Abstract:Two ultrasound based fertility prediction methods were tested prior to embryo transfer (ET) and artificial insemination (AI) in cattle. Female bovines were submitted to estrous synchronization prior to ET and AI. Animals were scanned immediately before ET and AI procedure to target follicle and corpus luteum (CL) size and vascularity. In addition, inseminated animals were also scanned eleven days after insemination to target CL size and vascularity. All data was compared with fertility by using gestational diagnosis 35 days after ovulation. Prior to ET, CL vascularity showed a positive correlation with fertility, and no pregnancy occurred in animals with less than 40% of CL vascularity. Prior to AI and also eleven days after AI, no relationship with fertility was seen in all parameters analyzed (follicle and CL size and vascularity), and contrary, cows with CL vascularity greater than 70% exhibit lower fertility. In inseminated animals, follicle size and vascularity was positive related with CL size and vascularity, as shown by the presence of greater CL size and vascularity originated from follicle with also greater size and vascularity. This is the first time that ultrasound based fertility prediction methods were tested prior to ET and AI and showed an application in ET, but not in AI programs. Further studies are needed including hormone profile evaluation to improve conclusion.

We evaluated the effects of nulliparous, primiparous, and multiparous conditions on the estrus and pregnancy rates in females that did not show estrus but were treated with gonadotropin-releasing hormone (GnRH) at the time of timed artificial insemination (TAI). Nelore females (n = 531) were allocated according to the following categories: nulliparous (n = 144), primiparous (n = 132), and multiparous (n = 255). The animals received a conventional TAI protocol, and estrus expression was identified by the absence of paint in the sacrococcygeal region on the day of TAI. Females that did not show estrus were treated with 10 μg of GnRH together with insemination. The rates of estrus and pregnancy were analyzed using a logistic regression model (P < 0.05). The estrus expression was lower (P = 0.006) in the primiparous (61.36%) group than in the nulliparous (76.39%) and multiparous (75.69%) groups. Similar pregnancy rates were observed in females that showed estrus (nulliparous 84.54%, primiparous 86.42%, and multiparous 80.31%; P = 0.39) and in females that did not show estrus and received GnRH (nulliparous 41.18%, primiparous 56.86%, and multiparous 58.06%; P = 0.24). The total pregnancy rates were also similar (P = 0.98) among the categories (nulliparous 74.3%, primiparous 75.0%, and multiparous 74.9%). The primiparous females had a lower rate of estrus, and the pregnancy rates were similar among the categories that received GnRH.

Offspring derived from artificial reproductive techniques are already known to present several postnatal undesirable phenotypes and clinical disorders. Despite its benefits, cloning by somatic cell nuclear transfer (SCNT) is extremely inefficient. The birth rate in cattle is around 5% of the transferred blastocysts, and ~50% of delivered calves die in the first 48 h. Neonatal respiratory distress is reported to be one of the main causes of such deaths. Veterinary intervention is often needed to promote or improve blood oxygenation, avoiding respiratory acidosis and improving carbon dioxide delivery from blood/lungs to the environment. This study aimed to evaluate a neonatal support therapy over the blood gas and acid-base balance on newborn calves derived from SCNT or AI. Four cloned and 3 AI-derived calves delivered by Caesarean section were used for the experiment. Postnatal therapeutic procedures were comprised 4 doses of 400 mg of intratracheal surfactant every 15 min, 25 mg of oral sildenafil every 8 h for 3 days, and 5 L min–1 intranasal oxygen. Blood collections were performed within 30 min (T0), at 12 (T12), 24 (T24) and 48 (T48) hours after delivery. Blood samples were collected from the caudal auricular artery with a butterfly and a blood gas syringe. Oxygen saturation (sO2), arterial pressure of oxygen (PaO2) and carbon dioxide (PaCO2), pH, and bicarbonate (HCO3–) were evaluated with a portable blood gas analyzer (i-STAT, Abbott Point of Care Inc., Princeton, NJ, USA). Data obtained were submitted to ANOVA (Proc MIXED; SAS/STAT, version 9; SAS Institute Inc., Cary, NC, USA). There were significant differences between groups in blood pH (P = 0.0182) and between groups (P = 0.0281) and time of collection (P = 0.0303) in blood bicarbonate (HCO3–). The AI calves were born with normal pH (7.468 ± 0.033) and the cloned calves were born in acidosis (7.216 ± 0.166). These calves were stabilised in T48 (7.427 ± 0.017) using their own HCO3– that increased over time. Although there were no differences in sO2 (P = 0.4525), PaO2 (P = 0.3086), or PaCO2 (P = 0.2514), sO2 and PaO2 were numerically increased at the same time that PaCO2 decreased in both groups. In the cloned calves, the sO2, PaO2, and PaCO2 at T0 were 61.3 ± 28.6%, 39.8 ± 18.5 mmHg, and 65.8 ± 29.3 mmHg, respectively and reached 90.0 ± 3.4%, 57.7 ± 15.8 mmHg, and 42.0 ± 3.7 mmHg. In the AI calves, T0 blood gas analysis were 79.8 ± 19.4%, 56.1 ± 42.1 mmHg, and 39.1 ± 4.8 mmHg, and at T48 were 89.0 ± 2.6%, 82.3 ± 43.5 mmHg, and 43.0 ± 4.9 mmHg for sO2, PaO2, and PaCO2 respectively. The neonate support therapy improved calves' oxygenation and helped to eliminate the carbon dioxide from the blood. In our experience, the neonatal treatment was essential in supporting the lives of the cloned calves.Funding support was received from FAPESP 2011/19543–9.