The effect of stage of growth on the genetic and phenotypic parameter estimates of food intake in pigs using a covariance function model

2000 ◽  
Vol 2000 ◽  
pp. 40-40
Author(s):  
A.D. Hall ◽  
P.R. Bampton ◽  
A.J. Webb

Many traits that are of interest to breeders, such as food intake, are expressed continuously during the life of an animal and the individual's phenotype will change with age. Traditional genetic analysis of these traits has treated as them as discrete traits, ignoring the correlations among records at different ages. Recently methods have been developed to overcome this deficiency and allow an infinite dimensional approach, which can provide more accurate estimates of genetic and phenotypic parameters (Kirkpatrick et al. 1994, Meyer and Hill 1997). The aim of this study was to investigate the effect of stage of growth on the genetic and phenotypic parameter estimates of daily food intake.

1994 ◽  
Vol 59 (2) ◽  
pp. 271-279 ◽  
Author(s):  
N. D. Cameron ◽  
M. K. Curran ◽  
J. C. Kerr

AbstractResponses to four generations of divergent selection in pigs for lean growth rate (LGS) with restricted feeding were studied. The selection criterion was designed to obtain equal correlated responses in growth rate and carcass lean content, measured in phenotypic s.d. Animals were to be performance tested in individual pens with a mean starting weight of 30 kg for a period of 84 days. Daily food intake was equal to 0·75 gig of the daily food intake for pigs offered food ad-libitum. In the high, low and control lines, there ivere 1250 Large White-Edinburgh (LW) pigs and 875 British Landrace-Wye (LR) pigs. Each selection line consisted of 10 sires and 20 dams, with a generation interval ofl year.After four generations of selection, cumulative selection differentials were 5·9 and 4·8 phenotypic s.d. for LW and LR populations, with similar responses, 1·8 (s.e. 0·17) phenotypic s.d. Mean weight at the end of test, growth rate and backfat depths at the shoulder, mid back and loin were 89 kg, 712 g/day, 26,13 and 13 mm for LW and for LR pigs were 87 kg, 683 g/day, 28,10 and 10 mm. High line pigs were heavier at the end of test (4·3 (s.e.d. 1·4) kg and 4·0 (s.e.d. 1·6) kg) for LW and LR populations, with corresponding responses in growth rate (54 (s.e.d. 16) g/day and 47 (s.e.d. 18) g/day). Responses in the three backfat depths were −4·1 (s.e.d. 1·2) mm, −2·6 (s.e.d. 0·7) mm and −2·9 (s.e.d. 0·7) mm for LW and −2·2 (s.e.d. 0·05) mm, −2·2 (s.e.d. 0·4) mm and −2·4 (s.e.d. 0·5) mm for LR populations. Responses in weight off test and backfat depths were symmetric about the control lines.Heritabilities for LGS were 0·34 and 0·28 (s.e.d. 0·5) for the LW and LR populations, when estimated by residual maximum likelihood. Common environmental effects for LGS were 0·11 (s.e. 0·03) for LW and 0·17 (s.e. 0·04) for LR. Heritabilities for growth rate and average backfat depth were similar for LW and LR populations (0·17 and 0·29, s.e. 0·05), as were common environmental effects (0·10 s.e. 0·04). Average phenotypic and genetic correlations between growth rate and backfat, for LW and LR populations, were small (0·15 (s.e. 0·03) and −0·06 (s.e. 0·16), respectively).Responses to selection and genetic parameter estimates demonstrate that there is substantial genetic variation in growth and fat deposition when pigs are performance tested on restricted feeding.


