Serum insulin-like growth factor-1 concentration in pigs divergently selected for daily food intake or lean growth rate

Divergent selection lines for lean growth on a restricted feeding regime, in Large White and Landrace pigs, were established to complement the lean growth selection lines on ad-libitum feeding. This study estimated the direct and correlated responses after four generations of selection and the corresponding genetic and phenotypic parameters.The selection objective for lean growth on restricted or scale (LGS) feeding was to obtain equal correlated responses in growth rate and carcass lean content, measured in phenotypic s.d. The selection criterion included measurements of growth rate and ultrasonic backfat depth.Large White (LW) and Landrace (LR) boars and gilts were purchased from eight British nucleus herds and boars from national artificial insemination centres in 1982. Homozygous or heterozygous halothane positive pigs were not included in the experiment. The base populations consisted of 31 LW and 19 LR sires and 57 LW and 67 LR dams. Within each population, there were high and low selection lines with a control line, each consisting of 10 boars and 20 gilts, with a generation interval of 13.5 and 12 months for LW and LR pigs. Animals were performance tested in individual pens from 30±3 kg for a period of 84 days and fed a high energy (13.8 MJ DE/kg DM) and high protein (210 g/kg DM crude protein) pelleted ration. Daily food intake was equal to 0.75 g/g of the daily food intake for ad-libitum fed pigs and the total food intake was 134 kg for LW pigs and 150 kg for LR pigs. On average, 3 boars and 3 gilts were tested per litter. The total number of pigs tested per line and average inbreeding coefficients at generation four, by population are given below.

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Selection for components of efficient lean growth rate in pigs 4. Genetic and phenotypic parameter estimates and correlated responses in performance test traits with ad-libitum feeding

Animal Science ◽

10.1017/s0003356100007777 ◽

1994 ◽

Vol 59 (2) ◽

pp. 281-291 ◽

Cited By ~ 31

Author(s):

N. D. Cameron ◽

M. K. Curran

Keyword(s):

Growth Rate ◽

Food Intake ◽

Performance Test ◽

Food Conversion ◽

Daily Food Intake ◽

Lean Growth ◽

Daily Food ◽

Genetic And Phenotypic Correlations ◽

Selection For ◽

Ad Libitum Feeding

AbstractGenetic and phenotypic parameters and correlated responses in performance test traits were estimated for populations of Large White (LW) and British Landrace (LR) pigs tested in Edinburgh and Wye respectively, to four generations of divergent selection for lean growth rate (LGA), lean food conversion (LFC) and daily food intake (DFI) with ad-libitum feeding.There were differences between the two populations in genetic parameters, as LW heritabilities for growth rate, daily food intake and backfat depths were higher and the correlation between growth rate and backfat was positive for LW, but negative for LR. However, heritabilities, genetic and phenotypic correlations were generally comparable between selection groups, within each population. Genetic and phenotypic correlations indicated that animals with high daily food intakes were faster growing, had positive residual food intakes (RFI), were fatter with higher food conversion ratios. RFI was highly correlated with daily food intake and food conversion ratio, but phenotypically independent of growth rate and backfat, as expected.Selection for LGA, in LW and LR populations, increased growth rate (54 and 101 g/day), but reduced backfat (−3·9 and −2·0 mm), food conversion ratio (−0·23 and −0·25) and total food intake (−11·8 and −12·6 kg). There was no change in daily food intake in LW pigs (−19 g/day), but daily food intake increased in the LR pigs (69 g/day). With selection for LFC in LW and LR populations, there was no response in groivth rate (9 and 9 g/day), but backfat (−4·1 and −2·1 mm), total (−6·6 and −11·8 kg) and daily food intake (−90 and −172 g) were reduced, as animals had lower food conversion ratios (−0·13 and −0·22). LW and LR pigs selected for DFI ate more food in total (6·8 and 5·9 kg) and on a daily basis (314 and 230 g), grew faster (94 and 51 g/day) and had higher food conversion ratios (0·12 and 0·13). Backfat was increased in LW pigs (3·7 mm), but not in the LR population.In general, efficiency of lean growth was improved by increasing groivth rate, with little change in daily food intake from selection for LGA, but was primarily due to reduced daily food intake with selection on LFC.

