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See detailGenetic parameters for methane indicator traits based on milk fatty acids in Dual Purpose Belgian Blue cattle
Kandel, Purna Bhadra ULg; Gengler, Nicolas ULg; Soyeurt, Hélène ULg

Poster (2012, June 18)

Dairy production is pointed out for its large methane emission. Therefore, specific nutritional strategies are applying to abate methane emission but very less information is available about the animal ... [more ▼]

Dairy production is pointed out for its large methane emission. Therefore, specific nutritional strategies are applying to abate methane emission but very less information is available about the animal genetic variability of methane emission. Methane indicators using traits indirectly related to methane and easily recorded like the mid-infrared (MIR) prediction of fatty acid could be used to conduct genetic studies. MIR methane indicators used in this study were derived from published fatty acid based methane indicators using 597 calibration samples. Genetic parameters of these MIR indicators were estimated by single trait random regression test-day models from 13,389 records collected on 1602 Dual Purpose Belgium Blue cows in their first 3 lactations. For the published indicator showing the highest relationship (R2 =0.88) with Sulphur hexafluoride (SF6) methane emission data, the average daily heritability was 0.25±0.06, 0.25±0.07 and 0.18±0.09 for the first three lactations, respectively. Similarly, the lactation heritability was 0.45±0.09, 0.46±0.11 and 0.24±0.14. The sire genetic variability was 3.60, 4.08, 1.19 kg2 of methane for the first three lactation, respectively. The genetic difference between the sires having cows eructing the highest and the lowest methane content was 11.62, 13.01 and 5.98 kg per lactation for the first three parities. This study suggested that methane indicator traits can be predicted by MIR and the genetic variability of these traits seems to exist. Therefore, it also suggests the genetic variability of methane content eructed by dairy cows. These first finding might open new opportunities for animal selection program on methane emission. [less ▲]

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See detailGenetic parameters for mid-infrared methane indicators based on milk fatty acids in dairy cows
Kandel, Purna Bhadra ULg; Gengler, Nicolas ULg; Soyeurt, Hélène ULg

in Journal of Applied Animal Research (in press)

Dairy production is identified as a major source of methane (CH4) emissions. Selective breeding canbe one method used to mitigate CH4 emissions but practical and cheap measurement of this trait is not ... [more ▼]

Dairy production is identified as a major source of methane (CH4) emissions. Selective breeding canbe one method used to mitigate CH4 emissions but practical and cheap measurement of this trait is not currently available. The mid-infrared (MIR) prediction of milk fatty acids is relevant in this context. Five MIR methane indicators were derived from the literature and were calibrated from 600 samples analyzed by gas chromatography. Genetic parameters for these traits were estimated using single trait random regression test-day models from 619,265 records collected from 2007 to 2011 on 71,188 Holstein cows in their first three lactations. For the published indicator showing the highest relationship with the methane data (R2 = 0.88), the average daily heritability was 0.34±0.01, 0.37±0.01 and 0.34±0.01 for the first three lactations, respectively. The methane emission (g/day) was increased from beginning of lactation, reached at the highest in peak of lactation and decreased towards end of lactation. The largest differences between estimated breeding values (EBV) of sires having daughters in production eructing the highest and the lowest methane content was 21.80, 22.75 and 24.89 kg per lactation for the first three parities. Positive genetic correlations were estimated between indicator traits and milk fat and protein content. Low negative correlation was observed with milk yield. In conclusion, this study shows the feasibility to predict methane indicator traits by MIR. Moreover, the estimated genetic parameters suggest also a potential genetic variability of the quantity of methane eructed by dairy cows. [less ▲]

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See detailGenetic parameters for Tunisian Holsteins using a test-day random regression model.
Hammami, Hedi ULg; Rekik, Boulbaba; Soyeurt, Hélène ULg et al

in Journal of Dairy Science (2008), 91(5), 2118-26

Genetic parameters of milk, fat, and protein yields were estimated in the first 3 lactations for registered Tunisian Holsteins. Data included 140,187; 97,404; and 62,221 test-day production records ... [more ▼]

