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BACKGROUND: Heat stress (HS) poses significant threats to the sustainability of livestock production. Genetically improving heat tolerance could enhance animal welfare and minimize production losses during HS events. Measuring phenotypic indicators of HS response and understanding their genetic background are crucial steps to optimize breeding schemes for improved climatic resilience. The identification of genomic regions and candidate genes influencing the traits of interest, including variants with pleiotropic effects, enables the refinement of genotyping panels used to perform genomic prediction of breeding values and contributes to unraveling the biological mechanisms influencing heat stress response. Therefore, the main objectives of this study were to identify genomic regions, candidate genes, and potential pleiotropic variants significantly associated with indicators of HS response in lactating sows using imputed whole-genome sequence (WGS) data. Phenotypic records for 18 traits and genomic information from 1,645 lactating sows were available for the study. The genotypes from the PorcineSNP50K panel containing 50,703 single nucleotide polymorphisms (SNPs) were imputed to WGS and after quality control, 1,622 animals and 7,065,922 SNPs were included in the analyses. RESULTS: A total of 1,388 unique SNPs located on sixteen chromosomes were found to be associated with 11 traits. Twenty gene ontology terms and 11 biological pathways were shown to be associated with variability in ear skin temperature, shoulder skin temperature, rump skin temperature, tail skin temperature, respiration rate, panting score, vaginal temperature automatically measured every 10 min, vaginal temperature measured at 0800 h, hair density score, body condition score, and ear area. Seven, five, six, two, seven, 15, and 14 genes with potential pleiotropic effects were identified for indicators of skin temperature, vaginal temperature, animal temperature, respiration rate, thermoregulatory traits, anatomical traits, and all traits, respectively. CONCLUSIONS: Physiological and anatomical indicators of HS response in lactating sows are heritable but highly polygenic. The candidate genes found are associated with important gene ontology terms and biological pathways related to heat shock protein activities, immune response, and cellular oxidative stress. Many of the candidate genes with pleiotropic effects are involved in catalytic activities to reduce cell damage from oxidative stress and cellular mechanisms related to immune response.

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The use of mixed nonlinear models reduces the residual variance by including random effects, thereby improving the estimates in growth curves. Therefore, we tested distinct mixed nonlinear models (Richards, Brody, Gompertz, Logistic, and Von Bertalanffy) to model the growth curves of Zebu cattle herds raised on pasture in Brazil. In addition, we evaluated the diversity among breeds using hierarchical cluster multivariate analysis (full linkage) based on asymptotic weight (A), maturity rate (K), absolute growth rate (AGR), and absolute maturity rate (AMR) adjusted to 205, 365, 550, and 730 days of age. Body weight data from 311,834 males and females of Guzerat, Nellore, Tabapuã, and Polled Nellore breeds provided by the Brazilian Association of Zebu Breeders were used. The Brody model considering breed-sex fixed and animal random effects was the most suitable to describe the growth in the four breeds. The Guzerat and Tabapuã males showed increased precocity (higher K values) when compared to polled Nellore and Nellore males, which were characterized by higher A and AMR values. Females were more precocious than males (high K and low A values), particularly within Tabapuã and Guzerat breeds, respectively. Regardless of sex, the highest AGR values were observed from weaning up to 2 years of age in Tabapuã and Guzerat breeds. The cluster analyses revealed two groups: (1) Polled Nellore and Nellore males with high A, AGR_205, AGR_365, AGR_550, and AGR_730 values, represented by large adult animals, and (2) males and females of Guzerat and Tabapuã, characterized as animals of increased precocity. A subgroup encompassing males of Guzerat and Tabapuã was also observed, with intermediate values ​​for all parameters. This information is useful to help breeders and producers in strategies for feeding management and defining the most precocious beef cattle breed to increase the economic gains in pasture-based raising systems.

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The objective of this study was to evaluate the effect of dietary electrolyte balance (DEB) levels on performance characteristics (feed intake, FI; body weight gain, BWG; and feed efficiency, FE), energy balance (retained energy, RE; metabolizable energy ingested, MEI; heat production, HP; and energy retention efficiency, ERE), and the expression of genes related to acid-base balance, nutrient absorption, and transport in broilers from 1 to 21 days of age. A total of 245 male Cobb chickens were used in a completely randomized design with five DEB levels (110, 175, 240, 305, and 370 mEq/kg) and seven replicates of seven birds each. The inclusion of DEB levels influenced FE; 110 mEq/kg provided the better values for this characteristic both in the pre-initial phase and in the initial phase but was different only concerning 175 mEq/kg (1-7 days) and 240 mEq/kg (1-21 days). Birds that ingested diets with a level of 240 mEq/kg of DEB had a higher MEI and HP. This DEB level caused a lesser and greater expression of the SLC12A2 gene in the liver and the ATP1A1 gene in the intestine, respectively. On the other hand, the ATP1A1 gene was less expressed in the liver and kidney of broilers supplemented with 370 mEq/kg compared to a level of 110 mEq/kg. In general, a level of 110 mEq/kg DEB in the ration seems to be the most suitable for good performance, energy balance, and gene expression of broilers from 1 to 21 days of age.