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Major gene effect on serum insulin-like growth factor-1 concentration in pigs

Proceedings of the British Society of Animal Science ◽

10.1017/s1752756200004075 ◽

2001 ◽

Vol 2001 ◽

pp. 25-25

Author(s):

N.D. Cameron ◽

E. McCullough ◽

K. Troup ◽

J.C. Penman ◽

R. Pong-Wong

Keyword(s):

Growth Factor ◽

Genetic Association ◽

Serum Insulin ◽

Major Gene ◽

Insulin Like Growth Factor ◽

Gene Effect ◽

Protein Deposition ◽

Major Gene Effect ◽

Lean Growth ◽

Daily Food

Insulin-like growth factor-1 has been positively associated components of growth in pigs, such as protein deposition. Therefore, serum insulin-like growth factor-1 concentration (IGF-1) was measured in lines of pigs divergently selected for daily food intake (DFI) or for efficient lean growth rate (LGS) to determine if there was a non-zero genetic association between IGF-1 and the selection criteria. If a genetic association did exist, then IGF-1 could be used as a physiological predictor of genetic merit in a breeding programme. The presence of a major gene effect on IGF-1 was also examined in the study.

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Responses in carcass composition to divergent selection for components of efficient lean growth rate in pigs

Animal Science ◽

10.1017/s1357729800013904 ◽

1995 ◽

Vol 61 (2) ◽

pp. 347-359 ◽

Cited By ~ 20

Author(s):

N. D. Cameron ◽

M. K. Curran

Keyword(s):

Growth Rate ◽

Food Intake ◽

Fat Content ◽

Restricted Feeding ◽

Food Conversion ◽

Daily Food Intake ◽

Lean Growth ◽

Daily Food ◽

Ad Libitum ◽

Selection For

AbstractCarcass composition was measured after six generations of divergent selection for lean growth rate on ad-libitum and restricted feeding, lean food conversion and daily food intake in populations of Large White (LW) and Landrace (LR) pigs. There were 161 half-carcass dissections in LW pigs and for LR pigs, a double sampling procedure combined information from 53 half-carcass and 53 hand joint dissections. The performance test started at 30 kg and finished at 85 kg with ad-libitum feeding and after 84 days with restricted feeding, and pigs were slaughtered at the end of the test.In the LR population, selection for lean growth on restricted feeding increased carcass lean content (605 v. 557 (s.e.d. 19) g/kg), but there were no significant responses in carcass lean content with the selection strategies on adlibitum feeding. Selection for lean food conversion and high lean growth on restricted feeding reduced carcass fat content (201 v. 241 (s.e.d. 14) and 150 v. 218 (s.e.d. 18) g/kg), but selection for high lean growth rate with adlibitum increased carcass fat content (212 v. 185 (s.e.d. 11) g/kg). Responses in carcass composition were not significant with selection on daily food intake.In the LW population, selection for high lean food conversion or low daily food intake increased carcass lean content (539 v. 494 and 543 v. 477 (s.e.d. 11) g/kg) to a greater extent than selection on lean growth rate (509 v. 475 g/kg). Responses in carcass fat content were equal and opposite to those in carcass lean content. Selection on lean growth rate with ad-libitum feeding increased lean tissue growth rate (LTGR) (491 v. 422 (s.e.d. 23) g/day), but there was no change in fat tissue growth rate (FTGR) (206 v. 217 (s.e.d. 15) g/day). In contrast, FTGR was reduced with selection on lean food conversion (169 v. 225 g/day), but LTGR was not significantly increased (520 v. 482 g/day). Selection for lean growth rate with restricted feeding combined the desirable strategies of lean growth rate on adlibitum feeding and lean food conversion, as LTGR was increased (416 v. 359 (s.e.d. 12) g/day) and FTGR decreased (126 v. 156 (s.e.d. 7) g/day). The preferred selection strategy may be lean growth rate on restricted feeding, which simultaneously emphasizes rate and efficiency of lean growth.For ad-libitum fed LW pigs, coheritabilities for growth rate, daily food intake and backfat depth with carcass lean content were negative (-0·12, -0·22 and -0·50 (s.e. 0·05), but positive with carcass subcutaneous fat content (0·22, 0·24 and 0·50), when estimated from six generations of performance test data and carcass dissection data in generations 2, 4 and 6.

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Rate and site of fat deposition in pigs selected for components of efficient lean growth rate

Proceedings of the British Society of Animal Science ◽

10.1017/s0308229600027835 ◽

1995 ◽

Vol 1995 ◽

pp. 12-12

Author(s):

N.D. Cameron

Keyword(s):

Growth Rate ◽

Food Intake ◽

Divergent Selection ◽

Fat Deposition ◽

Food Conversion ◽

Large White ◽

Daily Food Intake ◽

Lean Growth ◽

Daily Food ◽

Ad Libitum

Rates and sites of fat deposition were measured in a population of Large White pigs, after six generations of divergent selection on lean growth rate with ad-libitum (LGA) and restricted (LGS) feeding, lean food conversion (LFC) and daily food intake (DFI).

