Monitoring of health status, performance and transcript abundance of some genes in dairy heifers produced by embryo transfer or artificial insemination.

The use of multiple ovulation and embryo transfer (MOET) technology in the dairy cattle industry has increased dramatically in recent decades for the production of offspring from genetically superior cows. Yet, its long-term ramifications on adult performance have not been adequately clarified. Therefore, this study targeted comparing dairy heifers born after the transfer of in vivo-produced embryos (MOET-heifers, n = 400) and those born after artificial insemination (AI-heifers, n = 340). The performance of MOET-heifers and AI-heifers was compared from birth till completion of the first lactation regarding health, fertility and some lactational performance parameters. The transcript abundance of several genes was also assessed in peripheral blood leukocytes (PBWC). Results showed greater pre-weaning mortalities, greater likelihood of being culled as a nulliparous heifer and younger age at first insemination in AI-heifers (p < .001). At their first calving, primiparous MOET-heifers experienced a greater (p < .01) incidence of stillbirth compared to primiparous AI-heifers. In spite of that, primiparous AI-heifers were more likely to be culled due to infertility (p < .001), took a greater number of inseminations to achieve pregnancy (p < .01) and displayed a longer first calving interval. There was a similar lactational performance between the two groups. Upregulation of the transcript levels of TAC3, LOC522763, TFF2, SAXO2, CNKSR3 and ALAS2 was interestingly observed in primiparous MOET-heifers, compared to primiparous AI-heifers. In conclusion, MOET-heifers were less likely to be culled during the first year of life, had superior reproductive performance versus AI-heifers during their first lactation and expressed upregulation of genes associated with fertility.

Heat stress during critical windows of the oestrous cycle and risk of pregnancy establishment in embryo-recipient dairy heifers.

This study aimed to determine effects of exposure of recipient dairy heifers to heat stress (THI ≥ 73) during the oestrous cycle coinciding with embryo transfer (ET) on the risk of pregnancy establishment after transfer of in vivo produced embryos. Recipients exposed to THI values ≥73 during Days zero (recipient estrus), 7 (day of ET), 14 (seven days after ET), 15 and 16 (maternal recognition of pregnancy) of the ET cycle were considered as heat-stressed heifers (n = 254), while heifers in the control group (n = 470) were not exposed to THI ≥ 73 at any of the previous days. Results revealed no significant effects of any of the investigated factors on the risk of pregnancy following ET. However, the mean THI above 77 was associated with a drastic numerical decrease in PR/ET (36.63%), when compared to a mean THI 72 (78.78%). In addition, PR/ET after transfer of second- and third-grade embryos were numerically lower in heat-stressed recipients, compared with first-grade embryos (41.17% vs. 56.36%, respectively). Our findings confirmed that transfer of blastocysts was associated with numerically higher PR/ET in heat-stressed and control recipients, as compared to morula stage. Interestingly, PR/ET tended to be higher when sexed embryos were transferred to the control recipients compared with heat-stressed ones. In conclusion, PR/ET in dairy heifers was not significantly affected by heat stress during critical windows of their oestrous cycle coinciding with ET, whereas transfer of sexed embryos gives lower results under conditions of heat stress.

Physiological Roles of Red Carrot Methanolic Extract and Vitamin E to Abrogate Cadmium-Induced Oxidative Challenge and Apoptosis in Rat Testes: Involvement of the Bax/Bcl-2 Ratio.

The precise analysis of the contents of the red carrot is still ambiguous and its role in the maintenance of male fertility needs to be further reconnoitered. Hence, this study targets the physiological impacts of either red carrot methanolic extract (RCME) or vitamin E (Vit. E), co-administrated with cadmium chloride (CdCl2) on rat testes, specifically those concerned with apoptosis and oxidative challenge. Four groups of adult male rats (n = 12) are used; control, CdCl2, CdCl2 + Vit. E and CdCl2 + RCME. LC-MS analysis of RCME reveals the presence of 20 different phytochemical compounds. Our data clarify the deleterious effects of CdCl2 on testicular weights, semen quality, serum hormonal profile, oxidative markers and Bax/Bcl-2 ratio. Histopathological changes in testicular, prostatic and semen vesicle glandular tissues are also observed. Interestingly, our data clearly demonstrate that co-administration of either RCME or Vit. E with CdCl2 significantly succeeded in the modulation (p < 0.05) of all of these negative effects. The most striking is that they were potent enough to modulate the Bax/Bcl-2 ratio as well as having the ability to correct the impaired semen picture, oxidant status and hormonal profile. Thus, RCME and Vit. E could be used as effective prophylactic treatments to protect the male reproductive physiology against CdCl2 insult.

Transcript abundance of anti-Mullérian hormone and follicle-stimulating hormone receptor predicted superstimulatory response in embryo donor Holstein cows.