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This study investigated phenotypic differences of zebu females from four breeds using variables of growth, feed efficiency, and age at first calving. Weights throughout the life were recorded, and a growth curve was fitted using the Gompertz model. The growth was also evaluated at standardized ages (205, 365, and 550 days) using the body weight and the total and daily weight gains. The Kleiber index and age at first calving were used as measures of feed efficiency and sexual precocity, respectively, totaling 25 variables. New variables were created using the factor analysis and used in new multivariate analyzes. Only six factors explained 95.41% of the total variance and were used for the subsequent analyses. The factors were defined as maturity, precocity, feed efficiency postweaning, feed efficiency post 1 year of age, puberty, and birth weight. There were differences between breeds according to the multivariate analysis of variance. Each breed appeared in a quadrant on the Biplot graph, showing relationship with different factors, demonstrating the diversity of zebu females. There is a difference in growth, feed efficiency, and sexual precocity in Brazilian zebu females, allowing the identification of potentials of the animals and help breeders and decision-makers.

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The selection of animals with lower production costs can be achieved by using feed efficiency and growth curve information. Kleiber ratio (KR) is an alternative option for discriminating against the animals that have the greatest weight gain about their final weight. Alternative feed efficiency and growth curves for ostriches of the African Black (AB) and Red Neck (RN) breeds and their crossbreeds (CB) were investigated using KR and Gompertz equation. Univariate and multivariate analyses were used. The highest adult weight was identified in the RN and CB. AB was more precocious than the RN and CB individuals. Only AB animals reached 75% of their mature weight at one year of age. At 180 days, AB showed better KR. AB was different from the others, mainly for KR at 90 days and 180 days. Considering multivariate analysis, AB animals were different from the others, regardless of sex, mainly for KR at 90 days and KR at 180 days. Other subgroups separated the animals by sex. In a market preferring animals of minor structure (smaller cuts) and greater precocity, it would be suitable to opt for AB. When animals with greater body structure (larger cuts) are desired, males RN and CR is the best option, however, it will be slaughtered with greater age and lower value for KR (may generate a bigger production cost ). It is possible to obtain animals with precocity and high KR, being well represented by the AB breed.(AU)

A seleção de animais com custos de produção mais baixos pode ser alcançada usando a eficiência alimentar e informações da curva de crescimento. A razão de Kleiber (KR) é uma alternativa para discriminar os animais que apresentam maior ganho de peso em relação ao peso final. Eficiência alimentar alternativa e curvas de crescimento para avestruzes das raças African Black (AB) e Red Neck (RN) e seus cruzamentos (CB) foram investigadas usando a equação de KR e Gompertz. Análises univariadas e multivariadas foram utilizadas. O maior peso adulto foi observado no RN e no CB. AB foi mais precoce do que os indivíduos RN e CB. Apenas animais AB atingiram 75% de seu peso adulto até um ano de idade. Aos 180 dias, AB tem maior KR. AB foi diferente dos demais, principalmente para KR aos 90 dias e 180 dias. Considerando a análise multivariada, os animais AB diferiram dos demais, independente do sexo, principalmente pelos seguintes parâmetros: KR aos 90 dias, KR aos 180 dias. Outros subgrupos separaram os animais por sexo. Em um mercado que prefere animais de menor estrutura corporal (cortes menores) e maior precocidade, seria adequado optar pela AB. Para animais com maior estrutura corporal (cortes maiores), os machos RN e CR são a melhor opção, porém, serão abatidos com maior idade e menor valor para KR (pode gerar um maior custo de produção). É possível obter animais com precocidade e alto KR, sendo bem representados pelo AB.(AU)

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The increase in productivity in the cattle sector can be boosted with the use of biotecnias that can decrease the generation interval and increase the intensity of selection, and facilitate the dissemination of genetic material quality. During the period of November 13 to December 13, 2015, it was used 40 pairs of epididymis coming from bulls without defined breed (SPRD) compared the sperm viability after cooling, using two extenders (ACP and TRIS). Overall, there was no significant difference between the diluent, however, motility use with the ACP is less than TRIS after 12 hours of cooling.

