Effect of heat stress on milk production of goats from Alpine and Saanen breeds in Brazil.

The purpose of this bibliography review was to approach the thermal comfort rates on milk production of goats from Alpine and Saanen breeds in Brazil. The caloric stress caused by weather changes to which the animals are submitted, influence on the mechanisms of normal physiological processes of the body. Thus, the effect on the lactation process in goats can be mentioned, where it decreases the amount of water in the body with the consequent decrease in synthesis and milk ejection interfering in the production of hormone prolactin and growth hormone. The animal?s interaction with the environment must be considered when the aim in livestock farming is welfare, because the different responses of the animal to the peculiarities of each region are crucial for the success of the animal adaptation. So, the correct identification of the factors that influence the productive life of the animal, such as the stress caused by the seasonal fluctuations of the environment, allow production systems management, making it possible to make them sustainable and viable. The maintenance of these parameters in normal levels is very important, to the point of being used in the evaluation of climate adaptability of breeds to a certain environmental condition. In this way, the concerns about animal welfare and environmental comfort are due to the climatic variables and the behavioral, physiological and productive responses are prevailing when implementing the suitability of certain production systems.

Ruminal methane emission by dairy cattle in southeast Brazil.

ABSTRACT: Ruminal gases, particularly methane, generated during the fermentative process in rumen, represent a partial loss of feed energy and are also pointed to as an important factors in greenhouse effect. This study aimed at quantifying methane (CH 4) emission rates from lactating and dry cows and heifers, 24 month-old in average, on pasture under Southeast Brazil tropical conditions, using the tracer gas technique, sulphur hexafluoride (SF 6), four animals per category, distributed in four blocks. Measurements were performed in February and June, 2002, with Holstein and Brazilian Dairy Crossbred (Holstein ¾ x Gir (Zebu) ¼), maintained on fertilized Tanzania-grass (Panicum maximum Jacq. cv. Tanzania) and fertilized Brachiaria-grass (Brachiaria decumbens cv. Basilisk) pastures. Heifers of both breeds were maintained on unfertilized Brachiaria-grass to simulate conditions of extensive cattle farming systems. CH 4 and SF 6 levels were measured with gas chromatography. Differences in CH4 emissions were measured (p < 0.05) for genetical groups. Holstein produced more methane (299.3g day?1) than the Crossbred (264.2 g day?1). Lactating cows produced more methane (353.8 g day?1) than dry cows (268.8 g day?1) and heifers (222.6 g day?1). Holstein, with greater milk production potential, produced less CH4 (p < 0.05) per unit of dry matter intake (19.1 g kg?1) than the Crossbred (22.0 g kg?1). Methane emission by heifers grazing fertilized pasture (intensive system) was 222.6 g day?1, greater (p < 0.05) than that of heifers on unfertilized pasture (179.2 g day?1). Methane emission varied as function of animal category and management intensity of production system.

Genome-wide copy number variation (CNV) detection in Nelore cattle reveals highly frequent variants in genome regions harboring QTLs affecting production traits.

Background: Copy number variations (CNVs) have been shown to account for substantial portions of observed genomic variation and have been associated with qualitative and quantitative traits and the onset of disease in a number of species. Information from high-resolution studies to detect, characterize and estimate population-specific variant frequencies will facilitate the incorporation of CNVs in genomic studies to identify genes affecting traits of importance. Results: Genome-wide CNVs were detected in high-density single nucleotide polymorphism (SNP) genotyping data from 1,717 Nelore (Bos indicus) cattle, and in NGS data from eight key ancestral bulls. A total of 68,007 and 12,786 distinct CNVs were observed, respectively. Cross-comparisons of results obtained for the eight resequenced animals revealed that 92 % of the CNVs were observed in both datasets, while 62 % of all detected CNVs were observed to overlap with previously validated cattle copy number variant regions (CNVRs). Observed CNVs were used for obtaining breed-specific CNV frequencies and identification of CNVRs, which were subsequently used for gene annotation. A total of 688 of the detected CNVRs were observed to overlap with 286 non-redundant QTLs associated with important production traits in cattle. All of 34 CNVs previously reported to be associated with milk production traits in Holsteins were also observed in Nelore cattle. Comparisons of estimated frequencies of these CNVs in the two breeds revealed 14, 13, 6 and 14 regions in high (>20 %), low (<20 %) and divergent (NEL > HOL, NEL < HOL) frequencies, respectively. Conclusions: Obtained results significantly enriched the bovine CNV map and enabled the identification of variants that are potentially associated with traits under selection in Nelore cattle, particularly in genome regions harboring QTLs affecting production traits.

