Effects of heat and chemical treatment of whole oilseeds on site and extent of digestion of protein and lipid by cattle

A series of experiments were conducted to determine the impact of treatment processes applied to whole soybeans (SB) and canola seed (CS) on shifting the site of protein and lipid digestion from the rumen to the small intestine of steers. Experiment 1, a 4 x 5 Youden square design utilized four steers (avg BW 373 $\pm$ 30.7 kg) fed 1.8% of BW that were cannulated at the rumen, duodenum, and ileum. Diets contained corn silage (50%) and alfalfa hay (24%) were supplemented with soybean oil (3.4%), raw SB or roasted SB (exit temperature of 141$\sp\circ$, 149$\sp\circ$, or 157$\sp\circ$C in a commercial roaster; 16%). Roasting SB had no effect on ruminal characteristics, did not spare the unsaturated fatty acids in soybeans from hydrogenation in the rumen, improved small intestinal fatty acid digestibility, increased ruminal soybean nitrogen escape and increased small intestinal digestibility. A cecectomized rooster bioassay verified that the improved intestinal digestibility was due to a reduction in trypsin inhibitor activity (TIU) due to roasting, but TIU was not affected by ruminal fluid incubation. Experiment 2, five steers (average BW 259 kg) cannulated in the rumen, proximal duodenum, and terminal ileum were fed 2.05% of BW in a 5 x 5 Latin square design. Diets were primarily composed of ammoniated corn cobs (50%) and alfalfa hay (22%; basal) supplemented with whole canola seed (untreated, crushed, or treated with alkaline hydrogen peroxide; 10%), or Ca-LCFA (5%) and contained 5.6% (avg) more total fatty acids than basal. Ruminal fermentation characteristics and digestibility of OM, GE, N, NDF, and ADF were unaffected (P $>$.05) by diet. Steers fed treated canola seed spared more mono- and polyunsaturated fatty acids from biohydrogenation in the rumen than steers fed crushed canola seed and provided more intestinally available unsaturated fatty acids than steers fed untreated canola seed. Experiment 3, multiparous lactating Holstein cows (n = 12; 618 kg; 47 days in milk) were allotted to three replicates of a 4 x 4 Latin square design and fed TMR's containing alfalfa silage (45%), ground corn (37%) and canola meal (5.6%; control). Test diets contained crushed or treated canola seed (11.2%) or Ca-LCFA (5.6%) in exchange for canola meal and corn of the control. Total fatty acid intakes were greater (P $<$.01) for cows fed the fat-supplemented diets than for cows fed the control diet (avg 2,050 vs 982 g/d, respectively). No differences were detected among treatments for milk production (kg/d). Milk from cows fed treated canola seed had a.34 percentage unit milk fat advantage, yet a similar milk protein percentage to milk from cows fed crushed canola seed. Milk fatty acids from cows fed canola seed (treated or crushed)-supplemented diets had lower proportions of total fatty acids from C16:0 and greater proportions from C18:0 and C18:1 than cows fed the control or Ca-LCFA diets.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Animal Science

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2011

Author dc:creator

• Aldrich, Charles Gregory

Contributors dc:contributor

• Merchen, Neal R.

• Agriculture, Animal Culture and Nutrition

Statement dc:rights

• Copyright 1995 Aldrich, Charles Gregory

Language dc:language

eng

Identifier

AAI9543513
(UMI)AAI9543513

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/22743