The goal was to investigate the relationship among mRNA expressions of anti-Mullérian hormone (AMH), follicle-stimulating hormone receptor (FSHR) and responses to superovulation (SO) in embryo donor dairy cows. Holstein cows (n = 19) were submitted to a standard SO protocol, with twice daily FSH treatments, and artificially inseminated. Prior to SO (Day 0), relative mRNA expressions of AMH and FSHR in blood were determined for all cows. Day 7 embryos were collected and were graded to determine superovulatory response for each donor. Results showed that relative mRNA expressions of AMH and FSHR were positively correlated (R2  = 0.94). Relative mRNA expressions of both AMH and FSHR were positively correlated with total embryos (R2  = 0.68 and 0.69, respectively), total transferable embryos (R2  = 0.92 and 0.97, respectively) and total grade 1 embryos (R2  = 0.54 and 0.59, respectively). Further, transcript abundances of AMH and FSHR positively associated with milk production of donor cows, and meanwhile, they were negatively associated with days in milk (DIM) at submission of cows to SO (p < .05) protocol. The relative mRNA expression of AMH was higher (p < .05) in donor cows <5 years of age. However, age of donor at superovulation did not influence mRNA expression of FSHR. Collectively, we infer that the mRNA expressions of AMH and FSHR prior to superovulation can predict donor cows' positive response to superovulation.

Dose- dependent ameliorative effects of quercetin and l-Carnitine against atrazine- induced reproductive toxicity in adult male Albino rats.

This study aimed to determine the protective effects of co-administration of Quercetin (QT) or l-Carnitine (LC) against the oxidative stress induced by Atrazine (ATZ) in the reproductive system of intact male Albino rats. 36 rats were divided equally into 6 groups. Rats in the control negative "CNT" group received 1.5 ml distilled water for 21 days. All rats in the other groups received ATZ (120 mg/kg bw) through gavage. Groups 3 and 4 were co-administered with either low or high dose of QT (10 "ATZLQT" and 50 "ATZHQT" mg/kg bw, respectively). Groups 5 and 6 were co-administered with either low or high dose of LC (200 "ATZLLC" and 400 "ATZHLC" mg/kg bw, respectively). At the end of the experiment, animals were sacrificed and all samples were collected. ATZ significantly increased serum level of malondialdehyde (MDA) and decreased total antioxidant capacity (TAC). Also, ATZ increased significantly the sperm cell abnormalities and reduced both testicular IgA and serum testosterone levels. Testicular DNA laddering % and CYP17A1 mRNA expression were significantly reduced in ATZ group. Interestingly, co-administration with low dose QT or different doses of LC succeeded to counteract the negative toxic effects of ATZ on serum oxidative stress indicators, serum testosterone levels, testicular IgA level and improved testicular CYP17A1 mRNA expression. In conclusion, QT in low dose and LC in both low and high doses exerted a significant protective action against the reproductive toxicity of ATZ, while higher dose of QT failed induce immune-stimulant effect against ATZ in adult male Albino rats.

The impact of using newborn bovine serum as fetal calf serum substitute in the in vitro bovine embryos production system.

This study was conducted to assess the effects of addition of 10% newborn bovine serum (NBS) in the maturation and culture media of bovine system on oocytes maturation and developed morula and blastocyst rates. For this purpose, 10% NBS was added to in vitro maturation (IVM) medium alone (Experiment I), in vitro culture (IVC) (Experiment II), and in IVM + IVC (Experiment III). In vitro bovine oocytes maturation and developmental rates of bovine embryos were then compared with control group where the basal maturation or culture media were supplemented with 10% fetal calf serum (FCS). Results revealed that maturation, cleavage, morula, and blastocyst formation rates of in vitro fertilized embryos were not significantly different in NBS and control groups in the 3 experiments. In conclusion, NBS is an efficient macromolecule in bovine system when added either to IVM or to IVC or to both stages. Thus, NBS could provide cheaper and more available treatment to be used as FCS substitute in the IVC system of bovines.

Impact of Seasonal Conditions on Quality and Pathogens Content of Milk in Friesian Cows.

Heat stress negatively affects milk quality altering its nutritive value and cheese making properties. This study aimed at assessing the impact of seasonal microclimatic conditions on milk quality of Friesian cows. The study was carried out in a dairy farm from June 2013 to May 2014 at Beni-Suef province, Egypt. Inside the barn daily ambient temperature and relative humidity were recorded and used to calculate the daily maximum temperature-humidity index (mxTHI), which was used as indicator of the degree of heat stress. The study was carried out in three periods according to the temperature-humidity index (THI) recorded: from June 2013 to September 2013 (mxTHI>78), from October 2013 to November 2013 (mxTHI 72-78) and from December 2013 to April 2014 (mxTHI<72). Eighty Friesian lactating dairy cows were monitored in each period. The three groups of cows were balanced for days in milk and parity. Milk quality data referred to somatic cell count, total coliform count (TCC), faecal coliform count (FCC), Escherichia coli count, percentage of E. coli, and Staphylococcus aureus, percentage of fat, protein, lactose, total solid and solid non-fat. Increasing THI was associated with a significant decrease in all milk main components. An increase of TCC, FCC, and E. coli count from mxTHI<72 to mxTHI>78 was observed. In addition, the isolation rate of both S. aureus and E. coli increased when the mxTHI increased. The results of this study show the seriousness of the negative effects of hot conditions on milk composition and mammary gland pathogens. These facts warrant the importance of adopting mitigation strategies to alleviate negative consequences of heat stress in dairy cows and for limiting related economic losses.