to consider these differences when establishing reproductive management strategies. It has been well described that Bos indicus cattle have a delayed onset of puberty and longer periods of postpartum anestrus, yet through the utilization of estrus synchronization protocols these challenges can be attenuated. However, when Bos indicus females are exposed to these protocols, they are known to have smaller dominant follicles, lower expression of estrus, and decreased pregnancy rates to artificial insemination (AI) when compared to Bos taurus females. These factors can be overcome through the utilization of estradiol and progesterone based synchronization protocols, which improve follicular dynamics and yield acceptable pregnancy rates to assisted reproductive technologies in cattle adapted to tropical or subtropical conditions. However, the use of estrogens for synchronization purposes is not permitted in the United States, and cattle producers need to rely on GnRH-based protocols. Another key difference between subspecies, is that Bos indicus females have greater antral follicle counts than Bos taurus females, which proves beneficial for in vitro embryo production. Therefore, an opportunity exists to explore the greater productivity of donors in embryo production in order to improve genetics in herds that utilize these breeds.
209 Genomic selection for multiple maternal and growth traits in large white pigs using Single-Step GBLUP
Authors: Fragomeni Breno , Vitezica Zulma , Liu Justine , Huang Yijian , Gray Kent , Lourenco Daniela , Misztal Ignacy
Published: December 2019

The objective of this study was to implement a multi-trait genomic evaluation for maternal and growth traits in a swine population. Phenotypes for preweaning mortality, litter size, weaning weight, and average daily gain were available for 282K Large White pigs. The pedigree included 314k individuals, of which 35,731 were genotyped for 45K SNPs. Variance components were estimated in a multi-trait animal model without genomic information by AIREMLF90. Genomic breeding values were estimated using the genomic information by single-step GBLUP. The algorithm for proven and young (APY) was used to reduce computing time. Genetic correlation between proportion and the total number of preweaning deaths was 0.95. A strong, positive genetic correlation was also observed between weaning weight and average daily gain (r = 0.94). Conversely, the genetic correlations between mortality and growth traits were negative, with an average of -0.7. To avoid computations by expensive threshold models, preweaning mortality was transformed from a binary trait to two linear dam traits: proportion and a total number of piglets dead before weaning. Because of the high genetic correlations within groups of traits, inclusion of only one growth and one mortality trait in the model decreases computing time and allows for the inclusion of other traits. Reduction in computing time for the evaluation using APY was up to 20x, and no differences in EPD ranking were observed. The algorithm for proven and young improves the efficiency of genomic evaluation in swine without harming the quality of predictions. For this population, a binary trait of mortality can be replaced by a linear trait of the dam, resulting in a similar ranking for the selection candidates.
219 Relationship between host-genetics and the vaginal microbiome in commercial gilts
Authors: Sanglard Leticia , Schmitz-Esser Stephan , Gray Kent , Linhares Daniel C L , Yeoman Carl J , Dekkers Jack C , Niederwerder Megan C , Serão Nick V
Published: December 2019

The objective of this study was to investigate host-genetic contributions to the vaginal microbiome of commercial gilts vaccinated for Porcine Reproductive and Respiratory Syndrome (PRRS). Vaginal swab samples (n = 576) from 308 F1 gilts (183±12 days old) were collected on day 4 (D4) and 52 (D52) post-vaccination with a commercial modified live virus PRRS vaccine. Samples were used to profile the vaginal microbiome by 16S rRNA gene sequencing, with sequences clustered into operational taxonomic units (OTUs) and taxonomically classified. All animals were genotyped for 45,536 SNPs. Arcsine of the square root-transformed OTUs abundance data were analyzed using a linear mixed animal model with age at vaccination as a covariate and animal (random) for estimation of genetic parameters. The same model was used for GWAS for the 100 most abundant OTUs but with addition of genotype of SNPs as a covariate, one at a time. For D4, heritability estimates ranged from < 0.001±0.01(13 OTUs) to 0.60±0.13 (Fusobacterium), with OTUs corresponding to the genera Fusobacterium, Pasteurellaceae, Clostridiales, Prevotellaceae, and Lactobacillus having high estimates (0.41±0.13 to 0.60±0.13). For D52, heritability estimates ranged from < 0.001±0.01 (10 OTUs) to 0.63±0.12 (Terrisporobacter), with OTUs corresponding to Clostridium, Terrisporobacter, Romboutsia, Turicibacter, Phascolarctobacterium, Muribaculaceae, and Ruminococcaceae having high estimates (0.42±0.14 to 0.63±0.12). Forty-six QTLs were significantly (P < 0.00001) associated with OTU across days. Among these, one main QTL on chromosome 12 (20–23Mb), a gene-rich region with previously identified QTL for immune-related traits, was identified for 5 and 6 OTUs on D4 and D52, respectively. These OTUs were mainly of the phyla Proteobacteria and Firmicutes on D4 and D52, respectively. In conclusion, there is evidence of substantial host genetic variation for vaginal microbiome in commercial PRRS-vaccinated gilts, including the identification of many QTLs. Additional research is needed to investigate the genetic relationship between vaginal microbiome, health, and production in pigs.
214 Correlation among host gut microbiome and their relationship with meat quality and carcass composition traits of swine
Authors: Khanal Piush , Maltecca Christian , Schwab Clint , Fix Justin , Tiezzi Francesco
Published: December 2019