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Genetic variation in measures of food efficiency in pigs and their genetic relationships with growth rate and backfat

Animal Science ◽

10.1017/s0003356100021309 ◽

1993 ◽

Vol 56 (2) ◽

pp. 225-232 ◽

Cited By ~ 60

Author(s):

R. A. Mrode ◽

B. W. Kennedy

Keyword(s):

Growth Rate ◽

Food Intake ◽

Genetic Correlations ◽

Conversion Ratio ◽

Maximum Likelihood Estimates ◽

Food Conversion ◽

Daily Food Intake ◽

Lean Growth ◽

Food Conversion Ratio ◽

Daily Food

AbstractData on 3783 Yorkshire, 2842 Landrace and 937 Duroc littermate pairs of boars, station tested between 1976 and 1989, were used to measure genetic parameters of average daily gain (ADG) from 30 to 90 kg, live backfat at 90 kg (BF), estimated lean growth rate (LGR), average daily food intake, food conversion ratio (FCR) and lean food conversion ratio (LFCR), as well as measures of residual daily food intakes over and above requirements for growth and lean growth. A method was developed to obtain restricted maximum likelihood estimates of genetic variances and covariances under an animal model when observations are on the means of sib pairs. Heritabilities of ADG, BF, LGR, FCR and LFCR were 0·43, 0·59, 0·39, 0·28 and 0·34, respectively. Heritability of daily food intake was 0·45, and heritability of measures of residual daily food intake ranged from 0·30 to 0·38. About half of the variation in daily food intake was residual (0·48 to 0·56). Genetic correlations of ADG with daily food intake, FCR and LFCR were 0·80, −0·28 and −0·09, respectively, and were small and positive (0·18 to 0·34) with measures of residual daily food intake. Backfat had genetic correlations of 0·42, 0·24 and 0·52 with daily food intake, FCR and LFCR, respectively, and genetic correlations between backfat and measures of residual daily food intake ranged from 0·15 to 0·61. Selection against residual food intake may be a useful means of improving efficiency of food utilization.

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Selection for components of efficient lean growth rate in pigs 3. Responses to selection with a restricted feeding regime

Animal Science ◽

10.1017/s0003356100007765 ◽

1994 ◽

Vol 59 (2) ◽

pp. 271-279 ◽

Cited By ~ 21

Author(s):

N. D. Cameron ◽

M. K. Curran ◽

J. C. Kerr

Keyword(s):

Growth Rate ◽

Food Intake ◽

Environmental Effects ◽

Genetic Correlations ◽

Parameter Estimates ◽

Selection Line ◽

Restricted Feeding ◽

Daily Food Intake ◽

Lean Growth ◽

Daily Food

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.

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Multibreed comparisons of British cattle. Variation in body weight, growth rate and food intake

Animal Science ◽

10.1017/s0003356100041520 ◽

1984 ◽

Vol 38 (3) ◽

pp. 323-340 ◽

Cited By ~ 17

Author(s):

R. B. Thiessen ◽

Eva Hnizdo ◽

D. A. G. Maxwell ◽

D. Gibson ◽

C. S. Taylor

Keyword(s):