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The aim of this work was to verify the adaptability of crossbred calves (Holstein x Gyr) created in the field and in the facilities in Bom Jesus, PI. Six crossbred calves (Holstein x Gyr) were distributed in two treatments: T1= Field and T2= Facilities, with three animals in each, with 32 repeated measurements over time, totaling 192 observations (6 animals x 32 repetitions per animal) during the experimental period. The physiological characteristics, such as respiratory rate (RR), heart rate (HR), rectal temperature (RT), and the sweating rate (SR) were recorded. The meteorological variables were: air temperature (AT), relative humidity (RH), globe temperature index and humidity (BGT1 and BGT2), where BGT1 was inside the facilities and BGT2 in the open field. All weather variables showed significant differences (p < 0.05) between shifts (morning and afternoon). It was found that RT and SR showed no significant difference (p>0.05). The RR was higher (p < 0.05) for T1, with an average of 55.88 mov/min. There was a significant difference (p < 0.05) between treatments for HR, with averages of 92.19 and 86.25 bat/min. for T1 and T2, respectively. According to the results it can be stated that the facilities for calves positively influenced the performance of heat loss, giving values closer to the comfort zone.(AU)

Objetivou-se neste trabalho verificar a adaptabilidade de bezerros mestiços (Holandês x Gir) criados a campo e nas instalações, em Bom Jesus, PI. Foram utilizados seis bezerros mestiços (Holandês x Gir) distribuídos em dois tratamentos: T1= Campo e T2= Instalações, com três animais em cada um, e mensurou-se 32 medidas repetidas no tempo, totalizando 192 observações (6 animais x 32 repetições por animal) durante o período experimental. Nos animais foram registradas as características fisiológicas como: a frequência respiratória (FR), frequência cardíaca (FC), temperatura retal (TR) e a taxa de sudação (TS). As variáveis meteorológicas foram: Temperatura do Ar (TA), Umidade Relativa do Ar (UR), Índice de Temperatura de Globo e Umidade (ITGU1 e ITGU2), onde ITGU1 estava dentro das instalações e o ITGU2 no campo aberto. Todas as variáveis meteorológicas apresentaram diferença significativa (p < 0,05) entre os turnos (manhã e tarde). Verificou-se que TR e TS não apresentaram diferença significativa (p>0,05). A FR foi maior (p < 0,05) para T1, apresentando média de 55,88 mov/min. Houve diferença significativa (p < 0,05) entre os tratamentos para a FC, com médias de 92,19 e 86,25 bat/min. para os T1 e T2, respectivamente. De acordo com os resultados obtidos pode-se afirmar que as instalações para bezerros influenciaram positivamente no desempenho da perda de calor, conferindo valores mais próximos da zona de conforto.(AU)

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The increase in productivity in the cattle sector can be boosted with the use of biotecnias that can decrease the generation interval and increase the intensity of selection, and facilitate the dissemination of genetic material quality. During the period of November 13 to December 13, 2015, it was used 40 pairs of epididymis coming from bulls without defined breed (SPRD) compared the sperm viability after cooling, using two extenders (ACP and TRIS). Overall, there was no significant difference between the diluent, however, motility use with the ACP is less than TRIS after 12 hours of cooling.(AU)

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The aim of this work was to verify the adaptability of crossbred calves (Holstein x Gyr) created in the field and in the facilities in Bom Jesus, PI. Six crossbred calves (Holstein x Gyr) were distributed in two treatments: T1= Field and T2= Facilities, with three animals in each, with 32 repeated measurements over time, totaling 192 observations (6 animals x 32 repetitions per animal) during the experimental period. The physiological characteristics, such as respiratory rate (RR), heart rate (HR), rectal temperature (RT), and the sweating rate (SR) were recorded. The meteorological variables were: air temperature (AT), relative humidity (RH), globe temperature index and humidity (BGT1 and BGT2), where BGT1 was inside the facilities and BGT2 in the open field. All weather variables showed significant differences (p 0.05). The RR was higher (p < 0.05) for T1, with an average of 55.88 mov/min. There was a significant difference (p < 0.05) between treatments for HR, with averages of 92.19 and 86.25 bat/min. for T1 and T2, respectively. According to the results it can be stated that the facilities for calves positively influenced the performance of heat loss, giving values closer to the comfort zone.

Objetivou-se neste trabalho verificar a adaptabilidade de bezerros mestiços (Holandês x Gir) criados a campo e nas instalações, em Bom Jesus, PI. Foram utilizados seis bezerros mestiços (Holandês x Gir) distribuídos em dois tratamentos: T1= Campo e T2= Instalações, com três animais em cada um, e mensurou-se 32 medidas repetidas no tempo, totalizando 192 observações (6 animais x 32 repetições por animal) durante o período experimental. Nos animais foram registradas as características fisiológicas como: a frequência respiratória (FR), frequência cardíaca (FC), temperatura retal (TR) e a taxa de sudação (TS). As variáveis meteorológicas foram: Temperatura do Ar (TA), Umidade Relativa do Ar (UR), Índice de Temperatura de Globo e Umidade (ITGU1 e ITGU2), onde ITGU1 estava dentro das instalações e o ITGU2 no campo aberto. Todas as variáveis meteorológicas apresentaram diferença significativa (p 0,05). A FR foi maior (p < 0,05) para T1, apresentando média de 55,88 mov/min. Houve diferença significativa (p < 0,05) entre os tratamentos para a FC, com médias de 92,19 e 86,25 bat/min. para os T1 e T2, respectivamente. De acordo com os resultados obtidos pode-se afirmar que as instalações para bezerros influenciaram positivamente no desempenho da perda de calor, conferindo valores mais próximos da zona de conforto.

