Developmental changes in the histological structure of the testes, and testosterone profiles in male guinea fowls (Numida meleagris)

Owing to the paucity of information on the reproductive biology of guinea fowls, a study involving a total of 66 males was conducted, and documented the developmental changes in histological structure of the testes of guinea cocks from hatching until adulthood. Changes in testosterone synthesis during sexual development were also determined. Age-related changes were analysed using univariate analysis for completely randomised design and means separated using Tukey's test/Kruskal-Wallis test and medians separated by Mann-Whitney U test. Total germ cell population per testis and testicular histological morphometric parameters increased significantly (p < 0.0001) from 12 weeks of age (WOA), and stabilized between 20 and 24 WOA. Peripheral testosterone concentrations increased gradually from 4 WOA, and peaked at 20 WOA. Correlations among all the testicular morphometric parameters were positive and highly significant (p < 0.01). Similarly, significant (p < 0.05) positive correlations existed between testicular weight and testicular sperm production, tubular diameter, Sertoli cell population, tubular length and peripheral testosterone concentration. Testicular sperm production was positively correlated with meiotic index (p < 0.01) and round spermatids population (p < 0.05). The correlations between peripheral testosterone concentrations, tubular diameter and Sertoli efficiency were also significant (p < 0.05) and positive. Testicular morphometric parameters stabilized between 20 and 24 WOA, while peripheral testosterone concentrations showed two patterns of secretion, initial and final phases of increasing and decreasing testosterone secretions, respectively, and may be implicated in the development of histological structures of the testes and spermatogenesis. [Abstract copyright: Copyright © 2017 Elsevier Inc. All rights reserved.

Transition of hemoglobin between two tertiary conformations: The transition constant differs significantly for the major and minor hemoglobins of the Japanese quail (Cortunix cortunix japonica)

We demonstrate that 5,5′-dithiobis(2-nitrobenzoate) – DTNB – reacts with only CysF9[93]β and CysB5[23]β among the multiple sulfhydryl groups of the major and minor hemoglobins of the Japanese quail (Cortunix cortunix japonica). Kequ, the equilibrium constant for the reaction, does not differ very significantly between the two hemoglobins. It decreases 430-fold between pH≈5.6 and pH≈9: from a mean of 7±1 to a mean of 0.016±0.003. Quantitative analyses of the Kequ data based on published X-ray and temperature-jump evidence for a tertiary structure transition in liganded hemoglobin enable the calculation of Krt, the equilibrium constant for the r←→t tertiary structure transition. Krt differs significantly between the two hemoglobins: 0.744±0.04 for the major, 0.401±0.01 for the minor hemoglobin. The mean pKas of the two groups whose ionizations are coupled to the DTNB reaction are about the same as previously reported for mammalian hemoglobins

A Dynamics and Stability Framework for Avian Jumping Take-off

Jumping take-off in birds is an explosive behaviour with the goal of providing a rapid transition from ground to airborne locomotion. An effective jump is predicated on the need to maintain dynamic stability through the acceleration phase. The present study concerns understanding how birds retain control of body attitude and trajectory during take-off. Cursory observation suggests that stability is achieved with relatively little cost. However, analysis of the problem shows that the stability margins during jumping are actually very small and that stability considerations play a significant role in selection of appropriate jumping kinematics. We use theoretical models to understand stability in prehensile take-off (from a perch) and also in non-prehensile take-off (from the ground). The primary instability is tipping, defined as rotation of the centre of gravity about the ground contact point. Tipping occurs when the centre of pressure falls outside the functional foot. A contribution of the paper is the development of graphical tipping stability margins for both centre of gravity location and acceleration angle. We show that the nose-up angular acceleration extends stability bounds forward and is hence helpful in achieving shallow take-offs. The stability margins are used to interrogate simulated take-offs of real birds using published experimental kinematic data from a guinea fowl (ground take-off) and a diamond dove (perch take-off). For the guinea fowl the initial part of the jump is stable, however simulations exhibit a stuttering instability not observed experimentally that is probably due to absence of compliance in the idealised joints. The diamond dove model confirms that the foot provides an active torque reaction during take-off, extending the range of stable jump angles by around 45{\deg}.Comment: 21 pages, 11 figures; supplementary material: https://figshare.com/s/86b12868d64828db0d5d; DOI: 10.6084/m9.figshare.721056