Study on correlation among host gut microbiome and their relationship with meat quality and carcass composition traits remains limited. The objectives of this study were 1) to estimate the microbial correlation between meat quality and carcass traits; and 2) to estimate the genetic correlation between microbial alpha diversity, and meat quality and carcass traits in commercial swine population. Data were collected from Duroc sired three-way cross individuals (n = 1,123) genotyped with 60K SNP chips. Fecal 16S microbial sequences for all individuals were obtained at three different stages: weaning (WEAN: 18.64 ± 1.09 days); week 15 (W_15: 118.2 ± 1.18 days); and off test (OT: 196.4 ± 7.80 days). Alpha diversity was measured at each stage [WEAN (alpha_w), W_15 (alpha_15) and OT (alpha_off)] using the Shannon index, which was computed as: ∑ ni=1piln(pi) where pi was the proportional abundance of ith operational taxonomic unit. Microbial correlations were estimated using multi-trait model, which included fixed effects of dam line, contemporary group and sex, as well as random effects of pen, additive genetic and microbiome. Bivariate analyses were conducted between different traits and alpha_w, alpha_15 and alpha_off with the same fixed effects and random pen and additive genetic effect. Analyses were conducted in ASREML v.4. Microbial correlations ranged from -0.93 ± 0.11 between firmness and slice shear force to 0.97 ± 0.02 between carcass average daily gain (CADG) and loin weight. For meat quality traits, correlations were weak, except for alpha_15 with Minolta a* (-0.45±0.19). Alpha_15 showed weak correlations except with CADG (-0.43±0.19). All correlations between alpha_ot and growth, carcass and meat quality traits were weak. These results may establish a newer approach of genetic evaluation process by utilizing gut microbiome information.
216 Contribution of host gut microbiome in prediction of meat quality and carcass composition traits in swine
Authors: Khanal Piush , Maltecca Christian , Schwab Clint , Fix Justin , Tiezzi Francesco
Published: December 2019

The objective of this study was to assess the improvement in predictive ability (PA) for meat quality and carcass composition traits by including the effect of host gut microbiome. Data were collected from Duroc sired three-way crossbred individuals (n = 1,123) genotyped from 60k SNP chips. Fecal 16S microbial sequences for all individuals were obtained at three different stages: weaning (WEAN: 18.64±1.09 days); week 15 (W_15: 118.2±1.18 days); and off test (OT: 196.4±7.80 days). A 4-fold cross validation was used, with animals grouped based on sire relatedness. Analysis was conducted in “BGLR” package in R. The first model included the fixed effect of dam line, contemporary group, and sex, as well as random pen and additive genetic effect (with genomic relationship matrix). The second model included same fixed and random effects with the addition of the microbiome effect (with microbiome relationship matrix). With the inclusion of microbiome, the PA increased for majority of traits. For carcass traits, the increase in PA was greatest for belly weight which changed from 0.22±0.06 to 0.32±0.06 at OT and lowest for loin depth and ham weight which changed from 0.14±0.06 to 0.15 ±0.06 and 0.12±0.02 to 0.13 ±0.03 at WEAN respectively. For meat quality traits, the increase in PA was greatest for subjective firmness score which changed from 0.16±0.04 to 0.19±0.04 at OT and lowest for marbling score and intramuscular fat which changed from 0.27±0.09 to 0.28±0.08 and 0.39±0.05 to 0.40±0.05 at WEAN respectively. Higher predictive ability was observed at OT rather than at WEAN and W_15 microbiome information. The results may lead to a newer approach to the genetic evaluation program of swine.
333 Animal –GRIN a platform for animal genetic information
Authors: Blackburn Harvey D , Manahan Ted , Wilson Carrie S , Fu Wenkai , Cajueiro Eduardo , Thomas Milton G , Paiva Samuel
Published: December 2019

An information system, Animal-GRIN, has been constructed as part of the U.S., Brazilian, and Canadian livestock genetic resource programs. It is designed to provide information to gene bank managers, the research community, and livestock producers about livestock breeds and subpopulations acquired in gene bank collections. The system was developed using a range of free software tools, including: MySQL, Ruby on Rails, Java Script, etc. The system is dynamic and publically accessible (https://nrrc.ars.usda.gov/A-GRIN). Exemplary information in Animal-GRIN consists of: animal identifiers, number and type of samples in the collection, pedigrees, coefficients of genetic relationships between animals within a breed, breeding values, phenotypes, and geographic source. To meet the national need for the long term archiving of genomic information developed with public funds, Animal-GRIN was expanded to store and make publically available genomic information (SNP) from any SNP chip, including custom products. Researchers are encouraged to submit their data upon completion of their publically funded projects. With the drill down concept, users can search the database for genomic information, physical samples associated with the genomic information, and phenotypic information on specific animals. Once animals of interest are found, on-line tools enable users to request either germplasm samples or genomic data. Progress in meeting genetic security for a breed’s collection can also be viewed. To date the U.S. collection has 52,639 animals with almost a million samples representing 36 species, 167 breeds, and 331 subpopulations and these have been entered into Animal-GRIN. Genomic data has been acquired on 1,899 animals representing 36 breeds. The next phase of Animal-GRIN development will be development of landscape genomics components. Acquisition of germplasm samples and associated genomic information are a continuing effort.
47 Genomic selection and gene editing in plant breeding – an industry perspective
Authors: Geha Makram
Published: December 2019