1999 ◽  
Vol 68 (3) ◽  
pp. 407-412 ◽  
Author(s):  
A. D. Hall ◽  
W.G. Hill ◽  
P. R. Bampton ◽  
A. J. Webb

AbstractThe main aims of this study were to predict the increase in the accuracy of selection and the response to selection achieved by including feeding pattern traits, such as number and size of meals, as selection criteria in indices to improve growth rate, lean content of the carcass and food conversion ratio. Genetic and phenotypic parameters obtained for pigs given foodad libitumusing single space electronic feeders were used to construct the indices. The predicted genetic gain in the index increased for indices with more feeding pattern traits. The inclusion of part test records for feeding patterns resulted in similar predicted correlated responses and predicted accuracy of selection to those using whole test records of daily food intake. The inclusion of feeding patterns as selection criteria resulted in indices that were less robust to inaccurate parameter estimates. It was concluded that feeding pattern traits could be used to improve the predicted accuracy of selection for the efficiency of lean growth but the most effective and robust index would include only daily gain, backfat depth, daily food intake and mean number of visits to the feeders per day. These traits may also be useful in reducing the length of the test period necessary for accurate measures of food intake, so increasing the potential intensity of selection using a given number of feeders.


2001 ◽  
Vol 204 (11) ◽  
pp. 1947-1956 ◽  
Author(s):  
M. S. Johnson ◽  
S. C. Thomson ◽  
J. R. Speakman

SUMMARYTo determine whether mice were limited in their capacity to absorb energy during late lactation, we attempted to increase the energy burden experienced by a group of female mice during late lactation by mating them at the postpartum oestrus, hence combining the energy demands of pregnancy and lactation. These experimental mice were therefore concurrently pregnant and lactating in their first lactation, and were followed through a normal second lactation. In a control group, females also underwent two lactations but sequentially, with the second mating after the first litter had been weaned. Maternal mass and food intake were measured throughout the first lactation, second pregnancy and second lactation. Maternal resting metabolic rate (RMR) was measured prior to the first mating and then at the peak of both the first and second lactations. Litter size and litter mass were also measured throughout both lactations. In the first lactation, experimental mice had a lower mass-independent RMR (F1,88=5.15, P=0.026) and raised significantly heavier pups (t=2.77, d.f.=32, P=0.0093) than the control mice. Experimental mice delayed implantation at the start of the second pregnancy. The extent of the delay was positively related to litter size during the first lactation (F1,19=4.58, P=0.046) and negatively related to mean pup mass (F1,19=5.78, P=0.027) in the first lactation. In the second lactation, the experimental mice gave birth to more (t=2.75, d.f.=38, P=0.0092) and lighter (t=−5.01, d.f.=38, P<0.0001) pups than did the controls in their second lactation. Maternal asymptotic daily food intake of control mice in the second lactation was significantly higher (t=−4.39, d.f.=37, P=0.0001) than that of the experimental mice and higher than that of controls during their first lactation. Despite the added burden on the experimental females during their first lactation, there was no increase in their food intake, which suggested that they might be limited by their capacity to absorb energy. However, control females appeared to be capable of increasing their asymptotic food intake beyond the supposed limits estimated previously, suggesting that the previously established limit was not a fixed central limitation on food intake. As RMR increased in parallel with the increase in food intake during the second lactation of control mice, the sustained energy intake remained at around 7.0×RMR.


2009 ◽  
Vol 6 (3) ◽  
pp. 480-487
Author(s):  
Baghdad Science Journal

The aim of this study was to assess the nutritional status for samples at the age of 17-15 years. These samples were taken from secondary schools and universities in Baghdad area, 123 of them were male and 261 were female. Data on weight, height and body mass index (BMI) were determined in each individual. Smaller sample of 215 individuals (male and female) from the original sample was taken in order to record their nutritional behavior and daily food intake during the 24 hours prior to the visit through personal meeting using special questionnaire. The results showed that the weight and the height were within the range of the people of neighboring Arab countries, who are in the same age. Beside 44.4- 55.95% of these samples were within the normal weight using body mass index. Percentages of obesity and overweight were between 43.5- 6.5% for male and female respectively. There was an increase in daily food intake in general for essential diet and energy indeed, as recorded in nutritional behavior. 67% of samples have their breakfast every day. There were 51% of the samples having snacks (additional meal) between the major meals everyday and 62% have beverages every day. Also high percentage of samples were having milk and its products, vegetables, fruits (as nutritional sources) every day and the percentages were 47%, 67%, 78% respectively. In general their nutritional behavior and daily food intake were within the limits which showed by American recommended daily dietary, still there was some incorrect nutritional behavior which need more education and learning about nutrition.


