Heat stress effects on farrowing rate in sows: Genetic parameter estimation using within-line and crossbred models1

Abstract The pork supply chain values steady and undisturbed piglet production. Fertilization and maintaining gestation in warm and hot climates is a challenge that can be potentially improved by selection. The objective of this study was to estimate 1) genetic variation for farrowing rate of sows in 2 dam lines and their reciprocal cross; 2) genetic variation for farrowing rate heat tolerance, which can be defined as the random regression slope of farrowing rate against increasing temperature at day of insemination, and the genetic correlation between farrowing rate and heat tolerance; 3) genetic correlation between farrowing rate in purebreds and crossbreds; and 4) genetic correlation between heat tolerance in purebreds and crossbreds. The estimates were based on 93,969 first insemination records per cycle from 24,456 sows inseminated between January 2003 and July 2008. These sows originated from a Dutch purebred Yorkshire dam line (D), an International purebred Large White dam line (ILW), and from their reciprocal crosses (RC) raised in Spain and Portugal. Within-line and crossbred models were used for variance component estimation. Heritability estimates for farrowing rate were 0.06, 0.07, and 0.02 using within-line models for D, ILW, and RC, respectively, and 0.07, 0.07, and 0.10 using the crossbred model, respectively. For farrowing rate, purebred-crossbred genetic correlations were 0.57 between D and RC and 0.50 between ILW and RC. When including heat tolerance in the within-line model, heritability estimates for farrowing rate were 0.05, 0.08, and 0.03 for D, ILW, and RC, respectively. Heritability for heat tolerance at 29.3°C was 0.04, 0.02, and 0.05 for D, ILW, and RC, respectively. Genetic correlations between farrowing rate and heat tolerance tended to be negative in crossbreds and ILW-line sows, implying selection for increased levels of production traits, such as growth and reproductive output, is likely to increase environmental sensitivity. This study shows that genetic selection for farrowing rate and heat tolerance is possible. However, when this selection is based solely on purebred information, the expected genetic progress on farrowing rate and heat tolerance in crossbreds (commercial animals) would be inconsequential.

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Realized Sampling Variances of Estimates of Genetic Parameters and the Difference Between Genetic and Phenotypic Correlations

Genetics ◽

10.1093/genetics/143.3.1409 ◽

1996 ◽

Vol 143 (3) ◽

pp. 1409-1416 ◽

Cited By ~ 1

Author(s):

Kenneth R Koots ◽

John P Gibson

Keyword(s):

Genetic Correlation ◽

Genetic Parameters ◽

Genetic Parameter ◽

Genetic Correlations ◽

Phenotypic Correlation ◽

Parameter Estimates ◽

Sampling Variance ◽

Phenotypic Correlations ◽

Genetic And Phenotypic Correlations ◽

Heritability Estimates

Abstract A data set of 1572 heritability estimates and 1015 pairs of genetic and phenotypic correlation estimates, constructed from a survey of published beef cattle genetic parameter estimates, provided a rare opportunity to study realized sampling variances of genetic parameter estimates. The distribution of both heritability estimates and genetic correlation estimates, when plotted against estimated accuracy, was consistent with random error variance being some three times the sampling variance predicted from standard formulae. This result was consistent with the observation that the variance of estimates of heritabilities and genetic correlations between populations were about four times the predicted sampling variance, suggesting few real differences in genetic parameters between populations. Except where there was a strong biological or statistical expectation of a difference, there was little evidence for differences between genetic and phenotypic correlations for most trait combinations or for differences in genetic correlations between populations. These results suggest that, even for controlled populations, estimating genetic parameters specific to a given population is less useful than commonly believed. A serendipitous discovery was that, in the standard formula for theoretical standard error of a genetic correlation estimate, the heritabilities refer to the estimated values and not, as seems generally assumed, the true population values.

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Genotype by environment interactions for performance and thermoregulation responses in growing pigs1,2

Journal of Animal Science ◽

10.1093/jas/skz245 ◽

2019 ◽

Vol 97 (9) ◽

pp. 3699-3713 ◽

Cited By ~ 1

Author(s):

Jean-Luc Gourdine ◽

Juliette Riquet ◽

Roseline Rosé ◽

Nausicaa Poullet ◽

Mario Giorgi ◽

...

