College of Agriculture
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As the foundation of the land grant mission at Montana State University, the College of Agriculture and the Montana Agricultural Experiment Station provide instruction in traditional and innovative degree programs and conduct research on old and new challenges for Montana’s agricultural community. This integration creates opportunities for students and faculty to excel through hands-on learning, to serve through campus and community engagement, to explore unique solutions to distinct and interesting questions and to connect Montanans with the global community through research discoveries and outreach.
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Item Associations among the genome, rumen metabolome, ruminal bacteria, and milk production in early-lactation Holsteins(Elsevier, 2023-03) Golder, H.M.; Thomson, J.; Rehberger, J.; Smith, A.H.; Block, E.; Lean, I.J.A multicenter observational study to evaluate genome-wide association was conducted in early-lactation Holstein cows (n = 293) from 36 herds in Canada, the USA, and Australia. Phenotypic observations included rumen metabolome, acidosis risk, ruminal bacterial taxa, and milk composition and yield measures. Diets ranged from pasture supplemented with concentrates to total mixed rations (nonfiber carbohydrates = 17 to 47, and neutral detergent fiber = 27 to 58% of dry matter). Rumen samples were collected <3 h after feeding and analyzed for pH, ammonia, d- and l-lactate, volatile fatty acid (VFA) concentrations, and abundance of bacterial phyla and families. Eigenvectors were produced using cluster and discriminant analyses from a combination of pH and ammonia, d-lactate, and VFA concentrations, and were used to estimate the probability of the risk of ruminal acidosis based on proximity to the centroid of 3 clusters, termed high (24.0% of cows), medium (24.2%), and low risk (51.8%) for acidosis. DNA of sufficient quality was successfully extracted from whole blood (218 cows) or hair (65 cows) collected simultaneously with the rumen samples and sequenced using the Geneseek Genomic Profiler Bovine 150K Illumina SNPchip. Genome-wide association used an additive model and linear regression with principal component analysis (PCA) population stratification and a Bonferroni correction for multiple comparisons. Population structure was visualized using PCA plots. Single genomic markers were associated with milk protein percent and the center logged ratio abundance of the phyla Chloroflexi, SR1, and Spirochaetes, and tended to be associated with milk fat yield, rumen acetate, butyrate, and isovalerate concentrations and with the probability of being in the low-risk acidosis group. More than one genomic marker was associated or tended to be associated with rumen isobutyrate and caproate concentrations, and the center log ratio of the phyla Bacteroidetes and Firmicutes and center log ratio of the families Prevotellaceae, BS11, S24-7, Acidaminococcaceae, Carnobacteriaceae, Lactobacillaceae, Leuconostocaceae, and Streptococcaceae. The provisional NTN4 gene, involved in several functions, had pleiotropy with 10 bacterial families, the phyla Bacteroidetes and Firmicutes, and butyrate. The ATP2CA1 gene, involved in the ATPase secretory pathway for Ca2+ transport, overlapped for the families Prevotellaceae, S24-7, and Streptococcaceae, the phylum Bacteroidetes, and isobutyrate. No genomic markers were associated with milk yield, fat percentage, protein yield, total solids, energy-corrected milk, somatic cell count, rumen pH, ammonia, propionate, valerate, total VFA, and d-, l-, or total lactate concentrations, or probability of being in the high- or medium-risk acidosis groups. Genome-wide associations with the rumen metabolome, microbial taxa, and milk composition were present across a wide geographical and management range of herds, suggesting the existence of markers for the rumen environment but not for acidosis susceptibility. The variation in pathogenesis of ruminal acidosis in the small population of cattle in the high risk for acidosis group and the dynamic nature of the rumen as cows cycle through a bout of acidosis may have precluded the identification of markers for acidosis susceptibility. Despite a limited sample size, this study provides evidence of interactions between the mammalian genome, the rumen metabolome, ruminal bacteria, and milk protein percentage.Item Identification of SNP Markers Associated with Grain Quality Traits in a Barley Collection (Hordeum vulgare L.) Harvested in Kazakhstan(MDPI AG, 2022-10) Genievskaya, Yuliya; Almerekova, Shyryn; Abugalieva, Saule; Chudinov, Vladimir; Blake, Thomas; Abugalieva, Aigul; Turuspekov, YerlanBarley (Hordeum vulgare L.) is a cereal crop traditionally used in animal feed, malting, and food production. In this study, a collection of barley was analyzed according to key grain quality traits, including protein content (GPC), starch content (GSC), extractivity (EX), and grain test weight per liter (TWL). A genome-wide association study (GWAS) was conducted to identify the quantitative trait loci (QTLs) associated with GPC, GSC, EX, and TWL using a collection of 658 barley accessions from the USA and Kazakhstan. The collection was grown at three breeding organizations in Kazakhstan in 2010 and 2011 and genotyped using the 9K SNP Illumina chip. As a result, 18 marker-trait associations (MTAs) for GPC, 19 MTAs for GSC, 12 MTAs for EX, and 27 MTAs for TWL were detected, resulting in 30 identified QTLs. It was shown that the genetic locations of 25 of these 30 QTLs were in similar positions to the QTLs and genes previously reported in the scientific literature, suggesting that the 5 remaining QTLs are novel putative genetic factors for the studied grain quality traits. Five of the most significant SNP markers (p < 2.6 × 10−5) for the studied quality traits identified in the GWAS were used for the development of reliable and informative competitive allele-specific PCR (KASP) genotyping assays. The effectiveness of two assays (ipbb_hv_6 and ipbb_hv_128) was confirmed via validation in a separate collection of barley breeding lines grown in large field plots in northern Kazakhstan. Therefore, these KASP assays can be efficiently used in a marker-assisted selection of grain quality traits in barley breeding.