scholarly journals Heritabilities of growth curve parameters and age-specific expression of genetic variation under two different feeding regimes in Japanese quail (Coturnix coturnix japonica)

1993 ◽  
Vol 62 (1) ◽  
pp. 45-55 ◽  
Author(s):  
Sabine G. Gebhardt-Henrich ◽  
Henry L. Marks
Keyword(s):  
Body Weight ◽  
Genetic Variation ◽  
Japanese Quail ◽  
Growth Curve ◽  
Genetic Correlations ◽  
Growth Period ◽  
Restricted Feeding ◽  
Tarsus Length ◽  
Final Size ◽  
Ad Libitum

SummaryThis study investigated genetic variation in growth and final size in relationship to differences in heritabilities under good and poor feeding conditions. Heritabilities of growth and final size were estimated for several traits underad libitumand restricted feeding conditions. A 30% feed restriction from hatching to 44 days of age in Japanese quail chicks decreased body weight and tarsus length at 44 days of age and the length of the third primary covert feather at 24 days of age relative to controls fedad libitum. Wing length at 44 days of age was not significantly different forad libitumfed and restricted quail. Genetic variances for body weight and tarsus length were very large throughout growth which resulted in heritability estimates close to one for these traits. The genetic correlations among feeding treatments were low, indicating that different genes were affecting growth under the two treatments. Growth was described by the components: asymptote, growth period, and shape of the growth curve following the modified Richards growth curve model (Brisbinet al.1986). Tarsus length, which had high heritability of the parameter ‘growth period’ of the model, tended to display a higher heritability under the restriction than underad libitumfeeding. Body weight and feather length, which had either no heritable or low heritable ‘growth periods’ estimates, tended to be more heritable underad libitumfeeding. The shape parameter of the growth curve was not heritable for any trait, except tarsus length under restricted feeding.

scholarly journals The influence of food restriction versus ad libitum feeding of chow and purified diets on variation in body weight, growth and physiology of female Wistar rats

2012 ◽  
Vol 46 (2) ◽  
pp. 101-107 ◽  
Author(s):  
M Moraal ◽  
P P A M Leenaars ◽  
H Arnts ◽  
K Smeets ◽  
B S Savenije ◽  
...  
Keyword(s):  
Body Weight ◽  
Food Restriction ◽  
Wistar Rats ◽  
Statistical Significance ◽  
Blood Parameters ◽  
Calorie Intake ◽  
Restricted Feeding ◽  
Organ Weights ◽  
Female Wistar Rats ◽  
Ad Libitum

Ad libitum (AL) supply of standard chow is the feeding method most often used for rodents in animal experiments. However, AL feeding is known to result in a shorter lifespan and decreased health as compared with restricted feeding. Restricted feeding and thus limiting calorie intake prevents many health problems, increases lifespan and can also increase group uniformity. All this leads to a reduced number of animals needed. So-called standard chows are known to be prone to variation in composition. Synthetic foods have a more standard composition, contributing to group uniformity which, like diet reduction, may decrease the number of animals necessary to obtain statistical significance. In this study, we compared the effects of AL versus restricted feeding (25% reduction in food intake) on standard chow versus synthetic food of three different suppliers on body weight (BW), growth, several blood parameters and organ weights in growing female Wistar rats over a period of 61 days. Diet restriction led to a decreased growth and significantly reduced variation in BW and growth as compared with AL feeding. AL feeding on synthetic diets caused a significantly higher BW gain than on chow diets. Due to experimental design, this same effect occurred on food restriction. Blood parameters and organ weights were affected neither by diet type nor by amount. Incidentally, variations were significantly reduced on food restriction versus AL, and on synthetic diets versus chow diets. This study demonstrates that food restriction versus AL feeding leads to a significantly reduced variation in BW and growth, thereby indicating the potential for reduction when applying this feeding schedule.