Keyword(s):

Heat Tolerance ◽

Feed Intake ◽

Genetic Correlations ◽

Likelihood Method ◽

Production Traits ◽

Feed Conversion ◽

Backcross Population ◽

Pig Production ◽

Tropical Areas ◽

Heritability Estimates

Abstract Heat stress affects pig health, welfare, and production, and thus the economic viability of the pig sector in many countries. Breeding for heat tolerance is a complex issue, increasingly important due to climate change and the development of pig production in tropical areas. Characterizing genetic determinism of heat tolerance would help building selection schemes dedicated to high performance in tropical areas. The main objective of our study was to estimate the genetic parameters for production and thermoregulation traits in two highly related growing pig populations reared in temperate (TEMP) or tropical humid (TROP) environment. Pigs came from a backcross population between Large White (LW, heat sensitive) and Creole (CR, heat tolerant) pigs. Phenotypic data were obtained on a total of 1,297 pigs using the same procedures in both environments, for body weight (BW, at weeks 11 and 23), daily feed intake (ADFI), backfat thickness (BFT, at weeks 19 and 23), cutaneous temperature (CT, at weeks 19 and 23), and rectal temperature (RT, at weeks 19, 21, and 23). Feed conversion ratio (FCR) and residual feed intake (RFI) were computed for the whole test period (11 to 23 wk). Criteria comparing the fits to the data revealed genotype × environment (G × E) interactions for most traits but not for FCR. The variance components were obtained using two different methods, a restricted maximum likelihood method and a Bayesian Markov chain Monte Carlo method, considering that traits are either similar or different in each environment. Regardless of the method, heritability estimates for production traits were moderate to high, except for FCR (lower than 0.18). Heritability estimates for RT were low to moderate, ranging from 0.04 to 0.34. The genetic correlations of each trait between environments generally differed from 1, except for FCR and ADG. For most thermoregulation traits, they also did not differ significantly from zero, suggesting that the main genetic bases of heat tolerance may vary in different environment. Within environments, the unfavorable genetic correlations between production traits and RT suggest an antagonism between the ability to maintain inner temperature and the ability to increase ADFI and ADG. However, greater RT were also associated to leaner pigs and better feed efficiency. Nevertheless, due to large inaccuracies of these estimations, larger cohorts would be needed to decide about the best breeding schemes to choose for tropical pig production.

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Random regression models to estimate genetic parameters for test-day milk yield and composition in Iranian buffaloes

Archives Animal Breeding ◽

10.7482/0003-9438-56-027 ◽

2013 ◽

Vol 56 (1) ◽

pp. 276-284 ◽

Cited By ~ 1

Author(s):

M. Madad ◽

N. Ghavi Hossein-Zadeh ◽

A. A. Shadparvar ◽

D. Kianzad

Keyword(s):

Milk Yield ◽

Milk Fat ◽

Milk Protein ◽

Genetic Parameters ◽

Genetic Correlations ◽

Random Regression ◽

Production Traits ◽

Environmental Correlations ◽

Protein Percentage ◽

Heritability Estimates

Abstract. The objective of this study was to estimate genetic parameters for milk yield and milk percentages of fat and protein in Iranian buffaloes. A total of 9,278 test-day production records obtained from 1,501 first lactation buffaloes on 414 herds in Iran between 1993 and 2009 were used for the analysis. Genetic parameters for productive traits were estimated using random regression test-day models. Regression curves were modeled using Legendre polynomials (LPs). Heritability estimates were low to moderate for milk production traits and ranged from 0.09 to 0.33 for milk yield, 0.01 to 0.27 for milk protein percentage and 0.03 to 0.24 for milk fat percentage, respectively. Genetic correlations ranged from −0.24 to 1 for milk yield between different days in milk over the lactation. Genetic correlations of milk yield at different days in milk were often higher than permanent environmental correlations. Genetic correlations for milk protein percentage ranged from −0.89 to 1 between different days in milk. Also, genetic correlations for milk percentage of fat ranged from −0.60 to 1 between different days in milk. The highest estimates of genetic and permanent environmental correlations for milk traits were observed at adjacent test-days. Ignoring heritability estimates for milk yield and milk protein percentage in the first and final days of lactation, these estimates were higher in the 120 days of lactation. Test-day milk yield heritability estimates were moderate in the course of the lactation, suggesting that this trait could be applied as selection criteria in Iranian milking buffaloes.