The world population is on an inevitable growth trajectory presenting the challenge of feeding nearly 9 billion people within the next couple of decades. This anticipated population surge is projected to require a 50% increase in agricultural output by 2050 in comparison to the current decade’s output levels (FAO, 2017). This increase in output needs to occur in an environment that is witnessing foreseeable declines in farming operations and availability of agricultural land in addition to an increase in consumer’s demand for high quality sustainable food products. At Corteva Agriscience, we build upon our strong pillars of seeds and traits platform, crop protection and seed treatment solutions as well as advanced digital technologies to continuously provide innovative and sustainable solutions to our customers, helping farmers maximize the value of their investment by providing them with high-performing genetics and effective science-based solutions that optimize yield and crop quality. We capitalize on the use of state of the art technologies and applications in the fields of genomics, phenomics, chemistry, and the like, to drive our industry leading product pipelines. Following the conceptual introduction of genomic selection (Meuwissen et al., 2001) and the increased affordability of genotyping, incorporation of genomic information, via genomic selection, whole genome prediction or more recently gene editing into our breeding pipeline has helped us improve the efficiency and output of our breeding systems and present our customers with innovative and sustainable seed product solutions. This presentation will focus first on introducing some common plant breeding industry practices related to population and product development before providing an overview of genomic selection and its applications in an industrial plant breeding context and finally discuss how new seed product development tools like CRISPR-Cas gene editing could be used to further improve breeding and selection.
227 Leveraging on high-throughput phenotyping technologies to optimize livestock genetic improvement and husbandry
Authors: Rosa Guilherme J M , Dorea João R R , Fernandes Arthur Francisco Araujo , Passafaro Tiago L
Published: December 2019

The advent of fully automated data recording technologies and high-throughput phenotyping (HTP) systems has opened up a myriad of opportunities to advance breeding programs and livestock husbandry. Such technologies allow scoring large number of animals for novel phenotypes and indicator traits to boost genetic improvement, as well as for real-time monitoring of animal behavior and development for optimized management decisions. HTP tools include, for example, image analysis and computer vision, sensor technology for motion, sound and chemical composition, and spectroscopy. Applications span from health surveillance, precision nutrition, and control of meat and milk composition and quality. However, the application of HTP requires sophisticated statistical and computational approaches for efficient data management and appropriate data mining, as it involves large datasets with many covariates and complex relationships. In this talk we will discuss some of the challenges and potentials of HTP in livestock. Some examples to be presented include the utilization of automated feeders to record feed intake and to monitor feeding behavior in broilers, milk-spectra information to predict dairy cattle feed intake, and image analysis and computer vision to monitor growth and body condition in pigs and cattle. HTP and big data will become an essential component of modern livestock operations in the context of precision animal agriculture, boosting animal welfare, environmental footprint, and overall sustainability of animal production.
226 Genomics in animal agriculture: current technologies and applications
Authors: Smith Timothy P
Published: December 2019

The early impact of genomic research on animal agriculture was relatively modest, as it proved difficult to translate quantitative trait loci mapping to industrial application. Fortunately, developments in technology have facilitated the application of genomics to animal agriculture, which has led to more substantial impacts on many commercially produced animal species. A brief look back on the history of genomic research will be presented, followed by an overview of recent developments in genomic technologies. Examples of application of genomic research, focusing on beef cattle and comparative genomics with other bovinae specie, and the current status of some new genomic resources emerging for sheep, pigs, and goats, will also be presented.
228 ASAS-EAAP Exchange Speaker Talk: Big data and the development of resilience indicators for animal breeding
Authors: Mulder Han A , Poppe Marieke , Berghof Tom V L
Published: December 2019

