Scholarly Work - Research Centers
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Item Rumen microbiome response to sustained release mineral bolus supplement with low- and high-quality forages(Frontiers Media SA, 2023-06) Eberly, Jed O.; Wyffels, Samuel A.; Carlisle, Tanner J.; DelCurto, TimothyIntroduction: Limited forage quantity and quality are challenges faced in livestock production systems in semi-arid rangelands of the western United States, particularly when livestock face stressors such as cold weather or have increased nutritional requirements such as during pregnancy and lactation. To meet livestock nutrient requirements, producers frequently provide supplemental nutrition, however there is limited knowledge regarding the effects of these practices on the rumen microbiome in these environments. Methods: A study was conducted to evaluate changes in the rumen microbiome in response to high- and low- quality forage with sustained release mineral boluses. The study consisted of 16 ruminally-cannulated 2–3-year-old black angus cows fed high quality grass alfalfa hay or low-quality grass hay with a 90 or 180 day sustained release mineral bolus. Rumen samples were collected pre-feeding and 8 hours post feeding and bacterial 16S rRNA gene amplicons were sequenced from the rumen fluid. Results: Alpha diversity as measured by Shannon’s diversity index decreased significantly over time (p<0.01) and averaged 5.6 pre-feeding and 5.4 post- feeding and was not significantly different between high- and low-quality forages or between mineral bolus types (p>0.05). Principal coordinates analysis (PCoA) of the Bray-Curtis dissimilarity matrix showed distinct grouping by feed quality and time but not by mineral bolus type. Bacteroidetes and Firmicutes were the dominant phyla in all treatments and significant increases (p<0.05) in the relative abundance of the family Lachnospiraceae and the genus Prevotella were observed in high quality forage diets. Rumen VFA and NH3-N concentrations were also strongly associated with the high-quality forage diet. Predictive functional profiling indicated that functions associated with methanogenesis were negatively correlated with feed quality. Discussion: The results of this study suggest that mineral bolus type is unlikely to affect rumen bacterial community structure or function while forage quality can significantly alter community structure and predicted functions associated with methanogenesis and VFA production.Item Rumen microbiome response to sustained release mineral bolus supplement with low- and high-quality forages(Frontiers Media SA, 2023-06) Eberly, Jed O.; Wyffels, Samuel A.; Carlisle, Tanner J.; DelCurto, TimothyIntroduction: Limited forage quantity and quality are challenges faced in livestock production systems in semi-arid rangelands of the western United States, particularly when livestock face stressors such as cold weather or have increased nutritional requirements such as during pregnancy and lactation. To meet livestock nutrient requirements, producers frequently provide supplemental nutrition, however there is limited knowledge regarding the effects of these practices on the rumen microbiome in these environments. Methods: A study was conducted to evaluate changes in the rumen microbiome in response to high- and low- quality forage with sustained release mineral boluses. The study consisted of 16 ruminally-cannulated 2–3-year-old black angus cows fed high quality grass alfalfa hay or low-quality grass hay with a 90 or 180 day sustained release mineral bolus. Rumen samples were collected pre-feeding and 8 hours post feeding and bacterial 16S rRNA gene amplicons were sequenced from the rumen fluid. Results: Alpha diversity as measured by Shannon’s diversity index decreased significantly over time (p<0.01) and averaged 5.6 pre-feeding and 5.4 post- feeding and was not significantly different between high- and low-quality forages or between mineral bolus types (p>0.05). Principal coordinates analysis (PCoA) of the Bray-Curtis dissimilarity matrix showed distinct grouping by feed quality and time but not by mineral bolus type. Bacteroidetes and Firmicutes were the dominant phyla in all treatments and significant increases (p<0.05) in the relative abundance of the family Lachnospiraceae and the genus Prevotella were observed in high quality forage diets. Rumen VFA and NH3-N concentrations were also strongly associated with the high-quality forage diet. Predictive functional profiling indicated that functions associated with methanogenesis were negatively correlated with feed quality. Discussion: The results of this study suggest that mineral bolus type is unlikely to affect rumen bacterial community structure or function while forage quality can significantly alter community structure and predicted functions associated with methanogenesis and VFA production.Item Influence of residual feed intake and cow age on dry matter intake postweaning and peak lactation(Oxford University Press, 2021-11) Parsons, Cory T; Dafoe, Julia M; Wyffels, Samuel A; DelCurto, Timothy; Boss, Darrin LSupplemental nutrition for cattle is the greatest operating cost for cow-calf producers, accounting for 65% of the annual expenses (Meyer et al., 2008). Therefore, selection pressure for efficient animals that have lower feed intake but maintain production, or average intake with higher production, could have positive impacts on cow–calf profitability (Meyer et al., 2008). Thus, improving feed efficiency through genetic selection holds significant opportunity for the beef industry. Residual feed intake (RFI) is currently being used as a selection tool for purchasing and retaining heifers and for selecting bulls and semen. Most studies have used steers and terminal heifers when evaluating RFI impact on various aspects of beef cattle production (Kelly et al., 2010). Additionally, the majority of RFI studies have included energy-dense diets and rations focusing on feedlot performance (Lawrence et al., 2011). However, the use and relevance of RFI as a selection tool for the commercial cow–calf industry needs further research (Manafiazar et al., 2015). Research pertaining to RFI of cattle offered forage-based diets is limited (Arthur et al., 2005), with even fewer data available related to beef cattle forage-based production systems (Meyer et al., 2008). As a result, more research is needed to evaluate the utility of RFI estimates on the beef production in extensive forage base systems (Kenny et al., 2018). Therefore, the objectives of this study were to evaluate the influence of heifer postweaning RFI and cow age on dry matter intake (DMI), intake behavior, as well as milk production of dry-lotted black Angus beef cows. We hypothesized that heifers identified as low RFI eat less and the influence of RFI may interact with cow age.