Effect of cow parity and synchronization method with PGF2α on conception rates of Bos indicus cows in Cameroon

The objective of this work was to evaluate the effect of two synchronization methods with prostaglandins F2α (PGF2α) on heifers and multiparous cows. Fourty-three Bos indicus cows (white and Red Fulani) were divided into four groups in a two-by-two factorial structure, parity x method of synchronization. The synchronization methods consisted of a two-dose regime which involved injection of animals on day 0 with PGF2α (Lutalyse) at 5 ml per cow intramuscularly. On day 11, the injection was repeated at the same dosage. On day 14 (72 h after the second injection), a fixed-time artificial insemination (AI) was done. On day 15 (96 h after the second injection), a second insemination was done. The one-and-a-half-dose regime consisted of an injection similar to the first treatment mentioned above on day 0. Thereafter, cows were observed for heat, and anyone showing heat was inseminated. A second dose was given on day 11 to all animals not having shown any heat. A fixed-time AI was done on days 14 and 15. Blood samples were collected on the day 0 of insemination for each cow while day 11 and day 21 after insemination. Progesterone was analysed by means of standard ELISA progesterone kits to determine its profiles after insemination. Results show no evidence of the effect of treatments on conception rates (P?>?0.05). Similarly, heifers and multiparous cows had similar conception rates (P?>?0.05). Between 3 weeks and 3 months of pregnancy, there was a loss of embryos of 28 % in heifers and 20 % in multiparous cows, but the difference between the two groups was not significant (P?>?0.05). It recommended that farmers do not synchronize animals with poor body condition score (BCS). They should also monitor weight gains of heifers, remove them from the herd when they have been mixed with young growing bulls and put them in a breeding herd. The two-dose regime is better to be used in areas where the inseminator cannot easily be available.

     

Effect of phthalate esters on the secretion of prostaglandins (F2α and E2) and oxytocin in cultured bovine ovarian and endometrial cells

The influence of phthalate esters di-2-ethylhexyl phthalate (DEHP) and mono-2-ethylhexyl phthalate (MEHP) on uterine prostaglandin (PGF2α and PGE2) and ovarian oxytocin secretion was investigated. Endometrial, granulosa, and luteal cells from cows on days 8–12 of the estrous cycle were treated with DEHP or MEHP (0.1, 1, or 10 ng/mL). We found that DEHP and MEHP stimulated (P < 0.05) secretion of PGF2α and inhibited (P < 0.001) secretion of PGE2 from endometrial cells. The ratio of PGF2α to PGE2 was markedly altered. The endocrine disrupting chemicals also enhanced secretion of oxytocin (P < 0.05) from ovarian cells. Our results indicated that DEHP and its metabolite MEHP could affect the process of the estrous cycle by impairing secretion of prostaglandin from the uterus and oxytocin from the ovary.     

Effects of lycopene on in vitro quality and lipid peroxidation in refrigerated and cryopreserved turkey spermatozoa

1. The effects of lycopene-enriched extenders on the in vitro quality of turkey semen including lipid peroxidation were examined after chilled and frozen storage.

2. Five pools of semen diluted in extenders containing 0, 0·05 or 0·1?mg/ml of lycopene were stored at 5°C for 48?h or cryopreserved as pellets and the following variables determined in fresh samples and samples stored chilled or frozen: sperm motility, viability, osmotic resistance, DNA integrity and lipid peroxidation (as malonaldehyde production).

3. Semen quality was generally compromised after storage, especially post-freezing. However, in the presence of the highest dose of lycopene, both the viability and osmotic-resistance of chilled spermatozoa and the DNA integrity of frozen spermatozoa were similar to those of fresh spermatozoa.

4. Greater lipid peroxidation was detected in refrigerated compared to fresh or cryopreserved spermatozoa. However, spermatozoa chilled in lycopene-enriched extenders showed significantly lower malonaldehyde levels than those chilled without lycopene, while the addition of lycopene to the freezing medium served to maintain the lipid peroxidation levels observed in fresh semen.

5. In conclusion, the presence of lycopene in the extender improved the survival of turkey spermatozoa after liquid-storage and protected DNA integrity against cryodamage. The beneficial effects of lycopene observed could be related to its capacity to diminish sperm lipid peroxidation during refrigeration or cryopreservation.     

