Journal of animal science最新文献

{"title":"PSIX-22 Maternal methane, carbon dioxide, and oxygen flux compared with progeny gas flux","authors":"Stacey A Gunter, Corey A Moffet, Emalee J Friend","doi":"10.1093/jas/skae234.828","DOIUrl":"https://doi.org/10.1093/jas/skae234.828","url":null,"abstract":"Red Angus heifers [n = 19; body weight (BW) = 370 ± 8.1 kg) and their paired offspring (BW = 283 ± 4.2 kg; 18 heifers, 1 steer) were used to compare the respiration gas parameters between dams and their progeny over 2 calving cycles (8 pairs in the 1st cycle, 11 in the 2nd). The methane (CH4), carbon dioxide (CO2) emissions and oxygen (O2) consumption of the dams were measured at 14 mo of age over a 70-d period using an automated head-chamber system (AHCS) that measured the flux of these 3 gases. Dams grazed native mixed-grass prairie and were offered a daily supplement of alfalfa (Medicago sativa L.) pellets (1.0 kg) via the AHCS. Dams were artificially inseminated using sexed semen (female) from a single Black Angus sire. The gas fluxes of the progeny were measured, beginning at 11 mo of age, over a 70-d period. Like the dams, during their measurement period, the progeny grazed native mixed-grass prairie and were offered a daily supplement (1.0 kg) of alfalfa pellets via the AHCS. Pearson correlations were developed between the 70-d means of daily CH4 and CO2 emissions, O2 consumption, CH4:CO2 ratio, respiratory quotient (RQ), and heat of production estimates for the dams and their progeny by regressing maternal parameters on the parameters of the progeny, using beginning dam and progeny BW as covariates, and year as an indicator variable. A dam’s CH4 emission was very strongly correlated with that of their offspring (ρ = 0.86). The CO2 emission and O2 consumption of the dams were both also very strongly (ρ = 0.92 and ρ = 0.97, respectively) correlated, with that of their progeny. The heat production and CH4:CO2 ratio of the dams were very strongly (ρ = 0.96) and fairly (ρ = 0.50) correlated, respectively, with that of their progeny. Lastly, the RQ of the dam was also very strongly correlated (ρ = 0.87) with the RQ of the progeny. These results indicate that CH4 and CO2 emissions, O2 consumption, CH4:CO2 ratio, and heat of production of the dam are fairly to very strongly correlated to the gas flux parameters of their progeny. Hence, even with this small dataset, there is evidence that beef cattle traits related to greenhouse gas emissions are somewhat heritable and could potentially be selected in breeding animals to decrease greenhouse gas emission intensity.","PeriodicalId":14895,"journal":{"name":"Journal of animal science","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142233253","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"117 Population structure and genetic diversity of U.S. Polypay Sheep in the National Sheep Improvement Program","authors":"Carrie S Wilson, Jessica L Petersen, Luiz F Brito, Brad A Freking, Sara M Nilson, Ronald M Lewis","doi":"10.1093/jas/skae234.036","DOIUrl":"https://doi.org/10.1093/jas/skae234.036","url":null,"abstract":"The development of the Polypay breed focused on improving the lifetime productivity of the Western range ewe with the objective of ewes lambing twice a year starting at 1 yr of age. The Polypay was developed at the U.S. Sheep Experiment Station (USSES) in 1968 as a four-breed composite with 25% each of Dorset, Rambouillet, Targhee, and Finnsheep. The breed is versatile and rugged enough to be used extensively in Western sheep production and throughout the Central and Eastern U.S. in intensive accelerated lambing systems. Our objective was to define the current population structure and genetic diversity in this breed using pedigree- and genomic-based methods as the industry adopts genomic selection. Pedigree records from Polypay breeders participating in the National Sheep Improvement Program representing 193 flocks were combined with pedigree records from USSES (n = 162,997) tracing back to the origins of the breed. A subset of these pedigreed sheep from 32 flocks born from 2011 to 2023 were genotyped with the GGP Ovine 50K BeadChip (n = 1,856). Quality control measures were applied for marker and animal call rates and to remove markers in high linkage disequilibrium. Pedigree completeness and quality was 9.6, 2.3, and 4.6 for mean maximum, mean complete, and mean equivalent generations, respectively. Pedigree-based inbreeding for the full data was 2.19%; for the subset of pedigreed animals also genotyped, it was 2.94%. The rate of inbreeding was consistently 0.07%/yr across years (P = 0.88). Measures of genomic inbreeding for genotyped sheep were 1.26% for Wright’s inbreeding coefficient, measured as heterozygote deficiency, and 2.90% for inbreeding based on runs of homozygosity. Ten rams from 8 flocks contributed up to 20.3% of the current gene pool. Pedigree-based measures of effective population size ranged from 70 to 249 while the genomic estimate