Qualidade da carne de ovinos puros e cruzados criados no Semiárido Nordestino brasileiro.

Resumo: A procura por carne de qualidade tem proporcionado ao setor de ovinocultura a adoção por técnicas de produção que possam contribuir para disponibilizar ao mercado produtos que atendam as necessidades dos consumidores, que se tornam cada vez mais exigentes quanto à aquisição de produtos que possam trazer benefícios a saúde. Assim, objetivou-se determinar a qualidade da carne de ovinos puros e cruzados criados no semiárido Nordestino. Utilizaram-se 30 cordeiros machos e fêmeas, oriundos dos cruzamentos Morada Nova x Morada Nova, Rabo Largo x Morada Nova e Santa Inês x Morada Nova, alojados em baias e alimentados com dieta a base de capim Canarana, milho farelo de soja e calcário. Os animais foram abatidos com peso médio de 24 kg de peso vivo e as carcaças mantidas em câmara frigorífica a 4?C, por 24 horas. Após esse período, foi seccionado o músculo Longissimus dorsi que foi embalado, identificado e armazenado a 20?C. Foram determinados os atributos físicos de capacidade de retenção de água, perda de peso por cocção e força de cisalhamento; os atributos químicos como umidade, proteína, cinza, lipídios e colesterol; avaliações subjetivas da carcaça como cor, marmoreio, textura da carne, distribuição da gordura, espessura da gordura e área de olho de lombo; os sensoriais de dureza, suculência, sabor, aroma e aceitação global e o perfil de ácidos graxos. O delineamento utilizado foi em esquema fatorial 3x2 (três grupos genéticos e dois sexos) e as médias comparadas pelo teste de Duncan a 5%. Não houve diferença (p>0,05) entre os genótipos para a composição química da carne, exceto para a variável lipídio (p<0,05). Para as características subjetivas da carcaça o genótipo influenciou (p<0,05) nas variáveis cor, marmoreio e textura da carne. O genótipo promoveu efeito (p<0,05) para as características físicas de capacidade de retenção de água e perda de peso por cocção. Os atributos sensoriais não sofreram efeitos (p>0,05) dos genótipos avaliados. Os genótipos influenciaram (p<0,05) as concentrações dos ácidos graxos saturados, monoinsaturados e poli-insaturados assim como, nas relações ?3:?6 e AGM:AGS. O fator sexo influenciou (p<0,05) nas variáveis umidade, força de cisalhamento, dureza, ácidos graxos desejáveis e relação ?3:?6. O cruzamento entre raças nativas mostrou-se com potencial para a produção de carne de qualidade, a raça Morada Nova melhorou os atributos físico-químicos da carne e em seu perfil lipídico e, o fator sexo melhorou o atributo maciez dando destaque a carne das fêmeas. Abstract: The demand for quality meat products has given the sheep industry sector productions techniques that can contribute providing the market with products that supply the needs of consumers require, who are becoming more demanding as the acquisition of differentiated and bring health benefits. The objective was to evaluate the quality of the pure sheep meat and cross bred in the semiarid Northeast of Brazil. It was used 30 male lambs and female, that came from crosses Morada Nova x Morada Nova, Rabo Largo x Morada Nova and Santa Ines x Morada Nova, housed in pens and fed a diet of grass Canarana, corn soybean meal and limestone. The animals were slaughtered at average weight of 24 kg, live weight, and carcasses kept in refrigeration chamber at 4 ° C for 24 hours. After this period the Longissimus dorsi muscle was selected, packaged, labeled and stored at 20˚C. The physical attributes were determined such as water holding capacity, cooking weight loss and shear force; the chemical attributes such as moisture, protein, ash, lipids and cholesterol; Subjective evaluations such as color, marbling, meat texture, fat distribution, fat thickness and loin eye area; the hardness sensory, juiciness, flavor, aroma and global acceptance and fatty acid profile. The design was a 3x2 factorial arrangement (three genetic groups and two genders) and the measures compared by Duncan test at 5%. There was no difference (p> 0.05) between genotypes for the chemical composition of meat, except for the lipid variable (p <0.05). To the subjective characteristics of the carcass, the genotype influenced (p <0.05) in the variables color, marbling and meat texture. The genotype promoted significant effect (p <0.05) for the physical characteristics, water retention capacity and weight loss on cooking. The sensory attributes did not suffer significant effects (p> 0.05) of the evaluated genotypes. The genotypes influenced (p <0.05) in the concentrations of saturated fatty acids, monounsaturated and polyunsaturated as well as in the relations ω3: ω6 and AGM:AGS. The gender factor influenced (P <0.05) in the variables moisture, shear strength, hardness, desirable fatty acids and relation ω3: ω6. The cross between native breeds showed up with potential for quality meat production, the Morada Nova improved the physical and chemical attributes of the flesh and in their lipid profiles and sex factor improved softness attribute highlighting the meat of females.

