Institute for Pig Genetics IPG

Beuningen, Netherlands

Institute for Pig Genetics IPG

Beuningen, Netherlands
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Bergsma R.,Institute for Pig Genetics IPG | Bergsma R.,Wageningen University | Hermesch S.,University of New England of Australia
Journal of Animal Science | Year: 2012

The aims of this study were, first, to evaluate the effects of climatic variables on daily feed intake of lactating sows and, second, to establish whether the response of sows to variation in temperature on feed intake during lactation was heritable. A total of 82,614 records for daily feed intake during lactation were available for 848 sows with 3,369 litters farrowing from January 2000 to December 2007. Climatic parameters available from the nearest weather station were maximum 24 h outside temperature, day length changes, and humidity. Although ambient room temperature was modified at the animal level in the farrowing shed, these climatic variables still had a significant effect on feed intake during lactation. Regression coefficients temperature and humidity were 0.01385 ± 0.00300 (temperature) ± 0.00031 ± 0.00009 (temperature2) and 0.01443 ± 0.00620 (humidity) ± 0.00009 ± 0.00004 (humidity2). There was an interaction between temperature and humidity, partly due to the climate control in the farrowing shed. At low temperature, feed intake increased considerably with greater humidity, in contrast to a small reduction in feed intake with greater humidity at high temperature. Day length change was modeled with a cosine function. At the start of autumn (September 21), sows ate 0.36 ± 0.056 kg/d less feed than at the start of spring (March 21). Daily feed intake during lactation was described as a function of days in lactation and as a function of both days in lactation and temperature using random regression models. The average heritability and repeatability summarized over the day in lactation at the mean temperature were 0.21 and 0.69, respectively. Genetic variance of temperature response on feed intake was less than 20% of the day effect. The permanent environmental variance was 2-fold (day) and 4-fold (temperature) greater than the corresponding additive genetic variance. Heritabilities of daily feed intake were greater during the first week of lactation compared with the rest of lactation. The genetic correlation between days decreased as time increased down to about 0.2 between the first and last day in lactation. The genetic correlation between feed intake records at the extreme temperatures decreased to about -0.35. It was concluded that random regression models are useful for research and results may be used to develop simpler models that can be implemented in practical breeding programs. An effect of temperature on lactation feed intake was found even in this climatecontrolled environment located in a temperate climate zone. Larger effects are expected in more extreme climatic conditions with less temperature-controlled farrowing sheds. © 2012 American Society of Animal Science.


Young J.M.,Iowa State University | Bergsma R.,Institute for Pig Genetics IPG | Knol E.F.,Institute for Pig Genetics IPG | Patience J.F.,Iowa State University | Dekkers J.C.M.,Iowa State University
Journal of Animal Science | Year: 2016

As feed costs continue to rise and efficiency during finishing is emphasized, the impact of selecting for more efficient grow/finish pigs on reproductive performance and feed efficiency of sows must be evaluated. Therefore, the objectives of this study were to evaluate correlated responses for sow reproductive performance and lactation feed efficiency to selection for residual feed intake (RFI) during the grow/finish phase of production (RFIG/F) in 2 selection lines of pigs developed at Iowa State University (Ames, IA) and to estimate heritabilities of these traits. One line was selected over 7 generations for decreased RFIG/F (low RFI [LRFI] line) and the other line was randomly selected for 5 generations and then selected for increased RFIG/F (high RFI [HRFI] line). After 7 generations of selection, LRFI sows had 1.0 more piglets farrowed (P = 0.11) compared with HRFI sows, 1.3 more pigs born alive (P < 0.05), similar farrowing survival, 0.4 fewer mummies (P < 0.01), and more piglets weaned, both by litter (1.6 more; P < 0.01) and by sow (1.1 more; P < 0.01). Low RFI sows consumed 25 kg less feed and lost 9.8 kg more BW, 7.0 kg more fat mass, and 3.1 mm more backfat than HRFI sows (P < 0.001) during lactation. Although LRFI sows had a greater negative energy balance (−19.8 vs. −8.0 MJ ME/d; P < 0.001), they had better RFI during lactation (−28.6 vs. 8.2 kg; P < 0.0001), and the trend was for LRFI sows to have better lactation efficiency (61.3 vs. 57.8%; P = 0.47) than HRFI sows. Heritabilities for sow weights, sow body composition, sow maintenance requirements (estimated from BW), and piglet birth weight were high (h2 > 0.4, SE < 0.07). Traits pertaining to piglet growth during lactation and mobilization of body tissue of the sow were moderately heritable (0.2 < h2 < 0.4, SE < 0.07). In conclusion, selection for decreased RFIG/F has favorably affected piglet performance and lactation efficiency but has unfavorably affected sow body condition loss and energy balance during lactation. These results indicate that pigs selected for increased efficiency during grow–finish are better able to direct resources where needed during other life history phases, that is, reproduction and lactation. © 2016 American Society of Animal Science. All rights reserved.


