Dual‐purpose Guzerá cattle exhibit high dairy performance under heat stress

Júnior, Mário Luiz Santana; Pereira, Rodrigo Junqueira; Bignardi, Annaíza Braga; Faro, Lenira El; Pires, Maria de Fátima Ávila; Andrade, Ricardo Guimarães; Perez, Bruno; Bruneli, F. A. T.; Peixoto, Maria Gabriela Campolina Diniz

doi:10.1111/jbg.12450

Cited by 10 publications

(13 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The trend of slope showed a slight decrease over the years, indicating that the genetic selection for higher milk yield did not cause major damage in response to the heat stress of the buffaloes until the present moment. Similar previous studies with different breeds of dairy cattle found a deterioration of the genetic response to heat stress due to selection for high milk yield, with genetic correlation estimates between production level and the slope term ranging from −0.61 to −0.23 (Hammami et al, 2015;Santana et al, 2015Santana et al, , 2020. However, these authors reported that the genetic trends for slope became negative only after implementing respective breeding programs.…”

Section: Discussionsupporting

confidence: 79%

“…(Kolmodin & Bijma, 2004). Lower values have been reported in studies on different breeds of dairy cattle in temperate climates, ranging from 0.003 to 0.005 (Bernabucci et al, 2014;Bohmanova et al, 2008;, and similar values in tropical climates, ranging from 0.04 to 0.16 (Santana et al, 2016(Santana et al, , 2020. These facts support the importance of G × E for milk yield in dairy buffaloes reared under tropical climate.…”

Section: Discussionsupporting

confidence: 73%

“…They reported similar values ranging from −0.015 to −0.082 kg/day per unit increase in THI (Choudhary & Sirohi, 2019;Pawar et al, 2013;Upadhyay et al, 2007). In taurine and zebu cattle breeds, studies also reported that the most detrimental effect of THI on milk yield was observed in the intermediate stages of lactation (Bernabucci et al, 2010;Santana et al, 2015Santana et al, , 2020. Bernabucci et al (2010) reported that the stage of lactation is an important factor affecting how dairy animals respond to heat stress.…”

Section: Discussionmentioning

confidence: 86%

See 2 more Smart Citations

Genetics of tolerance to heat stress in milk yield of dairy buffaloes assessed by a reaction norm model

Stefani¹,

Júnior

Faro

et al. 2021

J Animal Breeding Genetics

Self Cite

View full text Add to dashboard Cite

The objectives of this study were to assess the effects of heat stress on the milk yield and investigate the presence of genotype × environment interaction (G × E) in Brazilian Murrah buffaloes reared under tropical conditions. With this, 58,070 test-day (TD) records for milk yield from 3,459 first lactations of buffaloes collected between 1987 and 2018 were evaluated. A mixed model considering days in milk (DIM) and temperature-humidity index (THI) was applied to quantify milk yield losses due to heat stress. The most detrimental effect of THI on TD milk yield was observed in the mid-stages of lactation, after lactation peak, in DIM 105-154 and 155-204 days (−0.020 and −0.015 kg/day per THI, respectively). The least-squares means of TD milk yield were used to identify a heat stress threshold using a piecewise linear regression model. A substantial reduction in TD milk yield due to heat stress was observed for THI values above 77.8 (−0.251 kg/day per increase of 1 THI unit). An analysis using a single-trait random regression animal model was carried out to estimate variance components and genetic parameters for TD milk yield over THI and DIM values. Increased additive genetic variance and heritability estimates were observed for extreme THI values (THI = 60 and 80) combined with mid-lactation stages. The lowest genetic correlation (0.50) was observed between TD records at opposite extremes of the THI scale (THI = 60 vs. THI = 80). The genetic trends observed for the regression coefficients related to the general level of production (0.02) and specific ability to respond to heat stress (−0.002) indicated that selection to increase milk yield did not affect the specific ability to respond to heat stress until the present moment. These trends reflect the low genetic correlation between these components (0.05 ± 0.14). In this sense, monitoring trends of genetic components related to response to heat stress is recommended.

show abstract

Section: Discussionsupporting

confidence: 79%

Section: Discussionsupporting

confidence: 73%

Section: Discussionmentioning

confidence: 86%

See 1 more Smart Citation

Genetics of tolerance to heat stress in milk yield of dairy buffaloes assessed by a reaction norm model

Stefani¹,

Júnior

Faro

et al. 2021

J Animal Breeding Genetics

Self Cite

View full text Add to dashboard Cite

show abstract

“…A G × E interaction has also been found when comparing genotypes at different levels of temperaturehumidity index (THI) as a method to quantify sensitivity to heat stress (Ravagnolo and Misztal, 2000;Hayes et al, 2003). Santana Jr. et al (2019) demonstrated that G × E interaction due to heat stress can influence test-day milk yield. They suggested that new strategies should be considered to mitigate the negative effects of heat stress on milk production.…”

Section: Introductionmentioning

confidence: 98%

Genotype by climate zone interactions for fertility, somatic cell score, and production in Iranian Holsteins

