References of "Hammami, Hedi"
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See detailGenetic analysis of heat stress effects on yield traits, udder health, and fatty acids of Walloon Holstein cows
Hammami, Hedi ULiege; Vandenplas, Jérémie; Vanrobays, Marie-Laure ULiege et al

in Journal of Dairy Science (2015), 98(7), 4956-4968

Genetic parameters that considered tolerance for heat stress were estimated for production, udder health, and milk composition traits. Data included 202,733 test-day records for milk, fat, and protein ... [more ▼]

Genetic parameters that considered tolerance for heat stress were estimated for production, udder health, and milk composition traits. Data included 202,733 test-day records for milk, fat, and protein yields, fat and protein percentages, somatic cell score (SCS), 10 individual milk fatty acids (FA) predicted by mid-infrared spectrometry, and 7 FA groups. Data were from 34,468 first-lactation Holstein cows in 862 herds in the Walloon region of Belgium and were collected between 2007 and 2010. Test-day records were merged with daily temperature-humidity index (THI) values based on meteorological records from public weather stations. The maximum distance between each farm and its corresponding weather station was 21km. Linear reaction norm models were used to estimate the intercept and slope responses of 23 traits to increasing THI values. Most yield and FA traits had phenotypic and genetic declines as THI increased, whereas SCS, C18:0, C18:1 cis-9, and 4 FA groups (unsaturated FA, monounsaturated FA, polyunsaturated FA, and long-chain FA) increased with THI. Moreover, the latter traits had the largest slope-to-intercept genetic variance ratios, which indicate that they are more affected by heat stress at high THI levels. Estimates of genetic correlations within trait between cold and hot environments were generally high (>0.80). However, lower estimates (< = 0.67) were found for SCS, fat yield, and C18:1 cis-9, indicating that animals with the highest genetic merit for those traits in cold environments do not necessarily have the highest genetic merit for the same traits in hot environments. Among all traits, C18:1 cis-9 was the most sensitive to heat stress. As this trait is known to reflect body reserve mobilization, using its variations under hot conditions could be a very affordable milk biomarker of heat stress for dairy cattle expressing the equilibrium between intake and mobilization under warm conditions. [less ▲]

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See detailAssessing resilience of dairy cattle by studying impact of heat stress on predicted feed intake
Vanrobays, Marie-Laure ULiege; Hammami, Hedi ULiege; Laine, Aurélie ULiege et al

in Proceedings of the Third DairyCare Conference 2015 (2015)

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See detailPotential use of milk based biomarkers to assess and to select for heat tolerance in dairy cattle
Hammami, Hedi ULiege; Vandenplas, Jérémie; Vanrobays, Marie-Laure ULiege et al

in Proceedings of the second DairyCare Conference 2015 (2015)

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See detailShort communication: Novel method to predict body weight of primiparous dairy cows throughout the lactation
Vanrobays, Marie-Laure ULiege; Vandenplas, Jérémie ULiege; Hammami, Hedi ULiege et al

in Journal of Dairy Science (2015), 98

Body weight (BW) of dairy cows can be estimated using linear conformation traits (calculated BW; CBW), which are generally recorded only once during a lactation. However, predicted BW (PBW) throughout the ... [more ▼]

Body weight (BW) of dairy cows can be estimated using linear conformation traits (calculated BW; CBW), which are generally recorded only once during a lactation. However, predicted BW (PBW) throughout the lactation would be useful, e.g., at milk-recording dates allowing feed-intake prediction for advisory purposes. Therefore, a 2-step approach was developed to obtain PBW for each milk-recording date. In the first step, a random-regression test-day model was used with CBW as observations to predict PBW. The second step consisted in changing means and (co)variances of prior distributions for the additive genetic random effects of the test-day model by using priors derived from results of the first step to predict again PBW. A total of 25,061 CBW from 24,919 primiparous Holstein cows were computed using equations from literature. Using CBW as observations, PBW was then predicted over the whole lactation for 232,436 dates corresponding to 207,375 milk-recording dates and 25,061 classification dates. Results showed that using both steps (the 2-step approach) provided more accurate predictions than using only the first step (the one-step approach). Based on the results of this preliminary study, BW of dairy cows could be predicted throughout the lactation using this procedure. These predictions could be useful in milk-recording systems to compute traits of interest (e.g., feed-intake prediction). The developed novel method is also flexible because actual direct measurements of BW can also be used together with CBW, the prediction model being able to accommodate different levels of accuracies of used BW phenotypes. [less ▲]