was 118. Fixed and rare (≤ 0.01) alleles accounted for 3.2% and 1.4% of the markers, respectively. The majority of runs of homozygosity (72.1%) were less than 6 Mb, indicative of founder effects and ancient inbreeding rather than recent inbreeding. Based on principal component (PC) analysis, PC 1 suggested a separation of USSES sheep from the rest. Model-based population structure showed differentiation among flocks as did Wright’s Fixation Index (FST) values with a mean of 0.07. High levels of genetic diversity exist in the Polypay as demonstrated by low inbreeding, high heterozygosity, and large effective population sizes. Population substructure exists in the population as shown by PC analysis, model-based population structure, and FST values. These parameters indicate that sufficient genetic diversity is present to move forward with genomic selection. Genetic diversity measures should be revisited periodically once genomic selection is implemented in the breed. USDA is an equal opportunity provider and employer.","PeriodicalId":14895,"journal":{"name":"Journal of animal science","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142233289","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"457 Prediction of methane emissions using rumination time and milk mid-infrared spectral data via artificial neural networks","authors":"Lucas S F Lopes, Saeed Shadpour, Filippo Miglior, Dan Tulpan, Flávio S Schenkel, Christine F Baes","doi":"10.1093/jas/skae234.364","DOIUrl":"https://doi.org/10.1093/jas/skae234.364","url":null,"abstract":"Cattle methane emissions (ME) account for approximately 6% of global anthropogenic greenhouse gas emissions. Given the challenges in measuring ME directly from individual animals, there is a need for the development of novel indirect methods. Rumination time (RT) and milk mid-infrared spectral data (MIR) show promise for the indirect assessment of ME in dairy cows. Both traits have been used as indicators of reproduction, production, and gas emission traits. Methodologies combining the use of MIR and machine learning algorithms such as artificial neural networks (ANN) for the prediction of ME have been successful; however, the inclusion of RT has not been assessed. This study aimed to evaluate the impact of RT on milk MIR-based models using ANN for the prediction of ME. One-week averages for RT, ME, and MIR from first-lactation Canadian Holstein cows (n = 412) were calculated. Six data sets were evaluated using a multilayer perceptron ANN. All sets included age at calving, season of calving and days in milk as model factors, but varied in using milk MIR data points (1,060 or 235) and including or not including RT. The ANN architecture consisted of one input layer, one hidden layer with one or more neurons, and one output layer. Results showed that sets using both RT and milk MIR data achieved correlations from 0.5 to 0.6 between predicted and observed ME. Notably, the inclusion of RT did not improve the performance of the models. Predictions may be improved through the use of larger data sets, the use of daily records, and inclusion of data across herds and lactations. Optimizing parameters of the ANN could also improve predictions. Further research is needed to fully assess the potential of RT as a predictor of ME in dairy cows.","PeriodicalId":14895,"journal":{"name":"Journal of animal science","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142233290","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"293 Impact of black soldier fly larvae meal in a dry extruded food on nutritional quality and health in adult cats","authors":"Guido Bosch, Bruna Loureiro, Dirkjan Schokker, Soumya Kar, Nicky Sluczanowski","doi":"10.1093/jas/skae234.128","DOIUrl":"https://doi.org/10.1093/jas/skae234.128","url":null,"abstract":"Insects like the black soldier fly larvae (Hermetia illucens; BSFL) have been proposed as protein-rich feed ingredients to support the growing demand for meat. The BSFL hold also promise for use as a protein source in pet foods and, as such, it has been studied for palatability, nutritional quality and health effects in dogs and cats. This study aimed to evaluate the effects of including BSFL meal in a dry, extruded food on nutritional quality and health in healthy adult cats. Two similar compositions of dry, extruded foods were formulated to meet the FEDIAF nutrition guidelines for adult cats of which one was chicken meal-based (control, with 34.3% chicken meal) and the other BSFL meal-based (inclusion of 37.5% BSFL meal). BSFL meal contained 95.0% dry matter, 53.1% crude protein, 14.3% crude fat, 6.0% ash (Protix, Dongen, The Netherlands). Two groups of four cats were each fed one of the two foods for two 28-d periods in a crossover design, with sample collection during the last 7 d of each period. Cats were housed in groups of the same sex during the first 21 d of each period. Both foods were well-accepted by the cats. No health problems (including coat and skin