Characteristics and Behavior of Guineafowl and Domesticated Chicken Hybrids

The description, behavior, and morphologic measurements are presented for two hybrid crosses of domesticated chicken and guineafowl. The ease at which gallinaceous birds hybridize might warrant a closer look at the classification system. Possibly the number of families in the superfamily Phasianoidea should be reduced as some other researchers suggest

ПРОУЧВАНЕ ВЛИЯНИЕТО НА СУХ ЕКСТРАКТ ОТ TRIBULUS TERRESTRIS ВЪРХУ ОСНОВНИ БИОХИМИЧНИ И ХЕМАТОЛОГИЧНИ ПОКАЗАТЕЛИ НА КРЪВТА ПРИ ТОКАЧКИ (NUMIDA MELEAGRIS)

The aim of the present research was to investigate the effect of Bulgarian additive Vemoherb-T (dry extract of the annual plant Tribulus terrestris – L), produced by Vemo 99 Ltd Company, Sofia on main biochemical characteristics and hematological parameters of the blood in guinea fowl (Numida meleagris). An experiment was carried out with 30 Pearl-gray Guinea fowl (32 weeks old), distributed in two groups – a control and an experimental, 12 female and 3 male each. All birds were fed the same mixture for breeder guinea fowl. Vemoherb-T was supplemented to the compound feed of the experimental group in a daily dose of 10 mg/kg body weight for a period of 12 weeks. The tested product decreased significantly the levels of total triglycerides (P < 0.05), total cholesterol (P <0.01) and glucose (P < 0.01; P < 0.001 in male and female birds respectively) in the blood serum. It was established significantly higher total protein- ((P < 0.001) and calcium (P<0.01) values in the blood serum of the treated birds. The addition of Vemoherb-T increased significantly hemoglobin level, the number of erythrocytes and leukocytes and decreased the number of eosinophils in guinea fowl from the both sexes.Целта на настоящото изследване беше да се установи влиянието на Българския продукт Vemoherb-T (сух екстракт от едногодишното растение Tribulus terrestris-L), произведен от фирма Вемо 99 ООД, София, върху основни биохимични характеристики и хематологични показатели на кръвен серум при токачки (Numida meleagris). Беше проведен научен експеримент с 30 Бисерносиви токачки (на 32 седмична възраст), разпределени в две групи – опитна и контролна, 12 женски и 3 мъжки всяка. Всички птици получаваха една и съща смеска за разплодни токачки. Vemoherb-T беше добавян към комбинирания фураж на опитната група ежедневно в доза 10 mg/kg жива маса в продължение на 12 седмици. Изпитваният продукт понижава достоверно нивата на общите триглицериди (P < 0.05), общия холестерол (P <0.01) и глюкозата (P < 0.01; P < 0.001 съответно за мъжките и женски птици) в кръвния серум. Бяха установени достоверно по- високи стойности на общия протеин ((P < 0.001) и на калция (P < 0.01) в кръвния серум на третираните птици. Добавката на Vemoherb-T повишава достоверно нивото на хемоглобина, броя на еритроцитите и лeвкоцитите, и понижава броя на еозинофилните левкоцити при токачките и от двата пола

Don't break a leg: Running birds from quail to ostrich prioritise leg safety and economy in uneven terrain

Cursorial ground birds are paragons of bipedal running that span a 500-fold mass range from quail to ostrich. Here we investigate the task-level control priorities of cursorial birds by analysing how they negotiate single-step obstacles that create a conflict between body stability (attenuating deviations in body motion) and consistent leg force–length dynamics (for economy and leg safety). We also test the hypothesis that control priorities shift between body stability and leg safety with increasing body size, reflecting use of active control to overcome size-related challenges. Weight-support demands lead to a shift towards straighter legs and stiffer steady gait with increasing body size, but it remains unknown whether non-steady locomotor priorities diverge with size. We found that all measured species used a consistent obstacle negotiation strategy, involving unsteady body dynamics to minimise fluctuations in leg posture and loading across multiple steps, not directly prioritising body stability. Peak leg forces remained remarkably consistent across obstacle terrain, within 0.35 body weights of level running for obstacle heights from 0.1 to 0.5 times leg length. All species used similar stance leg actuation patterns, involving asymmetric force–length trajectories and posture-dependent actuation to add or remove energy depending on landing conditions. We present a simple stance leg model that explains key features of avian bipedal locomotion, and suggests economy as a key priority on both level and uneven terrain. We suggest that running ground birds target the closely coupled priorities of economy and leg safety as the direct imperatives of control, with adequate stability achieved through appropriately tuned intrinsic dynamics

Humans, geometric similarity and the Froude number: is ''reasonably close'' really close enough?