Polymorphisms in the DGAT1 gene in buffaloes (Bubalus bubalis) in the Amazon.

Water buffaloes (Bubalus bubalis) are quite well adapted to climatic conditions in the Amazon, and in this biome, they are noted for the considerable amount of meat and milk they produce and how hard they are able to work. Because of a lack of research dedicated to improving the rearing of buffaloes in the Amazon, the objective of this study was to genetically characterize the Murrah and Mediterranean breeds, as well as a mixed-breed population, based on polymorphisms in the diacylglycerol O-acyltransferase 1 gene (DGAT1), and associate the genotypes with milk production. By using the polymerase chain reaction-single-strand conformation polymorphism technique, the alleles A (0.79), B (0.20), and D (0.01) were found in the Murrah breed. In the Mediterranean and mixed-breed buffaloes, we found alleles A (0.69) and (0.77) and B (0.31) and (0.23), respectively. The Murrah breed had the genotypes AA (0.63), AB (0.29), BB (0.05), and AD (0.03), and the Mediterranean and mixed-breed buffaloes had the genotypes AA (0.44) and (0.61), AB (0.50) and (0.31), and BB (0.06) and (0.08), respectively. For the Murrah, Mediterranean, and mixedbreed buffaloes, respectively, the expected heterozygosity values were 0.34, 0.43, and 0.35, the inbreeding coefficients were 0.78, -0.15, and 0.17, and the Hardy-Weinberg probabilities were 0.70, 0.67, and 0.52. The genotypes evaluated did not have an effect on milk production; however, the single nucleotide polymorphisms can be used in studies on genetic variability.

Genome-wide detection of CNVs and their association with meat tenderness in Nelore cattle.

Brazil is one of the largest beef producers and exporters in the world with the Nelore breed representing the vast majority of Brazilian cattle (Bos taurus indicus). Despite the great adaptability of the Nelore breed to tropical climate, meat tenderness (MT) remains to be improved. Several factors including genetic composition can influence MT. In this article, we report a genome-wide analysis of copy number variation (CNV) inferred from Illumina1 High Density SNP-chip data for a Nelore population of 723 males. We detected >2,600 CNV regions (CNVRs) representing 6.5% of the genome. Comparing our results with previous studies revealed an overlap in 1400 CNVRs (>50%). A total of 1,155 CNVRs (43.6%) overlapped 2,750 genes. They were enriched for processes involving guanosine triphosphate (GTP), previously reported to influence skeletal muscle physiology and morphology. Nelore CNVRs also overlapped QTLs for MT reported in other breeds (8.9%, 236 CNVRs) and from a previous study with this population (4.1%, 109 CNVRs). Two CNVRs were also proximal to glutathione metabolism genes that were previously associated with MT. Genome-wide association study of CN state with estimated breeding values derived from meat shear force identified 6 regions, including a region on BTA3 that contains genes of the cAMP and cGMP pathway. Ten CNVRs that overlapped regions associated with MT were successfully validated by qPCR. Our results represent the first comprehensive CNV study in Bos taurus indicus cattle and identify regions in which copy number changes are potentially of importance for the MT phenotype.