condition) were noted throughout the study. Food type did not impact body weight (P = 0.850). Food intake was greater when cats were fed the BSFL-based food (P < 0.001). Consistency scores of fresh feces were optimal and did not differ between the foods. Compared with the control food, the food with BSFL meal had decreased apparent fecal digestibility values for dry matter, organic matter, nitrogen, and gross energy (P < 0.05) although all values were high. Digestibility values for acid-hydrolyzed fat were similar for both foods (P = 0.628). Diets resulted in changes in fermentation product concentrations, like fecal ammonia was less when cats fed this food compared with the control food (P < 0.001), but the fecal concentrations of the short-chain fatty acids and biogenic amines were generally increased (P < 0.05). Moreover, reduced fecal bacterial diversity and affected bacterial relative abundance suggested that inclusion of BSFL meal steered the microbial composition in the distal gut of cats. It was observed increased relative abundance of bacteria genus considered beneficial for host health like Bifidobacterium (P < 0.001) and Megasphaera (P < 0.036); and inhibition of genus Negativibacillus and Lachnoclostridium (P < 0.001), previously associated to digestive issues and negative for gut health. Overall, the data gathered in this study suggests that BSFL meal is an adequate alternative ingredient for extruded dry cat foods and may exert a prebiotic effect on intestinal microbiota.","PeriodicalId":14895,"journal":{"name":"Journal of animal science","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142233486","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"PSIX-25 Sums and relationships of fatty acids of lamb meat fed with marine microalgae meal (Schizochytrium sp.) and vitamin E","authors":"Roberta Lima de Valença, Américo Garcia Silva Sobrinho, Nomaiací de Andrade, Marco Túlio Costa Almeida","doi":"10.1093/jas/skae234.904","DOIUrl":"https://doi.org/10.1093/jas/skae234.904","url":null,"abstract":"The meat production chain, while seeking to reduce production costs, has been demanding in terms of quality, with growing consumer concern regarding the benefits and harms that meat can bring to health. In this sense, the composition of ruminant fat has been a concern for the community in general, due to it being mostly composed of saturated fatty acids (SFA), Supplementary sources of polyunsaturated fatty acids (PUFA) in the diet of ruminants are being researched, especially long-chain ones, such as those present in some species of marine microalgae; however, these fatty acids are susceptible to oxidation, and the use of an antioxidant is recommended, like vitamin E. Given the above, the objective of this work was to evaluate the concentrations and relationships of fatty acids in the meat of Ile de France lambs fed with marine microalgae meal (Schizochytrium sp.) and vitamin E. Newly weaned (n = 32), 60-d-old, intact Ile de France breed lambs, with body weight (BW) = 20.0 kg were randomly distributed into four treatments: CO: control diet; FA: diet with 4% seaweed meal; VE: diet with 1,000 mg of vitamin E; or FAVE: diet with 4% seaweed meal and 1,000 mg of vitamin E. The lambs were slaughtered at 35 kg BW and their meat was evaluated regarding the fatty acid profile, to then obtain concentration and relationships of fatty acids in lamb meat. The data were evaluated in a completely randomized design, with four treatments and eight replications, with the means of the analysis of variance compared using the Tukey test, with 5% significance. A greater (P < 0.01) AGS and decreased AGI concentration were observed in the VE diet (51.47 and 48.53%, respectively), the greatest (P < 0.01) AGI and monounsaturated (AGMI) concentrations, were observed in the CO diet, with 53.63 and 45.14%, respectively. The concentration of PUFA in the FA treatment was greater (P < 0.01) in relation to the VE treatment and like the others (Table 1). The Σn–6 was greater in the CO treatment (7.44%) and less in the VE (4.22%), whereas the Σn–3 was 9.6 times greater (P < 0.01) in the FA treatment (4. 04%) in relation to CO (0.42%), the AVEF treatment exhibited the second greatest values (2.63%), followed by VE (0.49%). The n-6:n-3 ratio was 14 times less (P < 0.01) in the FA treatment (1.24) compared with CO (17.71), the second least value was in the FAVE (1.64), in the VE treatment, a ratio of 8.61 was observed. Seaweed flour from the genus Schizochytrium potentially increases concentration of n-3 in lamb meat and greatly reduces the n-6:n-3 ratio, resulting in a healthier food. Vitamin E, combined or not with a source of PUFA, does not bring benefits in terms of the fatty acid profile.","PeriodicalId":14895,"journal":{"name":"Journal of animal science","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142233510","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"23 Physiological and health implications of trace mineral