Changes in Plasma Progesterone Levels in the Caudal Vena Cava and the Jugular Vein and Luteinizing Hormone Secretion Pattern After Feeding in Lactating and Non-lactating Dairy Cows

The present study was designed to assess progesterone profiles at the secreted (caudal vena cava) and circulating levels (jugular vein) and luteinizing hormone (LH) secretion pattern in lactating and non-lactating cows with reference to feeding. Four lactating and four non-lactating cycling Holstein cows were examined. Blood samples were collected simultaneously from the caudal vena cava (via a catheter inserted from the coccygeal vein) and the jugular vein every 15 min for 12 h (0500–1700 h) during the functional luteal phase. Cows were fed 50% of the daily diet 6 h after the start of blood sampling. During the 12-h sampling period, mean progesterone concentrations in the caudal vena cava did not differ between lactating and non-lactating cows (49.0 ± 2.9 and 53.3 ± 3.7 ng/ml; mean ± SE), whereas mean progesterone concentrations in the jugular vein in lactating cows were higher than those in non-lactating cows (6.4 ± 0.1 and 5.6 ± 0.1 ng/ml, P < 0.001). Lactating cows had a higher frequency of LH pulses than non-lactating cows (7.0 ± 0.7 and 4.3 ± 0.9 pulses/12 h, P<0.05). The influence of feeding was not observed on LH profiles but was observed on progesterone profiles in both veins. Progesterone concentrations in the caudal vena cava increased after feeding in both groups. Progesterone concentrations in the jugular vein decreased after feeding in lactating cows but not in non-lactating cows. These results indicate the difference in feeding-related changes in progesterone dynamics between lactating and non-lactating cows.     

Differential Effects of Continuous Exposure to the Investigational Metastin/Kisspeptin Analog TAK-683 on Pulsatile and Surge Mode Secretion of Luteinizing Hormone in Ovariectomized Goats

The aim of the present study was to determine if the estradiol-induced luteinizing hormone (LH) surge is influenced by the constant exposure to TAK-683, an investigational metastin/kisspeptin analog, that had been established to depress the pulsatile gonadotropin-releasing hormone (GnRH) and LH secretion in goats. Ovariectomized goats subcutaneously received TAK-683 (TAK-683 group, n=6) or vehicle (control group, n=6) constantly via subcutaneous implantation of an osmotic pump. Five days after the start of the treatment, estradiol was infused intravenously in both groups to evaluate the effects on the LH surge. Blood samples were collected at 6-min intervals for 4 h prior to the initiation of either the TAK-683 treatment or the estradiol infusion, to determine the profiles of pulsatile LH secretion. They were also collected at 2-h intervals from –4 h to 32 h after the start of estradiol infusion for analysis of LH surges. The frequency and mean concentrations of LH pulses in the TAK-683 group were remarkably suppressed 5 days after the start of TAK-683 treatment compared with those of the control group (P<0.05). On the other hand, a clear LH surge was observed in all animals of both groups. There were no significant differences in the LH concentrations for surge peak and the peak time of the LH surge between the TAK-683 and control groups. These findings suggest that the effects of continuous exposure to kisspeptin or its analog on the mechanism(s) that regulates the pulsatile and surge mode secretion of GnRH/LH are different in goats.     

Enzymatic saccharification and ethanol production of <Emphasis Type="Italic">Acacia mangium</Emphasis> and <Emphasis Type="Italic">Paraserianthes falcataria</Emphasis> wood,and <Emphasis Type="Italic">Elaeis guineensis</Emphasis> trunk

We examined the saccharification and fermentation of meals from Acacia mangium wood, Paraserianthes falcataria wood, and Elaeis guineensis trunk. The levels of enzymatic hydrolysis of cellulose and ethanol production were highest for P. falcataria wood and lowest for A. mangium wood. Ultrasonication pretreatment of meal further increased the rates of hydrolysis and ethanol production in meal from P. falcataria wood. Through this pretreatment, hemicelluloses (xylan and xyloglucan) and cellulose were released in the meal from P. falcataria wood. Loosening of hemicellulose associations can be expected to make P. falcataria wood more useful for bioethanol production.     

Comparison of productive and reproductive performance and hair cortisol levels between Brown Swiss cross‐bred and Holstein cows housed in the same barn

The productive and reproductive characteristics of Brown Swiss (B) cross‐bred cows were investigated by comparing with those of Holstein (H) cows housed in the same barn. Additionally, their hair cortisol levels were analyzed to evaluate the extent of stress experienced during dry and lactation periods. B cross‐bred cows had lower milk yields and higher milk fat rates than H cows. Reproductive records showed that days from parturition to first artificial insemination (AI) in B cross‐bred (n = 16) and H (n = 27) cows were not significantly different, but conception rate at first AI of B cross‐bred cows tended to be higher than that of H cows. Percentage of B cross‐bred cows that resumed ovarian cyclic activity within 45 days after parturition was higher than that of H cows (6/6 (100%) and 5/11 (45.5%), P < 0.05), and B cross‐bred cows had higher body condition scores at that time. Hair cortisol level at 60 to 90 days after parturition in H cows increased significantly compared with in the dry period, and it was higher than that of B cows during the same period. These results suggest that B cross‐bred cows experience less metabolic stress during early lactation, which may result in earlier resumption of reproductive function.     