Omega-3 Fatty Acid Supplementation Reduces Basal TNFα but Not Toll-Like Receptor-Stimulated TNFα in Full-Sized and Miniature Mares

It has been well documented that omega-3 long-chain polyunsaturated fatty acids (n-3 PUFA) confer a wide variety of health benefits to humans and animals. The current study was designed to evaluate the ability of n-3 PUFA to modulate the innate immune response in two diverse breeds of horses. Ten Quarter Horse and 10 American Miniature Horse mares were assigned to either an n-3-PUFA-supplemented or a control diet (five full-sized and five miniature mares/treatment) for 56 days. The treatment diet was designed to deliver 64.4 mg/kg body weight of combined eicosapentaenoic acid and docosahexaenoic acid daily. Blood was collected through jugular venipuncture into heparinized tubes on days 0, 28, and 56. Serum PUFA analysis was conducted by gas chromatography. Peripheral blood mononuclear cell production of tumor necrosis factor-α (TNFα) in response to toll-like receptor (TLR) ligands lipopolysaccharide, flagellin, and lipoteichoic acid was estimated using an equine-specific enyme-linked immunosorbent assay. Peripheral blood samples from day 56 were also analyzed for total and differential leukocyte counts and subjected to flow cytometric analysis. Body type did not affect basal or TLR-stimulated TNFα production. Serum PUFA analysis revealed a decrease in α-linolenic acid and substantial increases in arachidonic acid, eicosapentaenoic acid, docosahexaenoic acid, and docosapentaenoic acid at both day 28 and day 56 in horses fed n-3 PUFA (P < .0001 for all). Dietary n-3 PUFA supplementation reduced (P < .05) unstimulated basal, but not TLR-stimulated, TNFα production by peripheral blood mononuclear cells. Supplementation with n-3 PUFA neither affected total or differential leukocyte counts nor selected cell surface markers. These results suggest that n-3 PUFA supplementation in the horse can modify circulating PUFA and alter the inflammatory response by reducing basal TNFα production. Furthermore, under conditions of the current study and considering the end points evaluated, the American Miniature Horse could potentially be used as a model for full-sized horse breeds.     

Effect of Gossypol on Hepatic and Serum γ-glutamyltransferase Activity in Rats

A single intraperitoneal dose (25 mg/kg) of gossypol given to male Sprague-Dawley rats caused marked changes in the activity of the hepatic and serum -glutamyltransferase (GGT) and microsomal monooxygenases. The GGT activity in liver homogenate, S-9 supernatant fraction and microsomes was significantly depressed; however, the level of serum GGT was elevated. While the hepatic glutathione concentration was not greatly changed, the aminopyrine N-demethylase activity and microsomal cytochrome P450 content of the liver were significantly decreased in the treated rats. At necropsy, the livers of the treated rats appeared generally pale with distinct pinpoint foci. Histopathological examination of the liver showed degenerative changes and coagulative necrosis. The results indicate that gossypol is a strong hepatotoxic agent which can produce severe hepatic damage.     

Effect of β-glucosidase on the meat quality and digestibility in broilers

This study investigated the effects of supplementary β-glucosidase on the carcass composition, meat quality, weight of digestive organ and apparent digestibility in male broilers. Two hundred and forty male, 1-day avine broiler chicks were randomly allocated into four treatment groups and fed with corn-soya bean meal supplemented with 0 (control), 0.6, 1.2 and 1.8 U/g of β-glucosidase respectively. The results showed that there were no significant differences (p > 0.05) among groups in carcass composition (percentages of eviscerated yield, half-eviscerated yield, muscle yield of breast and leg). However, adding 0.6 U/g β-glucosidase to the diet not only altered the meat quality by decreasing the drip loss ratio (p < 0.05) and relative lightness (L*) value (p < 0.01), increasing relative redness (a*) value (p < 0.01), but also significantly decreased the pancreas to body weight ratio (p < 0.05), however, with little effect on liver, proventriculus and gizzard to body weight ratio (p > 0.05). The length and width of duodenum villus were not affected by the addition of β-glucosidase, but the coefficients of total tract apparent digestibility of protein and fat increased by 9.02% (p < 0.05) and 7.40% (p < 0.01) respectively; the parameters of ash were not affected by β-glucosidase addition (p < 0.05). This study provided valuable information for evaluation of the effect of supplementary β-glucosidase on the meat quality and digestibility of broilers.     

