Expression of estrus modifies the gene expression profile in reproductive tissues on Day 19 of gestation in beef cows

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Reproductive efficiency of Nellore cows nursing Nellore or crossbred Simmental x Nellore calves

The objective of this study was to analyze the influence of genetic group (GG) of the calf during gestation, mobilization of body reserves and period of postpartum anestrus in Nellore cows. Thirty-seven primiparous and multiparous cows were used: 24 gave birth to Nellore (NEL), and 13 gave birth to 1/2 Simmental x 1/2 Nellore (SIM) calves. According to the date of calving, cows were divided into three blocks, with intervals of 20 days between blocks. The body condition (BC) of the cows was estimated subjectively on a scale from 0 to 5 points, with intermediate grading of 0.5 points. We measured the thickness of subcutaneous fat (SF) between the 12th and 13th ribs and rump by ultrasound. Blood samples from each cow were collected weekly from the third week after birth until weaning, to analyze the level of progesterone; in the samples collected until 16 weeks postpartum, we analyzed the concentration of nonesterified fatty acids(NEFA). The gestation period of mothers of NEL calves was eight days longer, on average. The variables relating to the mobilization of body reserves (NEFA, BC and SF) were not influenced by calf GG, with the only significant effects being the number of days postpartum, witha peak in the concentration of NEFA between the sixth and eighth weeks and linear decrease in BC and NF. Mothers of NEL calves remained in anestrus for 4.6 weeks longer than the mothers of crossbred calves.

Influence of lineage of oocyte donor on the yield and morphology of oocytes recovered by ultrasound-guided follicular aspiration in nellore cows

The objective of this study was to investigate the influence of lineage of oocytes donors on the number and quality of oocytes obtained through ultrasound-guided follicular aspiration in Nellore breed cows derived from two lineages of bulls (Karvadi; K and Taj-Mahal; T). Both maternal (Km and Tm) and paternal (Kp and Tp) lineages, as well as their combinations were investigated. Oocyte aspirations were repeatedly performed with an aspiration interval of 15 days in 56 donor females. Recovered cumulus oocyte-complexes (COCs) were counted, morphologically examined and classified into seven categories (grades from I to VII) according to the number of layers of the cumulus oocyte and cytoplasm appearance. The mean number of oocytes retrieved from donors of lineage Tp-Tm was significantly higher (28.23±1.92, P<0.05) than those obtained from lineages Kp-Tm, Kp-Km, and Tp-Km (21.34±1.32, 21.28±1.73, and 16.72±1.31, respectively). There was no significant difference in the mean number of recovered oocytes between donors of lineages Kp-Km and Kp-Tm, whereas animals of lineage Tp-Km yielded the lowest number of oocytes. Higher mean number of grade III oocytes was recovered from donors of lineage Kp than lineage Tp (10.11±0.66 versus 8.79±0.58, respectively), with more grade III oocytes being obtained in both lineages as compared to the others. Paternal lineage did not influence the quality of recovered oocytes in any other category, but both Kp and Tp yielded a great mean number of oocytes graded as I, II, and III (3.14±0.21; 4.93±0.33, and 10.11±0.66 versus 3.19±0.21, 5.59±0.44, and 8.79±0.58, respectively) than those classified as IV, V, VI, and VII. However, when considering the data from the maternal lineage significantly more oocytes (P<0.05) of grade I, II and III were obtained from Taj-Mahal (11.67 ± 0.67, 5.9±0.42 and 3.64±0.25, respectively) than for lineage Karvadi, with similar results for oocytes of grades IV, V, VI, and VII. Similarly to the paternal lineage, the number of oocytes of grade III was superior (P<0.05) when compared to other categories for both lineages. In conclusion, we demonstrate here a direct influence of lineage of oocyte donor on the production and quality of oocytes obtained through ultrasound-guided follicular aspiration in Nellore cows.

Hypospadias in buffalo (Bubalus bubalis) mediterranean breed-case report

Hypospadias is a rare congenital condition characterized by abnormal development of the penile urethra, penis, scrotum and prepuce. The etiopathogenesis is still not fully elucidated, but it is based on a deficiency of testosterone during the critical stage of morphogenesis. At UNESP’s experimental farm was born a Mediterranean breed buffalo calf with congenital abnormalities in the reproductive system, being diagnosed with hypospadias.

Prostaglandin receptors (EP2 and EP4) and angiotensin receptor (AGTR2) mRNA expression increases in the oviducts of Nelore cows submitted to ovarian superstimulation

Many peptides are responsible for the coordination of muscle contraction, secretion and ciliary beating of the oviduct epithelium to allow the transport of gametes and embryos, including vascular endothelial growth factors (VEGF), prostaglandins (PGs), endotelin-1 (ET-1) andangiotensinII(Ang II). The effect of reproductive biotechnologiesusedto improve embryo yield on oviduct gene expression is poorly understood. Thus, the aim of the present study was to evaluate the effect of ovarian superstimulation on the mRNA expression of the genes encoding the major peptides involved in oviduct contraction in bovine. Therefore, Nelore cows were submitted to P-36 (n = 5) or P-36/eCG (n = 5) ovarian superstimulatory protocols and a control group of cows was not submitted to any superstimulatory protocol (n = 5). The relative expression of VEGF (VEGF, Flk1, Flt1), Ang II (AGTR2, ACE1), ET1 (ET1, ECE1) and PG pathway members (PGES, EP2, EP4, COX1, COX2) was analyzed using real time RT-PCR in each of oviduct segment (infundibulum, ampulla and isthmus). All target genes were expressed in the three segments of the bovine oviduct; however, specific genes were regulated by ovarian superstimulation: EP2 and EP4 receptors mRNA was affected by P- 36/eCG protocol, in the ampulla and infundibulum, respectively; and AGTR2 mRNA was up-regulated by both the P-36/eCG and P-36 protocols in the isthmus. The upregulation of EP2, EP4 and AGTR2 expression in the superstimulated cows suggests a suitable effect of FSH and eCG on bovine oviduct physiology, coordinating the contraction in Nelore cows