1980 ◽  
Vol 46 (5) ◽  
pp. 215-225
Author(s):  
Hiroyuki TOYOKAWA ◽  
Yuko MIYAKE ◽  
Eiji MARUI

1990 ◽  
Vol 68 (3) ◽  
pp. 591-595 ◽  
Author(s):  
D. J. Booth

Field experiments were conducted over the summer of 1983 to determine food-evacuation rate and measure stomach fullness of bluegill sunfish (Lepomis macrochirus). A combination of these data gave estimates of daily food intake of fish. Fish were captured and held in large holding pens in Lake Opinicon, Ontario, Canada, and periodically subsampled over 24 h to monitor changes in mean weight of stomach contents. Stomach-evacuation rates obtained in this way increased significantly with water temperature over the range 10–25 °C. However, variation in stomach-evacuation rate was considerable, reducing the utility of water temperature as a predictor of stomach-evacuation rate. It is suggested that the simple field methods employed here to estimate stomach evacuation and food intake are more useful in the estimation of daily ration than the more commonly employed laboratory-based methods.


1989 ◽  
Vol 256 (1) ◽  
pp. R181-R186
Author(s):  
A. Bado ◽  
M. J. Lewin ◽  
M. Dubrasquet

The brain and gut peptide bombesin has been reported both to stimulate gastric secretion and to induce satiety. To understand how the peripheral administration of bombesin affects food intake and whether gastric mechanisms are involved, a comparative study of the doses of bombesin active on gastric secretion, gastric emptying, and food intake was undertaken in cats provided with a gastric fistula and a denervated Heidenhain pouch. The smallest dose of intravenous bombesin that stimulated significantly basal acid secretion (20 pmol.kg-1.h-1) by the gastric fistula also enhanced meal-stimulated acid secretion by the Heidenhain pouch (+138%, P less than 0.01), delayed gastric emptying of a liquid protein meal (-30%, P less than 0.01), and suppressed food intake when the test meal was allowed to reach the stomach (-15%, P less than 0.01). Conversely, in sham-feeding experiments, the same dose of bombesin increased food intake (+35%, P less than 0.01). In full-day experiments conducted in nonfasted cats, bombesin decreased both the food intake in the 4-h period after the infusion and the daily food intake, whereas octapeptide cholecystokinin induced a transient satiety but did not decrease daily food intake. These results indicate that in cats the interaction of bombesin with "pregastric" mechanisms is not sufficient to induce satiety and that a relation could exist between the effects of bombesin on gastric secretion, emptying, and food intake. A single class of receptors might be involved in these peripheral effects of bombesin.


2000 ◽  
Vol 2000 ◽  
pp. 22-22
Author(s):  
N.D. Cameron ◽  
J.C. Penman ◽  
E. McCullough

Leptin is synthesised and secreted from adipocytes into the blood stream and transported to the brain, where it acts to cause a release of factors which can reduce food intake (Houseknecht et al., 1998). There are two murine mutations of the recessive gene coding for leptin which are associated with obesity. The Lepob allele determines synthesis and secretion of leptin, while the Lepdb allele determines responsiveness to leptin. In the Edinburgh lean growth experiment in pigs, selection for high and low daily food intake (DFI) has been practiced for seven generations in a Large White herd, which provides the experimental resource to determine if the correlated response in fat deposition is consistent with insufficient leptin production or with insensitivity to leptin.


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