Plasma gonadotropins and ovarian hormones during the estrous cycle in high compared to low ovulation rate gilts

Mature gilts classified by low (12 to 16 corpora lutea [CL], n = 6) or high (17 to 26 CL, n = 5) ovulation rate (OR) were compared for plasma follicle-stimulating hormone (FSH), luteinizing hormone (LH), progesterone, estradiol-17beta, and inhibin during an estrous cycle. Gilts were checked for estrus at 8-h intervals beginning on d 18. Blood samples were collected at 8-h intervals beginning on d 18 of the third estrous cycle and continued for one complete estrous cycle. Analysis for FSH and LH was performed on samples collected at 8-h intervals and for ovarian hormones on samples collected at 24-h intervals. The data were standardized to the peak of LH at fourth (d 0) and fifth estrus for the follicular phase and analyzed in discrete periods during the periovulatory (-1, 0, +1 d relative to LH peak), early-luteal (d 1 to 5), mid-luteal (d 6 to 10), late-luteal (11 to 15), periluteolytic (-1, 0, +1 d relative to progesterone decline), and follicular (5 d prior to fifth estrus) phases of the estrous cycle. The number of CL during the sampling estrous cycle was greater (P < 0.005) for the high vs low OR gilts (18.8 vs 14.3) and again (P < 0.001) in the cycle subsequent to hormone measurement (20.9 vs 14.7). For high-OR gilts, FSH was greater during the ovulatory period (P = 0.002), the mid- (P < 0.05) and late-luteal phases (P = 0.01), and tended to be elevated during the early-luteal (P = 0.06), but not the luteolytic or follicular periods. LH was greater in high-OR gilts during the ovulatory period (P < 0.005), but not at other periods during the cycle. In high-OR gilts, progesterone was greater in the mid, late, and ovulatory phases (P < 0.005), but not in the follicular, ovulatory, and early-luteal phases. Concentrations of estradiol-17beta were not different between OR groups during the cycle. Inhibin was greater for the high OR group (P < 0.005) during the early, mid, late, luteolytic, and follicular phases (P < 0.001). The duration of the follicular phase (from last baseline estrogen value to the LH peak) was 6.5 +/- 0.5 d and was not affected by OR group. These results indicate that elevated concentrations of both FSH and LH are associated with increased ovulation rate during the ovulatory phase, but that only elevated FSH during much of the luteal phase is associated with increased ovulation rate. Of the ovarian hormones, both inhibin and progesterone are highly related to greater ovulation rates. These findings could aid in understanding how ovulation rate is controlled in pigs.     

Effect of boar exposure at time of insemination on factors influencing fertility in gilts

The effect of boar exposure during artificial insemination (AI) on semen backflow, fertilization, and embryo quality was evaluated. Gilts (approximately 170 d) were induced into estrus with PG600, and ovulation was synchronized using hCG 72 h later. Estrus detection was initiated after PG600 and continued at 12-h intervals. At estrus, gilts were allotted to receive boar exposure (BE, n = 20) or no boar exposure (NBE, n = 20) during AI. Gilts receiving NBE were identified to be in estrus prior to AI and the boar was then removed for 1 h, whereas gilts in the BE group received 15 min of exposure during AI. Insemination occurred in crates at 12 and 24 h after onset of estrus with 3 x 10(9) sperm/80 mL. Backflow was collected continuously with samples taken at time 0, (during AI), and at 0.25, 0.5, 0.75, 1, 2, 4, and 8 h after first and second AI. The effect of treatment was evaluated for time of insemination (min), backflow (mL), and sperm in backflow samples. Oviducts were flushed 2 d after first AI to evaluate the effect oftreatment on fertilization rate, accessory sperm numbers on embryos (scored 1 to 5), and embryo quality. There was no effect of first or second AI; therefore, data were pooled. Average duration of AI was 3.7 +/- 0.2 min and was not influenced by BE (P < 0.10). However, during the initial stage of AI, BE reduced the volume of semen (18.6 vs 32.4 +/- 3 mL) and the number of sperm lost (0.8 vs 1.3 +/- 0.15 x 10(9) sperm) compared to NBE (P < 0.05). There was a treatment x time effect (P < 0.05) for volume of backflow. By 45 min, the BE gilts lost more volume (9.0 vs 3.6 mL) compared to the NBE group, but sperm loss did not differ. Between 1 and 8 h after AI, neither volume nor sperm loss was influenced by treatment. By 8 h, total leakage (65 vs 63 mL) and total sperm loss (1.6 x 10(9) vs 1.8 x 10(9) sperm) were not influenced by BE (P > 0.10). However, more accessory sperm (P < 0.01) were found on embryos for the NBE (> or = 11 sperm/embryo) compared to BE embryos (< or = 10 sperm/embryo). Despite this observation, percentages of fertilized embryos (99.5 +/- 0.5 %) and number of embryos (11.5 +/- 0.1) were not different (P > 0.10). In conclusion, AI in the presence of a mature boar did not affect total semen leakage, sperm loss, fertilized embryos, or embryo quality. The importance of boar exposure during insemination was evident from less leakage during insemination, but had no effect on fertility; this suggests that the elimination of boar exposure during AI may not be deleterious to reproductive performance.     