Effect of body weight on the attainment of puberty and reproductive performance of Galway and Fingalway female lambs

1979 ◽  
Vol 28 (3) ◽  
pp. 297-307 ◽  
Author(s):  
J. F. Quirke
Keyword(s):  
Body Weight ◽  
Breeding Season ◽  
Litter Size ◽  
Conception Rate ◽  
Restricted Feeding ◽  
Ewe Lambs ◽  
Younger Age ◽  
Body Weights ◽  
The Mean ◽  
Ad Libitum

ABSTRACTGroups of spring-born Galway (G) and Fingalway (F) ewe lambs were fed a concentrate diet either ad libitum (H) or at a restricted level (L) during the period 25 July to 16 October 1974 in order to induce differences in body weight at the start of the breeding season. The mean live weights of the GL, GH, FL and FH groups on 16 October 1974 were 37·8 ± 1·3, 44·6 ± 1·3, 35·1 ± 1·1 and 41·9 ± 1·2 kg respectively. More than 95% of the lambs in all four groups attained puberty before 28 February 1975. Galway ewe lambs reached puberty later in the breeding season and were older and heavier at puberty than Fingalways. Animals fed ad libitum were heavier at puberty and attained puberty earlier in the season and at a younger age than those on the restricted feeding regime.Both conception rate and litter size were lower in Galways than Fingalways. There was no evidence of any effect of the nutritional treatments on conception rate or litter size. The mean body weights at puberty for ewes which lambed and those which were barren were 41·9 ± 0·49 and 41·5 ± 0·78 kg respectively. The birth weight and growth rate of the progeny of the ewe lambs was similar for the two breeds and was not influenced by the previous nutritional treatment of the dams. The total lamb mortality between birth and weaning was 40·3%, and 72% of all deaths occurred within 48 h of birth. Losses among twins (48%) were particularly heavy.

The association of food conversion ratio, age at slaughter and carcass quality in pigs fed ad libitum

1969 ◽  
Vol 11 (3) ◽  
pp. 317-324 ◽  
Author(s):  
J. B. Owen ◽  
J. R. Morton
Keyword(s):  
Genetic Correlations ◽  
Conversion Ratio ◽  
Residual Effects ◽  
Progeny Testing ◽  
Restricted Feeding ◽  
Food Conversion ◽  
Large White ◽  
Related Factors ◽  
Food Conversion Ratio ◽  
Ad Libitum

SUMMARYData from a boar progeny testing scheme based on ad libitum feeding were analysed to test the hypothesis that the resultant correlations of food conversion ratio with related factors would differ from those found under conditions of restricted feeding.The results support the hypothesis, showing that the primarily genetic correlations derived from boar effects for growth and conversion ratio, are lower than those reported elsewhere for restricted feeding. It was also shown that these primarily genetic correlations could vary between breeds, the leanness associated with rapid growth in Wessex not being found in Large White, and that the correlations due to residual effects containing a greater environmental component varied widely from test to test.It is concluded that the parameters used in the design of a genetic improvement scheme should be derived specifically for each breed and feeding system. However, if the marked variability in phenotypic correlations noted here is generally applicable, this could present a difficult problem in the design of pig improvement programmes with multiple objectives.

Changes in body composition of sheep selected for high and low backfat thickness, during periods of ad libitum and maintenance feeding

1996 ◽  
Vol 63 (3) ◽  
pp. 395-406 ◽  
Author(s):  
J. Afonso ◽  
J. M. Thompson
Keyword(s):  
Body Weight ◽  
Lower Proportion ◽  
Restricted Feeding ◽  
Allometric Growth ◽  
Age Changes ◽  
Lean Tissue ◽  
Growth Coefficient ◽  
Intermuscular Fat ◽  
Ad Libitum ◽  
Total Fat

AbstractCoopworth sheep from the high and low backfat selection lines and from one random-bred line developed at Invermay, New Zealand, were used to examine the interaction between the degree offatness of sheep and a period of maintenance feeding (from 20 to 35 weeks of age), in terms of total fat, carcass lean tissue, bone and viscera weights, relative to the empty body weight measured in computer-aided tomography scans. A similar study was done for weights of subcutaneous, intermuscular and internal (abdominal) fat partitions relative to total fat weight. During two a d libitum feeding periods (front 10 to 20 and from 35 to 43 weeks of age) changes in the same components relative to the ‘whole’ (empty body weight or total fat, depending on the case) were expressed in allometric terms.Only the allometric growth coefficient for total fat weight was significantly affected by the period of restricted feeding, decreasing after this period. No line or sex effect was observed on any growth coefficient. As a result, there were no changes in differences between treatments over the ad libitum feeding periods, with fat animals and females having significantly higher proportions of fat, while females also had a significantly lower proportion of intermuscular fat.During maintenance feeding, line and sex differences in dissectible component weights did not change significantly, except in terms of intermuscular fat, with the males showing an increasingly larger proportion than the females.