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A genetic analysis of wool characteristics and lamb performance traits in Scottish Blackface sheep

Animal Science ◽

10.1017/s1357729800054308 ◽

2003 ◽

Vol 77 (3) ◽

pp. 355-362 ◽

Cited By ~ 1

Author(s):

J. Conington ◽

A. Murphy

Keyword(s):

Genetic Correlations ◽

Live Weight ◽

Scoring Systems ◽

Production Traits ◽

Genetic And Phenotypic Correlations ◽

Selection For ◽

Heritability Estimates ◽

Wool Quality ◽

Fleece Weight ◽

The Uk

AbstractGenetic parameters were estimated for wool quality, fleece characteristics and lamb production traits for Scottish Blackface sheep reared under extensive hill conditions in the UK. In two separate studies, heritabilities and genetic correlations were estimated for wool quality traits measured on lambs at 5 months of age and again on the shorn fleece a year later. The wool traits included birth coat length (BCT), 10-point scores for proportion of grey and kemp fibres present in the fleece (grey, kemp), British Wool Marketing Board (BWMB) recommendation (REC), greasy fleece weight (FLWT), BWMB fleece grade (FLGR), and average staple length (ASL). Genetic and phenotypic correlations were estimated between lamb wool traits and lamb live weights at birth (BWT), marking (at mid lactation with an average age of 7 weeks) (MWT), weaning (at an average age of 17 weeks) (WWT) and slaughter (SLWT), average fat depth (AVFD) and average muscle depth (MD). Individual lamb carcass measurements included Meat and Livestock Commission (MLC) conformation score (CONF) and fat class (FATC). Heritability estimates measured on 2524 or more live lambs were 0·69, 0·52, 0·26, 0·42 and 0·31 for BCT, ASL, grey, kemp and REC respectively. Heritability estimates for traits measured on the shorn fleece a year later for 1415 ewes were 0·37, 0·02, 0·57, 0·43, 0·46 and 0·14 for ASL, grey, kemp, REC, FLWT and FLGR respectively. Genetic correlations between FLWT in hoggets and other wool were positive and moderate to high in magnitude, ranging from 0·22 for kemp in lambs to 0·48 for grey in hoggets. Genetic correlations between REC and live-weight traits were 0·39 for MWT, 0·37 for WWT and 0·44 for SLWT. Genetic correlation between ASL and ultrasonic fat depth was 0·15 and for ASL and ultrasonic muscle depth was -0·30. The results indicate that the simple scoring systems derived to assess these traits are useful indicators of fleece quality, are highly repeatable over time and are a good gauge of likely future wool production. The results indicate that selection for heavier, leaner lambs should not compromise fleece quality, as assessed in this study.

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Genetic Parameters Estimation of Milking Traits in Polish Holstein-Friesians Based on Automatic Milking System Data

Animals ◽

10.3390/ani11071943 ◽

2021 ◽

Vol 11 (7) ◽

pp. 1943

Author(s):

Joanna Aerts ◽

Dariusz Piwczyński ◽

Heydar Ghiasi ◽

Beata Sitkowska ◽

Magdalena Kolenda ◽

...

Keyword(s):

Genetic Correlation ◽

Milk Yield ◽

Genetic Correlations ◽

Parameters Estimation ◽

Random Regression ◽

Effective Selection ◽

Milking Frequency ◽

Selection For ◽

Automatic Milking System ◽

Automatic Milking

The automatic milking system (AMS) provides a large amount of information characterizing the course of each milking cow, which is not available in the conventional system. The aim of our study was to estimate heritability and genetic correlations for milk yield (MY), milking frequency (MF), and speed (MS) for 1713 Polish Holstein-Friesian primiparous cows milked in barns with an AMS. Daily heritability indicators estimated using second-order Legendre polynomials and Random Regression Models showed high variation during lactation, ranging 0.131–0.345 for MY, 0.153–0.322 for MF, and 0.336–0.493 for MS. The rates of genetic correlation between traits ranged: 0.561–0.929 for MY-MF, (−0.255)−0.090 for MF-MS, (−0.174)−0.020 for MY-MS. It is possible to carry out effective selection for milking speed, which provides an opportunity to increase the number of cows per milking robot, and thus increase the profitability of production in the herd. The results proved that selection for milk yield and daily milking frequency is also feasible. The research showed a high, positive genetic correlation between milking frequency and milk yield, which allows us to conclude that preferring breeding cows with a natural tendency to frequent visits to the milking robot should indirectly improve the genetic basis of milking.