Sell-Kubiak E.,Wageningen University | Knol E.F.,Institute for Pig Genetics IPG | Bijma P.,Wageningen University
Journal of Animal Science | Year: 2012

The sow provides a specific environment to her offspring during gestation and lactation. Certain features in the early life of the sow (sow history features) may affect her ability to deliver and feed a healthy litter. In genetic analyses of grow-finish traits, these effects are estimated as common litter or permanent sow effects. The objective of this research was to identify sow history features that affect the growth rate (GR) and feed intake (FI) of her offspring during the grow-finish stage. Data from 17,743 grow-finish pigs, coming from 604 sires and 681 crossbred sows, were recorded between May 2001 and February 2010 at the experimental farm of the Institute for Pig Genetics (Beilen, the Netherlands). The grow-finish stage was divided into 2 phases (phase 1: 26 to 75 kg; phase 2: 75 to 115 kg). The sow history features were birth litter size, birth year and season, birth farm, weaning age, age of transfer to the experimental farm, and age at first insemination. The sow features were added to the basic model one at a time to study their effect on the grow-finish traits of the pigs. Subsequently, significant sow features (P < 0.1) were fitted simultaneously in an animal model. With every extra piglet in the birth litter of the sow, the GR of her offspring decreased by 1 g/d and the FI decreased by 4 g/d. Every extra day to the first insemination increased the GR of grow-finish pigs by 0.1 g/d. The heritability estimates for GR and FI (only in phase 2 of the grow-finish stage) decreased after adding the sow features to the model. No differences were found in estimates of the common litter effects between the basic model and the model with all significant sow features. The estimates of the permanent sow effect changed for FI from 0.03 (basic model) to 0.00 (model with sow features), and for FI in phase 1, the permanent sow effect decreased from 0.03 (basic model) to 0.01 (model with sow features). In conclusion, selected sow features do affect the grow-finish traits of the pigs, but their estimates are small and explain only a small proportion of the differences in the GR and FI of grow-finish pigs. The sow features partially explained the permanent sow effect of FI-related traits and did not explain the common litter effect. Although the sow early life features can affect piglet traits, they do not predict which sows produce better performing offspring in the grow-finish stage. © 2012 American Society of Animal Science.


Duijvesteijn N.,Institute for Pig Genetics IPG | Duijvesteijn N.,Wageningen University | Knol E.F.,Institute for Pig Genetics IPG | Bijma P.,Institute for Pig Genetics IPG
Journal of Animal Science | Year: 2012

