Sheep meat production in the Brazilian semi-arid region: crossing between indigenous breeds.

Investigations in the Brazilian semi-arid region evaluating the performance and carcass traits of sheep of indigenous breeds and their crossings have been performed; however, these studies use exotic breeds which produce precocious lambs with heavier carcasses, but not adapted to climatic conditions and the extensive production system, jeopardizing the sustainability of the sheep production system. We crossed between three indigenous breeds: Morada Nova (MN - maternal breed); Rabo Largo (RL - paternal breed), and Santa Inês (SI - paternal breed) with the objective of evaluating the effect of genotype and sex on the performance and carcass traits of purebred and crossbred animals. A total of 30 lambs, males and females, reared in a semi-intensive system were evaluated. Birth and weaning weights were 2.26 ± 0.53 and 7.31 ± 1.85, respectively. All lambs were slaughtered at 10 months of age. A completely randomized design in a 3 × 2 factorial scheme (three genotypes and two sexes) was used. Multivariate techniques were also performed to reduce group and discriminate variables. Birth and weaning weight were similar (P > 0.05) among genetic groups and sexes. The weight gain, carcass and morphometric trait characteristics, and the main commercial cuts were higher in crossbred lambs (P < 0.05). All indicators have discriminatory power between genotypes and sexes, but the carcass traits have a higher discriminatory power (P < 0.001). All genotypes, regardless of sex, have particular characteristics, i.e. MN × SI was characterized by greater forelimb and ham perimeters (P < 0.001), and the MN × RL by higher hot carcass weight and finish (P = 0.001). The cluster analysis and the heatmap plot revealed associations between SI and the size of cuts and RL with the cut commercial yield and the reduction in weight loss due to cooling. Our findings confirm the hypothesis that crossing between indigenous breeds represents an adequate alternative in sheep meat production systems in semi-arid regions. Finally, we encourage the use of indigenous breeds for sheep meat production with breed identity in order to favor the conservation of genetic resources and the sustainability of the production system.

Understanding the dairy production systems in rural settlements in the Brazilian semi-arid region: characterization, typology, and holistic perception.

The objective of this study was to characterize and typify dairy farms and to evaluate society's perception of dairy production in rural settlements in the Brazilian semi-arid region. A questionnaire containing questions related to socioeconomic, livestock, physical, herd management, and production indicators was applied to 17 milk farmers for typological analysis. A second questionnaire was subsequently applied to the same 17 farmers for the holistic perception of dairy farming in rural settlements, in addition to 47 technicians in the area of animal science and 140 laypeople. Milk samples were collected in the settlement's community cooling tank, while the water used for milking management was collected in the milking parlor at the 17 farms. Multivariate analysis techniques and thematic analysis were performed. Three dairy production systems were identified: low production group (0-25 L), medium production group (25-50 L), and high production group (50-100 L). The physicochemical properties (composition, density, and cryoscopy) of milk attended the Brazilian regulation values. The microbiological parameters of milk and water used for milking are at odds with regulations. Regarding the typology, the indicators, livestock, and productivity showed discriminatory power (P < 0.05) between the productive systems. The responses from the segments of society showed different views on dairy production in rural settlements. It is concluded that the dairy farmers have low education and the cleaning product and water used in milking are out of regulation. The livestock and production indicators typified mainly dairy farms, while the holistic perception showed a lack of efficiency in rural extension, ignorance of the potential of the productive system. Finally, the creation of public policies focusing on the development of the milk production system in settlements is recommended.

Development of an animal adaptability index: Application for dairy cows.