Evaluation of the juice brix of wild sugarcanes (Saccharum spontaneum) indigenous to Japan

Modern sugarcane cultivars are derived from the interspecific crossing between Saccharum officinarum and wild sugarcane, Saccharum spontaneum. The introgression of valuable characteristics from wild sugarcane is recognized as extremely important, but this process typically requires long-term effort over multiple generations of backcrosses owing to the low sugar content of the initial interspecific hybrids. In this study, we aimed to identify Japanese wild sugarcanes with high juice brix in order to promote effective interspecific crossing of sugarcane. Sixty-four accessions from the Nansei Islands and 70 accessions from the Honshu were evaluated for juice brix. Wild sugarcanes with high juice brix were demonstrated to exist among wild sugarcanes indigenous to the Honshu. A significant difference was observed between the median juice brix values of wild sugarcanes of the Nansei Islands and those of the Honshu. The relationship between juice brix and stem traits was then examined in 20 wild sugarcanes, 10 each from the Nansei Islands and the Honshu. The reproducibility of juice brix value in both experiments was confirmed. In contrast to juice brix, stem traits, such as length, diameter, and volume, were typically smaller in wild sugarcanes from the Honshu. Moreover, a negative correlation was observed between the index of stem volume and juice brix. In this study, we identified outstanding wild sugarcanes with high juice brix. Using germplasms from the identified wild sugarcanes in interspecific crossing could contribute to the increases in both yield and sugar content.     

Changes in the ovary and the peripheral concentrations of sex hormones after the aspiration of follicular fluid from the spontaneous follicular cysts of dairy cows

The aim of the present study was to clarify the ovarian and hormonal dynamics after the aspiration of follicular fluid in cows with follicular cysts. Follicular fluid was aspirated from the follicular cysts and follicles that were fated to become cystic follicles and other coexisting normal follicles, respectively, in lactating cows (n = 3). After the aspiration procedure, new follicles developed and reached a diameter of 25 mm without ovulation within 13–19 days. The plasma concentrations of inhibin decreased and follicle-stimulating hormone increased rapidly after the aspiration procedure, and subsequently increased and decreased, respectively, as a new follicle grew. No luteal structures developed after the aspiration procedure, and the animals’ plasma progesterone levels remained low. The present study indicates that the cystic follicles are never luteinized by the aspiration of follicular fluid, and consequently, new follicular cysts are observed to repeatedly develop.     

Pathogenicity evaluation of Ralstonia pseudosolanacearum race 4 on ginger by leaf-clipping inoculation

Journal of General Plant Pathology - An easy, rapid method has been needed to test the pathogenicity of strains of Ralstonia pseudosolanacearum, the cause of serious bacterial wilt on ginger...     

Renal Tubular Cyst Formation in Newborn Rats Treated with p-Cumylphenol

In this study, we investigated the sequential changes in the development of renal tubular cysts in newborn rats treated with p-cumylphenol (PCP). Fifteen animals per sex were treated orally with 300 mg/kg/day of PCP for up to 18 days from postnatal day (PND) 4 and were sacrificed on PNDs 8, 12, 19 and 22 and after a 7 day recovery period. On PNDs 8 and 12, slight dilatation of the collecting ducts was frequently observed in the medulla and slight papillary necrosis was also noted in some cases. These dilated collecting ducts were lined with slightly hyperplastic epithelial cells. On PNDs 19 and 22, multiple large cystic changes arising from the collecting ducts in the outer medulla were seen. These cystically dilated ducts were also lined with hyperplastic epithelial cells. During the dosing period, the labeling index of proliferating cell nuclear antigen in the collecting duct epithelium was higher in the PCP-treated group than in the control group at all time points. After a 7 day recovery period, the cystic change still remained, although the cell density was decreased and the epithelial cells became flattened. On the other hand, basophilic tubules with peritubular lymphoid cell infiltration were multifocally observed in the cortex. In conclusion, PCP induced multiple renal cysts that developed in the collecting ducts of the outer medulla in neonatal rats, and it is suggested that epithelial cell proliferation may play some roles in the induction of cystic lesions.     

The effects of short-term nutritional stimulus before and after the luteolysis on metabolic status, reproductive hormones and ovarian activity in goats

The effect of short-term nutritional supplementation on hormonal and ovarian dynamics was studied in goats. Cycling Shiba goats were divided randomly into maintenance (group M, n=4) and high-energy (group H, n=4) groups. After the detection of the ovulation (Day 0, 1(st) ovulation), group H received a high-energy diet providing 2.5 times of the maintenance energy requirement for 7 days from Day 7 to Day 13 and were administered 2 mg of prostaglandin F(2alpha) (PGF(2alpha)) on Day 10 to induce luteal regression followed by the follicular phase. Follicular and luteal dynamics were monitored using ultrasonography daily or every other day, and blood samples were collected daily from Day 0 to the third ovulation (3(rd) ovulation) following the second ovulation (2(nd) ovulation) induced by PGF(2alpha) administration. Blood samples were also collected at 10-min intervals for 6 h on Day 9 and Day 11 for analysis of pulsatile LH secretion. The mean concentrations of glucose and insulin were significantly (P<0.05) higher in group H than in group M on Days 8, 9, 12, 13 and Days 8, 9 and 10, respectively. For both the 2(nd) and 3(rd) ovulations, no significant difference was detected in ovulation rate between groups M and H. On the other hand, the interpeak interval for wave-like patterns of FSH in group H was significantly (P<0.05) shorter than in group M during the period between the 1(st) and 2(nd) ovulations (4.3 +/- 0.3 vs. 6.5 +/- 1.5 days). The mean LH pulse frequency in group H was significantly (P<0.05) greater than in group M on Day 11 (4.5 +/- 0.6 vs. 3.3 +/- 0.5 pulses/6 h). The present study clearly demonstrated that short-term (7 days) nutritional supplementation promoted pulsatile LH and wave-like FSH secretions in cycling goats. However, no significant increase in ovarian performance was found under such endocrine and metabolic conditions.