Date of Award
5-1-2024
Degree Name
Master of Science
Department
Animal Science
First Advisor
Puthenpurayil, Sasidharannair
Abstract
The objective of this research was to evaluate the impact of strategical blending of by-products of pea protein extraction such as pea molasses (PMS) and pea starch and fiber (PSF) with canola meal (CM) or distillers dried grains (DDGS) on the growth performance, rumen fermentation, and total tract nutrient digestibility of beef cattle. Preliminary evaluation (study 1) involved 4 runs of in vitro and two runs of in situ to evaluate the rumen fermentation and nutrient degradation of strategically blended CM. The treatments included regular CM (CM), CM blends containing PMS and PSF at 5% (CM5) and 10% (CM10) levels in CM, 1.5% PMS in CM (CM+PMS) and 1.5% PSF in CM (CM+PSF) (% DM basis). The CM+PMS had greater (P < 0.05) DM and CP digestibility in vitro and in situ with significant total gas production, while the CM+PSF had lower methane per gram of DM. In study 2, a 56-d backgrounding and a 145-d finishing trial were carried out to evaluate the growth performance and carcass characteristics of growing and finishing beef steers fed diets containing strategically blended protein supplements. The treatments used were CM (CM), CM+PMS (PMS at 1.5% of CM DM), DDGS, and DDGS+PSF (PSF at 2% diet DM). There was no treatment effect detected during both backgrounding and finishing for overall ADG, DMI or gain:feed. There were numerical improvements in carcass characteristics, indicating likely improvements in carcass traits at a greater level of inclusion in the diets. Study 3 involved a metabolism study using cannulated beef heifers fed the same finishing diets as the feedlot study in a 4 × 4 Latin square design to evaluate the impact of feeding strategically blended protein by-products on rumen fermentation, total tract nutrient digestibility, and nitrogen balance. There was no variation in total tract nutrient digestibility evaluated. The DM, OM, and CP digestibility were numerically greater for heifers fed CM treatments than those fed DDGS treatments, while the NDF and ADF digestibility were numerically greater for the DDGS treatments. There was no treatment variation in rumen pH measurements. There was also no diet effect on nitrogen balance measured. The results of these studies indicate that the inclusion of PMS and PSF in the diet of beef cattle had no negative influence on the growth performance. Numerical improvements in carcass traits, rumen fermentation, and total tract nutrient digestibility indicate that the growth performance and carcass characteristics may be improved by these food industry by-products at a greater level of inclusion in the beef cattle diets.
Access
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