Genetic parameters of milk, fat, and protein yields were estimated in the first 3 lactations for registered Tunisian Holsteins. Data included 140,187; 97,404; and 62,221 test-day production records collected on 22,538; 15,257; and 9,722 first-, second-, and third-parity cows, respectively. Records were of cows calving from 1992 to 2004 in 96 herds. (Co)variance components were estimated by Bayesian methods and a 3-trait-3-lactation random regression model. Gibbs sampling was used to obtain posterior distributions. The model included herd x test date, age x season of calving x stage of lactation [classes of 25 days in milk (DIM)], production sector x stage of lactation (classes of 5 DIM) as fixed effects, and random regression coefficients for additive genetic, permanent environmental, and herd-year of calving effects, which were defined as modified constant, linear, and quadratic Legendre coefficients. Heritability estimates for 305-d milk, fat and protein yields were moderate (0.12 to 0.18) and in the same range of parameters estimated in management systems with low to medium production levels. Heritabilities of test-day milk and protein yields for selected DIM were higher in the middle than at the beginning or the end of lactation. Inversely, heritabilities of fat yield were high at the peripheries of lactation. Genetic correlations among 305-d yield traits ranged from 0.50 to 0.86. The largest genetic correlation was observed between the first and second lactation, potentially due to the limited expression of genetic potential of superior cows in later lactations. Results suggested a lack of adaptation under the local management and climatic conditions. Results should be useful to implement a BLUP evaluation for the Tunisian cow population; however, results also indicated that further research focused on data quality might be needed. [less ▲]

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See detailGenetic Parameters of Butter Hardness Estimated by Test-Day Model
Soyeurt, Hélène ULg; Dehareng, Frédéric; Bertozzi, Carlo et al

in Interbull Bulletin (2007), 37

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See detailGenetic parameters of mastitis-correlated milk components in first parity dairy cows
Gillon, Alain ULg; Bastin, Catherine ULg; Soyeurt, Hélène ULg et al

Conference (2010, August 06)

Ind. of lactoferrin content, ind. of Na content, and lactose content were the three most correlated milk components with somatic cell score among available milk components predicted by mid-infrared ... [more ▼]

Ind. of lactoferrin content, ind. of Na content, and lactose content were the three most correlated milk components with somatic cell score among available milk components predicted by mid-infrared spectrometry on 590,083 test-day records from Walloon Region of Belgium collected between 2007 and 2009. Mean daily heritabilities and mean genetic correlations of these four traits were estimated using Gibbs sampling methodology applied to a multi-trait random regression test-day model with a subset of these records. Mean daily heritabilities of ind. lactoferrin content (0.34), ind. Na content (0.37) and lactose content (0.42) were higher then SCS (0.16) and mean genetic correlations were moderate (from -0.18 to -0.73), showing that these traits could be used together to describe udder health in genetic evaluations instead of SCS alone when clinical mastitis data are not available. [less ▲]

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See detailGenetic parameters of mastitis-correlated milk components in first parity dairy cows
Gillon, Alain ULg; Bastin, Catherine ULg; Soyeurt, Hélène ULg et al

in Proceedings of the 9th World Congress on Genetics Applied to Livestock Production (2010, August)

Ind. of lactoferrin content, ind. of Na content, and lactose content were the three most correlated milk components with somatic cell score among available milk components predicted by mid-infrared ... [more ▼]

Ind. of lactoferrin content, ind. of Na content, and lactose content were the three most correlated milk components with somatic cell score among available milk components predicted by mid-infrared spectrometry on 590,083 test-day records from Walloon Region of Belgium collected between 2007 and 2009. Mean daily heritabilities and mean genetic correlations of these four traits were estimated using Gibbs sampling methodology applied to a multi-trait random regression test-day model with a subset of these records. Mean daily heritabilities of ind. lactoferrin content (0.34), ind. Na content (0.37) and lactose content (0.42) were higher then SCS (0.16) and mean genetic correlations were moderate (from -0.18 to -0.73), showing that these traits could be used together to describe udder health in genetic evaluations instead of SCS alone when clinical mastitis data are not available. [less ▲]

