Effect of dietary fat on uptake of lysine, phenylalanine, leucine and methionine by bovine mammary tissue slices in vitro

Journal Article · Tue Aug 01 04:00:00 EDT 1989 · Journal of Dairy Science; (USA)

OSTI ID:5102196

Nianogo, A J; Amos, H E; Dean, R; Froetschel, A ^[1]; Fernandez, J M ^[2]

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1. Univ. of Georgia, Athens (USA)
2. Langston Univ., OK (USA)

Four mature Holstein cows in late lactation were blocked in two groups based on milk production, in a 2x2 reversal with 21-day periods, and fed: (A) control diet; (B) A plus 1 kg/day tallow. Cows were fed sorghum silage ad libitum. Blood samples were collected from the jugular vein on day 15, 17, and 19 of each period. Fat did not effect DM intake or milk yield, however milk CP yield was 20% lower. Plasma lipids increased 33.6%, glucose decreased 9% and insulin/glucagon ratio decreased 21.2% in cow fed fat. After period two, cows were slaughtered and mammary tissue sampled for incubation in Krebs Ringer bicarbonate buffer containing 22 AA at arterial concentration and .225 {mu}Ci/ml of {sup 14}C-labelled L-Leu, L-Phe, L-Lys or D/L Met. Dietary fat decreased tissue AA uptake rate by 21.2%. Uptake was 4.8, 10.3, 17.8 and 2.4 {times} 10{sup {minus}3} {mu}M/min/gm of tissue DM for Phe, Lys, Leu and Met, respectively. Results suggest that dietary fat may decrease milk protein synthesis by lowering the rate of AA uptake.

• OSTI ID: 5102196
• Journal Information: Journal of Dairy Science; (USA), Journal Name: Journal of Dairy Science; (USA) Vol. 72:8; ISSN 0022-0302; ISSN JDSCA
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
AMINO ACIDS
ANIMALS
BIOCHEMICAL REACTION KINETICS
BODY
CARBON 14 COMPOUNDS
CARBOXYLIC ACIDS
CATTLE
COWS
DIET
DOMESTIC ANIMALS
DRUGS
FATS
GLANDS
HORMONES
INSULIN
ISOTOPE APPLICATIONS
KINETICS
LABELLED COMPOUNDS
LEUCINE
LIPOTROPIC FACTORS
LYSINE
MAMMALS
MAMMARY GLANDS
METHIONINE
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC SULFUR COMPOUNDS
ORGANS
PEPTIDE HORMONES
PHENYLALANINE
REACTION KINETICS
RUMINANTS
TRACER TECHNIQUES
VERTEBRATES