The optimum duration of test for the measurement of ADG, ADFI, feed:gain ratio [which is the reciprocal of the efficiency of gain (G:F) and therefore increases as the efficiency of gain decrease and vice versa], and residual feed intake was examined in growing pigs. Data from 144 hybrid (mainly Large White x Landrace) pigs involved in a longitudinal (n = 54) and serial slaughter (n = 90) experi...

The aim of this project was to optimise selection indices for efficient lean meat growth. Traditionally, genetic improvement of lean meat growth and feed efficiency has been based on ad libitum feeding. However, selection for lean meat growth and feed conversion ratio under ad libitum feeding has led to a reduction in feed intake in modern genotypes to the extent that feed intake is often not s...

A better understanding of the factors regulating feed efficiency and their potential as predictors of feed efficiency in cattle is needed. Therefore, the potential of three classes of traits, namely, feeding behavior characteristics: daily time at feeder (TF; min/day), time per meal (TM; min), meal size (MS; g DM), eating rate (ER; g DM/min), number of daily meals (NM) and daily visits to the f...

Differences in allometric scaling of physiological characters have the appeal to explain species diversification and niche differentiation along a body mass (BM) gradient - because they lead to different combinations of physiological properties, and thus may facilitate different adaptive strategies. An important argument in physiological ecology is built on the allometries of gut fill (assumed ...

Thirty-eight Angus-based, crossbred, nulliparous beef heifers (BW = 280 ± 26.3 kg) sired by 2 Angus sires were used to determine if dam BW affected heifer performance, DMI, residual feed intake (RFI), and endocrine markers. Heifers were housed in individual pens (2.2 by 9.1 m) equipped with 2.2 m of bunk space and fed a diet (90.4% DM, 13.7% CP, 67.2% NDF, and 56.2% TDN) consisting of 87.2% ber...

Complete energy balance measurements were made in exercise-trained (treadmill running) rats subjected to 27 d of exercise detraining. The 20% difference in body-weight that existed at the end of the training period between sedentary and trained rats was negated by detraining. Detrained rats had twice the body-weight gain of their untrained controls. An elevation (12%) in metabolizable energy (M...

the mechanism of the genesis and development of obesity is not yet known. in particular, it is not known whether the main reason is and increase in energetic efficiency, i.e. better utilization of food consumed, or hyperplasia. this study was undertaken to throw some light on this subject. obesity was produced by chemical methods, i.e. by injections of gold-thioglucose and mono-sodium glutamate...

Thirty-two Angus steers were used in a 140d feeding trial to examine the effects of ad libitum feed intake or a programmed rate of gain on feedlot performance and carcass characteristics. Ad libitum-fed steers had greater (P < .06) DMI, ADG, and feed efficiency from d 0 to 28, 0 to 56, and 0 to 84 than programmed-fed steers; however, no differences in ADG, DMI, or feed efficiency were detected ...

Dilution of the intake air of the SI engine with the inert gases is one of the emission control techniques like exhaust gas recirculation, water injection into combustion chamber and cyclic variability, without scarifying power output and/or thermal efficiency (TE). This paper investigates the effects of using argon (Ar) gas to mitigate the spark ignition engine intake air to enhance the perfor...