In their lifetime, animals experience various environmental perturbations, such as heat stress, a disease or a change in feed, which require a response. Animals differ in their capacity to respond to various perturbations; this is called resilience, which is the capacity of animals to be minimally affected by perturbations or to rapidly return to the state before exposure to perturbations. The main obstacle in research on genetics of resilience is how to define and quantify resilience. Big data offers great opportunities because longitudinal profiles of animals, such as feed intake, body weight, milk yield or egg production, contain information about how animals respond to perturbations. The objectives of our research were to define resilience indicators and estimate heritable variation in resilience indicators and to estimate associations with existing health and longevity traits to assess the utility of resilience indicators to improve resilience by breeding. The resilience indicators studied were log-transformed variance of deviations (LnVar), lag-1 autocorrelation (Auto) of deviations and skewness of deviations (Skew) based on daily milk yield in dairy cattle and four-weekly body weight measures in laying hens. In dairy cattle, we estimated a heritability of 0.20–0.24 for LnVar, a heritability of 0.08–0.10 for Auto, and a heritability of 0.01 for Skew. The strongest genetic correlations between a resilience indicator and existing health and longevity traits were found for LnVar with udder health (-0.22 to -0.33), ketosis (-0.27 to -0.33) and longevity (-0.29 to -0.34). In laying hens, we estimated similar heritabilities for the three resilience indicators: 0.10 for LnVar, 0.11 for Auto, and 0.09 for Skew. We found predictive value of LnVar breeding values for lesion scores after challenge with an E-coli infection. These results show that especially the variance of deviations is a promising resilience indicator to improve resilience and health in animals by genetic selection.
231 Structure and mechanism of CRISPR/Cas9
Authors: Taylor David W
Published: December 2019

Recent advances in genome editing using CRISPR-Cas9 and related technologies have revolutionized the ability to manipulate genes in a rapid, precise, and flexible manner. These advances have spurred an explosion of interest in the possible ways in which genome editing can improve human health. I will provide an overview of CRISPR-Cas systems, the structure and function of CRISPR-Cas9, and the repurposing of CRISPR-Cas9 for genome engineering.
54 The Heat is On: Heat stress induces radical changes in skeletal muscle
Authors: Selsby Josh , Ganesan Shanthi , Rhoads Robert , Baumgard Lance H
Published: December 2019

Heat stress continues to undermine efficient meat production and meat quality. It also jeopardizes human and animal health and wellbeing, regionalizes animal production, and threatens food security. Environmental models predict more frequent and severe heat waves, even in areas previously considered temperate indicating this problem will continue to have a progressively expanding, deleterious impact on agricultural productivity. Despite the broad, negative impact of heat stress little is known about underlying mechanisms leading to phenotypic outcomes. Because of its mass and energetic demands, skeletal muscle contributes greatly to regulation of systemic metabolism. We have discovered heat stress causes robust but transient oxidative stress and activation of apoptotic signaling in skeletal muscle in as little as two hours. Interestingly, these declined linearly through six hours concomitant with markers of increased autophagy and mitophagy, which would facilitate the removal of damaged mitochondria. Continued heating through 24 h causes a resumption of oxidative stress and autophagic dysfunction with an accumulation of autophagosomes and mitochondria. As mitochondrial injury and autophagic dysregulation appear to be key mediators of hyperthermic muscle dysfunction we propose a model that posits progressive mitochondrial injury leads to production of free radicals that overwhelms antioxidant systems and impairs autophagy facilitating accumulation of damaged, pro-oxidant mitochondria. Ultimately, these aforementioned changes may reduce efficient protein accretion. Our current work is focused on stimulating autophagy and protecting mitochondria during heat stress in an effort to maintain efficient muscle growth.
243 Digestibility, fecal characteristics, and blood parameters of adult dogs fed high fat diets
Authors: Kilburn Logan R
Published: December 2019

The objective was to evaluate the effects of feeding adult dogs increasing levels of fat in low carbohydrate diets on apparent digestibility, fecal characteristics, and health status. Eight adult beagles were used in a 4x4 replicated Latin square design. Dogs were randomly assigned to 1 of 4 fat levels within a phase: 32% (T1), 37% (T2), 42% (T3), and 47% (T4). Fat levels were adjusted with inclusion of canola oil to a commercial diet. Each dog was fed to exceed their energy requirement based on NRC recommendation. Dogs were fed their respective diet twice daily for 15 days. Total fecal collections were done d 11–15 and blood samples were taken on d 15. Data were analyzed using PROC MIXED of SAS (diet and room as fixed effects; period and dog were random). Covariates of baseline, initial body weight, and/or initial body condition score were dependent on trait. Digestibility improved linearly with fat level for dry matter (P = 0.021), organic matter (P = 0.019), and fat (P = 0.001). Fecal output decreased as levels of fat increased in the diet (P = 0.002). There was no effect of fat level on stool quality or short chain fatty acid and ammonia concentrations in fecal samples (P > 0.1). Blood samples were analyzed for complete blood counts and chemistry profiles. All parameters remained within normal reference intervals. Blood urea nitrogen levels decreased with increased fat level (P = 0.03). No significant differences were seen in canine pancreatic lipase immunoreactivity. In addition, serum metabolomics were analyzed among T1 and T4. Metabolite data were log2-transformed and changes among diets were detected using a linear mixed model, the metabolomic profile among diets was characterized using linear discriminant analysis. 19 metabolites, primarily phosphatidylcholines, were statistically significant among treatments. Increase of dietary fat improved digestibility, did not disrupt fecal characteristics, and maintained the health status of each dog.
237 Evaluation of cooked and raw garbanzo beans as main plant protein sources in extruded feline diets
Authors: Reilly Lauren M , He Fei , Mangian Heather , Hoke Jolene , Davenport Gary , Godoy Maria R C de
Published: December 2019

