The role of prostaglandins in livestock production

Prostaglandins belong to the family of lipid. Soluble unsaturated hydroxyl acid containing twenty carbon (c) atoms and based on the prostanoic acid skeleton. There are two main types of Prostaglandins (PGs), the E and F series each having 3 members E1, E2, E3 and F1σ, F2σ, F3σ. The other PGs are known as secondary PGs and are products of enzymic or chemical dehydrations of PGEs e.g PG+2, PGA2, PGD2 and PGB. Prostaglandins are probably the most important regulators of female productive functions (ovulation, uterine receptivity, Implantation and parturition) and associated with pathologies (pain, fever, and inflammation), apart from sex steroids. Prostaglandins are not stored in tissues but are synthesized and released in response to a given stimulus. Prostaglandins are produced by all nucleated cells of the body and act locally in a paracrine (locally active) or autocrine (acting on the same cell from which it is in a synthesized) fashion. Prostaglandins are therefore regarded as essential mediators of female reproductive processes, hence, this paper seeks to review the role of Prostaglandins which is exploited in livestock production especially oestrus synchronization and induced parturition.KEYWORDS: Prostaglandins, Production, Role, Livestoc

Correlation, regression estimates and heterosis of Archachatina marginata snails in Calabar, Nigeria

Eighty sexually mature Archachatina marginata snails, forty each of the black skinned and white skinned ectotypes were used in a study to estimate  heterosis, correlation and regression. Data collected on the snails and their eggs included body weight (BWT), shell length (SLH), shell width (SWH), “mouth” length (MLH) and “mouth” width (MWH); and egg weight (EWT), egg length (ELH) and egg width (EWH), respectively. These data were used to estimate correlations between pairs of traits, heterosis and to predict weight from other morphometric traits among three mating groups [black skinned x black skinned (BAM X BAM), white skinned x white skinned (WAM X WAM) and their cross BAM X WAM)]. Results obtained from the study showed that evaluated traits expressed strong, positive and highly significant (P<0.01) correlation values that ranged from rp = 0.86 to rp = 0.99  among  the snails mating groups. The correlation values of traits evaluated on eggs laid by these snails ranged from mild (rp = 0.49) through moderate (rp = 0.59, rp = 0.70) to strong/close (rp = 0.89). Regression estimates values obtained ranged from mild (1.30) to high (6.25), and shell width best predicted hatchlings body weight in the black skinned x black skinned (BAM X BAM) mating group, while “mouth” length best predicted  hatchlings body weight in the white skinned x white skinned (WAM X WAM) mating group. Traits evaluated for percent heterosis expressed positive and significant (P<0.05) values between the mating groups, with the crossbred (BAM X WAM) mating group having advantage over the purebred  (BAM X BAM and WAM X WAM) mating groups. It could therefore be concluded that in the face of appropriate selection programme, heterosis can be exploited to improve snails reproductive and growth traits. It can thus be recommended that having information regarding the association of weight with other contributing traits/parameters is crucial before starting any breeding programme. Keywords: Correlation, Estimates, Heterosis, Regression, Snail

Progressive review of solar drying studies of agricultural products with exergoeconomics and econo-market participation aspect

An analysis of review articles on solar drying of agricultural products is presented. The review also discusses detailed economic evaluation methods and market participation approaches for transitioning solar dryers from the workshop to the market. This study aims to serve as a model for future solar drying reviews. In addition to broad perspective reviews, most reviews focused on using thermal storage, hybrid technologies, solar greenhouses, 4E evaluations, software applications and crop quality. From most of the reviews, solar dryers with thermal storage are now a viable substitute for fossil energy source dryers and can provide the continuous temperature range of 40–60 °C required to dry food crops. When phase change material is deployed, the transition temperature should be at 5 °C above the desired drying temperature. However, all reviews included sections on types, classification, mode of airflow through the collector, and use of thermal storage in solar drying. Hence, the authors review nearly the same research material, but review gaps remain. Thus that aspect was covered by examining the economic and exergoeconomic analysis methods used in solar dryer evaluations. Again agribusiness inter-phasing between researchers and users, which will spore market participation of solar dryer fabricators lacking in the literature were presented. Therefore, for a more market-oriented development of solar thermal technologies, solar dryer producers must engage in market-oriented production. The nature of markets located at different places calls for better strategies to improve market orientation and access to solar dryers and fabricators