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See detailGenetic parameters of milk production traits and fatty acid contents in milk for Holstein cows in parity 1 – 3
Bastin, Catherine ULg; Soyeurt, Hélène ULg; Gengler, Nicolas ULg

in Journal of Animal Breeding & Genetics (2013), 130(2),

The objective of this study was to estimate genetic parameters of milk, fat, and protein yields, fat and protein contents, somatic cell count, and 17 groups and individual milk fatty acid (FA) contents ... [more ▼]

The objective of this study was to estimate genetic parameters of milk, fat, and protein yields, fat and protein contents, somatic cell count, and 17 groups and individual milk fatty acid (FA) contents predicted by mid-infrared spectrometry for first-, second- and third-parity Holstein cows. Edited data included records collected in the Walloon region of Belgium from 37 768 cows in parity 1, 22 566 cows in parity 2 and 8221 in parity 3. A total of 69 (23 traits for three parities) single-trait random regression animal test-day models were run. Approximate genetic correlations among traits were inferred from pairwise regressions among estimated breeding values of cow having observations. Heritability and genetic correlation estimates from this study reflected the origins of FA: de novo synthetized or originating from the diet and the body fat mobilization. Averaged daily heritabilities of FA contents in milk ranged between 0.18 and 0.47. Average daily genetic correlations (averaged across days in milk and parities) among groups and individual FA contents in milk ranged between 0.31 and 0.99. The genetic variability of FAs in combination with the moderate to high heritabilities indicated that FA contents in milk could be changed by genetic selection; however, desirable direction of change in these traits remains unclear and should be defined with respect to all issues of importance related to milk FA. [less ▲]

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See detailGenetic parameters of racing performance traits of Arabian horses in Algeria
Tennah, Safia ULg; Kafidi, Nacereddine; Antoine-Moussiaux, Nicolas ULg et al

Poster (2013, October 11)

The data used in the present study were recorded at the Algerian Horse Racing Society for 36492 racing performance of 913 Arabian horses from 1995 to 2007. The aim of the study was to identify the genetic ... [more ▼]

The data used in the present study were recorded at the Algerian Horse Racing Society for 36492 racing performance of 913 Arabian horses from 1995 to 2007. The aim of the study was to identify the genetic parameters underlying three traits: two earnings traits, namely the logarithm of average annual virtual earnings (LAEV) and the logarithm of average annual virtual earnings per start (LAEV/S), and a ranking trait, the normalized ranking (PERF). To identify the fixed effects to be included in the genetic mixed model, a preliminary analysis was conducted using the General Linear Models (GLM) procedure from SAS software. The effects of age, sex, year and the interaction between year of the race and age and between sex and age were included in the model for the three traits. Afterwards, two random effects, a direct genetic effect of the animal and a permanent environmental effect were included in the mixed model. The variance components and genetic parameters were estimated using the restricted maximum likelihood (REML) procedure with the MTDFREML program. The analyses with this repeatable animal model led to the following estimation of the genetic parameters: for LAEV, heritability was 0.225 (±0.041), while estimate of repeatability was 0.330 (±0.040). For LAEV/S, heritability was 0.164 (±0.027), while estimate of repeatability was 0.215 (±0.022). The heritability for the normalized ranking was higher, 0.369 (±0.054), indicating that this trait might provide faster progress for breeding programs of Arabian horses in Algeria. The repeatability estimate for the normalized ranking was 0.587 (±0.045). The genetic correlation between LAEV and LAEV/S was 0.99, revealing a almost complete genetic dependence between these two traits, 0.69 between PERF and LAEV and 0.79 between PERF and LAEV/S. [less ▲]