Garbanzo beans (GB; Cicer arietinum) are a readily available pulse crop that have gained popularity as a plant-based protein source in the pet food industry. However, raw GB contain anti-nutritional factors that can reduce digestibility and cause effects in pets that are undesirable to owners. The objective of this study was to determine GB effects on digestibility, gastrointestinal tolerance, and fermentative end-products in cats fed extruded diets containing raw or cooked GB. Five diets were formulated to have either raw GB at 0%, 7.5%, 15%, or 30% or cooked GB at 30% inclusion. Ten, adult, male cats (mean age: 1.0 ± 0.0 years, mean BW: 4.7 ± 0.4 kg) were used in a replicated 5x5 Latin square design. Each period consisted of 14 d, with 10 d of diet adaptation followed by 4 d of total fecal and urine collection. At the end of each period, 4 mL of blood was collected and analyzed for a serum chemistry and complete blood count to ensure all animals remained healthy throughout the study. Cats were fed twice daily and food intake was calculated to maintain body weight. Food intake was highest (P < 0.05) for cats fed 0% raw GB (72.2 g/d, DMB) compared to higher GB inclusions (average 70.3 g/d, DMB). Dry matter and organic matter apparent total tract digestibility (ATTD) were lowest (P < 0.05) among all treatments for the cats consuming the 30% cooked GB diet (77.3% and 81.7%, respectively). Cats fed 7.5% raw GB had higher (P < 0.05) crude protein ATTD (86.2%) than cats fed 15% raw GB (82.3%) or 30% cooked GB (81.6%). In conclusion, all inclusion levels of raw GB showed high digestibility (average >80%) and ideal fecal scores (average 2.9) demonstrating their adequacy as the primary protein source in feline diets up to 30% inclusion levels.
61 Nutritive feed ingredients that pose toxicological potential
Authors: Matulka Ray A
Published: December 2019

A variety of different substances can promote adverse effects on livestock and companion animals, varying from a decrease in overall growth, to frank toxicological response and death. Many substances that are the cause of adverse effects are either components in feed, part of the forage landscape for grazing animals, or even a part of the nutritive feed composition for pets. It has been well-known that vitamin D intake increases bone mineralization, but methionine consumption may also positively impact bone density. Excess consumption of other nutrients may lead to adverse effects, as current research found that excess tryptophan consumption in weaned pigs adversely affects intestinal morphology and tight junction proteins in other species. However, some studies have found that different animals can have opposing effects from consuming the same substances. For example, a study in mice has found that consumption of chitosan impairs intestinal barrier integrity, while twice the intake by weaned piglets improved the average daily gain. This presentation will discuss examples of nutrients and other substances that may adversely impact the growth and reproductive capacity of companion animals and livestock, underscoring the need for the completion of safety studies of potentially new ingredients to evaluate their long-term use in commercial feed formulations.
86 Evaluation of ensiled triticale varieties (‘Taza’ and ‘Bunker’ Triticosecale) and barley (Hordeum vulgare) on performance of backgrounding beef steers
Authors: Ross Brittany E , McKinnon John J , Penner Greg B , McAllister Tim A , Larson Kathy A , Nair Jayakrishnan , Lardner Bart
Published: December 2019

A 3-year study compared two triticale (Triticosecale) varieties, Bunker and Taza, with a conventional barley (Hordeum vulgare) fed as silage to backgrounding beef steers on the basis of crop dry matter (DM) yield, nutritive value, steer performance, and total daily feeding costs. Each year, 240 fall weaned beef steers were stratified by BW (308 ± 4.9 kg) and allocated to 1 of 3 replicated (n = 4) dietary treatments containing Bunker triticale, Taza triticale, or barley silage. Steers were fed a total mixed ration (TMR) consisting of silage (55–68%), barley grain (20–34%), supplement (5%), and (0.4–6%) canola meal (DM basis). Diets were formulated to be isonitrogenous and isocaloric to meet or exceed NRC (2001) requirements for TDN and CP. Crop DM yield of Taza (6750 kg DM ha-1) and Bunker triticale (6592 kg DM ha-1) was similar (P > 0.05), and both were greater (P = 0.01) than barley (6008 kg DM ha-1). Over 2 years, steer ADG, DMI, G:F, and the calculated NEm, and NEg did not differ (P > 0.05) among treatments. Cost per head per day was lowest for Taza fed steers at $1.26 hd-1 d-1, followed by Bunker silage at $1.33 hd-1 d-1, and Barley silage at $1.34 hd-1 d-1. Total cost of gain for Taza, Bunker, and barley fed steers was $0.84, $0.91, and $0.93, per kg of gain, respectively. Study results suggest that Taza and Bunker triticale silage can be used as an alternative to barley silage when fed to backgrounding beef steers.
96 Development of genomics-based precision management model for Hanwoo steers; response to the divergent selection for marbling tested under different dietary energy levels
Authors: Gajaweera Chandima Jayanath , Chung Ki Yong , Lee Seung Hwan
Published: December 2019

