Thesis
The effect of an enzymatically hydrolyzed yeast supplement on metabolic health, reproductive health, pathogen shedding, milk production and quality in transition Holstein dairy cattle and the impact of utilizing by-products in dairy cattle rations on human edible protein conversion efficiency
Washington State University
Master of Science (MS), Washington State University
2018
Handle:
https://hdl.handle.net/2376/102983
Abstract
This thesis research focused on the areas of transition dairy cattle nutrition and the use of by-product feeds to enhance the sustainability of milk production. One experiment was conducted to determine the effect an enzymatically hydrolyzed yeast, Celmanax, has on metabolic and reproductive health, pathogen shedding, and milk production and quality in transition dairy cattle. The second study utilized a systems modeling approach to determine the impact that utilizing by-product feedstuffs in lactating dairy cattle rations on cow's ability to convert human-inedible feed to human-edible protein. In the first study, cows were either fed Celmanax during the pre-partum period (56 g/head/d) and post-partum period (28 g/head/d) or no yeast at all. Milk production, milk components, milk pathogens, fecal pathogens, reproductive parameters, [beta]-hydroxybutyrate, body weight, body condition score, and dry matter intake were recorded for all cows throughout the duration of the experiment for each group. Cows supplemented with Celmanax had consistently higher milk protein and milk fat concentrations, decreased days to first standing heat, but no differences in dry matter intake, milk yield, or health events. The second study looked at milk production sustainability on four different farms using four sustainability parameters, human-edible protein feed conversion ratio, economics, greenhouse gas production, and carbon footprint. When commonly used feeds in dairy production were replaced with feeds with a lower human-edible portion, cow net feed contribution increased on a protein basis. Dairy cattle are able to convert foods that humans cannot digest, like by-products of the food and fiber industry, to milk. Utilizing by-products lowered the cost to produce a hundred weight (cwt) of milk on all four farms, but greenhouse gas emission and carbon footprint varied among farms and the use of human-edible protein on each farm. Results of this study suggest that the inclusion of by-products in dairy cattle rations can increase the efficiency of producing milk protein while increasing producers' profits.
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Details
- Title
- The effect of an enzymatically hydrolyzed yeast supplement on metabolic health, reproductive health, pathogen shedding, milk production and quality in transition Holstein dairy cattle and the impact of utilizing by-products in dairy cattle rations on human edible protein conversion efficiency
- Creators
- Hannah Athleen Chiapetta
- Contributors
- Joe Harrison (Degree Supervisor)
- Awarding Institution
- Washington State University
- Academic Unit
- Animal Sciences, Department of
- Theses and Dissertations
- Master of Science (MS), Washington State University
- Publisher
- Washington State University; [Pullman, Washington] :
- Identifiers
- 99900525190101842
- Language
- English
- Resource Type
- Thesis