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See detailGenotype x Climate interactions for protein yield using four European Holstein Populations
Hammami, Hedi ULiege; Carabaño, Maria-Jesus; Logar, Betka et al

in Proceedings of 10th World Congress of Genetics Applied to Livestock Production (2014, August)

Reaction norm models were applied to investigate genetic variation in heat tolerance of Holsteins across environments using long term protein milk yield test-day records and weather variables as proxy of ... [more ▼]

Reaction norm models were applied to investigate genetic variation in heat tolerance of Holsteins across environments using long term protein milk yield test-day records and weather variables as proxy of climate change. Data represented four European regions characterized by different management systems and environments. Daily protein yield changed across the trajectory of temperature humidity index (THI) for all studied populations, pointing out negative associations between warm conditions and cow performance. For most regions, additive genetic variances for daily protein yield decrease when THI increases. Antagonistic relationships between level and intercept were relatively limited for Slovenia compared to the three other regions. Rank correlations of estimated breeding values for three proposed heat tolerance measures ranged from 0.56 (Spain and Slovenia) to 0.81 (Walloon Region of Belgium and Luxembourg), indicating a possibility of genotype by environment (G x E) for some pairs of regions. [less ▲]

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See detailPrediction of Body Weight of Primiparous Dairy Cows Throughout Lactation
Vanrobays, Marie-Laure ULiege; Vandenplas, Jérémie ULiege; Hammami, Hedi ULiege et al

in Proceedings of the 10th World Congress on Genetics Applied to Livestock Production (2014, August)

Body weight (BW) can be computed using linear conformation traits (CBW). However, these traits are recorded mostly once during a lactation. Therefore, predicted BW (PBW) is needed throughout the lactation ... [more ▼]

Body weight (BW) can be computed using linear conformation traits (CBW). However, these traits are recorded mostly once during a lactation. Therefore, predicted BW (PBW) is needed throughout the lactation (e.g., allowing feed intake prediction in milk recording systems). A two-step procedure was developed to obtain PBW using a random regression test-day model using CBW as observations. Added second step consisted in changing prior distribution for additive genetic random effects using results from first step to predict again PBW. This method was applied on 24,919 primiparous Holstein cows having 25,061 CBW to obtain PBW for 232,436 test-days. Results showed that applying both steps provided more accurate estimates than using only the first step. Furthermore, this procedure predicting PBW throughout lactation is also extremely flexible because actual BW can also be used together with CBW, the prediction model being able to accommodate different levels of accuracies. [less ▲]

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See detailNon-genetic sources of variation of milk production and reproduction and interactions between both classes of traits in Sicilo-Sarde dairy sheep.
Merai, A.; Gengler, Nicolas ULiege; Hammami, Hedi ULiege et al

in Animal (2014), 8(9), 1534-9

This work aimed to study the sources of variation in productive and reproductive traits of the dairy Sicilo-Sarde ewes and to further investigate the interaction between both classes of traits. After ... [more ▼]

This work aimed to study the sources of variation in productive and reproductive traits of the dairy Sicilo-Sarde ewes and to further investigate the interaction between both classes of traits. After edits, a database containing 5935 lactation records collected during 6 successive years in eight dairy flocks in the North of Tunisia was used. Total milked milk (TMM) in the milking-only period was retained as productive trait. The interval from the start of the mating period to the subsequent lambing (IML) and the lambing status (LS) were designed as reproductive traits. Sicilo-Sarde ewes had an average TMM of 60.93 l (+/-44.12) during 132.8 days (+/-46.6) after a suckling period of 100.4 days (+/-24.9). Average IML was 165.7 days. In a first step, the major factors influencing milk production and reproductive traits were determined. The significant sources of variation identified for TMM were: flock, month of lambing, year of lambing, parity, suckling length, litter size and milking-only length. Flockxmonth of the start of the mating period, parity, year of mating and litter size were identified as significant factors of variation for IML, while flockxmonth of the start of the mating period, parity and year of mating were identified as significant sources of variation for LS. In a second step, variance components were estimated using a three traits threshold mixed model, which combined LS as categorical trait and TMM and IML as continuous traits. Repeatability estimates were 0.21 (+/-0.03) for TMM, 0.09 (+/-0.02) for IML, and 0.10 (+/-0.05) for LS. Moreover, TMM and IML were found to be favorably associated for the flockx year of lambing effect (-0.45+/-0.18) but unfavorably associated for the animal effect (0.20+/-0.09). [less ▲]

