The relationship between appetite and plasma non-esterified fatty acid levels in housed calves.
Non-esterified fatty acid (NEFA) levels in housed, 3-month-old calves were monitored in two experiments designed to establish (i) the effect of diet and time of sampling in relation to feeding on blood levels; and (ii) the relationship between appetite and plasma NEFA in animals on chopped hay. In the first experiment, a significant drop in NEFA levels was recorded after feeding. Furthermore, the NEFA levels of calves maintained on concentrate were significantly lower than those on hay throughout the post-feeding period. In the second study, a significant negative correlation was established between NEFA levels and intake of chopped hay in (i) ad-lib-fed calves infected with the abomasal nematode Ostertagia ostertagi; (ii) worm-free animals pair-fed with those in group (i); and (iii) ad-lib-fed worm-free calves. Regression analysis of raw and transformed data from all three groups combined also yielded significant correlations. It is suggested that the measurement of blood NEFA may be a useful indirect indicator of feed intake in conditioned housed calves offered hay diets.
Fox
M T
MT
Department of Veterinary Pathology, Royal Veterinary College, London, UK.
Gerrelli
D
D
Pitt
S R
SR
Jacobs
D E
DE
D000821:Animal Feed; D000818:Animals; D001066:Appetite / Q000502:physiology*; D002417:Cattle / Q000097:blood / Q000502:physiology*; D004435:Eating / Q000502:physiology; D005230:Fatty Acids, Nonesterified / Q000097:blood*; D005260:Female; D006799:Housing, Animal; D008297:Male; D012044:Regression Analysis; D013997:Time Factors
D005230:Fatty Acids, Nonesterified