scholarly journals Effect of 4-h time restricted feeding on body weight, leptin concentration and lipid profile in healthy non-obese male Wistar rats

2021 ◽  
Author(s):  
Michael A. Olamoyegun ◽  
Folasade O. Ajao ◽  
Marcus O. Iyedupe
Keyword(s):  
Body Weight ◽  
Blood Glucose ◽  
Lipid Profile ◽  
Wistar Rats ◽  
Metabolic Diseases ◽  
Restricted Feeding ◽  
Mean Values ◽  
Male Wistar Rats ◽  
Ad Libitum ◽  
Obese Male

Abstract Background: Obesity greatly increases the risk of metabolic diseases and preventive approaches for obesity are often inadequate to effectively prevent and manage the diseases. Altering feeding time strategy intervention decreases caloric intake without calorie counting and may be an effective therapy. Therefore, this study investigates the effect of 4-h time restricted feeding on body weight, leptin concentration and lipid profile in healthy non-obese male Wistar rats. Methods: Rats placed on time-restricted feeding (TRF) regimen had freely access to food for 4 hour per day at designated periods. Twenty four rats divided into four groups (n=6) were used. Group I animals were placed on a 4 hour per day TRF between 8am-12noon. Group II rats were also placed on a 4 hour per day TRF between 12noon-4pm. Group III rats also placed on a 4 hour per day TRF between 8pm-12 midnight while Group IV rats had access food and water ad libitum. This diet strategy resembles taking only breakfast, lunch or dinner once a day. The study lasted for a period of 4 weeks with daily food intake and weekly body weight determined throughout the period. At the end of the experimental period, blood glucose, lipid profile and leptin concentration were assessed. SPSS 21.0 package was used for data analysis, one-way analysis of variance (ANOVA) was used to compare the mean values of variables among the groups and bonferroni’s posthoc test was used for significance of pair wise comparisons of mean values among the groups. Significance was set at p < 0.05.Results: In this study, the body weights and leptin concentrations of 8pm – 12am and ad libitum groups significantly increased compared with the 8am - 12noon and 12noon -4pm groups. Dyslipidemia was observed in the ad libitum group when compared with the 8am - 12noon and 12noon - 4pm groups. Conclusion: From this study, 4-hr time restricted feeding has beneficial effects on body weight, blood glucose, lipid profile and leptin concentration. This feeding restriction patterns may be helpful in obesity management and in preventing metabolic diseases development in non obese.

Influence of feeding intensity on the growth, body composition and sexual maturity of male New Zealand White rabbits

2003 ◽  
Vol 51 (3) ◽  
pp. 305-319 ◽  
Author(s):  
Kinga Fodor ◽  
L. Zöldág ◽  
S. Gy. Fekete ◽  
A. Bersényi ◽  
A. Gáspárdy ◽  
...  
Keyword(s):  
Body Composition ◽  
Body Weight ◽  
New Zealand ◽  
Sexual Maturity ◽  
Dry Matter ◽  
The Body ◽  
Restricted Feeding ◽  
Feeding Intensity ◽  
Ad Libitum ◽  
Average Body