Summary Understanding locomotor energetics is imperative, because energy expended during locomotion, a requisite feature of primate subsistence, is lost to reproduction. Although metabolic energy expenditure can only be measured in extant species, using the equations of motion to calculate mechanical energy expenditure offers unlimited opportunities to explore energy expenditure, particularly in extinct species on which empirical experimentation is impossible. Variability, either within or between groups, can manifest as changes in size and/or shape. Isometric scaling (or geometric similarity) requires that all dimensions change equally among all individuals, a condition that will not be met in naturally developing populations. The Froude number (Fr), with lower limb (or hindlimb) length as the characteristic length, has been used to compensate for differences in size, but does not account for differences in shape. To determine whether or not shape matters at the intraspecific level, we used a mechanical model that had properties that mimic human variation in shape. We varied crural index and limb segment circumferences (and consequently, mass and inertial parameters) among nine populations that included 19 individuals that were of different size. Our goal in the current work is to understand whether shape variation changes mechanical energy sufficiently enough to make shape a critical factor in mechanical and metabolic energy assessments. Our results reaffirm that size does not affect mass-specific mechanical cost of transport (Alexander and Jayes, 1983) among geometrically similar individuals walking at equal Fr. The known shape differences among modern humans, however, produce sufficiently large differences in internal and external work to account for much of the observed variation in metabolic energy expenditure, if mechanical energy is correlated with metabolic energy. Any species or other group that exhibits shape differences should be affected similarly to that which we establish for humans. Unfortunately, we currently do not have a simple method to control or adjust for size–shape differences in individuals that are not geometrically similar, although musculoskeletal modeling is a viable, and promising, alternative. In mouse-to-elephant comparisons, size differences could represent the largest source of morphological variation, and isometric scaling factors such as Fr can compensate for much of the variability. Within species, however, shape differences may dominate morphological variation and Fr is not designed to compensate for shape differences. In other words, those shape differences that are “reasonably close” at the mouse-to-elephant level may become grossly different for within-species energetic comparisons

Autentificación de carne y productos cárnicos procedentes de codorniz, faisán, perdiz y pintada mediante una técnica de PCR con cebadores especie-específicos

Polymerase chain reaction (PCR) based on oligonucleotide primers targeting the mitochondrial 12S rRNA gene has been applied to the specific identification of meats from quail (Coturnix coturnix), pheasant (Phasianus colchicus), partridge (Alectoris spp), and guinea fowl (Numida meleagris)

Don't break a leg: Running birds from quail to ostrich prioritise leg safety and economy in uneven terrain

Cursorial ground birds are paragons of bipedal running that span a 500-fold mass range from quail to ostrich. Here we investigate the task-level control priorities of cursorial birds by analysing how they negotiate single-step obstacles that create a conflict between body stability (attenuating deviations in body motion) and consistent leg force–length dynamics (for economy and leg safety). We also test the hypothesis that control priorities shift between body stability and leg safety with increasing body size, reflecting use of active control to overcome size-related challenges. Weight-support demands lead to a shift towards straighter legs and stiffer steady gait with increasing body size, but it remains unknown whether non-steady locomotor priorities diverge with size. We found that all measured species used a consistent obstacle negotiation strategy, involving unsteady body dynamics to minimise fluctuations in leg posture and loading across multiple steps, not directly prioritising body stability. Peak leg forces remained remarkably consistent across obstacle terrain, within 0.35 body weights of level running for obstacle heights from 0.1 to 0.5 times leg length. All species used similar stance leg actuation patterns, involving asymmetric force–length trajectories and posture-dependent actuation to add or remove energy depending on landing conditions. We present a simple stance leg model that explains key features of avian bipedal locomotion, and suggests economy as a key priority on both level and uneven terrain. We suggest that running ground birds target the closely coupled priorities of economy and leg safety as the direct imperatives of control, with adequate stability achieved through appropriately tuned intrinsic dynamics