Effectiveness of training parturition and dystocia management on days open of dairy cows in traditional farming systems: a field trial.

The interval between parturition and subsequent pregnancy is called the days open or calving to conception interval and is affected by several factors, especially dystocia. Dystocia is an ab-normal or difficult calving that may require assistance during labor. This study is a field trial in health education and the research team developed a comprehensive training program for farmers to educate them about the normal process of parturition in dairy cows and when and how to assist in parturition or dystocia. A series of classes was held for farmers and the study covered 486 multi-parous dairy cows, with 173 belonging to the group of trained farms (educated farmers) and 313 to the control group (non-educated farmers). Although dystocia was lower in the educated group, there were no significant differences in retained placenta between two groups. However, cows in the educated group had a better conception rate (lower service per conception) in sub-sequent parturitions. Hence, the median number of days open for cows from trained farmers was significantly lower than other farmers (85 days compared to 120 days, respectively). Based on Cox regression analysis, uterine prolapse, retained placenta, and dystocia could significantly impact subsequent pregnancies. Dystocia affects days open, and training on parturition and dystocia management can effectively reduce the numbers of days open in dairy cows.

Effect of Mechanical Micro-Vibrations on The Efficiency of Leopard Inter-Species Somatic Cell Nuclear Transfer.

OBJECTIVE: Scarcity of oocytes for assisted reproduction in endangered species can be bypassed by interspecies somatic cell nuclear transfer (iSCNT). In Felids, domestic cat (Felis catus) oocytes can serve as recipients for the nucleus of the endangered Persian leopard (Panthera pardus saxicolor). However, in vitro oocyte maturation is still suboptimal in cats, whereas it has been reported to benefit from micro-vibration in non-felid species. Therefore, the present study is aimed to determine whether micro-vibration, applied during in vitro maturation (IVM), improves the embryogenic potential of cat oocytes transplanted with fibroblast nuclei of the Persian leopard. MATERIALS AND METHODS: In the experimental study, cat cumulus-oocyte complexes (COCs) were randomly assigned to the treatment group (micro-vibration) or control group (static culture). Resultant metaphase II (MII) oocytes were enucleated and reconstructed with nucleus transplants from leopard fibroblasts, followed by artificial oocyte activation and embryo culture under the same condition (static) for 7 days. RESULTS: While cumulus cell expansion and oocyte maturation profited from micro-vibration (P<0.05), the quantity and quality of blastocysts were significantly lower in micro-vibration than in the control group (P<0.05). The total number of blastocyst cells tended to be lower in the micro-vibration than in the control group (P=0.075). Nevertheless, the proportion of ICM and TE cells did not differ between the micro-vibration and control groups (P>0.05). CONCLUSION: The present study indicated that micro-vibration at a frequency of 44 Hz for 5 secs per hour enhanced nuclear maturation and cumulus cell expansion of cat oocytes. However, exposure to micro-vibration during IVM impaired the survival rate of reconstructed oocytes during the iSCNT process and their developmental competence toward the blastocyst stage.

Effect of health disorders on the hazard of culling on the first or second lactation in Iranian dairy herds.

We conducted a longitudinal retrospective study in order to assess the effect of health disorders (HDs) on culling in the 1st or 2nd lactation cows, in Iranian dairy herds. In total, 7067 first- and second-parity Holstein cows, from 32 Iranian dairy herds, which calved from March 2007 to March 2008, were followed until the next calving or culling. Parametric survival models with time-dependent covariates were used to capture the effect of HDs with different duration and recurrence episodes on the risk of culling. Mastitis, locomotor disorders, ovarian cysts, abortion, diarrhea, rumen disorders, displaced abomasum and respiratory disorders were associated with an increased risk of culling. Hazard ratios and 95% confidence intervals were 2.78 (2.31; 3.35), 3.4 (2.79; 4.13) and 1.62 (1.15; 2.78) for mastitis, locomotor disorders and ovarian cysts as common HDs, respectively. Parity and milk-yield were identified as confounder and effect modifier, respectively. The risk of culling in the presence of uterine infection or traumatic reticulo-peritonitis increased with decreasing milk yield.