Theses and Dissertations at Montana State University (MSU)
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Item The influence of heifer post-weaning residual feed intake on subsequent production, reproduction, grazing behavior, supplement intake behavior, dry matter intake and milk production of Black Angus beef cattle(Montana State University - Bozeman, College of Agriculture, 2021) Parsons, Cory Todd; Chairperson, Graduate Committee: Timothy DelCurto; Julia Dafoe, Samuel Wyffels, Tim DelCurto, Darrin Boss and Megan Van Emon were co-authors of the article, 'Impacts of heifer post-weaning residual feed intake classification on reproductive and performance measurements of first, second and third parity Angus beef' in the journal 'Translational animal science' which is contained within this dissertation.; Julia Dafoe was a co-author of the article, 'The influence of residual feed intake and cow age on body weight and body condition change, supplement intake, resource use, and grazing behavior of beef cattle winter grazing mixed-grass rangelands' in the journal 'Animals' which is contained within this dissertation.; Julia Dafoe, Samuel Wyffels, Tim DelCurto and Darrin Boss were co-authors of the article, 'The influence of residual feed intake and cow age on dry matter intake post-weaning and peak lactation of Black Angus cows' in the journal 'Animals' which is contained within this dissertation.Residual feed intake (RFI) is a recognized measure of biological efficiency in beef cattle. However, RFI determination is expensive, time consuming and not well studied in beef cattle fed forage-based diets, nor how post-weaning RFI influences grazing behavior, supplement intake behavior or dry matter intake at different ages and physiological stages of production. Thus, the objectives of this research were to investigate how post-weaning RFI influences reproductive and productive performance, grazing behavior, supplement intake behavior as well as dry matter intake at different ages and physiological stages of production. A commercial herd of black Angus cows were utilized to conduct three experimental studies. Results indicate that classification of RFI for replacement heifers had little to no effect on subsequent beef cattle production and reproductive efficiency through the weaning of the 3rd calf. Subtle differences were denoted for cow Julian birth dates based on RFI classification and conception of 1st calf-heifers categorized as low RFI. However, heifer post-weaning RFI had little effect on subsequent cow performance (BW or BCS), grazing behavior, supplement intake behavior, and resource use. In addition, cow age significantly influenced cow performance, grazing behavior, supplement intake behavior, and resource use. We also observed high individual variability in grazing site selection, suggesting that individual-level factors may be driving grazing resource use and grazing behavior. Heifer post-weaning RFI did not influence mature cow dry matter intake, and this was consistent for both lactating and non-lactating beef cows. In contrast, cow age did correspond to quadratic increases of DMI and intake rates of mature cows. However, when DMI was expressed as g x kg body weight-1 no differences were observed with respect to cow age in lactating and non-lactating cows. Milk production was influenced by heifer post-weaning RFI for 2/3 and 5/6-yr old cows. Therefore, our studies suggests that selection for low RFI females would not impact overall herd productivity of cattle on foraged-based production systems, and that cow age has more of an impact on resource use, supplement intake, and grazing behavior, as well as DMI than heifer post-weaning RFI while grazing dormant-season mixed-grass prairie rangelands.Item Grazing, feed intake, and milk production differences in beef cows of varying efficiency classification and size(Montana State University - Bozeman, College of Agriculture, 2018) Williams, Alyson Rose; Chairperson, Graduate Committee: Timothy DelCurto; C.T. Parsons, J.G.P. Bowman, D.L. Boss and T. DelCurto were co-authors of the article, 'The influence of weaning weight ratio and cow size on feed intake behavior, milk yield, and milk constituents' submitted to the journal 'Journal of animal science' which is contained within this thesis.; S.A. Wyffels, C.T. Parsons, J.G.P. Bowman, D.L. Boss and T. DelCurto were co-authors of the article, 'The influence of weaning weight ratio and cow size on winter grazing and supplement intake behavior' submitted to the journal 'Journal of animal science' which is contained within this thesis.Metrics that identify beef cow efficiency in extensive rangeland environments has long been desired in both beef cattle research and production settings. However, research is limited relative to matching cattle metrics to western production systems. Previous research has suggested the ratio of calf weight weaned to cow weight, or weaning weight ratio, is an accurate estimate of cow efficiency. Furthermore, milk production has been attributed to influence calf pre-weaning average daily gain. Few studies have evaluated how cow type or cow characteristics influence grazing distribution and supplement consumption on native landscapes. The objectives of this study were to assess cow feed intake, grazing behavior, supplement intake, and milk production differences between cows of differing weaning weight ratio and body weight classification. Individual cow average daily feed consumption, average daily feeding bout duration, number of visits per day, and total time spent eating per day were collected during a feed intake period and a supplement intake period. Total distance traveled and time spent grazing were collected on individual cows with global positioning system collars. Milk samples were analyzed for fat, solids not fat, total solids, protein, and lactose content, and milk yield was calculated as the change in calf weight following a weigh-suckle-weigh procedure. High weaning weight ratio cows consumed more feed when expressed on a g/kg bodyweight basis (P < 0.001) but did not differ in supplement consumption (P > 0.10). High weaning weight ratio cows produced more milk both in total kg (P < 0.03) and when expressed as /kg bodyweight (P < 0.001). Heavy bodyweight cows tended to consume more feed than light bodyweight cows (P < 0.09) but neither bodyweight group ate more supplement than the other (P > 0.10). High weaning weight ratio cows spent an hour longer grazing per day than low weaning weight ratio cows (P < 0.02). Total distanced traveled per day did not differ (P > 0.10). Results suggest weaning weight ratio and cow size are not accurate metrics of cow efficiency and the use of weaning weight ratio may unintentionally favor cows with higher milk production and higher feed requirements.Item Lactation curves and milk production in beef cattle with varying degrees of crossbred influence(Montana State University - Bozeman, College of Agriculture, 1984) Casebolt, David GeorgeItem Influence of supplementation on the productivity of ewes grazing improved pasture and suckling twins(Montana State University - Bozeman, College of Agriculture, 1988) Frey, Ana LidiaItem Induced lactation in non-pregnant ewes(Montana State University - Bozeman, College of Agriculture, 1958) Bellows, Robert A.Item Early reproductive traits in beef heifers differing in milk production(Montana State University - Bozeman, College of Agriculture, 1983) Steffan, Charles AllanItem Influence of separation interval on weigh-suckle-weigh estimates of milk production and relationships between milk production and physical measurements in Hereford cattle(Montana State University - Bozeman, College of Agriculture, 1977) Williams, John HerbertItem Effect of short term, prepartum feeding level and type of protein on subsequent lactation(Montana State University - Bozeman, College of Agriculture, 1996) Roeder, Brent LyleItem The plane of nutrition in relation to milk production(Montana State University - Bozeman, College of Agriculture, 1933) Shaw, Joseph C.Item The effect of dam milk production on daughter maternal ability in Hereford cattle(Montana State University - Bozeman, College of Agriculture, 1988) Reed, William Andrew