In the pig industry, male piglets are surgically castrated early in life to prevent boar taint. Boar taint is mainly caused by androstenone and skatole. Androstenone is a pheromone that can be released from the salivary glands when the boar is sexually aroused. Boars are housed in groups and as a consequence boars can influence and be influenced by the phenotype of other boars by (non-)heritable social interactions. The influence of these social interactions on androstenone is not well understood. The objective of this study is to investigate whether androstenone concentrations are affected by (non-)heritable social interactions and estimate their genetic correlation with growth rate and backfat. The dataset contained 6,245 boars, of which 4,455 had androstenone observations (68%). The average number of animals per pen was 7 and boars were housed in 899 unique pen-groups (boars within a single pen) and 344 unique compartment- groups (boars within a unique 'room' within a barn during time). Four models including different random effects, were compared for androstenone. Direct genetic, associative (also known as social genetic or indirect genetic effects), group, compartment, common environment and residual effects were included as random effects in the full model (M3). Including random pen and compartment effects (non-heritable social effects) significantly improved the model (M2) compared with including only direct, common environment and residual as random effects (M1, P < 0.001), and including associative effects even more (M3, P < 0.001). The sum of the direct and associative variance components determines the total genetic variance of the trait. The associative effect explained 11.7% of the total genetic variance. Backfat thickness was analysed using M2 and growth using M3. The genetic correlation between backfat (direct genetic variance) and total genetic variance for androstenone was close to 0. Backfat and the direct and associative effects for androstenone had genetic correlations of 0.14 ± 0.08 and -0.25 ± 0.18, respectively. The genetic correlation between total genetic variances for growth rate and androstenone was 0.33 ± 0.18. The genetic correlation between direct effects was 0.11 ± 0.09 and between associative effects was 0.42 ± 0.31. The genetic correlations and current selection towards lower backfat and greater growth rate suggest that no major change in androstenone is expected when breeding goals are not changed. For selection against boar taint and therefore also against androstenone, results recommend that at least the social environment of the boars should be considered. © 2012American Society of Animal Science. All rights reserved.


Hoving L.L.,Wageningen University | Soede N.M.,Wageningen University | Graat E.A.M.,Wageningen University | Feitsma H.,Institute for Pig Genetics IPG | Kemp B.,Wageningen University
Animal Reproduction Science | Year: 2010

An impaired reproductive performance in second parity compared to first parity sows, decreases reproductive efficiency and, perhaps, longevity of sows. This study aims to quantify the effect of live weight development and reproduction in first parity on reproductive performance of second parity sows, i.e. pregnancy rate as well as litter size. Measures of sow development (live weight at first insemination, farrowing and weaning) and reproduction (total number of piglets born, weaning to insemination interval, lactation period, number piglets weaned) were recorded on two experimental farms. Logistic regression analysis was done for the binary outcome 'non-pregnancy from first insemination after first weaning' (yes/no). General linear regression analysis was used for litter size from 1st insemination in second parity. Repeat breeders were omitted from the analysis on litter size in second parity, since a prolonged period between weaning and conception can positively influence litter size. Farms differed significantly in measures of sow live weight development and therefore data were analyzed per farm. Compared with gilts from farm A, gilts from farm B were older and heavier at: first insemination (275 ± 0.9 days and 145 ± 0.8. kg for farm B vs. 230 ± 0.6 days and 124 ± 0.5. kg for farm A), first farrowing (resp. 189 ± 1.1 vs. 181 ± 0.9. kg) and first weaning (resp. 165 ± 1.1 vs. 156 ± 0.9. kg). Weight loss during pregnancy was similar for both farms (resp. 24.9 ± 0.7 and 23.7 ± 1.0. kg). Gilts from farm A, however, gained more weight in the period between first insemination and first weaning compared with gilts from farm B (resp. 36.1 ± 0.8 and 20.9 ± 1.3. kg). Non-pregnancy in second parity was 11% for farm A and 15% for farm B. Litter sizes in first and second parity were, respectively, 10.7 ± 0.1 and 11.6 ± 0.2 for farm A and 11.8 ± 0.1 and 11.6 ± 0.1 for farm B. Variables associated with non-pregnancy and litter size in second parity differed between farms. On farm A, mainly sow live weight development was associated with non-pregnancy and litter size in second parity, whilst on farm B variables like total number born in 1st parity and sow line, were associated with non-pregnancy and litter size in second parity. On both farms, higher weight gain from first insemination to first weaning was associated with a decrease in non-pregnancy (odds ratio 0.7 per 10. kg for farm A and 0.8 per 10. kg for farm B) and on farm A with higher litter size in second parity (β=0.42 per 10. kg weight gain). Results show that sow live weight development affects reproductive performance in second parity, especially on farm A where gilts are relatively light or young at first insemination. Management of these animals should aim to optimize development at first insemination and to increase growth between first insemination and first weaning in order to optimize production in second parity. © 2010 Elsevier B.V.