An experiment was carried out with young male New Zealand White (NZW) rabbits to establish live body weight changes, body measurements, body composition and sexual maturity as a function of feeding intensity. Animals in Group 1 ('AL', n = 10) were fed ad libitum, while those in Group 2 ('RS', n = 10) received restricted feeding corresponding to 70% of the ad libitum level. The starting liveweights were practically the same (0.907 ± 0.146 and 0.911 ± 0.147 kg in Group AL and Group RS, respectively). The feeding trial lasted from 6 to 22 weeks of age. The average body weight was significantly higher in Group AL from 7 to 22 weeks of age. At 22 weeks of age the body weight of RS rabbits was 85.64% of the weight of AL animals (3.22 ± 0.52 kg and 3.76 ± 0.33 kg, respectively). Average body weights of RS males at 8, 9, 11, 19 and 21 weeks of age were similar to those of ad libitum fed (AL) animals at 7, 8, 10, 15 and 16 weeks of age, respectively. The growth of bucks fed restricted tended to be allometric. The most significant difference was found at 16 and 18 weeks of age, while the lowest difference occurred at 6, 12, 15 and 19 weeks of age. It can be stated that low-intensity feeding up to slaughtering weight causes backwardness in rear cannon length and this backwardness remains also after the 15th week, which is well over the optimal slaughtering age. Based on the present data, the 70% restricted feeding cannot be recommended either for the future breeding bucks or for broiler males reared for slaughter. To determine the major chemical components of the body, rabbits were euthanised. Original dry matter and crude fat content of the body significantly (P < 0.05) decreased under restricted feeding (41.42%; 32.48% and 16.73%; 7.35%) while the percentage of protein within the dry matter increased (49.6%; 65.0%) and fat decreased (40.17%; 22.1%) significantly. Libido unambiguously decreases as a consequence of feed deprivation. The most conspicuous difference was found in the level of blood testosterone. Although a few RS bucks produced semen but only much later than the rabbits fed ad libitum. On the other hand, there was no difference in the motility of spermatozoa and ejaculate volume in comparison with AL animals. There was no relationship between the body fat content and the reproductive status of bucks in the present trial.

The effects of genotype, sex and feeding regimen on pig carcass development: 1. Primary components, tissues and joints

1979 ◽  
Vol 93 (2) ◽  
pp. 339-347 ◽  
Author(s):  
D. G. Evans ◽  
A. J. Kempster
Keyword(s):  
Growth Period ◽  
Carcass Weight ◽  
Restricted Feeding ◽  
Alternative Models ◽  
Lean Growth ◽  
Feeding Regimen ◽  
Ad Libitum ◽  
Pig Carcasses

SUMMARYDissection data for 1006 pig carcasses taken from the first 2 years of the Meat and Livestock Commission's (MLC) Commercial Pig Evaluation (CPE) were used to examine the relationships between carcass components and carcass weight over the growth period from 46 to 92 kg carcass weight. Alternative models were tested and parameters examined for different genotypes (pigs from different companies in CPE), sexes (barrows and gilts), feeding regimens (ad libitumand restricted feeding) and years.Generally, linear allometry provided an acceptable description of carcass development, although some curvilinearity was indicated for the head, kidneys, rump back joint, M. psoas and total dissected lean. Growth coefficients conformed to the generally accepted pattern of carcass development in pigs. Using linear allometry, proportional weight increases were comparable for all genotypes and sexes, but dissected fat increased relatively faster on the restricted feeding regimen.At a constant carcass weight of 66·5 kg, all tissue weights and the weights of primary components and most joints differed by genotype. The ratio of carcass lean weights for the two extreme genotypes was 1·04; comparable ratios for carcass fat weights were 1·13 (restricted-fed pigs) and 1·07 (ad libitum-fed pigs).Significant differences were recorded between sexes and between feeding regimens, largely reflecting differences in fatness. Some important year differences were also found.

THE EFFECT OF NUTRITIONAL STATE ON ABILITY OF THE RAT TO SWIM TO EXHAUSTION

1966 ◽  
Vol 44 (4) ◽  
pp. 597-603 ◽  
Author(s):  
John R. Beaton ◽  
V. Feleki
Keyword(s):  
Body Weight ◽  
Food Intake ◽  
Work Load ◽  
Swimming Exercise ◽  
Time To Exhaustion ◽  
Apparent Difference ◽  
Restricted Feeding ◽  
High Fat ◽  
High Carbohydrate ◽  
Ad Libitum

Following 9 days' provision of a high-protein (HPD), high-fat (HFD), or high-carbohydrate (HCD) diet (isocaloric), rats were made to swim to exhaustion in water at a temperature of 25–26 °C. Lead weight was strapped to the base of the tail at a level of 6% of body weight to increase the work load and decrease the exhaustion time. Under both ad libitum and restricted feeding conditions, animals fed the HPD had the longest exhaustion time, there being no apparent difference between exhaustion times of animals fed the HFD or HCD. Restriction of food intake increased the time to exhaustion. Provision of a meal just before swimming exercise decreased the time to exhaustion. Daily swimming for 15 minutes (training) prior to the test increased and decreased exhaustion time in HCD- and HPD-fed rats respectively with no significant effect on exhaustion time of HFD-fed rats.

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