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Genetic variation and correlation of agronomic traits in meadow bromegrass (Bromus riparius Rehm) clones

Ciência Rural ◽

10.1590/s0103-84782004000200026 ◽

2004 ◽

Vol 34 (2) ◽

pp. 505-510 ◽

Cited By ~ 14

Author(s):

Marcelo Renato Alves de Araújo ◽

Bruce Coulman

Keyword(s):

Genetic Variation ◽

Crude Protein ◽

Genetic Correlations ◽

Neutral Detergent Fiber ◽

Broad Sense ◽

Grass Species ◽

Broad Sense Heritability ◽

Bromus Riparius ◽

Heritability Estimates ◽

Meadow Bromegrass

Meadow bromegrass (Bromus riparius Rehm.) is a recently introduced pasture grass in western Canada. Its leafy production and rapid regrowth have made it a major grass species for pasturing beef animals in this region. As relatively little breeding work has been done on this species, there is little information on its breeding behaviour. The main objective of this study was to estimate total genetic variability, broad-sense heritability, phenotypic and genetic correlations. Forty-four meadow bromegrass clones were evaluated for agronomic characters. Genetic variation for dry matter yield, seed yield, fertility index, harvest index, plant height, plant spread, crude protein, neutral detergent fiber and acid detergent fiber, was significant. Broad-sense heritability estimates exceeded 50% for all characters. Heritability estimates were at least 3.5 times greater than their standard errors. Phenotypic and genetic correlation between all possible characters were measured. There was general agreement in both sign and magnitude between genetic and phenotypic correlations. Correlations between the different characters demonstrated that it is possible to simultaneously improve seed and forage yield. Based on the results, it appears that the development of higher yielding cultivars with higher crude protein, and lower acid and neutral detergent fibers concentration should be possible.

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Genetic variation in net feed efficiency in Hereford cattle and its association with other production traits

Proceedings of the British Society of Animal Science ◽

10.1017/s1752756200002027 ◽

1999 ◽

Vol 1999 ◽

pp. 47-47

Author(s):

R.M. Herd ◽

S.C. Bishop

Keyword(s):

Growth Rate ◽

Genetic Variation ◽

Feed Intake ◽

Feed Efficiency ◽

Genetic Correlations ◽

Feed Consumption ◽

Production Traits ◽

Performance Measurements ◽

Hereford Cattle ◽

Rate Selection

Net feed efficiency refers to variation in feed consumption between animals net of requirements for maintenance and production, and may be measured as residual feed intake (RFI). Because RFI is independent of liveweight (LW) and growth rate, selection for improved net feed efficiency is likely to reduce feed intake with little change in growth. The purpose of this study was to establish whether there exists genetic variation in RFI in young British Hereford bulls, and to determine the phenotypic and genetic correlations of RFI with key production traits.The data consisted of performance measurements on 540 bull progeny of 154 British Hereford sires, collected over ten 200-day postweaning performance tests conducted between 1979 and 1988. The traits analysed were food intake (FI), 200 to 400-day daily gain (ADG), 400-day weight (W400), predicted carcass lean content (LEAN), lean growth rate (LGR), food conversion ratio (FI/ADG) and lean FCR (LFCR; FI/(ADG x LEAN), described by Bishop (1992).

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Genetic variation in fatty acid composition of subcutaneous fat in cattle

Animal Production Science ◽

10.1071/an12154 ◽

2013 ◽

Vol 53 (2) ◽

pp. 129 ◽

Cited By ~ 17

Author(s):

M. J. Kelly ◽

R. K. Tume ◽

S. Newman ◽

J. M. Thompson

Keyword(s):