Oral eosinophilic granulomas in tigers (Panthera tigris)--a collection of 16 cases.

Oral eosinophilic granulomas were diagnosed in 16 tigers (Panthera tigris). All lesions were located on the hard or soft palate and typically consisted of flat or slightly raised circular ulcers. Histologic features of these lesions were essentially identical to those seen in oral eosinophilic granulomas of domestic cats and dogs. No clinical signs were noted in eight cases, though various degrees of inappetence, excessive salivation, and dysphagia were noted in the other eight tigers. Six cases were not treated. Treatment for the remaining 10 cases centered on corticosteroids and additional treatments included surgical removal, cryotherapy, antibiotics, and chlorpheniramine. Treatment with corticosteroids did appear to be effective in some cases, though lesions would worsen after cessation of therapy and no cases were cured. In addition, three cases developed complications possibly related to this corticosteroid therapy. The etiology of these lesions remains unknown, though an underlying allergic condition is likely.     

Inoculative release strategies of Macrolophus pygmaeus Rambur (Hemiptera: Miridae) in tomato crops: population dynamics and dispersal

Journal of Plant Diseases and Protection - Macrolophus pygmaeus Rambur (Hemiptera: Miridae) is a key biological control agent in greenhouse tomato crops. In the present study, we describe the...     

Preparation of gluten-free bread using a meso-structured whey protein particle system

This article presents a novel method for making gluten-free bread using mesoscopically structured whey protein. The use of the meso-structured protein is based on the hypothesis that the gluten structure present in a developed wheat dough features a particle structure on a mesoscopic length scale (100 nm–100 μm). Whey protein particles were prepared by cold gelation of soluble whey protein aggregates during phase separation. The addition of a 2.4% whey protein particle suspension to wheat starch resulted in a dough that could be baked into a leavened bread with a specific volume up to 3.7 ml/g and a bubble size comparable with a normal bread. The relevance for structuring the whey protein into mesoscopic particles was confirmed by tests in which only a homogeneous whey protein gel or a whey protein solution was used. The protein particle system gave better results after proving and baking compared with these systems.     

DNA‐analysis to monitor fisheries and aquaculture: Too costly?

Evidence from DNA‐analysis is commonplace in human criminal investigations, and while it is increasingly being used in wildlife crime, to date, its application to control and enforcement activities in fisheries and aquaculture has only been sporadic. Contemporary DNA‐analysis tools are capable of addressing a broad range of compliance issues, species identification, mislabelling of fish products, determining the origin of catches and the farm of origin of aquaculture escapees. Such applications have the potential to ensure traceability along the fish product supply chain and to combat consumer fraud and Illegal, Unreported and Unregulated fishing. Nevertheless, DNA‐analysis is not yet used routinely in investigations into compliance with fisheries and aquaculture legislation. One potential reason for this is that DNA‐analysis techniques may have been regarded as too expensive. However, costs have plummeted over the past decade prompting us to objectively assess whether the costs associated with routine use of DNA‐analysis techniques for fisheries and aquaculture control and enforcement activities do constitute an impediment. Based on a number of recent fisheries and aquaculture compliance investigations that incorporated DNA‐analysis, our results indicate that the use of genetic analysis was justified and worthwhile in all cases examined. We therefore conclude that the costs associated with DNA‐analysis do not represent a barrier to the routine adoption of DNA‐analysis techniques in fisheries and aquaculture compliance investigations. Thus, control and enforcement agencies should be encouraged to use such techniques routinely.     

Participatory plant breeding approach for host plant resistance to bean fly in common bean under semi-arid Kenya conditions

Common bean (Phaseolus vulgaris L.) is the most important legume crop in Kenya. It is cultivated across a wide range of agro-ecologies which include high potential and marginal areas. Eastern Kenya alone, largely semi-arid, accounts for 35% of the country’s total bean production. Bean farmers mainly small-scale have limited access to quality seed, chemical pesticides and fertilizer. Therefore, bean yield under on-farm conditions still remains below 500 kg ha⁻¹ while the potential is about 1,200 kg ha⁻¹ under semi-arid conditions. To asses the farmers’ views on bean varieties and a key insect pest and associated constraints contributing to yield loss, research was undertaken. The research included survey to quantify the yield loss and Participatory Rural Appraisal to determine the level of adoption and criteria for variety choice in semi-arid eastern Kenya (SAEK). The results show that farmers consider drought and insect pest problems as main causes for low yields. The adoption rate for improved varieties is high but self sufficiency in beans stands at 23% in the dry transitional (DT) agro-ecology and at 18% in the dry mid-altitude (DM) agro-ecology, respectively. This could be attributed to low adaptability since most of the improved varieties grown were selected for high potential areas but now found in marginal areas. Drought, earliness, yield stability, and insect pest resistance are the main reasons for choice of varieties by farmers. Bean fly (Ophiomyia sp.) was identified as one of the key crop pests of beans limiting yield. Besides, African bollworm (Helicoverpa armigera) and bean aphid (Aphis fabae) were ranked higher. Due to limitations of the conventional breeding approach, a participatory plant breeding approach is suggested so as to provide an opportunity to develop insect pest resistant varieties adapted to the SAEK region.