Ontogeny of OPN4, OPN5, GnRH and GnIH mRNA Expression in the Posthatch Male and Female Pekin Duck (Anas platyrhynchos domesticus) Suggests OPN4 May Have Additional Functions beyond Reproduction

The hypothalamic–pituitary–gonadal axis (HPG) is known to be regulated by daylength through the deep brain photoreceptor (DBP) system. The post-hatch ontogeny is not known for any of the DBPs. We set out to determine the ontogeny of OPN4 and OPN5 gene expression relative to GnRH and GnIH using qRT-PCR. Brains and serum were collected from five drakes and five hens on the day of hatching (Day 0) and again at 2, 4, 6, 10, 14, 19, 25 and 31 weeks of age and analyzed by qRT-PCR. Hen and drake serum was assayed for circulating levels of estradiol and testosterone, respectively. Data were analyzed between sexes over time using a repeated measures two-way ANOVA. Interestingly, the results show that on the day of hatching (Day 0), ducks showed adult-like levels of relative OPN4, but not OPN5, gene expression. During week 10, DBP levels increased, achieving highest relative expression levels at week 19 that maintained through week 31, typically peak fertility in ducks. GnRH mRNA levels increased following the DBP expression at the onset of puberty, and gonadal steroids increased after GnRH at week 14 while estradiol preceded testosterone. GnIH mRNA levels did not appreciably change during the time course of this experiment. These observations suggest that OPN4 may be active during the peri-hatch period and may have physiological roles beyond puberty and fertility.

It’s All About Timing: Early Feeding Promotes Intestinal Maturation by Shifting the Ratios of Specialized Epithelial Cells in Chicks

The small intestine (SI) of chicks (Gallus gallus) matures rapidly during the initial post-hatch period and acquires digestive, absorptive, and secretive capabilities. The effects of the timing of first feeding on the quantities and distribution of specialized epithelial cells, which generate and maintain SI morphology and functionality, have not yet been examined. In this study, we identified specialized SI epithelial cell sub-types, including stem, progenitor, proliferating, and differentiated cells within crypts and villi of chicks during the first 10 days post-hatch, by in situ hybridization (ISH), immunofluorescence (IF), and histochemical staining. We then examined their quantities and ratios between day of hatch and d10 in chicks that were fed upon hatch [early feeding (EF)], compared to chicks that were fed 24 h post-hatch [delayed feeding (DF)]. Results showed that EF increased total cell quantities in the crypts and villi at days 1, 3, 7, and 10, compared to DF (p < 0.0001). At d3, EF, in comparison to DF, decreased crypt stem cell proportions (p < 0.0001), increased crypt proliferating (p < 0.01) and differentiated (p < 0.05) cell proportions, and increased villus enterocyte proportions (p < 0.01). By d10, EF increased both the quantities and proportions of villus enterocytes and goblet cells, compared to DF. We conclude that feeding upon hatch, compared to 24 h-delayed feeding, enhanced SI maturation and functionality by increasing the quantities and proportions of proliferating and differentiated cells, thus expanding the digestive, absorptive, and secretive cell populations throughout the initial post-hatch period.

Greenbelly Stinkbug Biology in Different Temperatures

The green-belly stinkbug (Dichelops melacanthus) stands out due to its damage potential towards corn and wheat crops. The population distribution and size greatly influence the potential damage. The insect’s reproductive capacity depends on different temperature conditions during various crop seasons and its lifecycle. The study aimed to evaluate the influence of different constant temperatures on the D. melacanthus biology. The study was performed twice, once in the year of 2017, and again in 2019. The biological features were observed in temperature-controlled climate chambers with the following temperatures: 11, 16, 21, 26, 31 and 36 °C, each with a fluctuation of ±1 °C, using a RH of 65±15% and photophase of 14 h. The evaluations were conducted from eggs to adults in terms of: nymphal hatch period, each instar duration, female fecundity and egg viability. There were no eggs hatching at 11 ºC and it also reached 100% mortality during the second instar at 16 °C. The eggs-to-adult duration for the temperatures 21, 26, 31 and 36 °C in the trial of 2017 was 58.4, 30.1, 18.2 and 16.3 days, respectively. In the same temperatures, but during the 2019 trial, the eggs to adult duration was 58.1; 29.7; 21.3 and 19.1 days, respectively. The reproductive capacity in the temperatures of 21 and 36 °C impaired the female fecundity and egg viability. The temperatures 26 and 31 °C favored the development of D. melacanthus.

Early post hatch feeding in chicks and practical constrains-A review

At present, broilers reach slaughter weight at a physiologically younger age and the embryonic developmental period as well as the first week after hatching represents a larger proportion (45%) of the whole life span. Thus, pre-hatch as well as the transitional post-hatch period must be achieved efficiently. It is known that body weight is increased three to four fold during the first week and considerable changes in gut, and muscle weight and morphology are observed. The post-hatch period is critical for the digestive tract because the system is switching itself from off to on. The first day after hatch is critical for the development of body systems in the chicken and certain types of manipulation must occur during the first days after hatch in order to achieve long-term effects. Meat-type broilers are capable of achieving 70 g/day until 40 days. This achievement requires emphasis on early phase nutrition (i.e. pre-starter diets). The use of pre-starter diets assumes that starter diets are somewhat inefficient in providing balanced nutrients. Early nutritional strategies offer the promise of sustaining progress in production efficiency and welfare of commercial poultry. In order to achieve broiler potential several unconventional changes must be made: supplying nutrients to the developing embryo before hatch, supplying feed within hatchery, developing highly digestible pre-starter diets. Integrate all of the above to create a continuous feeding process from several days prior to hatch, during hatch and till farm placement where first feed is provided.

Persistence of the nematicide fluensulfone in potato (Solanum tuberosum ssp. tuberosum) beds under field conditions

As part of a broader study to evaluate the efficacy of fluensulfone for control of the potato cyst nematode,Globodera pallida, two field experiments in Shropshire (at Woodcote and Howle in 2010 and 2011, respectively) England, were used to monitor the persistence of fluensulfone in potato beds treated with Nimitz 15G®(fluensulfone) at 27 kg ha−1. Fluensulfone dissipated at similar rates in the two fields, with a trend best described by a sigmoidal curve. The time to 50% dissipation (DT50) was 24.3 days at Woodcote, and 23.7 days at Howle. No differences were found between the DT50for fluensulfone and that observed for fosthiazate. The short DT50demonstrated for fluensulfone in this study is a positive attribute as this nematicide may pose a negligible hazard to the environment. However, its persistence at an effective dose may be long enough to be effective over the peak hatch period ofG. pallida.

Using temperature-dependent embryonic growth models to predict time of hatch of American lobster (Homarus americanus) in nature

Hatch time of American lobster (Homarus americanus) varies between years and regions, which affects temperature experienced by the developing larvae and hence the time and distance these drift before settling. Hatch time can be assessed by working with fishermen and inspecting the brood of gravid females caught in their traps. However, this would require frequent sampling as the hatch period is protracted (≈7–12 weeks) and would require dedicated sampling in many regions where hatching occurs outside of the fishing season. To address these limitations, we tested the accuracy with which hatch time can be predicted by taking egg samples during the fishing season and estimating embryo development using embryonic eye size (Perkins eye index) and lab-derived, temperature-dependent development functions. Using a linear development function and observed variability in Perkins eye index at hatch, we successfully predicted 100% of the observed 50-day hatch period, and 96% of predicted hatch dates fell within this period. Our results suggest that samples can be obtained in collaboration with fishermen to predict the timing and progression of hatch of American lobster.