Fatty Acids ◽

Genetic Variation ◽

Fatty Acid Composition ◽

Fatty Acid ◽

Acid Composition ◽

Saturated Fatty Acids ◽

Genetic Correlations ◽

Subcutaneous Fat ◽

Monounsaturated Fatty Acids ◽

Selection For

Genetic parameters were estimated for fatty acid composition of subcutaneous beef fat of 1573 animals which were the progeny of 157 sires across seven breeds grown out on pasture and then finished on either grain or grass in northern New South Wales or in central Queensland. There was genetic variation in individual fatty acids with estimates of heritability for the proportions of C14 : 0, C14 : 1c9, C16 : 0, C16 : 1c9, C18 : 0 and C18 : 1c9 fatty acids in subcutaneous beef fat of the order of 0.4 or above. Also substantial correlations between some fatty acids were observed. Genetic correlations between fatty acids and fat depth at the P8 site suggested that much of the genetic variation in fatty acid composition was related to changes in fatness. Selection for decreased fatness resulted in decreased proportions of C18 : 1c9 with concomitant increases in C18 : 0, C14 : 0 and C16 : 0. This suggested that selection for decreased fatness at a given weight will result in a decrease in the proportions of monounsaturated fatty acids in the subcutaneous fat in the carcass with a corresponding increase in the proportions of saturated fatty acids.

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An analysis of the variation in the lean tissue distribution of sheep

Animal Science ◽

10.1017/s0003356100010199 ◽

1982 ◽

Vol 34 (3) ◽

pp. 257-264 ◽

Cited By ~ 13

Author(s):

B. T. Wolf

Keyword(s):

Tissue Distribution ◽

Genetic Correlation ◽

Average Daily Gain ◽

Genetic Correlations ◽

Maximum Difference ◽

Lean Tissue ◽

Heritability Estimates ◽

The Relationship ◽

Daily Gain ◽

Sire Breed

ABSTRACTThe distribution of lean tissue between eight standard joints was examined in 956 crossbred lambs slaughtered at constant live weights of either 35 or 40 kg. The sire breeds used were the Dorset Down, Ile-de-France, Oldenburg, Oxford, Suffolk and Texel. Sire breed did not have a significant effect on the proportion of total carcass lean found in the higher-priced joints but did show significant differences in the proportion of total carcass lean found in individual joints, with a maximum difference of 7·7 g total lean per kg joint being recorded. Similarly, small but significant effects due to ewe age (1 to 3 years), rearing type (single, twin, triplet), sex (male castrate, female) and weight of total lean were reported for the proportion of total carcass lean found in different joints.Heritability estimates ranged from 0·07 (s.e. 008) to 0·65 (s.e. 0·16) for the proportion of total lean in the best-end neck and higher-priced joints respectively. Phenotypic standard deviations of 5·8g/kg and 17·9g/kg were reported for the proportion of total lean found in the best-end neck and the higher-priced joints respectively. The genetic correlations between the proportion of total lean in each of the higher-priced joints and the proportion of total lean in the higher-priced joints combined were positive. A genetic correlation of 017 (s.e. 0·20) was found for the relationship between average daily gain from birth to slaughter and the proportion of total lean in the higher-priced joints.

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Genetic parameters of production and reproduetive traits in on a farm tested Danish Large White and Landrace swine in Greece

Archives Animal Breeding ◽

10.5194/aab-43-287-2000 ◽

2000 ◽

Vol 43 (3) ◽

pp. 287-298

Author(s):

J. Bizelis ◽

A. Kominakis ◽

E. Rogdakis ◽

F. Georgadopoulou

Keyword(s):

Maximum Likelihood ◽

Genetic Correlation ◽

Genetic Parameters ◽

Genetic Correlations ◽

Production Traits ◽

Likelihood Methods ◽

Large White ◽

Reproduction Traits ◽

Maximum Likelihood Methods ◽

Genetic And Phenotypic Correlations

Abstract. Production and reproduetive traits in Danish Landrace (LD) and Large White (LW) swine were analysed by restricted maximum likelihood methods to obtain heritabilities as well as genetic and phenotypic correlations. Production traits were: age, backfat thickness (BT), muscle depth (MD) and the ratio BT/MD, adjusted to Standard bodyweight of 85 kg. Reproduction traits were: number of pigs born (NB) and number of pigs weaned (NW) per sow and parity. Heritabilities for age, BT, MD and BT/MD were 0.60, 0.44, 0.51 and 0.42 for LD and 0.36, 0.44, 0.37 and 0.45 for LW, respectively. Genetic correlations between age and BT were −0.22 in LD and – 0.44 in LW. The genetic correlation between age and MD was close to zero in both breeds. Genetic correlation between BT and MD were −0.36 and −0.25 in LD and LW, respectively. Heritabilities for NB were 0.25 in LD and 0.13 in LW while heritabilities for NW were close to zero in both breeds. Genetic correlation between NB and NW was 0.46 and 0.70 in LD and LW, respectively.

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