Twenty-four cows in a production trial and 8 cows fitted with ruminal and duodenal cannulas were used in 4 x 4 Latin squares to investigate the effects of dietary protein degradability and supplemental fat on rumen, blood, and milk components. Diet dry matter contained 16% CP with two levels of rumen undegradable protein (RUP) obtained by substituting blood meal for soybean meal. Treatments were 29% RUP, 0% added fat; 29% RUP, 2.7% added fat (Calcium soaps of fatty acids); 41% RUP, 0% added fat; and 41% RUP, 2.7% added fat. Dry matter intake was depressed 6.2% by added fat. Plasma urea N (PUN) increased with added fat and 41% RUP, however greater changes were observed due to time of feeding. Milk production increased 7.1% in both breeds and 4% fat corrected milk increased by 8.4% in Jerseys fed added fat. Milk protein yield decreased in Holsteins fed 41% RUP. Milk protein content was reduced 7.1% by added fat and 3.9% by 41% RUP, and milk urea N (g/100g N) was increased by added fat and 41% RUP. Milk urea N followed PUN pattern throughout the day. Added fat reduced content, but not yield, of milk components. Blood meal substitution decreased content and yield of milk protein and casein N. / Master of Science
| Identifer | oai:union.ndltd.org:VTETD/oai:vtechworks.lib.vt.edu:10919/40821 |
| Date | 31 January 2009 |
| Creators | Rodriguez, Luis Alberto |
| Contributors | Dairy Science |
| Publisher | Virginia Tech |
| Source Sets | Virginia Tech Theses and Dissertation |
| Language | English |
| Detected Language | English |
| Type | Thesis, Text |
| Format | xi, 166 leaves, BTD, application/pdf, application/pdf |
| Rights | In Copyright, http://rightsstatements.org/vocab/InC/1.0/ |
| Relation | OCLC# 32290514, LD5655.V855_1994.R6375.pdf |
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