Growth Rate ◽

Body Weight ◽

Genetic Variation ◽

Weight Gain ◽

Food Intake ◽

Daily Weight Gain ◽

Daily Food Intake ◽

Daily Food ◽

Breed Selection ◽

Voluntary Food Intake

ABSTRACTA multibreed cattle experiment involving 25 British breeds was set up to study genetic variation between breeds and genetic inter-breed relationships for a wide spectrum of traits in order to examine the problems of between-breed testing and selection. The experimental design is described and results on between-breed variation are presented for four traits.All animals were housed indoors and from 12 weeks of age were given a single complete pelleted diet ad libitum through a system of Calan-Broadbent electronic gates. Females were mated to produce one purebred and three crossbred calves, which were reared to slaughter in order to measure the efficiency of the cow-calf unit of production.Results based on a total of 292 animals, with an average of 12 per breed, are presented for body weight, cumulated voluntary food intake, daily weight gain and daily food intake over the age range from 12 to 72 weeks. The 25 breed-mean curves for body weight and cumulated food intake displayed a remarkably uniform pattern of rankings at all ages and the rankings were very similar for both traits.The multibreed design used was effective in estimating between-breed variation as a proportion of total variation for the four traits examined. After approximately 1 year of age, the proportion of variation between breeds was approximately 0·70 for body weight and 0·60 for cumulated voluntary food intake. Changes in these traits could therefore be brought about more effectively by selection between breeds rather than within breeds. For average daily weight gain measured over 12-week intervals, between-breed selection was estimated to be most effective in the period of maximum growth rate between 6 and 9 months of age, when between-breed variation was 0·52 of the total. For average daily food intake, measured over 12-week intervals, between-breed selection was likely to be effective beyond 6 months of age, when the proportion of between-breed variation plateaued at 0·48.At all ages, the coefficient of genetic variation between breeds was approximately 0·14 for body weight and daily gain, and remarkably constant at approximately 0·12 for both daily and cumulated food intake. It is suggested that, for growth and intake traits, the genetic variances within and between breeds remain proportional to each other at all ages.

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Growth and food intake curves for group-housed gilts and castrated male pigs

Animal Science ◽

10.1017/s1357729800015356 ◽

1996 ◽

Vol 63 (3) ◽

pp. 457-464 ◽

Cited By ~ 28

Author(s):

S. Andersen ◽

B. Pedersen

Keyword(s):

Growth Rate ◽

Food Intake ◽

Live Weight ◽

Simulation Models ◽

Random Regression ◽

Lower Growth ◽

Daily Food Intake ◽

Food Efficiency ◽

Daily Food ◽

The Difference

AbstractPolynomial models with random regression coefficients were used to describe cumulated food intake and gain as a function of number of days on test for gilts and castrated male pigs which were on test from 30 to 115 kg live weight. Growth rate and daily food intake were expressed as the derivative of the curves. The applied models allowed a separation of between and within animal variation. Confidence limits for average curves and prediction limits for individual curves were also obtained. A similar model was used to describe gain as a function of cumulated food intake. From this function food efficiency was obtained. The application of the results in stochastic simulation models is discussed.Growth rate and daily food intake had a more curvilinear progress for castrated males than for gilts. It was estimated that 98% of the castrated males and 96% of the gilts had a lower growth rate at day 80 than at day 50; 74% of the castrated males and 48% of the gilts had a lower daily food intake at day 100 than at day 80. On average food efficiency of gilts was higher than food efficiency of castrated males and the difference increased through the test period.

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Genetic variation and responses in reproductive performance of sows in lines selected for growth rate under restricted feeding

Animal Science ◽

10.1079/asc20052 ◽

2006 ◽

Vol 82 (1) ◽

pp. 7-12 ◽

Cited By ~ 3

Author(s):

N. H. Nguyen ◽

C. P. McPhee ◽

C. M. Wade

Keyword(s):

Growth Rate ◽

Body Weight ◽

Birth Weight ◽

Food Intake ◽

Reproductive Performance ◽

Likelihood Method ◽

Gestation Length ◽

Daily Food Intake ◽

Daily Food ◽

Reproduction Traits

AbstractThe objective of this study was to examine genetic changes in reproduction traits in sows (total number born (TNB), number born alive (NBA), average piglet birth weight (ABW) and number of piglets weaned (NW), body weight prior to mating (MW), gestation length (GL) and daily food intake during lactation (DFI)) in lines of Large White pigs divergently selected over 4 years for high and low post-weaning growth rate on a restricted ration. Heritabilities and repeatabilities of the reproduction traits were also determined. The analyses were carried out on 913 litter records using average information-restricted maximum likelihood method applied to single trait animal models. Estimates of heritability for most traits were small, except for ABW (0·33) and MW (0·35). Estimates of repeatability were slightly higher than those of heritability for TNB, NBA and NW, but they were almost identical for ABW, MW, GL and DFI. After 4 years of selection, the high growth line sows had significantly heavier body weight prior to mating and produced significantly more piglets born alive with heavier average birth weight than the low line sows. There were, however, no statistical differences between the selected lines in TNB or NW. The lower food intake of high relative to low line sows during lactation was not significant, indicating that daily food intake differences found between grower pigs in the high and low lines (2·71 v. 2·76 kg/day, s.e.d. 0·024) on ad libitum feeding were not fully expressed in lactating sows. It is concluded that selection for growth rate on the restricted ration resulted in beneficial effects on important measures of reproductive performance of thea sows.

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