scholarly journals Effect of growth compensation on subsequent physical fitness in green swordtails Xiphophorus helleri

2005 ◽  
Vol 2 (1) ◽  
pp. 39-42 ◽  
Author(s):  
Nick J Royle ◽  
Jan Lindström ◽  
Neil B Metcalfe

Early environmental conditions have been suggested to influence subsequent locomotor performance in a range of species, but most measurements have been of initial (baseline) performance. By manipulating early growth trajectories in green swordtail fish, we show that males that underwent compensatory growth as juveniles had a similar baseline swimming endurance when mature adults to ad libitum fed controls. However, they had a reduced capacity to increase endurance with training, which is more likely to relate to Darwinian fitness. Compensatory growth may thus result in important locomotor costs later in life.

2017 ◽  
Vol 26 (2) ◽  
Author(s):  
Katariina Manni ◽  
Marketta Rinne ◽  
Erkki Joki-Tokola ◽  
Arto Huuskonen

The objective of this study was to determine the effects of restricted feeding strategies on performance of growing and finishing dairy bulls. The feeding experiment comprised in total 32 Finnish Ayrshire bulls with an initial mean live weight (LW) of 122 kg and age of 114 days. Feeding treatments were silage ad libitum and daily barley allowance of 93 g kg-1 LW0.60 (A); restricted feeding (R) at 0.80 × A; increasing feeding (I) similar to R until LW of 430 kg and thereafter similar to A; and decreasing feeding (D) similar to A until LW of 430 kg and thereafter similar to R. Restricted feeding strategies decreased daily dry matter intake and LW gain and increased the time to reach the target carcass weight (300 kg). Bulls on I exhibited compensatory growth. There were no significant differences in feed efficiency between the treatments. The present experiment indicates that silage intake ad libitum and supplemented with concentrate resulted in most effective beef production.


1995 ◽  
Vol 268 (5) ◽  
pp. F793-F801 ◽  
Author(s):  
F. Terzi ◽  
C. Ticozzi ◽  
M. Burtin ◽  
V. Motel ◽  
H. Beaufils ◽  
...  

It is generally accepted that renal compensatory growth after unilateral nephrectomy (Uni) is due to prominent hypertrophy with no involvement of protooncogenes. Neither the balance between hypertrophy and hyperplasia nor the expression of the early-growth-related genes has been studied after subtotal nephrectomy (Nx). The occurrence of cystic tubular dilatations after Nx may suggest an excessive cell proliferation in this model. We measured DNA, RNA, and protein content, number of nuclei per tubular section, as well as c-fos, c-jun, c-myc, c-H-ras, c-sis, and c-erb-B2 protooncogene expression in kidneys taken at time of surgery and 2, 7, and 14 days after sham operation (control rats), Uni, or Nx. After Uni, hyperplasia was greater than expected (+79% for DNA at day 14) and was associated with moderate hypertrophy (+11% for protein/DNA ratio). After Nx, compensatory growth was due only to hyperplasia (+117% for DNA at day 14), with unchanged protein/DNA ratio (vs. Uni, P < 0.02). The greater hyperplasia after Nx was confirmed by nuclei counting. The protooncogene mRNA expression was constantly absent in control and Uni rats, whereas that of c-fos and c-jun genes was detected in Nx rats at day 14 with a 2- to 12-fold increment. The c-fos and c-jun protein levels were also increased at that time in Nx rats. This suggests the following: 1) the cellular events following Uni and Nx are not the same, and 2) the late protooncogene expression in Nx exclusively could favor a particular type of cell proliferation possibly more related with cystic formation than with actual compensatory growth.


2015 ◽  
Vol 47 (7) ◽  
pp. 264-273 ◽  
Author(s):  
Kate Keogh ◽  
Sinéad M. Waters ◽  
Alan K. Kelly ◽  
Alastair R. G. Wylie ◽  
David A. Kenny

The objective of this study was to characterize the effect of feed restriction and compensatory growth during re-alimentation on the functionality of the somatotropic axis. We blocked 60 bulls into one of two groups: 1) restricted feed allowance for 125 days ( period 1) (RES, n = 30) followed by ad libitum feeding for 55 days ( period 2) or 2) ad libitum access to feed throughout (ADLIB, n = 30). A growth hormone releasing hormone (GHRH) challenge was performed during each period. At the end of each period, 15 animals from each treatment were slaughtered and hepatic tissue collected. Hepatic expression of 13 genes of the somatotropic axis was measured by qRT-PCR. RES displayed a lower growth rate during period 1 (0.6 vs. 1.9 kg/day; P < 0.001), subsequently gaining more than ADLIB animals during period 2 (2.5 vs. 1.4 kg/day; P < 0.001). Growth hormone response to GHRH was not different between treatments at either time-point ( P > 0.05); however, resultant plasma IGF-1 was lower in period 1 and greater in period 2 in RES animals ( P < 0.05). Expression of IGFBP2 was higher ( P < 0.01) and IGF1 ( P < 0.001) and GHRIA ( P < 0.05) lower in RES compared with ADLIB during period 1, with no difference evident in period 2 ( P > 0.05). Collectively, the results of this study are consistent with uncoupling of the somatotropic axis following feed restriction. However, there is no evidence from this study that the somatotropic axis per se is a significant contributor to compensatory growth.


2012 ◽  
Vol 63 (12) ◽  
pp. 1231 ◽  
Author(s):  
Carina J. Sim-Smith ◽  
Andrew G. Jeffs ◽  
Craig A. Radford

For many fish species, growth and mortality of larvae are closely coupled, with faster-growing larvae generally experiencing higher survivorship in the plankton, which may lead to higher recruitment. Using back-calculated growth trajectories derived from otolith increments we used the modified Fry model to estimate the growth rate of larvae and early juveniles of the commercially important sparid, Chrysophrys auratus, at four sites around northern New Zealand. Back-calculated growth rates were used to test the hypothesis that fish with a short pelagic larval duration (≤20 days) grew faster than did fish with a long pelagic larval duration (>24 days) during both the larval and juvenile periods. At three of the four sites, fish with a short larval duration grew significantly faster during the larval period, and these larvae generally continued to have a larger size-at-age as juveniles up to 70-day-old. Growth rates for both the larval and early juvenile period were also found to vary significantly among the four sites and were found to be unrelated to differences in water temperature. Localised variation in early growth of C. auratus among sites may be important in helping explain differences in their contribution to the recruitment to C. auratus populations.


Genetics ◽  
1984 ◽  
Vol 107 (1) ◽  
pp. 79-101 ◽  
Author(s):  
Bruce Riska ◽  
William R Atchley ◽  
J J Rutledge

ABSTRACT Effects of normal growth regulation on components of phenotypic variance and covariance of body weight were examined in a cross-fostering study of growth between 2 and 10 wk of age in ICR randombred mice. Different early growth rates caused genetic, postnatal maternal and residual environmental variances to increase, but these variances were subsequently reduced by negative autocorrelation between early and later growth. Postnatal maternal variance continued to increase for about 1 wk after weaning but then decreased substantially. Genetic variance caused by preweaning growth followed a pattern of increase and decrease very similar to that of postnatal maternal variance, but this pattern was masked by new genetic variance. Normal growth regulation affects the magnitudes of genetic variances and serial autocorrelations. The timing of these changes suggests that regulation of cell numbers reduces variance near the end of exponential growth, but this may be obscured by subsequent increase in cell size. In contrast with earlier studies, we find that targeted growth reduces both genetically and environmentally determined differences among early growth trajectories. Final size may be determined by an antagonistic balance between early growth rate and age at initiation of puberty.


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