Focusing high marble deposition, Hanwoo feedlot system uses high-energy diet over the prolonged fattening period. However, due to the individual genetic variation, around 40% of them are graded into inferior quality grades (QG), despite they utilized the same resources. Therefore, focusing to develop a genomic-based precision management model, this study was to evaluate the response to the divergent selection on genetic merit for marbling score (MS), under different dietary TDN (total digestible nutrient) levels. Total of 112 calves were genotyped and initially grouped for estimated breeding value (high and low) for marbling score (MS-EBV). Subsequently, managed under two levels of feed TDN%, over the growing period, early, middle, and final fattening periods following 2X2 factorial arrangement (figure 1). Carcasses were evaluated for MS, Backfat thickness (BFT) and Korean beef quality grading standard. As the direct response to the selection was significant, the results confirmed the importance of initial genetic grouping of Hanwoo steers for MS-EBV. However, dietary TDN level did not show an effect (P > 0.05) on the MS. Further, no genetic-by-nutrition interaction for MS (P > 0.05) was also observed. The present results showed no correlation response on BFT (P > 0.05), indicating that the selection based on MS-EBV can be used to enhance the MS without undesirable effect on BFT. Ultimate turnover of the Hanwoo feedlot operation is primarily determined by the QGs. The present model shows that the initial grouping for MS-EBV increased the proportion of carcasses graded for higher QGs (QG1++ and QG1+) by approximately 20%. Moreover, there appears to be a potential to increase the proportion of QG 1++ animals among the high-genetic group by further increasing the dietary energy content. Overall, this precision management strategy suggests the importance of adopting an MS based initial genetic grouping system for Hanwoo steers with a subsequent divergent management based on dietary energy level.
89 Evaluating the effect of Ca-gluconate and Ca-butyrate on SCFA absorption and permeability of the gastrointestinal tract
Authors: Watanabe Daniel H , Doelman John , Steele Michael A , Guan Leluo , Penner Greg B
Published: December 2019

The objective was to evaluate short-chain fatty acid (SCFA) absorption and permeability of the gastrointestinal tract (GIT) of heifers infused either with Ca-gluconate or Ca-butyrate. Thirty-two ruminally cannulated beef heifers were fed a common diet (forage-to-concentrate ratio of 50:50) for 28 d and once daily infused with water (ruminal infusion; control), Ca-gluconate embedded in a fat matrix (ruminal infusion; 0.192% BW), unprotected Ca-gluconate (abomasal infusion; 0.077% of BW), and unprotected Ca-butyrate (abomasal infusion; 0.029% BW). Treatments were designed to provide the same amount of butyrate to the small intestine. DMI was restricted to 95% of voluntary DMI on d 8 and was recorded until heifers were slaughtered on d 28. Rumen, jejunum, and colon tissues were collected to determine the rate and pathway of SCFA transport, and for measurement of permeability.14C-acetate and 3H-butyrate absorption across the ruminal and colonic epithelium was measured with no inhibition and under maximal inhibition. Permeability was assessed for the rumen, jejunum and colon using mucosal-to-serosal flux of 14C-mannitol. Initial and final BW were not different (P > 0.60) averaging 388 ± 5.5 kg and 409 ± 6.6 kg, respectively. DMI was not affected by treatment averaging 7.7 kg/d (P = 0.77). Treatment did not affect the flux of acetate or butyrate across the ruminal or colonic epithelium (P > 0.33), but flux rates of SCFA were numerically greater across the ruminal epithelium. Moreover, approximately 50% of the ruminal acetate was transported via bicarbonate-dependent mechanisms. Mannitol flux was not affected by treatment (P > 0.29) and was numerically lower in the rumen and colon than in the jejunum, supporting previous research evaluating permeability across the GIT. According to this experiment, provision of Ca-butyrate or Ca-gluconate in an attempt to increase intestinal butyrate supply does not impact SCFA absorption or permeability of the rumen, jejunum, or colon.
104 Leadership styles of state extension specialists
Authors: Lawyer Amy
Published: December 2019

The focus of this study was the leadership styles of extension specialists. Many studies have been conducted on leadership characteristics of extension agents and administrators, however the current knowledge base concerning leadership behaviors of extension specialists is lacking. Traditionally, specialists were strictly used as a resource for subject matter information, however, changes to cooperative extension have seen specialists move into a position that involves leading agent groups and conducting programing that directly serves the clientele. Many specialists find themselves with newly acquired expectations, yet lack training or educational background to ensure these skills. Using a mixed methodological approach, this sequential explanatory study was conducted using transformational leadership theory, with the purpose of examining current leadership characteristics among extension specialists. The specialists were sent a survey which contained questions relating to educational background, make-up and tenure of their position, and included the Multifactor Leadership Questionnaire (MLQ) to analyze self-perceived transformational leadership characteristics. This survey was followed by a voluntary individual interview. The purpose of the interview was to gain a broader understanding of the group’s leadership perspectives. Although no significant connections could be made concerning demographic information and MLQ leadership scores, the group as a whole registered below average for displaying transformational leadership characteristics, ranking in the 40th percentile for composite MLQ scores compared to the general population. The interview data showed that the specialists agreed with the concepts of transformational leadership, however MLQ scores and anecdotal evidence show that practical application of transformational leadership was lacking. Most participants indicated they did not initially feel prepared for their job, and many indicated that interpersonal relationship skills were used more often than their degree specialization. The findings from this study may help to encourage leadership training focused towards extension specialists, and to emphasize the need for leadership skills within this position.
258 Intake, digestibility and rumen fermentation in sheep offered alfalfa silage alone or alfalfa and tall fescue-mixtures harvested after a killing frost
Authors: Niyigena Valens , Coffey K P , Coblentz W K , Philipp D , Althaber C , Rhein R T , Pruden M C
Published: December 2019