nutrition","authors":"Rodrigo Marques","doi":"10.1093/jas/skae234.085","DOIUrl":"https://doi.org/10.1093/jas/skae234.085","url":null,"abstract":"Trace minerals are often recommended to avoid possible implications for beef cattle productivity. Trace minerals have several roles in livestock species, such as protein synthesis, enzyme activation, and immune functions. The primary trace minerals for cattle include zinc, copper, selenium, iron, manganese, cobalt, and iodine. These minerals serve as cofactors for numerous enzymes involved in metabolic pathways crucial for growth, reproduction, and immune function. Trace minerals such as zinc, copper, and manganese serve as cofactors for enzymes involved in metabolism. They have crucial roles in carbohydrates, protein, and lipid metabolism, facilitating energy production and nutrient utilization. Additionally, zinc, selenium and copper, are essential for maintaining a robust immune system. They are involved in the production and function of immune cells, antibody response, and the regulation of inflammation, thus aiding in the body’s defense against pathogens and diseases. Selenium, copper, and manganese act as cofactors for antioxidant enzymes that help neutralize harmful free radicals in the body. By scavenging free radicals, these trace minerals protect cells from oxidative damage and reduce the risk of chronic diseases such as cancer, cardiovascular diseases, and aging-related disorders. Cattle obtain trace minerals from various sources, including forages, grains, supplements, and water. However, the bioavailability of these minerals can be influenced by factors such as soil composition, forage type, and dietary interactions. Therefore, careful attention to mineral supplementation and management practices is necessary to meet the specific requirements of cattle at different stages of life and production. Furthermore, research continues to elucidate the complex interactions among trace minerals and their effects on cattle health and performance. Strategies such as targeted supplementation, mineral source selection, and dietary manipulation are being explored to optimize trace mineral nutrition in cattle production systems while minimizing environmental impact and economic costs. However, trace mineral sources might vary in water solubility and bioavailability, affecting their reactivity with antagonists and microorganisms in the rumen. Hence, understanding the importance of these micronutrients and implementing appropriate management practices can help ensure optimal performance and well-being of cattle herds, ultimately contributing to the efficiency and profitability of livestock operations.","PeriodicalId":14895,"journal":{"name":"Journal of animal science","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142231302","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"PSI-13 The impact of divergent nutritional planes on systemic immune status in mature bulls","authors":"Holly E Hamilton, Elizabeth Shepherd, Saulo M Zoca, Carl R Dahlen, Alexandria P Snider, Kyle J McLean","doi":"10.1093/jas/skae234.533","DOIUrl":"https://doi.org/10.1093/jas/skae234.533","url":null,"abstract":"Bull fertility is a major component of reproductive efficiency. One of the many factors influencing reproductive efficiency in bulls is nutrition. Improper nutrition influences physiological features, such as body weight (BW) and body condition scores (BCS), but also increases stress, which can alter the molecular composition of ejaculate. Following a breeding soundness exam and a 21-d dietary adjustment period, mature Angus bulls (n = 6) were randomly assigned to one of two nutritional planes for a 119-d period: 1) restriction (RES; targeted a 1.36 kg/d decrease in BW) or 2) maintenance (MNT; targeted to maintain BW). Body weight and BCS were evaluated every 14 d and feed amounts were adjusted to meet BW targets. On d 73 and 93, scrotal circumference and blood samples were collected for analysis. Serum samples were evaluated for an immunity score using the Nano Discovery D2Dx Immunity Test, that assesses samples for the presence of immunoglobulin (Ig) G, IgM, cytokines, and complement. Statistical analyses were conducted using R Studio to determine the effects of day, nutritional plane, and the interaction of day Î nutritional plane on BW, BCS, scrotal circumference, and systemic immunity score. At the onset of treatments, all bulls had a greater (P = 0.008) BW (845.5 ± 17.0 kg) and BCS (6.3 ± 0.15) than on d 73 (BW = 757.2 ± 17.0 kg; BCS = 5.5 ± 0.15, respectively) or 93 (BW = 749.6 ± 17.0 kg; BCS = 5.3 ± 0.15, respectively). According to the experimental model design, the MNT bulls had a greater (P = 0.001) BCS (6.1 ± 0.12) compared with the RES bulls (5.3 ± 0.12) throughout treatment. Body weights were also influenced by treatment with MNT bulls (845.7 ± 13.9 kg) having a greater BW (P > 0.001) compared with RES bulls (714.6 ± 13.9). Immunity scores were greater in the RES bulls (0.03 ± 0.003) compared with MNT bulls (0.003 ± 0.003). However, there was no effect of day or the interaction effect (P > 0.05) on the systemic immunity score. There was also no effect of day, nutritional plane, or interaction on scrotal circumference (P > 0.23). In conclusion, we observed nutritional planes to result in divergent BW and BCS and were influential on systemic immunity scores, which may lead to different seminal plasma compositions and reproductive outcomes. Further analyses are needed to elucidate the effects of paternal nutritional stress on the female uterine response after mating and reproductive efficiency. The authors would like to thank USDA-NIFA-AFRI (#2023-67015-39453) and USDA-NIFA Multi-State Project No. 1019048 for providing funding and support for this research. USDA is an equal opportunity employer and provider.","PeriodicalId":14895,"journal":{"name":"Journal of animal science","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142231305","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"342 Sow weight development: A pragmatic approach to crossbred and selection populations","authors":"Rob Bergsma, Huaigang Lei, Chengbo Yang, Egbert F Knol","doi":"10.1093/jas/skae234.050","DOIUrl":"https://doi.org/10.1093/jas/skae234.050","url":null,"abstract":"Feed used for maintenance in sows is around 1% of their live weight, and a 10 kg greater sow body weight (BW) from first lifetime insemination onwards requires 36.5 kg extra feed for maintenance annually, which increases the feed cost for a 1,000-sow operation unit by approximately $15,000 CAD per year. Genetic selection, through emphasis on feed efficiency, changes body development year after year. Phenotypic sow development should allow for adequate litter weight, litter size and longevity for an optimum lifetime production. In this study we wanted to understand sow mature weight and its variation. Sow BW (n = 14,554 of 5,292 sows) around farrowing and litter weights were collected on two crossbred and one purebred farm with industry accepted feeding protocols; that is, limited feeding at the different stages of production. Sow BW were corrected for stage of gestation and realized litter weights to represent empty BW at the day of farrowing. Body weight at the age of first insemination was added. When estimating genetic parameters, the statistical model for sow BW included, in addition to Line and HerdYearSeason, a rate parameter as a covariate (b1*AGE -1) within Farm. A bivariate analysis applying a repeatability model for the BW of purebred and crossbred animals yielded similar heritabilities (h2 = 0.58 ± 0.05 and h2 = 0.55 ± 0.05, for purebred and crossbred, respectively), and greater relevant genetic variances (335 ± 40 and 166 ± 13 kg2) with a clearly positive, but not significant genetic correlation of 0.49 ± 0.46. The (random) effect of a permanent environment was not significant for either characteristic. A second analysis in which genetic parameters were estimated simultaneously for the plateau and the rate parameter showed that genetic selection based on the repeatability model for BW only, affected both the plateau and the rate parameter. Only crossbreds were included in this analysis because the minimum required BW observations per sow were not met for purebred animals. Selection for mature BW might affect other key traits. The phenotypic correlations between the EBVs for the BW of crossbred sows and litter weight, litter size and longevity were -0.15, -0.02 and +0.02, respectively. Genetically heavier or smaller animals do not have better production with heavier ones possibly having slightly decreased performance. However, if animals are treated as equally and uniformly as possible, it is reasonable to assume that genetically heavier animals use more feed for growth, instead of for reproduction, given equal feeding rations. Heritability estimates point to a clear genetic drive to BW development. This study shows the relevance of weight observations at nucleus level and the necessity to estimate genetic correlations with production traits.","PeriodicalId":14895,"journal":{"name":"Journal of animal science","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142231354","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"178 Programing the rumen microbiome to optimize microbial efficiency in high forage diets","authors":"Tim A McAllister, Robert J Gruninger, Stephanie A Terry, Ajay Badhan, Yue Wang, Leluo Guan","doi":"10.1093/jas/skae234.452","DOIUrl":"https://doi.org/10.1093/jas/skae234.452","url":null,"abstract":"As the majority of energy and protein supplied to cattle arises as a result of ruminal fermentation, the rumen microbiome has an integral role in determining host feed efficiency. Counterintuitively, current evidence suggests that a less diverse rumen microbiome is associated with improved feed efficiency, possibly as a result of greater metabolic precision and avoidance of energy spilling fermentative