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See detailGenetic parameters of saturated and monounsaturated fatty acid content and the ratio of saturated to unsaturated fatty acids in bovine milk.
Soyeurt, Hélène ULg; Dardenne, Pierre; Dehareng, Frédéric et al

in Journal of Dairy Science (2008), 91(9), 3611-26

Fatty acid composition influences the nutritional quality of milk and the technological properties of butter. Using a prediction of fatty acid (FA) contents by mid-infrared (MIR) spectrometry, a large ... [more ▼]

Fatty acid composition influences the nutritional quality of milk and the technological properties of butter. Using a prediction of fatty acid (FA) contents by mid-infrared (MIR) spectrometry, a large amount of data concerning the FA profile in bovine milk was collected. The large number of records permitted consideration of more complex models than those used in previous studies. The aim of the current study was to estimate the effects of season and stage of lactation as well as genetic parameters of saturated (SAT) and monounsaturated (MONO) fatty acid contents in bovine milk and milk fat, and the ratio of SAT to unsaturated fatty acids (UNSAT) that reflect the hardness of butter (SAT:UNSAT), using 7 multiple-trait, random-regression test-day models. The relationship between these FA traits with common production traits was also studied. The data set contained 100,841 test-day records of 11,626 Holstein primiparous cows. The seasonal effect was studied based on unadjusted means. These results confirmed that milk fat produced during spring and summer had greater UNSAT content compared with winter (63.13 vs. 68.94% of SAT in fat, on average). The effect of stage of lactation on FA profile was studied using the same methodology. Holstein cows in early first lactation produced a lower content of SAT in their milk fat. Variance components were estimated using a Bayesian method via Gibbs sampling. Heritability of SAT in milk (0.42) was greater than heritability of SAT in milk fat (0.24). Estimates of heritability for MONO were also different in milk and fat (0.14 vs. 0.27). Heritability of SAT:UNSAT was moderate (0.27). For all of these traits, the heritability estimates and the genetic and phenotypic correlations varied through the lactation. [less ▲]

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See detailGenetic parameters of saturated and monounsaturated fatty acids estimated by test-day model in Walloon dairy cattle
Soyeurt, Hélène ULg; Bastin, Catherine ULg; Dardenne, Pierre et al

in Journal of Dairy Science (2008, July 07)

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See detailGenetic parameters of stearoyl coenzyme-A desaturase 9 activity estimated by test-day model
Arnould, Valérie ULg; Gengler, Nicolas ULg; Soyeurt, Hélène ULg

Conference (2008, July)

Dairy and beef products account for a large part of fat intake in human nutrition and therefore can be linked to dietary diseases. The stearoyl Coenzyme-A desaturase 9 (delta-9) gene was identified as a ... [more ▼]

Dairy and beef products account for a large part of fat intake in human nutrition and therefore can be linked to dietary diseases. The stearoyl Coenzyme-A desaturase 9 (delta-9) gene was identified as a potential functional candidate gene affecting milk fat composition in dairy cattle. The objective of this research was to estimate the genetic parameters of delta-9 activity indicator traits and to study the relationship between delta-9 activity as described by these indicator traits and common milk production traits. A total of 126,331 test-day records were obtained from 14,259 Holstein (> 84% Holstein gene) heifers belonging to 105 herds. The studied traits were milk yield, percentages of fat and protein, content of monounsaturated fatty acids, and 3 ratios reflecting the delta-9 activity (C14:1/ C14:0; C16:1/C16:0 and C18:1/C18). The used model was a multiple-trait random regressions test-day model and included as fixed effects: herd x date of test, class of age, and month x year. Random effects were herd x year of calving, permanent environmental, additive genetic, and residual effects. The fatty acid contents were estimated by mid-infrared spectrometry. Delta-9 activity varied within year and lactation. The obtained heritability estimates of delta-9 as well as the genetic and phenotypic correlation varied also through lactation. This study suggests potential improvements of delta-9 activity and subsequently milk fat composition can be achieved by animal management but also by breeding and animal selection. [less ▲]