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See detailThe uses of mid-infrared spectral information from milk recording organization to certify milk geographic origin
Dale, Laura Monica; Laine, Aurélie ULiege; Bastin, Catherine et al

in Book of Short Abstracts - 19th National Symposium on Applied Biological Sciences (2014, February 07)

This study investigated the opportunity to detect the geographic origin of milk from the midinfrared (MIR) analysis of milk. Milk MIR spectral data related to milk recording data were available in the ... [more ▼]

This study investigated the opportunity to detect the geographic origin of milk from the midinfrared (MIR) analysis of milk. Milk MIR spectral data related to milk recording data were available in the Belgium Walloon Region via European project OptiMIR (INTERREG IVB North West Europe Program). In Wallonia, the Ardenne region is associated to a traditional product of the area, a appellation d'origine “Beurre d’Ardennes”. Therefore, discrimination studies were conducted to distinguish Ardennes region from the rest of Wallonia. A total of 542,733 Walloon spectral records linked to their geographic origin were used (97,369 of MIR spectra for Ardennes region and 450,326 for the rest of Wallonia). The spectral data selected and pre-treated were adjusted for the effects of breeds, months, years and days in milk using ab appropriate mixed model. To test the MIR ability for milk authentication, chemometric tools, such as quadratic discriminant analysis were applied to the adjusted spectrafor three MIR spectral regions (e.g. 930-1600 cm-1, 1710-1810 per cm and 2560-2990 per cm). Results of classification showed that 94% of the records from the Ardernnes region were properly classified. Based on this results, MIR spectroscopy techniques may provide useful fingerprints to detect geographic origin and could be potentially used in routine management decision and quality assurance tools. [less ▲]

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See detailEvaluation de la qualité externe et interne des œufs de cinq variétés de pintades locales élevées au bénin.
Houndonougbo, Pascal ULiege; Chrysostome, A.A. Christophe; Houndonougbo, M. Frédéric et al

in Revue du Conseil Africain et Malgache pour l'Enseignement Supérieur (2014), 2(2), 42-47

The study aimed to evaluate the external and internal qualities of eggs from local varieties of guinea fowl (Common breed, Bonaparte, White, Grey and Black) of Benin. Twenty –four (24) guinea fowl of ... [more ▼]

The study aimed to evaluate the external and internal qualities of eggs from local varieties of guinea fowl (Common breed, Bonaparte, White, Grey and Black) of Benin. Twenty –four (24) guinea fowl of guinea fowl of each variety aged of 38 weeks were reared in station and five new-laid eggs were collected daily and analyzed weekly by variety during 8 weeks. It appears that White guinea fowl lay the heaviest eggs while Bonaparte laid the smallest (P<0.05). According to the egg size, White guinea fowls were the best followed by Black guinea fowl, Common guinea fowl and Grey guinea fowl. Eggshell color was mostly red bright and dark red. The predominant bright red eggs were obtained in black guinea fowl (55%), Bonaparte (42.5%) and Common (40%), while the dark red were mostly recorded in White (45%) and Grey guinea fowls (42.5%). The slight red shell eggs with grits were only obtained in White variety (2.5%) and mottled eggs were produced by the Grey guinea fowl (25%) followed by Bonaparte guinea fowl (20%). Furthermore, egg from white guinea showed the best physical quality that are egg white thickness, egg yolk thickness, egg white weight and egg yolk weight (respectively 6.82 mm 17.8 mm; 13g and 22g). The most colored egg yolk was found in black guinea fowls while the less colored was observed in the common greed. In short, it appears from this study that qualities of eggs depend on genetic type and could be used for characterization and genetic improvement by selection and crossing. [less ▲]

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See detailStrategies to combine novel traits across countries: example of heat stress
Hammami, Hedi ULiege; Vandenplas, Jérémie ULiege; Carabaño, Maria-Jesus et al

in Interbull Bulletin (2014), 48

Nowadays, novel traits are of great interest. However, phenotypes are siloed and mainly not shared. Heat stress is becoming problematic affecting animals’ performances and their well-being. Heat stress ... [more ▼]