The objective of this study was to determine the effect of harvesting alfalfa and fescue after frost and ensiling mixtures of these forages on silage fermentation characteristics, intake, digestibility and ruminal fermentation by ewes. Forages were harvested in October of 2018, wilted, and blended as either alfalfa alone, 67% alfalfa +33% fescue, 33% alfalfa + 67% fescue, or 100% fescue. Twenty bins were lined with 2 plastic bags, packed (n = 5/trt), stored for 3 months, and then randomly assigned to ewes (n = 20; mean BW = 34.7 ± 6.65 kg) for ad libitum consumption, using 5 animals per treatment. Ewes were given 17 d of adaptation followed by 5 d of total feces and urine collection. Data were analyzed using PROC-MIXED of SAS and orthogonal polynomial trends were used to identify the effects of different proportions of fescue-to-alfalfa silage. Silage total acids, lactate, and acetate increased linearly (P < 0.01) while silage moisture and ammonia decreased linearly (P < 0.01) with increasing proportions of fescue in the diet. The proportions of lactate to total acids (mole/100 moles) increased linearly (P < 0.01) and quadratically (P < 0.05) by adding more fescue to alfalfa. Intake (g/kg BW), digestibility (%), and intake of digestible DM and OM (g/kg BW) decreased linearly (P < 0.05) as fescue proportion was increased in the silages. Ruminal acetate and butyrate (%) increased linearly (P < 0.01) with increasing fescue concentrations in the diet. Ensiling alfalfa with fescue may improve forage fermentation characteristics, but may reduce intake and digestibility in sheep compared to feeding alfalfa silage alone. This study was supported in part by USDA-ARS specific cooperative agreement 58-3655-4-052.
257 Effects of feeding different levels of quebracho (Schinopsis balansae) extract in a high-roughage total mixed ration on seasonal manure gas emissions
Authors: Norris Aaron B , Tedeschi Luis O , Foster Jamie L , Muir James P , Pinchak Bill E
Published: December 2019

Our objective was to investigate how quebracho tannin (QT; Schinopsis balansae) fed at differing rates within a roughage-based diet affected manure gas emissions of growing steers. The utilization of ruminant species is required for efficient production of human-edible protein to meet global nutrient demands. However, gaseous byproducts from ruminant production systems, such as carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) are deleterious to the environment. It is estimated that CO2, CH4, and N2O from managed waste and grazed lands account for roughly 54% of emissions from the livestock sector within the United States, with approximately 80% being associated with beef and dairy cattle. Supplementation of condensed tannins is a plausible method for improving environmental efficiency through the mitigation of enteric CH4 and shifting route of N excretion. During two experimental periods, 12 crossbred steers (236 ± 16 kg) were fed a roughage-based diet at maintenance level with the addition of QT at 0, 1.5, 3, and 4.5% of DM serving as dietary treatments. Following adaptation, feces were collected and gas fluxes measured using vented static chamber technique with manure incubated on the soil surface at two locations, College Station and Stephenville, during two periods corresponding to winter and spring. The daily flux of CO2 was influenced by soil moisture and temperature (r = 0.34; P < 0.01), whereas CH4 and N2O were associated with soil moisture. Cumulative CO2 and gross CO2 equivalent (CO2e) exhibited a dietary treatment effect at College Station (P ≤ 0.01), with a linear reduction with increased dietary QT. At both locations, we observed significance or tendencies for period effects for CO2, CH4, N2O, and CO2e (P ≤ 0.07) with period 2 having higher gas production. Within certain environments, QT supplementation could potentially reduce manure gas emissions, but additional investigation into animal variation is required.
349 Empty body composition and retained energy of Jersey steers using an aggressive implant strategy
Authors: Kirkpatrick Tylo J , Wesley Kaitlyn , Pillmore Sierra L , Cooper Kimberly , Tennant Travis , Lawrence Ty
Published: December 2019