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See detailGenetic parameters of stearoyl coenzyme-A desaturase 9 activity estimated by test-day model
Arnould, Valérie ULg; Gengler, Nicolas ULg; Soyeurt, Hélène ULg

in Journal of Dairy Science (2008, July), 91(E-Suppl. 2), 542

Dairy and beef products account for a large part of fat intake in human nutrition and therefore can be linked to dietary diseases. The stearoyl Coenzyme-A desaturase 9 (delta-9) gene was identified as a ... [more ▼]

Dairy and beef products account for a large part of fat intake in human nutrition and therefore can be linked to dietary diseases. The stearoyl Coenzyme-A desaturase 9 (delta-9) gene was identified as a potential functional candidate gene affecting milk fat composition in dairy cattle. The objective of this research was to estimate the genetic parameters of delta-9 activity indicator traits and to study the relationship between delta-9 activity as described by these indicator traits and common milk production traits. A total of 126,331 test-day records were obtained from 14,259 Holstein (> 84% Holstein gene) heifers belonging to 105 herds. The studied traits were milk yield, percentages of fat and protein, content of monounsaturated fatty acids, and 3 ratios reflecting the delta-9 activity (C14:1/ C14:0; C16:1/C16:0 and C18:1/C18). The used model was a multiple-trait random regressions test-day model and included as fixed effects: herd x date of test, class of age, and month x year. Random effects were herd x year of calving, permanent environmental, additive genetic, and residual effects. The fatty acid contents were estimated by mid-infrared spectrometry. Delta-9 activity varied within year and lactation. The obtained heritability estimates of delta-9 as well as the genetic and phenotypic correlation varied also through lactation. This study suggests potential improvements of delta-9 activity and subsequently milk fat composition can be achieved by animal management but also by breeding and animal selection. [less ▲]

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See detailGenetic parameters of the major fatty acid (FA) contents in cow milk
Soyeurt, Hélène ULg; Gillon, Alain ULg; Vanderick, Sylvie ULg et al

in Book of Abstracts of the 58th Annual Meeting of the European Association for Animal Production (2007)

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See detailGenetic pattern of the recent recovery of European otters in southern France
Janssens, Xavier; Fontaine, Michael C; Michaux, Johan ULg et al

in Ecography (2008), 31(2), 176-186

We investigated how landscape affects the population genetic structure and the dispersal of the elusive European otter Lutra lutra in a contemporary colonization context, over several generations and at ... [more ▼]

We investigated how landscape affects the population genetic structure and the dispersal of the elusive European otter Lutra lutra in a contemporary colonization context, over several generations and at the level of hydrographic basins. Our study area included 10 basins located in the Cevennes National Park (CNP), at the southern front of the natural otter recovery in France. Each basin comprised 50 to 300 km of permanent rivers that were surveyed for otter presence from 1991 to 2005. Faecal samples collected in 2004 and 2005 in this area were genotyped at 9 microsatellite loci, resulting in the identification of 70 genetically distinct individuals. Bayesian clustering methods were used to infer genetic structure of the populations and to compare recent gene flow to the observed colonization. At the regional level, we identified 2 distinct genetic clusters (NE and SW; FST=0.102) partially separated by ridges, suggesting that the CNP was recolonized by 2 genetically distinct otter populations. At the basin level, the genetic distance between groups of individuals in different basins was positively correlated to the mean slope separating these basins. The probable origins and directions of individual movements (i.e. migration between clusters and basin colonization inside clusters) were inferred from assignment tests. This approach shows that steep and dry lands can stop, impede or divert the dispersal of a mobile carnivore such as the otter. [less ▲]

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See detailGenetic polymorphism in ethanol metabolism: acetaldehyde contribution to alcohol abuse and alcoholism
Quertemont, Etienne ULg

in Molecular Psychiatry (2004), 9(6), 570-581

Acetaldehyde, the first product of ethanol metabolism, has been speculated to be involved in many pharmacological and behavioral effects of ethanol. In particular, acetaldehyde has been suggested to ... [more ▼]