Atrian-Afiani

Gao

Joezy-Shekalgorabi

et al. 2021

Journal of Dairy Science

View full text Add to dashboard Cite

The objective of this study was to investigate genetic variation and genotype by environment (G × E) interactions for fertility (including age at first calving and calving interval), somatic cell score (SCS), and milk production traits for Iranian Holsteins. Different environments were defined based on the climatic zones (cold, semi-cold, and moderate) and considering the herd location. Data were collected between 2003 and 2018 by the National Animal Breeding Center of Iran (Karaj). Variance and covariance components and genetic correlations were estimated using 2 different models, which were analyzed using Bayesian methods. For both models, performance of traits in each climate were considered as different traits. Fertility traits were analyzed using a trivariate model. Furthermore, SCS and production traits were analyzed using trivariate random regression models (records in different climate zones considered as different traits). For the fertility traits, the largest estimates of heritability were observed in cold climate. Fertility performance was always better in cold environment. Genetic correlations between climatic zones ranged from 0.85 to 0.94. For daily measurements of SCS and production traits, heritability ranged from 0.031 to 0.037 and 0.069 to 0.209, respectively. Genetic variances were the highest in the semi-cold and moderate climates for the SCS and production traits, respectively. Furthermore, across the studied climates, 305-d genetic correlation ranged from 0.756 to 0.884 for SCS and from 0.925 to 0.957 for the production traits. The structure of genetic correlation within each climate indicated a negative correlation between early and late lactation for SCS, especially in the cold climate and for milk production in the moderate climate. For fat percentage, in all climatic zones, the lowest genetic correlations were observed between early and mid-lactation. In addition, for protein production in the cold climate, a negative correlation was observed between early and late lactation. Results indicated heterogeneous variance components for all the studied traits across various climatic zones. Estimated genetic correlations for SCS revealed that the genetic expression of animals may vary by climatic zone. Results indicated the existence of G × E interaction due to the climatic condition, only for SCS. Therefore, in Iranian Holsteins, the effect of G × E interactions should not be neglected, especially for SCS, as different sires might be optimal for use in different climatic zones.

show abstract

“…De acordo com Albuquerque (2004) Os modelos de normas de reação foram utilizados em diversos estudos que investigaram a ocorrência de IGA em características de produção de leite (SANTANA Jr. et al, 2016;SANTANA Jr. et al, 2019;CHERUIYOT et al, 2020;SANTOS et al, 2020;BOHLOULI et al, 2021;ERBE et al, 2021;MULIM et al, 2021a;TORO-OSPINA et al, 2022).…”

Section: Normas De Reaçãounclassified

Interação genótipo x ambiente para produção de leite, gordura e proteína utilizando modelos de normas de reação em bovinos Guzerá

Soares¹

View full text Add to dashboard Cite

O objetivo deste trabalho foi avaliar a ocorrência de interação genótipo x ambiente (IGA) em características de produção de leite (PL305), gordura (G305) e proteína (P305) truncadas em 305 dias de animais da raça Guzerá. Foram utilizados 6823 registros de PL305, 2466 registros de G305 e 1870 registros de P305 fornecidos pelo Programa Nacional de Melhoramento do Guzerá para Leite (PNMGuL), coordenado pela Embrapa Gado de Leite e pelo Centro Brasileiro de Melhoramento Genético do Guzerá (CBMG 2 ). A estação de parto foi divida em seca (abril a setembro) e chuvosa (outubro a março). Apenas as informações de vacas primíparas foram utilizadas. Os grupos de contemporâneos (GC) foram formados considerando rebanho e ano de parto. Foram incluídos nesse estudo apenas GC com no mínimo três registros de filhas de dois reprodutores diferentes. As análises foram realizadas em dois passos. No primeiro passo foram estimados os efeitos ambientais sobre os fenótipos utilizando um modelo animal multicaracterístico ignorando a IGA. No segundo passo, a ocorrência de IGA foi avaliada através de análises unicaracterísticas utilizando modelo de normas de reação e considerando variância residual heterogênea. As soluções de GC obtidas no passo 1, dadas como desvio da média, foram utilizadas como gradiente ambiental, representando ambientes de baixo a alto nível de manejo. Os reprodutores foram classificados quanto à sensibilidade e as normas de reação para os touros com no mínimo 15 filhas foram apresentadas graficamente. Observou-se incremento das estimativas de variância genética ao longo do gradiente ambiental para todas as características avaliadas. O mesmo ocorreu para a variância residual com exceção da classe 5 da G305 e da classe 4 da P305. As estimativas de herdabilidade aumentaram levemente conforme houve aumento do nível de manejo. As estimativas de correlação entre o intercepto e a inclinação da curva de norma de reação foram 0,998 para PL305; 0,989 para G305; e 0,987 para P305. A correlação genética entre os ambientes de baixo (quantil 5%), médio (quantil 55%) e alto (quantil 95%) nível de manejo foram de alta magnitude. A maioria dos reprodutores foram classificados como robustos para todas as características, seguidos pelos sensíveis e extremamente sensíveis. O mesmo foi observado para a quantidade de filhas. Não foi observada a reclassificação dos touros para PL305 e G305. Para P305 a reclassificação não foi significativa. Contudo, os valores genéticos dos animais foram alterados ao longo do gradiente ambiental, mesmo para animais classificados como robustos. Esses resultados permitem concluir que houve interação genótipo x ambiente com efeito escala para as características avaliadas com impacto sobre as predições de valores genéticos. Palavras-chave: Sensibilidade ambiental. Regressão aletória. Herdabilidade.

show abstract

Dual‐purpose Guzerá cattle exhibit high dairy performance under heat stress

Cited by 10 publications

References 17 publications

Genetics of tolerance to heat stress in milk yield of dairy buffaloes assessed by a reaction norm model

Genetics of tolerance to heat stress in milk yield of dairy buffaloes assessed by a reaction norm model

Genotype by climate zone interactions for fertility, somatic cell score, and production in Iranian Holsteins

Interação genótipo x ambiente para produção de leite, gordura e proteína utilizando modelos de normas de reação em bovinos Guzerá

Contact Info

Product

Resources

About