Nowadays, novel traits are of great interest. However, phenotypes are siloed and mainly not shared. Heat stress is becoming problematic affecting animals’ performances and their well-being. Heat stress tolerance as a novel trait is only addressed by isolated within-country research studies. Integration and combination of local and foreign information sources is needed for better accuracy genetic evaluations. Therefore, this study was aimed to test the potential combination of sources of external information towards the evaluation of heat stress tolerance of dairy cattle. Long-term cow performances linked to environmental descriptors (weather parameters as proxy to climate change) collected over 10 years under the temperate conditions of the Walloon Region of Belgium and the hotter and warm Mediterranean conditions of Andalusia and Castile-La-Mancha Spanish regions were available. A total of 1,604,775 milk, fat, and protein test-day (TD) records linked to average daily temperature humidity (THI) values for 3-day lag before each TD were considered. Under a first strategy considering free-access to raw-data (phenotype and pedigree), a joint evaluation was firstly run using reaction norm models where production traits were considered as function of THI. A Belgian and a Spanish evaluation were also run using the same model. An alternative strategy considering only access to external information (i.e. regression coefficients for additive genetic effects (â and their associated REL)) was tested. In this case, foreign â and their REL resulting from the Spanish evaluation were first converted to the Belgian trait and thereafter integrated in the Belgian <br /><br />evaluation using a Bayesian approach. Rank correlations between regression coefficients, â (of the 1,104 bulls having daughters only in Spain) estimated by Belgian evaluation and â estimated by the joint evaluation were moderate (<=0.70). Corresponding rank correlations between â estimated by joint and Bayesian evaluations were significantly higher (ranging from 0.967 to 0.998), indicating that the Bayesian evaluation integrating external information was in good concordance with the joint evaluation. Results from this study indicated that the integration of external information via the Bayesian approach has a good potential to improve the genetic evaluation of sparse and siloed novel traits. [less ▲]

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See detailImpact of Heat Stress on Production in Holstein Cattle in four EU Regions. Selection Tools
Carabaño, Maria-Jesus; Hammami, Hedi ULiege; Logar, Betka et al

Scientific conference (2014)

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See detailImpact of Heat Stress on Production in Holstein Cattle in four EU Regions. Selection Tools
Carabaño, Maria-Jesus; Hammami, Hedi ULiege; Logar, Betka et al

Conference (2014)

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See detailGenotype x Climate interactions for protein yield using four European Holstein Populations
Hammami, Hedi ULiege; Carabaño, Maria-Jesus; Logar, Betka et al

Conference (2014)

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See detailPotential use of mid-infrared milk spectrum in pregnancy diagnosis of dairy cows
Laine, Aurélie ULiege; Goubau, Amaury; Dale, Laura-Monica et al

in Book of Abstracts of the 64th Annual Meeting of the European Federation of Animal Science (2013, August 28)

Fertility issues are a large part of economic losses for the dairy farmers. Early identification of pregnant and non-pregnant cows is a key element to improve reproductive performances and reduce costs ... [more ▼]

Fertility issues are a large part of economic losses for the dairy farmers. Early identification of pregnant and non-pregnant cows is a key element to improve reproductive performances and reduce costs for the farmer. The mid-infrared (MIR) spectrum obtained from milk recording routines is an inexpensive and quick method to obtain a fingerprint of the milk composition. This study was conducted in the context of the European project OptiMIR (INTERREG IVB North West Europe Program). The objective was to investigate the potential use of the entire milk spectrum to identify if a cow is pregnant or not. Investigation was based on 7,840 spectral records linked to confirmed pregnancy status coming from Luxembourg milk recording. The method was based on comparing a given spectrum to the expected spectrum if the cow would have been non-pregnant. The expected spectra were obtained from solutions of a mixed model (fixed effects: parity, herd, milking moment and days in milk; random effects: animal across lactations) applied to MIR spectra from a subset of non-pregnant cow. Therefore the solutions obtained in the model were used on the whole dataset to obtain predicted MIR spectral values for all test-days and prediction errors (residuals) representing the factors not present in the model (reproductive status, unaccounted factors, and error). A predictive quadratic discriminant function was then constructed on the residual spectra to predict the pregnancy status. Leave one out cross-validation showed promising results with an error rate equal to 1.8% and 6.8% for non-pregnant cow and for pregnant cow respectively. Results have shown that MIR milk spectra might be used as a pregnancy diagnosis tool. Therefore, this kind of diagnosis could be made routinely and at a low cost for farmers. [less ▲]