The objective of this study was designed to evaluate the association between thermoregulatory responses, hormonal, hematological and serum biochemical values features aiming to propose an adaptability index (AI) for dairy cows under tropical conditions. Thirty adult dairy cows were used, including 15 Sindi and 15 Girolando breeds with mean weight of 338.52 ± 42.79 kg and 487.54 ± 60.67 kg, respectively. These data included rectal temperature (RT) and respiratory rate (RR). For the serum of blood sample, the levels of glucose (GLU), cholesterol (CHO), triglycerides (TRI), total protein (TP), creatinine (CRE), albumin (ALB), urea (URE), aspartate aminotrasferase (AST) and alanine aminotrasferase (ALT) and hormonal concentrations (triiodothyronine - T3 and thyroxine - T4). For the total blood samples were analyzed for hematology variables: red blood cell count (RBC); hemoglobin concentration (HC); packet cell volume (PCV); mean corpuscular volume (MCV); white blood cell (WBC). The AI was development using multivariate analysis to "weigh" the influence of each variable in the animal responses. The variables more important for adaptive aspects of Sindi and Girolando cows were respectively: GLU; MCV; AST; PCV; RBC; HE; TP; ALB; ALT; RR; T4; RT; T3; URE; CHO; TRI; CRE; WBC and ALB; GLU; TP; AST; RR; ALT; CRE; CHO; RT; RBC; T4; HE; PCV; MCV; URE; TRI; WBC; T3. The difference between breeds was just over 8% for AI. We developed a preliminary AI, able to measure the level of adaptability of dairy cows under tropical region. The methodological framework has potential to inform decision-makers on the adaptability animal conditions and high inference of the blood values from adaptability of cows.

Diversity of indigenous sheep of an isolated population.

BACKGROUND: Because of the influence of genetics on animal production and the risk of losing genetic diversity of naturally adapted breeds, this study evaluated the genetic diversity of sheep of the Morada Nova breed belonging to an animal science institute in Brazil. The herd in question is one of the country's most representative of the breed. Samples of DNA extracted from the plasma of 61 animals were used for later analysis of the genotypes using microsatellite molecular markers. RESULTS: The polymorphic information content was 0.66, the observed heterozygosity was 0.65 and the fixation index was 0.048. According to the results, there is moderate genetic diversity in the studied population, suggesting the implantation of breeding programs aimed at conservation of the observed genetic diversity. CONCLUSION: The results obtained in this study will be of great importance to decisions on herd structure, besides contributing to other work to be carried out at the research center.

Variants in the CYP19A1 gene can affect in vitro embryo production traits in cattle.

PURPOSE: This study aimed to associate DNA variants in promoter and exon flanking regions of the CYP19A1 gene with in vitro embryo production traits in cattle. The role of transcription factor binding sites created or lost due to DNA sequence variation and their possible effect on gene expression was also evaluated. METHODS: We collected date from Gyr dairy oocyte donor cows (Bos taurus indicus) at a commercial in vitro embryo production farm and analyzed the genotype-phenotype association with in vitro production traits. Using Sanger sequencing and web-based software, we assessed important CYP19A1 gene regions in oocyte donor cows and analyzed the effects of variants on the transcription factor binding sites. RESULTS: Two SNP mutations significantly associated with oocyte production, oocyte viability, embryo development, and pregnancies were found (T > C in the untranslated exon 1 flanking region ([GenBank: AJ250379.1]: rs718446508 T > C), and a T > C in the 5'-upstream region (1.1 promoter) ([GenBank: AC_000167.1]: rs41651668 T > C). Six new transcription factor binding sites were created. A binding site for transcription factors associated with the development of the placenta and embryo implantation was eliminated due to variations in the DNA sequence identified. CONCLUSIONS: The CYP19A1 gene contributes to genetic variation of in vitro embryo production traits in cattle. The complexity of the physiological phenomena related to estrogen pathways and their influence on reproduction in cattle allow indication of the mutations evaluated here as possible genetic markers for embryo production traits, which should be validated in the next steps of marker-assisted selection.

Characteristics of growth, carcass and meat quality of sheep with different feed efficiency phenotypes.

The objective was to evaluate the performance, carcass and meat quality of 40 lambs classified by RFI (residual feed intake) and RIG (residual intake and gain). Dry matter intake (DMI) was recorded to calculate the RFI and RIG, classified as efficient, moderately or inefficient. After the confinement period, they were slaughtered and the carcass and meat quality were determined. The efficient animals had DMI scores of 0.700 RFI and 0.400 kg/d RIG, lower than the inefficient ones with similar weight gain. The RFI efficient animals showed greater shear force, without effect in the RIG classification. In general, the variables analyzed were not influenced by RFI or RIG. Efficiency measures do not affect the carcass and meat quality of sheep, but they do have the advantage of identifying animals with lower feed consumption, making the system more efficient. However, as the dataset is limited to fully assess the effects, this manuscript can be used as preliminary results for future studies.

Evaluation of the breeding behavior of Brazilian Pony stallions.