pathways. The composition of the rumen microbiome is mainly determined by diet, but host traits such as rumen volume, rate of passage, rumination and immunity also have influence. Although less microbial diversity may improve feed efficiency in cattle fed a specific diet, reduced diversity may impair the ability of cattle to adapt to frequent changes in diet and the environment. Hydrogen exchange and capture is the energetic foundation of the rumen microbiome and considerable capital has been invested to develop additives that redirect hydrogen flow away from the reduction of CO2 to CH4 towards alternative sinks. These additives have been shown to reduce enteric CH4 emissions by 30 to 80%, but improvements in feed efficiency have been less than stoichiometric predictions. Approaches to improve the feed efficiency of cattle need to be multifaceted with consideration for host genetics, functional efficiency of the rumen microbiome, and the structure and composition of feed. Likewise, reductions in carbon emissions need to be broader than just CH4, with an appreciation of the role that cattle have within a circular bioeconomy to promote upcycling of nutrients and reductions in emissions from farming systems. Strategies to improve the efficiency of cattle production are a prerequisite for the sustainable intensification needed to ensure that the social license for milk and meat production from cattle is retained.","PeriodicalId":14895,"journal":{"name":"Journal of animal science","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142231219","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"PSVIII-19 Assessing methane and carbon dioxide production in beef cows across diverse foraging conditions","authors":"Amir Behrouzi, Hailey Bolen, Francisco José de Novais, John A Basarab, Edward bork, Carolyn J Fitzsimmons","doi":"10.1093/jas/skae234.674","DOIUrl":"https://doi.org/10.1093/jas/skae234.674","url":null,"abstract":"Beef cattle grazing across more than 40M ha of Canada’s grasslands is economically significant yet contributes to methane (CH4) emissions. Accurately measuring CH4 emissions across diverse environments presents substantial challenges. Our study investigated CH4 and carbon dioxide (CO2) production in 3-yr-old pregnant crossbred beef cows (n = 30) across different phases of the beef production cycle, including in drylot and while grazing on native rangeland, in Western Canada’s Aspen Parkland region using the GreenFeed Emissions Monitoring System (GEM). During the January to March drylot phase, enteric CH4 and CO2 production of the cows were monitored for 63 d in consort with feed efficiency testing while consuming a mixed oat-barley silage diet. Following this, cows were categorized into three distinct groups based on the standard deviation (SD) of CH4 yield [gּ kg−1 dry matter intake (DMI)]: Low (< 0.5 SD; n = 11), Medium (± 0.5 SD; n = 10), and High (> 0.5 SD; n = 9). Post-calving, cows and calves transitioned to native pastures for CH4 and carbon dioxide (CO2) assessment across three distinct foraging conditions: high-quality, high-quantity forage in summer (SUM; 50 d); moderate-quality, high-quantity forage in September (SEP; 22 d); and finally, low-quality, low-quantity forage in October (OCT; 22 d). We hypothesize that ranking cows based on their CH4 yield (gּ kg−1 DMI) in drylot settings may have the potential to reflect their CH4 production (g/d) during grazing conditions, even without feed intake data. Data were analyzed using the PROC MIXED procedure of SAS to examine CH4 production among cows categorized by their assigned ranking. Spot CH4 and CO2 measurements totaled 1,242, 1,145, and 1,205 for the SUM, SEP, and OCT, production phases, respectively. Average daily visits to GEM units were 1.4 ± 0.1, 1.84 ± 0.1, and 1.96 ± 0.1 for the corresponding phases. While High CH4-ranked cows had methane production similar to Low CH4-ranked cows (234.8 ± 8.2 vs. 235.0 ± 6.0 g/d, respectively), the Medium group had significantly greater methane production (260.5 ± 6.2 g/d; P = 0.008) than the Low and High CH4 groups. Furthermore, significant interactions were observed between CH4 ranking groups and CH4 production during the grazing phase (P = 0.035). Cows in the Medium CH4 group emitted greater amounts of CH4 compared with the High group in SUM (288.2 ± 9.3 vs. 247.0 ± 14.1 g/d) and to the Low group in SEP and OCT (276.5 ± 6.6 vs. 238.1 ± 6.3, and 216.7 ± 7.2 vs. 191.8 ± 7.5 g/d, respectively). In conclusion, the drylot CH4 ranking may hold promise in predicting outcomes for both Low and Medium CH4-ranked groups during grazing phases. However, High CH4-ranked cows had decreased methane production, likely influenced by grazing-induced changes in feed intake and individual feeding behaviors, prompting further exploration.","PeriodicalId":14895,"journal":{"name":"Journal of animal science","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142231418","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}