Differential Expression of IGF Family Members in Heat-Stressed Embryos Produced In Vitro from OPU-Derived Oocytes of Nelore (Bos indicus) and Holstein (Bos taurus) Cows

Contents The IGF system is related to embryo quality. We aim to determine the effect of the heat stress on the mRNA expression of IGF1 and IGF2, IGFR1 and IGFR2, IGFBP2 and IGFBP4, and PAPPA in in vitro production (IVP) blastocysts from Nelore and Holstein after ovum pick up (OPU) to better understand the differences between these breeds.Oocytes from four Nelore and seven Holstein were collected in six OPU sessions. Following in vitro maturation and fertilization using six Nelore or Holstein sires, embryos were divided into control (cultured at 39 degrees C) and heat stress (HS; exposed to 41 degrees C for 9h). Blastocysts were submitted to RNA extraction. The IGF1 expression was higher in blastocysts under HS in both breeds, and the expression of IGFBP2 and IGFBP4 was higher in Holstein blastocysts under HS. The high PAPPA expression and the low expression of IGFBP2 and IGFBP4 are associated with a more efficient degradation of IGFBPs, which results in greater IGF bioavailability in Nelore blastocysts and may contribute to the superior HS tolerance in Nelore, when compared to Holstein.

Characterization of methicillin-resistant coagulase-negative staphylococci in milk from cows with mastitis in Brazil

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Diversity of Staphylococcus species and prevalence of enterotoxin genes isolated from milk of healthy cows and cows with subclinical mastitis

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Single Nucleotide Variations in the Buffalo Kappa-Casein Gene (CSN3)

Caseins are the major milk proteins associated with lactation performance, milk composition and cheese yield efficiency, representing around 80% of the total amount of proteins found in milk. Among the caseins, kappa-casein is the protein that stabilizes micelle structure during milk coagulation process and being used during the cheese production. The kappa-casein gene (CSN3) has been previously mapped to buffalo chromosome 7 using a radiation hybrid panel and a comparative map was established using the sequence from bovine chromosome 6. The molecular structure of this gene has also been established in river buffalo, with a total length of 13,191 bp (GenBank: AM900443.1) and containing five exons. In this study we searched for single nucleotide variations in specific regions of the CSN3 gene in three animals representing the Murrah breed. Sequencing reactions were performed using ABI3730xl sequencer. The primer walking method was used to span the 5'-UTR and intron 2 regions of the gene, for which ten primer pairs were designed using Oligo 6 software. BLAST tool was used to verify the primers specificity. DNA sequences assemblies from all three animals were performed with Sequencher (R) software 4.1, while multiple alignments were performed using Clustal W software to identify single nucleotide variations. The sequencing revealed a total of 19 single nucleotide variations with 13 located in the upstream regulatory region of the gene (5'-UTR) and six on intron 2. These variations can be validated using commercial populations segregating specific economic traits.

Cattle-Derived Microsatellite Markers to Study the Water Buffalo Genome

Microsatellites are well-known DNA markers used in a variety of studies such as genome mapping, genetic diversity analysis, genetic conservation and phylogenetic studies. Although microsatellites are important markers, their development and characterization demands extensive time and high cost. Thus, before new markers are developed for a particular species, it is worthwhile to test the available markers from related species. In the present study, we evaluate cattle-derived microsatellite markers for genetic studies of water buffalo. Eighty-five percents of a total of 120 microsatellite markers were optimized using buffalo DNA (Bubalus bubalis). The results showed in this paper were also deposited in the National Center for Biological Information database (NCBI) (ProbeDB and UniSTS) for use in population genetic studies of buffalo by the scientific community. The use of heterologous primers significantly reduces the cost of developing specific markers for buffalo, providing a useful short cut for the genetic population analysis and gene mapping studies.

Control of Buffalo Follicular Dynamics for Artificial Insemination, Superovulation and In Vitro Embryo Production

Currently, timed ovulation induction and timed artificial insemination (TAI) can be performed in buffalo using GnRH or estradiol plus progesterone/progestin (P4)-releasing devices and prostaglandin F-2 alpha (PGF(2 alpha)). The control of the emergence of follicular waves and of ovulation at predetermined times, without the need for estrus detection, has facilitated the management and improved the efficiency of AI programs in buffalo during the breeding and nonbreeding season. Multiple ovulations, embryo transfer, ovum collection and in vitro embryo production have been shown to be feasible in buffalo, although low efficiency and limited commercial application of these techniques have been documented as well. These results could be associated with low ovarian follicular pools, high levels of follicular atresia and failures of the oocyte to enter the oviduct after superstimulation of follicular growth. This review discusses a number of key points related to the manipulation of ovarian follicular growth to improve pregnancy rates following TAI and embryo transfer of in vivo- and in vitro-derived embryos in buffalo.

Progestin-Based Protocol for Synchronization of Follicular Wave Emergence in Buffaloes During Summer and Winter

The aim of the present study was to evaluate the effects of type of norgestomet auricular implant (new - N or previously used during 5 days - U), season of the year (summer - S and winter - W), and parity (12 heifers - H and 23 cows - C) on synchronization of follicular wave emergence in buffaloes. For this purpose, 35 buffaloes were examined daily by ultrasonography until follicular wave emergence was detected. Data were analysed by ANOVA, using PROC GLIMMIX. No interactions were observed in none variables. Time of follicular wave emergence and number of follicles at emergence were not affected by type of implant or season of the year. Parity also did not influence the number of follicles at emergence. However, follicular wave emergence occurred later in heifers than in cows. In conclusion, the previous use of a norgestomet auricular implant independent of the season of the year does not affect the time or the number of follicles at follicular wave emergence in buffaloes. Nevertheless, although heifers and cows had a similar number of follicles at emergence, the time of follicular wave emergence occurs earlier in cows than in heifers.