Effect of genistein on the gene and protein expressions of CXCL–12 and EGR–1 in the rat ovary

The effect of genistein (GEN) on the gene expression level of stromal cell-derived factor-1/CXCL-12 and early growth response gene-1 was studied in ovarian tissue of young and initially ageing (early stages in the ageing process) female rats. Forty, young female Sprague Dawley (SD) rats of 2–3 months old (200 ±20 g) and forty, initially ageing female SD rats of 10–12 months (490 ± 20 g) old were selected. According to the weight, rats were divided into control group, low-dose group (L), medium-dose group (M) and a high-dose group (H) and were given 15, 30 and 60 mg/kg GEN respectively. The positive control (Oestrogen) group was given 0.5 mg/kg diethylstilbestrol. The treatment lasted for 30 days. The mRNA expression of C-X-C motif chemokine ligand 12 (CXCL-12) and early growth response factor-1 (EGR-1) was measured by real-time PCR, and protein expression of EGR-1 was detected by Western blot. When compared to the negative control group (NC), the ovary/body weight ratio in the young rats decreased in the GEN group, but the difference was not significant. Similarly, compared with NC, the ovary/body weight ratio in the initially ageing rats also decreased with the increase in GEN concentration, but the decrease was significant in M and H groups (p < .01). The administration of GEN enhanced both the gene and protein expression levels of CXCL-12 and EGR-1 in the ovary. Pearson's correlation analysis showed a synergistic effect between CXCL-12 and EGR-1. Thus, we conclude that the effect of GEN on CXCL-12 and EGR-1 in the initially ageing group was obvious than that in the younger group.     

The Effect of PGF2α-Induction of Estrus on Pregnancy Rates in Mares

In mares, the onset of estrus is routinely induced after a luteolytic dose of a prostaglandin F2alpha analogue. Mares in diestrus with a mature, functional corpus luteum will respond by coming into estrus 3 to 4 days after induction¹. Shortening the interestrous interval in mares has an important economic impact on the equine breeding industry. Because the breeding season of the mare is short, timing of insemination and appropriate coordination of endocrine events is critical to pregnancy success and ultimate foaling rates. Several recent studies have reported that the use of prostaglandin analogues is associated with lower pregnancy rates. In this study the induction of estrus with cloprostonol (125-250 ug IM) did not affect pregnancy rates in mares that have ovulatory cycles (n = 461).     

Cloning of Inhibin-α Gene and its mRNA Expression Pattern in the Ovary of Congjiang Xiang Pig

To reveal the relationship between inhibin-α(INHA) gene and the reproductive traits of Congjiang Xiang pig, INHA gene was cloned and sequenced taking the genomic DNA of Congjiang Xiang pigs as templates by polymerase chain reaction(PCR) method.The polymorphisms of INHA gene were tested in Congjiang Xiang pig populations with high-litter size and low-litter size using allele-specific PCR(AS-PCR) method.The expression profile of INHA gene in ovaries was detected from Congjiang Xiang pigs with high-litter yiled or low-litter yiled by Real-time PCR method.The complete coding region of INHA gene was 1095 bp in length, which coded for 364 amino acid residues.Compared with the known sequence, two candidate sites, G359A and A373G, were found out from exon 2 region of INHA gene in Congjiang Xiang pig.After investigation for the two sites in a large population, the frequency of alleles between two populations was not significant and without obvious relativity with the litter yiled of Congjiang Xiang pig.However, the INHA mRNA level in the ovary of Congjiang Xiang pig with high-litter yiled was higher than that with low-litter yiled.It suggested that INHA gene was much conserved, INHA gene expression level might be concerned for the regulation of ovary growth and follicle development in Congjiang Xiang pig breed.     

Impact of genotype 1 and 2 of porcine reproductive and respiratory syndrome viruses on interferon-α responses by plasmacytoid dendritic cells

Porcine reproductive and respiratory syndrome (PRRS) virus (PRRSV) infections are characterized by prolonged viremia and viral shedding consistent with incomplete immunity. Type I interferons (IFN) are essential for mounting efficient antiviral innate and adaptive immune responses, but in a recent study, North American PRRSV genotype 2 isolates did not induce, or even strongly inhibited, IFN-α in plasmacytoid dendritic cells (pDC), representing “professional IFN-α-producing cells”. Since inhibition of IFN-α expression might initiate PRRSV pathogenesis, we further characterized PRRSV effects and host modifying factors on IFN-α responses of pDC. Surprisingly, a variety of type 1 and type 2 PRRSV directly stimulated IFN-α secretion by pDC. The effect did not require live virus and was mediated through the TLR7 pathway. Furthermore, both IFN-γ and IL-4 significantly enhanced the pDC production of IFN-α in response to PRRSV exposure. PRRSV inhibition of IFN-α responses from enriched pDC stimulated by CpG oligodeoxynucleotides was weak or absent. VR-2332, the prototype genotype 2 PRRSV, only suppressed the responses by 34%, and the highest level of suppression (51%) was induced by a Chinese highly pathogenic PRRSV isolate. Taken together, these findings demonstrate that pDC respond to PRRSV and suggest that suppressive activities on pDC, if any, are moderate and strain-dependent. Thus, pDC may be a source of systemic IFN-α responses reported in PRRSV-infected animals, further contributing to the puzzling immunopathogenesis of PRRS.     