PubMed | Institute for Pig Genetics IPG
Type: Journal Article | Journal: Journal of animal science | Year: 2012

The aims of this study were, first, to evaluate the effects of climatic variables on daily feed intake of lactating sows and, second, to establish whether the response of sows to variation in temperature on feed intake during lactation was heritable. A total of 82,614 records for daily feed intake during lactation were available for 848 sows with 3,369 litters farrowing from January 2000 to December 2007. Climatic parameters available from the nearest weather station were maximum 24 h outside temperature, day length changes, and humidity. Although ambient room temperature was modified at the animal level in the farrowing shed, these climatic variables still had a significant effect on feed intake during lactation. Regression coefficients temperature and humidity were 0.01385 0.00300 (temperature) - 0.00031 0.00009 (temperature(2)) and 0.01443 0.00620 (humidity) - 0.00009 0.00004 (humidity(2)). There was an interaction between temperature and humidity, partly due to the climate control in the farrowing shed. At low temperature, feed intake increased considerably with greater humidity, in contrast to a small reduction in feed intake with greater humidity at high temperature. Day length change was modeled with a cosine function. At the start of autumn (September 21), sows ate 0.36 0.056 kg/d less feed than at the start of spring (March 21). Daily feed intake during lactation was described as a function of days in lactation and as a function of both days in lactation and temperature using random regression models. The average heritability and repeatability summarized over the day in lactation at the mean temperature were 0.21 and 0.69, respectively. Genetic variance of temperature response on feed intake was less than 20% of the day effect. The permanent environmental variance was 2-fold (day) and 4-fold (temperature) greater than the corresponding additive genetic variance. Heritabilities of daily feed intake were greater during the first week of lactation compared with the rest of lactation. The genetic correlation between days decreased as time increased down to about 0.2 between the first and last day in lactation. The genetic correlation between feed intake records at the extreme temperatures decreased to about -0.35. It was concluded that random regression models are useful for research and results may be used to develop simpler models that can be implemented in practical breeding programs. An effect of temperature on lactation feed intake was found even in this climate-controlled environment located in a temperate climate zone. Larger effects are expected in more extreme climatic conditions with less temperature-controlled farrowing sheds.


PubMed | Institute for Pig Genetics IPG
Type: Journal Article | Journal: Journal of animal science | Year: 2012

In the pig industry, male piglets are surgically castrated early in life to prevent boar taint. Boar taint is mainly caused by androstenone and skatole. Androstenone is a pheromone that can be released from the salivary glands when the boar is sexually aroused. Boars are housed in groups and as a consequence boars can influence and be influenced by the phenotype of other boars by (non-)heritable social interactions. The influence of these social interactions on androstenone is not well understood. The objective of this study is to investigate whether androstenone concentrations are affected by (non-)heritable social interactions and estimate their genetic correlation with growth rate and backfat. The dataset contained 6,245 boars, of which 4,455 had androstenone observations (68%). The average number of animals per pen was 7 and boars were housed in 899 unique pen-groups (boars within a single pen) and 344 unique compartment-groups (boars within a unique room within a barn during time). Four models including different random effects, were compared for androstenone. Direct genetic, associative (also known as social genetic or indirect genetic effects), group, compartment, common environment and residual effects were included as random effects in the full model (M3). Including random pen and compartment effects (non-heritable social effects) significantly improved the model (M2) compared with including only direct, common environment and residual as random effects (M1, P < 0.001), and including associative effects even more (M3, P < 0.001). The sum of the direct and associative variance components determines the total genetic variance of the trait. The associative effect explained 11.7% of the total genetic variance. Backfat thickness was analysed using M2 and growth using M3. The genetic correlation between backfat (direct genetic variance) and total genetic variance for androstenone was close to 0. Backfat and the direct and associative effects for androstenone had genetic correlations of 0.14 0.08 and -0.25 0.18, respectively. The genetic correlation between total genetic variances for growth rate and androstenone was 0.33 0.18. The genetic correlation between direct effects was 0.11 0.09 and between associative effects was 0.42 0.31. The genetic correlations and current selection towards lower backfat and greater growth rate suggest that no major change in androstenone is expected when breeding goals are not changed. For selection against boar taint and therefore also against androstenone , results recommend that at least the social environment of the boars should be considered.

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