Backfat Thickness Does Affect the Restoration of Ovarian Activity Postpartum in Different Breeding Programs in Zebu Cattle

The backfat thickness (BFT) was used to forecast the onset of ovarian activity and predict the calf growth. Eighty Brahman cows with their calves were allocated in two groups of 40 distributed in 4 months according to the month of calving, starting in March and finishing in June. One was synchronized and inseminated at fixed time following by natural mating (TAI+NM); whilst the other only by natural mating (NM). The programs started at 60 ± 5 days postpartum and ended 60 days later. From day 30 postpartum, serial ultrasound examinations and progesterone samples were used to monitor the onset of ovarian activity. The BFT in the rump area was measured by ultrasound from 30 days postpartum and every 15 days thereafter. The weight of the calves was recorded at birth and at weaning on 160 days. The adjusted effect of BFT on ovarian activity and the calves' development was assessed by binomial logistic regression at 30, 60, 75, and 120 days postpartum. The cycling cows averaged higher BFT irrespective of breeding program (P < 0.001). Also, slower changes in BFT were recorded during the follow-up at each time for all cows. However, the former had the higher BFT values from calving to the end of the study (P < 0.001). At 60, 75, and 120 days, the BFT measured, at the preceding time, was the only factor predicting the commencement of cyclicity (P < 0.001). The accumulative pregnancy through time was higher in TAI+NM (P = 0.003). Daily weight gain and weaning weight of the calves born in March was significantly heavier (P < 0.001) than peers born in April, May, or June. The most critical element to forecast the onset of ovarian activity is the monitoring of BFT around calving regardless of the breeding program. BFT to estimate the development of the calves until weaning was unpredictable.

Comparison of Aceh cow’s performance on different mating systems at BPTU HPT Indrapuri, Aceh Province, Indonesia

This research aimed to compare Aceh cow’s performance on different mating systems at BPTU HPT Indrapuri, Indonesia. This research uses 202 Aceh cows with varying systems of mating; natural mating (164 cows), and artificial insemination (AI; 38 cows). Cow’s performance data included birth weight, postpartum mating, calving interval, weaning weight, Cow Reproduction Index (CRI), and Cow Production Index (CPI), obtained from the recording in 2014-2019 and calculation. This research uses the Oneway Anova test to analyze the cow’s performance between mating systems. The results of the cow’s performance included birth weight, postpartum mating, calving interval, weaning weight, CRI, and CPI for natural mating system were 14.32±1.41 kg, 265.61±260.0 days, 558,.21±260.07 days, 54.32±19.32 kg, 0.69 calf/cow/year and 37,48 kg/cow/year respectively, while for AI system were 14,98±1,38 kg, 289.34±285,.06 days, 581.94±285.06 days, 59.10±21.83 kg, 0.70 calf/cow/year dan 41.37 kg/kg/cow/year. The results showed that the performance of the Aceh cows with natural mating dan artificial insemination was relatively the same.

Serum Progesterone profile of pregnant Ettawa crossbred does at day-0, -21, -42, -63 and -84

This study aimed to determine the progesterone concentrations of Ettawa crossbred does at day-0, -21, -42, -63, and -84 after mating. Five Ettawa crossbred does were injected with PGF2α twice with an interval of 11 days for estrous synchronization followed by natural mating on day-3 after the second PGF2α injection. Blood was collected through the jugular vein for the measurement of serum progesterone concentrations using ELISA, whereas pregnancy was diagnosed at 90 days after mating by abdominal palpation. The results showed that all does were on estrus onthethird day after the second PGF2α, three of them diagnosed to be pregnant following mating. The progesterone concentration at day-0 was 1.52 ± 0.33 ng/mL, increased (p <0.05) to 7.08 ± 1.02 and 5.50 ± 2.82 ng/mL at day-21 and day-42, and increased (p <0.05) again to 12.01 ± 5.30 and 12.04 ± 0.30 ng/mL at day 63 and day 84, respectively. There was no significant difference in progesterone concentrations between day 21 and day 42 and between day 63 and day 84. It could be concluded that there was a biphasic increase of progesterone concentrations of the pregnant Ettawa crossbred does, i.e. from day-0 to day-21/day-42 and from day-21/day-42 to day-63/day-84.

Preliminary Study of Body Temperature Emissivity in Rabbits Selected for Litter Size Residual Variability

A divergent selection for litter size residual variability has been carried out in rabbits during 12 generations. Litter size residual variability was estimated as phenotypic variance of litter size within females after correcting for the year-season and the parity-lactation status effects. Stress causes an increase in core body temperature. Infrared thermography (IRT) has been shown to be a useful technique for identifying changes in body temperature emissivity. The aim of this work is to study the correlated response to selection for litter size residual variability in body temperature emissivity at natural mating. Natural mating can be considered a stressful stimulus for does. Temperature was measured in the eyeball by IRT before mating (basal temperature) and after 5 min, 30 min, and 60 min in does of the lines selected to decrease and to increase litter size residual variability (i.e., the Low and the High lines). Both lines showed similar basal temperature. Eyeball temperature was increased slightly in the Low line from basal state to 5 min after stressful stimulus (from 35.69 °C to 36.32 °C), and this increase remained up to 60 min after stress (36.55 °C). The High line showed a higher temperature than the Low line at 30 min (+0.96 °C, p = 0.99). At 60 min, temperature was similar between lines. The evolution of temperature was different between lines: the High line reached the peak of temperature later than the Low line (at 30 min vs. 5 min), and its peak was higher compared to the Low line (36.95 °C vs. 36.32 °C). In conclusion, the does selected for reducing litter size variability showed a lower increase in temperature after a stressful stimulus, therefore showing lower stress and consequently better welfare.

DNA methylation profile of liver of mice conceived by in vitro fertilization

Offspring generated by in vitro fertilization (IVF) are believed to be healthy but display a possible predisposition to chronic diseases, like hypertension and glucose intolerance. Since epigenetic changes are believed to underlie such phenotype, this study aimed at describing global DNA methylation changes in the liver of adult mice generated by natural mating (FB group) or by IVF. Embryos were generated by IVF or natural mating. At 30 weeks of age, mice were sacrificed. The liver was removed, and global DNA methylation was assessed using whole-genome bisulfite sequencing (WGBS). Genomic Regions for Enrichment Analysis Tool (GREAT) and G:Profilerβ were used to identify differentially methylated regions (DMRs) and for functional enrichment analysis. Overrepresented gene ontology terms were summarized with REVIGO, while canonical pathways (CPs) were identified with Ingenuity® Pathway Analysis. Overall, 2692 DMRs (4.91%) were different between the groups. The majority of DMRs (84.92%) were hypomethylated in the IVF group. Surprisingly, only 0.16% of CpG islands were differentially methylated and only a few DMRs were located on known gene promoters (n = 283) or enhancers (n = 190). Notably, the long-interspersed element (LINE), short-interspersed element (SINE), and long terminal repeat (LTR1) transposable elements showed reduced methylation (P < 0.05) in IVF livers. Cellular metabolic process, hepatic fibrosis, and insulin receptor signaling were some of the principal biological processes and CPs modified by IVF. In summary, IVF modifies the DNA methylation signature in the adult liver, resulting in hypomethylation of genes involved in metabolism and gene transcription regulation. These findings may shed light on the mechanisms underlying the developmental origin of health and disease.