Effect of carotenoid β-cryptoxanthin on cellular and humoral immune response in rabbit

Beta-cryptoxanthin (b-Cr) is a pro-vitamin A and one of the major carotenoids that can be commonly found in mammalian serum and tissues. Foods rich in certain fatty acids are known to be effective to gain a healthy immune system. In the present study, we evaluated the effect of b-Cr on rabbit humoral and cellular immune responses to have a better vision about the mechanism of effect of carotenoids on immune system. Twenty rabbits were randomly divided into five groups (4 per group): Groups consisted of: 1) control group (normal saline; 2) b-Cr (control); 3) vaccine control; 4) 5 mg/kg b-Cr o.p. + vaccine; 5) 10 mg/kg b-Cr o.p. + vaccine. Blood samples were obtained from the marginal ear artery at three time points: days 0, 14 and 21 of the study. Blood CD4+ and CD8+ lymphocytes and Serum Immunoglobulin and Cytokines content were evaluated. Results show that b-Cr administration increased the blood CD4+ lymphocytes count (P?>?0.01). Serum IgG, IgM and IgA levels increased (P?>?0.05) following b-Cr administration. b-Cr treatment increased serum IL-4 levels (P?>?0.05). According to presented results, b-Cr may increase the humoral immunity in mammals. So, it would possible has a potentially beneficial effect on health and on prevention of the immunity related diseases.     

Immunoexpression of cytokine tumour necrosis factor-α suggesting its role in formation and regression of corpus luteum in Indian buffalo

Tumour necrosis factor-α (TNF-α) is a cytokine that plays multiple important roles in corpus luteum (CL). Immunolocalization of expression of TNF-α in CL of buffalo was studied in different stages of its development and regression. Corpus luteum of healthy buffaloes (24) was collected from local slaughterhouses and categorized into early (stage I, 1–5 days, n = 6), mid (stage II, 6–11 days, n = 6), late luteal (stage III, 12–16 days, n = 6) and regressing phase (stage IV, 17–20 days, n = 6). In earliest phase of cyclic CL, per cent immunoexpression of TNF-α was significantly (p < .05) lower as compared to all phases with its expression being restricted to few developing luteal cells, usually in neutrophils. A significantly (p < .05) higher number of neutrophils with TNF-α immunoexpression were observed as compared to mid-luteal phase that indicated its role in initiation of angiogenesis at this stage. TNF-α immunoexpression almost doubled in mid-luteal phase, but the number of neutrophils exhibiting TNF-α was significantly (p < .05) lower with respect to all phases of CL. Immunoexpression percentage in late luteal phase increased sharply being significantly (p < .05) higher than earlier two phases of CL. In regressing phase, per cent immunostaining was maximum with highly significant (p < .05) difference as compared to all other stages, observed in all degrading luteal cells, abundant immune cells, that is neutrophils and macrophages which finally led to apoptosis and phagocytosis. Immunoexpression of TNF-α in early luteal phases served its role in initiation of angiogenesis, and its intense expression in regressing phase of CL suggested a shift in its role to apoptosis and structural luteal regression signifying both luteotropic and luteolytic roles in buffalo. This is probably the first study of its kind in buffaloes.     

Expression of hypoxia-inducible factor-1α and vascular density in mammary adenomas and adenocarcinomas in bitches

Background

The study aimed at examining hypoxia-inducible factor (HIF)1α expression in adenocarcinomas and adenomas in bitches in regard to tumour malignancy grade, proliferation, apoptosis and vascularisation. Therefore, paraffin sections of 15 adenomas and 64 adenocarcinomas sampled from 79 dogs aged 6 to 16 years were analysed.

Results

A significantly higher HIF-1α expression was noted in adenocarcinomas in comparison to adenomas (P < 0.0004). Moreover, HIF-1α expression in adenocarcinomas correlated positively with tumour malignancy grade (r = 0.59, P < 0.05), Ki-67 antigen expression (r = 0.43; P < 0.0005), TUNEL-positive cells (r = 0.62, P < 0001) and tumour vascularity measured by quantification of vessels characterized by the expression of von Willebrand Factor (r = 0.57, P < 0.05).

Conclusion

Results of this study indicate a similar biological role of HIF-1α in dogs and in humans, which may confirm suitability of the animal model in investigations on progression of tumours in humans.