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See detailGenetic effects of heat stress on milk yield and MIR predicted methane emissions of Holstein cows
Vanrobays, Marie-Laure ULiege; Gengler, Nicolas ULiege; Kandel, Purna Bhadra ULiege et al

Conference (2013, August 28)

Dairy cows both contribute to and are affected by climate change. Breeding for heat tolerance and reduced methane (CH4) emissions is a key requirement to mitigate interactions between dairy cows and ... [more ▼]

Dairy cows both contribute to and are affected by climate change. Breeding for heat tolerance and reduced methane (CH4) emissions is a key requirement to mitigate interactions between dairy cows and climate change. This study was aimed to estimate genetic variation of milk yield and CH4 emissions over the whole trajectory of temperature humidity index (THI) using a reaction norm approach. A total of 257,635 milk test-day (TD) records and milk mid-infrared (MIR) spectra from 51,782 Holstein cows were used. Data were collected between January 2007 and December 2010 in 983 herds by the Walloon Breeding Association (Ciney, Belgium). The calibration equation developed by Vanlierde et al. (Abstract submitted to EAAP 2013; R² of cross-validation=0.70) was applied on the spectral data in order to predict CH4 emissions values (g CH4/d). These values were divided by fat and protein corrected milk yield (FPCM) defining a new CH4 trait (g CH4/kg of FPCM). Daily THI values were calculated using the mean of daily values of dry bulb temperature and relative humidity from meteorological data. Mean daily THI of the previous 3 days before each TD record was used as the THI of reference for that TD. Bivariate (milk yield and a CH4 trait) random regression TD mixed models with random linear regressions on THI values were used. Estimated average daily heritability for milk yield was 0.17 and decreased slightly at extreme THI values. However, heritabilities of MIR CH4 traits increased as THI values increase: from 0.10 (THI=28) to 0.14 (THI=75) for MIR CH4 (g/d) and from 0.14 (THI=28) to 0.21 (THI=75) for MIR CH4 (g/kg of FCPM). Genetic correlations between milk yield and MIR CH4 (g/d) ranged from -0.09 (THI=28) to -0.12 (THI=75) and those between milk yield and MIR CH4 (g/kg of FPCM) from -0.75 (THI=28) to -0.71 (THI=75). These results showed that milk production and CH4 emissions of dairy cows seemed to be influenced by THI. [less ▲]

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See detailInteractions between milk production and reproduction in Sicilo-Sarde dairy sheep
Meraï, A.; Gengler, Nicolas ULiege; Hammami, Hedi ULiege et al

in Book of Abstracts of the 64th Annual Meeting of the European Federation of Animal Science (2013, August 27)

This work aimed to investigate the association between productive and reproductive traits of the dairy Sicilo Sarde ewes. After edits, a database containing 5,935 lactation records collected during 6 ... [more ▼]

This work aimed to investigate the association between productive and reproductive traits of the dairy Sicilo Sarde ewes. After edits, a database containing 5,935 lactation records collected during 6 successive years in 8 dairy flocks in the North of Tunisia was used. Total milked milk in the milking-only period. (IMM) was retained as productive trait. The interval from the start of the mating period to the subsequent lambing (ML) and the status ofpregnancy (SP) was designed as reproductive traits. Sicilo-Sarde ewes had an average TMM of 60.93 L (+-44.12) milked during 132.8 days (+-46.6) after a suckling period of 1004 days (+-24.9). Average IML was 165.7 d. In a first step, the major factors influencing milk production and reproductive traits were determined. The significant sources of variation identified for TMM were: flock, month of lambing, year of lambing, parity, suckling length, litter size and milking-only length. Flock x month of mating, parity, year of mating and litter size were identified as significant factors of variation for IML. While, flock x month of mating, parity and year of mating were identified as significant sources of variation for PS. In a second step, variance components were estimated using a 3-traits threshold mixed model which combined SP as categorical trait and TMM and IML as continuous traits. Repeatability estimates were 0.21 (+-0.03) for TMM, 0.09 (+-0.02) for IML and 0.10 (+-0.05) for SP Moreover, TMM and IML were found to be favorably associated for the interval from the start of mating to the subsequent lambing (-0.45). This antagonism was largely explained by environmental factors specially flock x year of lambing effect (-0.45 +- 0.18) but unfavorably associated for the animal effect (0.20+-0.09) [less ▲]