Acetaldehyde, the first product of ethanol metabolism, has been speculated to be involved in many pharmacological and behavioral effects of ethanol. In particular, acetaldehyde has been suggested to contribute to alcohol abuse and alcoholism. In the present paper, we review current data on the role of acetaldehyde and ethanol metabolism in alcohol consumption and abuse. Ethanol metabolism involves several enzymes. Whereas alcohol dehydrogenase metabolizes the bulk of ethanol within the liver, other enzymes, such as cytochrome P4502E1 and catalase, also contributes to the production of acetaldehyde from ethanol oxidation. In turn, acetaldehyde is metabolized by the enzyme aldehyde dehydrogenase. In animal studies, acetaldehyde is mainly reinforcing particularly when injected directly into the brain. In humans, genetic polymorphisms of the enzymes alcohol dehydrogenase and aldehyde dehydrogenase are also associated with alcohol drinking habits and the incidence of alcohol abuse. From these human genetic studies, it has been concluded that blood acetaldehyde accumulation induces unpleasant effects that prevent further alcohol drinking. It is therefore speculated that acetaldehyde exerts opposite hedonic effects depending on the localization of its accumulation. In the periphery, acetaldehyde is primarily aversive, whereas brain acetaldehyde is mainly reinforcing. However, the peripheral effects of acetaldehyde might also be dependent upon its peak blood concentrations and its rate of accumulation, with a narrow range of blood acetaldehyde concentrations being reinforcing. [less ▲]

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See detailGenetic polymorphism of transforming growth factor-β1 and microvascular complications in type 1 diabetes
Weekers, Laurent ULg; Hadjadj, Samy; Bouhanick, Béatrice et al

in Diabetologia (2000), 43(1), 137

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See detailGenetic polymorphism of transforming growth factor-β1 and microvascular complications in type 1 diabetes
Weekers, Laurent ULg; Hadjadj, S.; Bouhanick, B. et al

Conference (2000)

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See detailGenetic predictors of asthma exacerbations among children in the childhood asthma management program
Celedon, J. C.; Van Steen, Kristel ULg; Lange, C. et al

in Conference Abstract Book (2005)

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See detailGenetic regulation of hepatic steroid 16 alpha-hydroxylase activities in inbred strains of mice.
Pasleau, Françoise ULg; Kolodzici, Claudine; Kremers, Pierre ULg et al

in Endocrinology (1984), 115

Steroid 16 alpha-hydroxylase activities and properties were studied in C57Bl/6J, 129/J, AKR/R, DBA/2J, C3H/I, and BALB/c mouse liver using four different substrates. The highest enzymatic activities were ... [more ▼]

Steroid 16 alpha-hydroxylase activities and properties were studied in C57Bl/6J, 129/J, AKR/R, DBA/2J, C3H/I, and BALB/c mouse liver using four different substrates. The highest enzymatic activities were measured in the female mice, with the exception of the 129/J females. As in the rat liver, the sexual differentiation of the steroid 16 alpha-hydroxylation observed in adult male and female mice took place at puberty. In the adult mouse liver, two steroid 16 alpha-hydroxylase activities (forms I and II) could be differentiated on the basis of their relative affinities for the various steroid substrates and their relative proportions in male and female mouse livers. In the immature mouse liver, no sexual differences could be detected, and the mice of both sexes presented phenotypes identical to those of the adult female. The adult 129/J females appeared genetically deficient with respect to the form I of the steroid 16 alpha-hydroxylase and presented a phenotype identical to that of the adult male mice of the various strains tested. Differences in hydroxylase activities between the C57Bl/6J and 129/J strains were investigated using standard genetic breeding protocols. Steroid 16 alpha-hydroxylase seemed to be inherited additively in the liver of the female mice obtained by crossing the C57Bl/6J male and the 129/J female or the 129/J male and the C57Bl/6J female. In the male mice, regardless of genotype, the observed phenotype was always identical to the two male parental types. Both hormonal and genetic regulations were responsible for the different phenotypes occurring in adult male and female C57Bl/6J and 129/J mouse livers. [less ▲]

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