The aim of this study was to evaluate the effect of daily biotin supplementation on the mineral composition and microstructure of the abaxial hoof wall in dairy heifers. The heifers were housed on a concrete floor and fed for weight gain more than 800 g per day, which is a challenging environment for the hoof. Twelve crossbred dairy heifers (Jersey × Holstein) were divided into two treatment groups. Animals in the control group (n = 6) received a diet without supplemental biotin, while the heifers in the biotin‐supplemented feed group (n = 6) each received 20 mg of biotin daily for 120 days. Samples of the abaxial hoof wall were collected from the outer claw of the fore and hind limb, before and after supplementation. The samples were evaluated by X‐ray fluorescence spectrometry, computed microtomography, atomic force microscopy and confocal laser scanning microscopy. Biotin supplementation increased the sulphur content and decreased the calcium and potassium content in the abaxial hoof wall. Biotin treatment also increased the percentage of horn tubules with smaller diameter marrow (17–51 µm). However, biotin did not influence the surface relief of the hoof wall, suggesting that its action is limited to the inner layers of the stratum corneum. Daily supplementation with 20 mg of biotin promoted changes in the mineral composition and microstructure of abaxial hoof wall of crossbred dairy heifers. These findings suggest biotin supplementation improves hoof quality and may help to understand the function of biotin in the stratum corneum.

Milk production phenotypes are the main focus of genetic selection in dairy herds, and although there are many genes identified as related to the biology of these traits in pure breeds, little is known about crossbreed animals. This study aimed to identify potential genes associated with the 305-day milk yield in 337 crossbreed Gir × Holstein (Girolando) animals. Milk production records were genotyped for 45,613 single-nucleotide polymorphisms (SNPs). This dataset was used for a genome-wide association study (GWAS) using the 305-day milk yield adjusted for the fixed effects of herd and year and linear and quadratic effects of age at calving (in days) and calving factor averaged per animal. Genes within the significant SNPs were retrieved from the Bos taurus ARS-UCD1.2 assembly (bosTau9) for gene ontology analysis. In summary, the GWAS identified 52 SNPs associated [p ≤ 10–4, false discovery rate (FDR) = 8.77%] with milk production, including NUB1 and SLC24A2, which were previously described as related to milk production traits in cattle. The results suggest that SNPs associated mainly with NUB1 and SLC24A2 could be useful to understand milk production in Girolando and used as predictive markers for selecting genetic predisposition for milk yield in Girolando.

No abstract

This study represents a first attempt to rescue germplasm of a traditional domestic equine cited in early Iberian and South American literature as Curraleiro horse. As an effort to identify and possibly characterize this type of horse we accessed traditional knowledge in strategic rural areas. Most areas were configured by hinterland settlements founded by runaway slave communities from the sixteenth century. Twenty interviews were conducted and analyzed using classical Speech Content Analysis. As a result, five response categories were recognized: 1) Identification and location of Curraleiro horses; 2) Characterization of Curraleiro horses; 3) Historical aspects; 4) Curraleiro horse conservation prospects and 5) Sanitary and productive aspects of Curraleiro horse breeding. We concluded that although scarce, the Curraleiro horse, cited in literature, still exists and showed phenotypical features which allow fine discrimination from any officially recognized breed in Brazil. Our findings may open the door for the recognition of a genuine animal resource which could play a role in rural development for specific regions and traditional communities. Speech Content Analysis was effective for in loco identification and characterization of rare traditional livestock. Thus, we encourage the usage of this tool as an alternative to subsidize identification and genetic conservation programs worldwide.

Chromosome banding techniques were applied and standardized to obtain karyotype characteristics for the first time in Brazil of Nelore cattle – Bos taurus indicus Linnaeus, 1758 – (bovine subspecies most prominent in Brazilian livestock). Blood samples were collected from the animals of the School of Agrarian and Biological Sciences of the Pontifical Catholic University of Goiás, two males and two females of pure breed. These samples were submitted to the cell culture method to study metaphase chromosomes. Chromosome banding techniques (C, G and NOR) revealed the karyotype architecture of Nelore cattle common with that of other breeds of zebu cattle formerly karyotyped. The diploid chromosome number was invariably normal, 2n = 60. C-banding revealed C-positive heterochromatin in centromeric regions almost in all chromosomes. G-banding presented the expected band pattern in the respective chromosome pairs in correspondence with the established chromosomal patterns for the species. Ag-staining for nucleolus organizer regions (AgNOR) was identified on the telomeric end of the long arm in 7 autosomal chromosomes. In this study we found more regions in chromosomes with staining than presented in the literature for the Bos indicus group (BIN). These NOR regions were repeated on the same chromosomes for the 4 animals studied.

Although vaccination is indispensable for animal production, the use of unhygienic needles can lead to post-vaccine abscesses and consequently loss of meat products and higher production costs. The aim of this study was to evaluate the efficiency of needle hygiene in the prevention of post-vaccine abscesses in cattle, estimate economic losses caused by post-vaccine abscesses, and verify whether cattle farmers sanitize the needles used in vaccination. Four groups containing 120 cattle were vaccinated against the foot-and-mouth disease. The GI, GII, and GIII groups were vaccinated using needles sanitized by different methods, while the GIV group served as control. Six months after vaccination, ultrasound exams were performed and abscesses were quantified. Subsequently, cattle were slaughtered, carcass losses due to the presence of abscesses were quantified, and economic losses were calculated. In slaughterhouses, 100 cattle farmers were interviewed on the adoption of needle hygiene for vaccines and the number of cattle they slaughtered. The numbers of abscesses diagnosed per group were as follows: GI (n = 3, 2.5%), GII (n = 5, 4.2%), GIII (n = 4, 3.3%), and GIV (n = 11, 9.2%). The occurrence of abscesses in GI, GII, and GIII did not differ statistically from each other but was statistically lower than that observed in GIV. The economic losses due to the presence of abscesses in the carcasses varied from R$ 0.12 to R$ 0.31 per animal of the herd whose needles were sanitized or not, respectively. Only 13% of the interviewed cattle farmers carried out some method of needle hygiene for vaccination. 78.8% of the slaughtered cattle were vaccinated with needles without any sanitization method. Thus, needle hygiene for cattle vaccination decreases the occurrence of post-vaccine abscesses. This practice minimizes losses by R$ 0.19 per animal due the damages caused by the removal of abscesses during the slaughter of animals. Most cattle farmers do not adopt needle hygiene for cattle vaccination.

No abstract

As doenças digitais ocasionam grandes prejuízos à bovinocultura, pois causam dor e resultam em claudicação que, por sua vez, promove redução do bem-estar animal e compromete a produtividade. As afecções podais em bovinos também ocasionam prejuízos relacionados a gastos com tratamento medicamentoso e cirúrgico, redução da fertilidade e descarte precoce de animais. A estrutura e a qualidade do casco dependem de um adequado processo de queratinização, que é influenciado pelo satisfatório suprimento de nutrientes como aminoácidos, lipídios, vitaminas e minerais. A deficiência de nutrientes importantes para a formação do estojo córneo promove síntese de tecido queratinizado de baixa qualidade e com maior suscetibilidade a danos químicos, físicos e microbianos. Dessa forma, a nutrição é importante para a formação de um estojo córneo resistente e, também, para a redução da incidência de doenças digitais em bovinos. Diante disso, objetivou-se com o presente artigo fazer uma revisão sobre a implicação dos aminoácidos, minerais e vitaminas para a saúde do casco bovino.