The aim of this study was to evaluate the breeding behavior of Brazilian Pony stallions during semen collection to examine the effect of age category (AC) and month of evaluation on the characteristics of breeding behavior. Nine stallions were evaluated during the breeding and non-breeding season, 5-8 (AC1) and 9-13 years (AC2) of age. The variables evaluated were reaction time (RT), mount time one (MT1) and two (MT2), mount and ejaculation time (MEjT), mounting without erection (MWEr), mounting without ejaculation (MWEj), flehmen, kicks, bites, smells, vocalizations and serum testosterone concentration. Analyses of variance and correlation were performed. The average scores were RT: 56.2±92.9s, MT1: 115.0±122.4s, MT2: 196.4±160.7s, MEjT: 21.8±3.2s, MWEr: 0.8±1.3s, MWEj: 2.1±3.5s, flehmen: 3.8±3.0s, kicks: 0.3±1.2s, bites: 1.0±2.0s, smells: 5.7±3.5s, vocalizations: 6.4±6.3s and testosterone: 0.89±0.52ng/mL. The AC affected the RT (P<0.05) but not the other traits. Month of evaluation did not affect most variables (P>0.05). The correlations between age and RT and between age and MT1 and MT2 were significant. The correlation between testosterone and MEjT was moderate and negative. The breeding behavior of Brazilian Pony stallions was similar across different months of evaluation and different age categories. The month of evaluation and age category also did not affect testosterone concentrations, meaning that semen collection is feasible throughout the year.

Identification of polymorphisms in the myostatin and leptin genes of santa inês breed and crossbreed sheep and association with carcass traits / Identificação de polimorfismo nos genes da miostatina e leptina em ovinos santa inês e cruzados e associação com características de carcaça

The objective of this study was to identify polymorphisms in the myostatin and leptin genes in Santa Inês (SI) and crossbreed (SI x Dorper) sheep, to verify the effect of these polymorphisms on carcass traits. We evaluated seventy sheep of 8-month-old at the Federal Institute of Espírito Santo, Brazil. Data collected were slaughter weight (SW), hot carcass weight (HCW), cold carcass weight (CCW), loin weight, tenderloin weight and fat thickness (FT). The hot carcass yield (HCY) was calculated by the formula (HCW/SW) x 100. We collected hairs from each animal for DNA extraction by the alkaline protocol. The animals were genotyped for the G>A mutation in nucleotide 9827 of the myostatin gene and for three polymorphisms in exon 3 of the leptin gene, by the PCR-RFLP technique. The amplicons the myostatin and leptin gene were cleaved with restriction enzyme for allelic discrimination. The alleles were recorded for each animal and analysis of variance was performed to check the influence of the mutations on the carcass traits. The mutant allele of the myostatin gene showed association with increased measures of CCW, FT and with reduced HCY. Among the three alleles of the leptin gene, only one showed an effect (increased CCW). The other alleles were not associated with any traits.

O objetivo deste estudo foi identificar os polimorfismos nos genes da miostatina e leptina em Santa Inês (SI) e mestiças (SI x Dorper) ovelhas, para verificar o efeito desses polimorfismos sobre características de carcaça. Foram avaliadas setenta ovelhas com oito meses de idade, do Instituto Federal do Espírito Santo, Brasil. Os dados coletados foram o peso de abate (PA), peso de carcaça quente (PCQ), peso de carcaça fria (PCF), peso de lombo, peso lombinho e espessura de gordura de cobertura (ECG). O rendimento de carcaça quente (RCQ) foi calculado pela fórmula (PCQ/PA) x 100. Foram coletados pelos de cada animal para a extração de DNA pelo protocolo alcalino. Os animais foram genotipados para a mutação G>A no nucleotídeo 9827 do gene da miostatina e para três polimorfismos no exon 3 do gene da leptina, através da técnica PCR-RFLP. Os produtos de amplificação do gene da miostatina e da leptina foram clivados com a enzima de restrição para diferenciação alélica. Os alelos encontrados foram registrados para cada indivíduo e então foi realizada a análise de variância para verificar os efeitos das mutações sobre as características de carcaça pelo procedimento GLM do SAS. O alelo mutante do gene da miostatina mostrou associação com o aumento das médias PCF e ECG e com a redução do RCQ. Entre os três alelos do gene da leptina, apenas um apresentou efeito com aumento do PCF. Os demais alelos e as demais características não apresentaram associação.