Influence of Parity and Season of the Year on Oocyte Quality and Number in Buffaloes

The aim of the present study was to evaluate the effects of season of the year (summer and winter) and parity (heifers and cows) on oocyte quality and number in buffaloes. For this purpose, 71 buffaloes had follicular wave emergence synchronized before OPU. OPU of all follicles >= 2mm was done 5 days after the beginning of the hormonal protocol, in 4 replicates (two for each season). Data were analyzed by ANOVA using PROC GLIMMIX, in a 2 x 2 factorial arrangement of treatments. No interactions were observed in following variables: number of follicles, number of total and viable oocytes, recovery rate, percentage of viable oocytes, grade I oocytes, grade II oocytes, grade III oocytes, denuded oocytes, expanded cumulus oocytes, and atretic/degenerated oocytes. Number of follicles visualized at OPU and recovery rate were not affected by parity or season. Relative to parity, number of total and viable oocytes were greater in heifers than in cows, respectively. Concerning season of the year, number of viable oocytes and viable oocyte rate were increased in winter. In conclusion, better oocyte quality can be obtained from heifers and during winter in buffaloes. However, the number of total oocytes seems to be more influenced by parity than by season of the year in this species.

Tuberculosis prevalence and risk factors for water buffalo in Para, Brazil

The prevalence of and possible risk factors for tuberculosis were studied in water buffalo from Para, Brazil. In this study, 3,917 pregnant and nonpregnant female Murrah and Mediterranean buffaloes were studied; 2,089 originated from Marajo Island, and 1,108 were from the mainland. The comparative cervical tuberculin test was used as a diagnostic test for tuberculosis in these animals. The prevalence of positive buffaloes was 3.5 % (100/2,809) on Marajo Island and 7.2% (80/1,108) on the mainland. The municipalities with the highest tuberculosis prevalence rates in animals were Ipixuna do Para (10.1 %), Marapanim (9.8 %), Chaves (9.4 %), Paragominas (8.6 %), and Cachoeira do Arari (6.7 %). The tuberculosis prevalence was not significantly different between the Murrah (4.3 %) and Mediterranean (4.8 %) breeds or between pregnant (5%) and nonpregnant (4.3%) buffaloes. Tuberculosis was detected in water buffaloes from Para, Brazil; the mainland buffalo exhibited the highest tuberculosis prevalence. These results indicate that this disease is dangerous to public health and buffalo farming in Para.

Detection of Shiga toxigenic (STEC) and enteropathogenic (EPEC) Escherichia coli in dairy buffalo

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Genetic association between milk yield, stayability, and mastitis in Holstein cows under tropical conditions

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Multiple-trait genomic evaluation for milk yield and milk quality traits using genomic and phenotypic data in buffalo in Brazil

The use of markers distributed all long the genome may increase the accuracy of the predicted additive genetic value of young animals that are candidates to be selected as reproducers. In commercial herds, due to the cost of genotyping, only some animals are genotyped and procedures, divided in two or three steps, are done in order to include these genomic data in genetic evaluation. However, genomic evaluation may be calculated using one unified step that combines phenotypic data, pedigree and genomics. The aim of the study was to compare a multiple-trait model using only pedigree information with another using pedigree and genomic data. In this study, 9,318 lactations from 3061 buffaloes were used, 384 buffaloes were genotyped using a Illumina bovine chip (Illumina Infinium (R) bovineHD BeadChip). Seven traits were analyzed milk yield (MY), fat yield (FY), protein yield (PY), lactose yield (LY), fat percentage (F%), protein percentage (P%) and somatic cell score (SCSt). Two analyses were done: one using phenotypic and pedigree information (matrix A) and in the other using a matrix based in pedigree and genomic information (one step, matrix H). The (co) variance components were estimated using multiple-trait analysis by Bayesian inference method, applying an animal model, through Gibbs sampling. The model included the fixed effects of contemporary groups (herd-year-calving season), number of milking (2 levels), and age of buffalo at calving as (co) variable (quadratic and linear effect). The additive genetic, permanent environmental, and residual effects were included as random effects in the model. The heritability estimates using matrix A were 0.25, 0.22, 0.26, 0.17, 0.37, 0.42 and 0.26 and using matrix H were 0.25, 0.24, 0.26, 0.18, 0.38, 0.46 and 0.26 for MY, FY, PY, LY, % F, % P and SCCt, respectively. The estimates of the additive genetic effect for the traits were similar in both analyses, but the accuracy were bigger using matrix H (superior to 15% for traits studied). The heritability estimates were moderated indicating genetic gain under selection. The use of genomic information in the analyses increases the accuracy. It permits a better estimation of the additive genetic value of the animals.

Diurnal behavior of dairy cows on alfalfa pastures supplemented with corn silage and concentrate

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Nutritional value of high moisture corn silage in the diet of Holstein cows

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Identification of Candida species isolated from cows suffering mastitis in four Brazilian states

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)