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O objetivo deste estudo foi observar o comportamento de parâmetros fisiológicos de cavalos submetidos a exercícios físicos e competições de lidar com o touro se relacionam com o ambiente físico usando os valores de IBUTG. 12 cavalos mestiços raça quarto de milha têm sido usados com idade entre 5 e 16 anos, sendo três com pele branca, casaco castanho com quatro e cinco casaco tordilho. O delineamento experimental foi inteiramente casualizado, com dois tratamentos, em que um tratamento que se refere à manhã (T1) e outra mudança para a tarde de tratamento (T2) turno. Freqüência respiratória (FR) e freqüência cardíaca (FC) e Wet Bulb Globe temperatura (IBUTG) foram medidos. Houve diferença significativa (p 0,05) entre as duas rodadas de coleções que corresponde à mudança de 1 manhã (T1) e 2 turno da tarde (T2) para FC, FR e IBUTG, com taxas mais altas após a competição pega o boi . A FC (0,76) positivamente correlacionada com a FR e WBGT positivamente correlacionada com a FR (0,75) e FC (0,86). Pode-se concluir que os cavalos no valor de pega o boi mostrou alterações fisiológicas devido ao estresse associado com o exercício.(AU)

The aim of this study was to observe the behavior of physiological parameters horses undergoing physical exercises and competitions handle the bull correlate with the physical environment using the values of Wet Bulb Globe Temperature (WBGT). 12 crossbred horses race quarter mile have been used aged 5 to 16 years, three with white fur, chestnut coat with four and five dapple coat. The experimental design was completely randomized with two treatments, where a treatment referred to the morning (T1) and other treatment shift to afternoon (T2) shift. Respiratory rate (RR) and heart rate (HR) and WBGT were measured. There was a significant difference (p<0.05) between the two rounds of collections that corresponds to the 1st morning shift (T1) and 2 afternoon shift (T2) for HR, RR and WBGT, with higher rates after the competition in handle the ox. The FC (0.76) positively correlated with the FR and WBGT positively correlated with FR (0.75) and HR (0.86). It can be concluded that horses valued at handle the ox showed physiological changes due to stress associated with exercise.(AU)

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O objetivo deste estudo foi observar o comportamento de parâmetros fisiológicos de cavalos submetidos a exercícios físicos e competições de lidar com o touro se relacionam com o ambiente físico usando os valores de IBUTG. 12 cavalos mestiços raça quarto de milha têm sido usados com idade entre 5 e 16 anos, sendo três com pele branca, casaco castanho com quatro e cinco casaco tordilho. O delineamento experimental foi inteiramente casualizado, com dois tratamentos, em que um tratamento que se refere à manhã (T1) e outra mudança para a tarde de tratamento (T2) turno. Freqüência respiratória (FR) e freqüência cardíaca (FC) e Wet Bulb Globe temperatura (IBUTG) foram medidos. Houve diferença significativa (p 0,05) entre as duas rodadas de coleções que corresponde à mudança de 1 manhã (T1) e 2 turno da tarde (T2) para FC, FR e IBUTG, com taxas mais altas após a competição pega o boi . A FC (0,76) positivamente correlacionada com a FR e WBGT positivamente correlacionada com a FR (0,75) e FC (0,86). Pode-se concluir que os cavalos no valor de pega o boi mostrou alterações fisiológicas devido ao estresse associado com o exercício.

The aim of this study was to observe the behavior of physiological parameters horses undergoing physical exercises and competitions handle the bull correlate with the physical environment using the values of Wet Bulb Globe Temperature (WBGT). 12 crossbred horses race quarter mile have been used aged 5 to 16 years, three with white fur, chestnut coat with four and five dapple coat. The experimental design was completely randomized with two treatments, where a treatment referred to the morning (T1) and other treatment shift to afternoon (T2) shift. Respiratory rate (RR) and heart rate (HR) and WBGT were measured. There was a significant difference (p<0.05) between the two rounds of collections that corresponds to the 1st morning shift (T1) and 2 afternoon shift (T2) for HR, RR and WBGT, with higher rates after the competition in handle the ox. The FC (0.76) positively correlated with the FR and WBGT positively correlated with FR (0.75) and HR (0.86). It can be concluded that horses valued at handle the ox showed physiological changes due to stress associated with exercise.

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