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See detailThe potential of milk MIR spectra to certify milk geographic origin
Dale, Laura-Monica ULiege; Laine, Aurélie ULiege; Goubau, Amaury et al

in Book of Abstracts of the 64th Annual Meeting of the European Federation of Animal Science (2013, August 26)

Protecting and supporting local production systems, regional authorities, as well as producers, give a very important role to milk quality. Therefore, this study was aimed to investigate the potential of ... [more ▼]

Protecting and supporting local production systems, regional authorities, as well as producers, give a very important role to milk quality. Therefore, this study was aimed to investigate the potential of mid-infrared spectroscopy (MIR) for certifying the geographic origin of milk. Because milk MIR spectral databases and extra phenotypes (breed, testday, livestock herd and origin appellation of traditional products) were available in the Belgium Walloon Region via European project OptiMIR (INTERREG IVB North West Europe Program), discrimination studies were conducted to distinguish Ardennes region (which is linked to PDO “Beurre d’Ardennes”) from the rest of Wallonia. A total of 542,733 spectral records linked to their geographic origin coming from Wallonia milk recording were used (97,369 of MIR spectra -Ardennes region and 450,326 -rest of Wallonia). A mixed model (fixed: breed, year and month of record, random: herd x year) was applied to obtain predicted MIR spectral values for all testdays and prediction errors (residuals) representing the factors not present in the model. In order to test the MIR ability to milk authentication, chemometric tools, such as partial least squat regression and linear discriminant analysis were applied to residuals for three MIR spectral regions (e.g. 930-1600 cm-1, 1710-1810 cm-1 and 2560-2990 cm-1). The classifications on not-corrected MIR spectral data were 95% and the cross-validation were 95% for Ardennes region. Results showed after correction of MIR spectra, the discriminant function constructed on the residuals spectra allowed a good discrimination. The results show that MIR spectroscopy techniques may provide useful fingerprints to detect geographic origin and could be potentially used in routine management decision and quality assurance tools. [less ▲]

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See detailGenetic effects of heat stress on milk yield and MIR predicted methane emissions of Holstein cows
Vanrobays, Marie-Laure ULiege; Gengler, Nicolas ULiege; Kandel, Purna Bhadra ULiege et al

in Book of Abstracts of the 64th Annual Meeting of the European Federation of Animal Science (2013, August)

Dairy cows both contribute to and are affected by climate change. Breeding for heat tolerance and reduced methane (CH4) emissions is a key requirement to mitigate interactions between dairy cows and ... [more ▼]

Dairy cows both contribute to and are affected by climate change. Breeding for heat tolerance and reduced methane (CH4) emissions is a key requirement to mitigate interactions between dairy cows and climate change. This study was aimed to estimate genetic variation of milk yield and CH4 emissions over the whole trajectory of temperature humidity index (THI) using a reaction norm approach. A total of 257,635 milk test-day (TD) records and milk mid-infrared (MIR) spectra from 51,782 Holstein cows were used. Data were collected between January 2007 and December 2010 in 983 herds by the Walloon Breeding Association (Ciney, Belgium). The calibration equation developed by Vanlierde et al. (Abstract submitted to EAAP 2013; R² of cross-validation=0.70) was applied on the spectral data in order to predict CH4 emissions values (g CH4/d). These values were divided by fat and protein corrected milk yield (FPCM) defining a new CH4 trait (g CH4/kg of FPCM). Daily THI values were calculated using the mean of daily values of dry bulb temperature and relative humidity from meteorological data. Mean daily THI of the previous 3 days before each TD record was used as the THI of reference for that TD. Bivariate (milk yield and a CH4 trait) random regression TD mixed models with random linear regressions on THI values were used. Estimated average daily heritability for milk yield was 0.17 and decreased slightly at extreme THI values. However, heritabilities of MIR CH4 traits increased as THI values increase: from 0.10 (THI=28) to 0.14 (THI=75) for MIR CH4 (g/d) and from 0.14 (THI=28) to 0.21 (THI=75) for MIR CH4 (g/kg of FCPM). Genetic correlations between milk yield and MIR CH4 (g/d) ranged from -0.09 (THI=28) to -0.12 (THI=75) and those between milk yield and MIR CH4 (g/kg of FPCM) from -0.75 (THI=28) to -0.71 (THI=75). These results showed that milk production and CH4 emissions of dairy cows seemed to be influenced by THI. [less ▲]

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