This experiment was designed to quantify the empty body composition of Jersey steers administered an aggressive implant strategy. Jersey steers {n = 30; initial body weight (BW) 183 ± 43 kg} were randomly assigned to one of two implant strategies: negative control (CON), or implanted with Revalor 200 (200 mg trenbalone acetate / 20 mg estradiol 17-β; (REV) every 70 d (d 0, d 70, d 140, d 210, d 280, d 350) during a 420 d feeding period. Steers were harvested on d 421; 6 CON and 6 REV steers were randomly selected for collection of blood, hide, ground viscera, bone, and ground lean and fat to determine empty body composition. Proximate analysis was completed for each sample to determine total body percentages of moisture, crude protein, fat, and ash. Data were analyzed via independent t-test. Percentage empty body moisture (46.48% CON vs 49.69% REV) and empty body protein (15.32% CON vs 17.58% REV) were greater (P < 0.01) in REV cattle. In contrast empty body fat (33.51% CON vs 26.93% REV) was greater (P < 0.01) for CON cattle. Empty body ash did not differ (P > 0.10; 4.69% CON vs 5.80% REV) between treatments. Negative control steers contained a total empty body protein to total empty body fat ratio of 0.44:1 compared to 0.62:1 for REV steers. These data suggest that an aggressive implant strategy alters composition of gain during the finishing of Jersey steers toward increased protein and decreased fat.
343 Wnt/β-catenin pathway is required for porcine satellite cell proliferation and differentiation to promote skeletal muscle growth
Authors: Zhang Zong-ming , Gao Chun-qi , Yan Hui-chao , Wang Xiu-qi
Published: December 2019

Wnt/β-catenin plays a crucial role in skeletal muscle growth, but its specific mechanism still unclear. In this study, due to the distinct role of lysine in pig industry, we provided it as an entry point to investigate the role of Wnt/β-catenin in governing skeletal muscle growth. Firstly, total 18 weaned piglets were divided into three groups: control group, lysine deficiency group and lysine re-supplementation group (lysine levels added from 0.83% to 1.31% at 14 d). After 28 d experiment, all pigs were slaughtered to measure the change of Wnt/β-catenin in skeletal muscle. Secondly, satellite cell (SC) was isolated and cultured with Wnt activator, such as Wnt3a and WRN (Wnt3a, R-spondin1, Noggin) after lysine deficiency for 48 h to investigate cell proliferation and differentiation ability and the level of Wnt/β-catenin in different conditions. The results showed that compared with the control group, lysine deficiency significantly reduced longissimus dorsi muscle weight and Pax7 positive SC, and inhibited Wnt/β-catenin (P < 0.05). Fortunately, these restrictions were rescued to the control levels by lysine re-supplementation (P > 0.05). Meanwhile, compared with the lysine deficiency group, the MTT and western blotting assay showed cell proliferation ability was significantly increased with re-activated Wnt/β-catenin by re-supplemented lysine, Wnt3a or WRN (P < 0.05), respectively. Moreover, under the condition of cell differentiation, compared with the control group, cell fusion index was significantly decreased in the lysine deficiency group (P < 0.05), whereas it was significantly increased with lysine re-supplementation group, Wnt3a or WRN respective supplementation group in comparison with the lysine deficiency group (P < 0.05). In addition, compared with the lysine deficiency group, the protein levels of myogenic regulatory factors and Wnt/β-catenin pathway were also re-activated by re-supplemented lysine, Wnt3a or WRN (P < 0.05). Collectively, we found Wnt/β-catenin activation is required for porcine SC proliferation and differentiation to promote skeletal muscle growth.
346 Supplementing Ca salts of soybean oil to enhance carcass quality of beef cattle via metabolic imprinting events
Authors: Schubach Kelsey , Cooke Reinaldo F , Brandão Alice , Bohnert David , Marques Rodrigo
Published: December 2019

This experiment evaluated the effects of supplementing Ca salts of soybean oil (CSSO) at 2 mo of age via creep-feeding, upon weaning at 6 months of age, or no CSSO supplementation on growth and carcass development of beef cattle. A total of 64 steers were enrolled in this study over 2 years (32 steers/year), with 4 phases per year: creep-feeding (d 0 to 60), pre-weaning (d 61 to 120), post-weaning (d 121 to 180) and feedlot (181 to slaughter). On d 0 steers were ranked by body weight (BW) and age (114 ± 2 kg; 66 ± 0.5 d) and randomly assigned, in a 2 x 2 factorial, to receive 80 g/steer daily (creep-feeding) or 150 g/steer daily (post-weaning) of CSSO. Non-supplemented steers (CON) were provided with equivalent saturated fat supplement. On d 0, 61, 120, 180, and 330 steers were evaluated for longissimus muscle depth, backfat thickness, and marbling via real time ultrasonography, blood was sampled for determination of plasma fatty acid composition, muscle samples were collected via needle biopsy, and BW was recorded. After the creep-feeding phase, CSSO steers had greater (P < 0.01) plasma concentrations of linoleic, omega-6, and total PUFA compared with CON. Steers that received CSSO during the postweaning phase had greater (P < 0.01) plasma concentrations of linoleic, omega·-6, and total FA compared with CON prior to feedlot entry. No treatment differences were detected for performance or body composition responses (P > 0.25) during any phase. However, mRNA expression of adipogenic/lipogenic genes was greater (P < 0.03) prior to slaughter (d 330) in muscle of steers that had received CSSO during the creep-feeding phase. Results from this experiment suggest that supplementing CSSO to nursing beef steers via creep feeding stimulated metabolic imprinting effects through enhanced adipogenic gene expression, however did not alter phenotypic variables.