Mineral requirements of hair sheep in tropical climates

In this study, we evaluated the requirements of calcium (Ca), phosphorus (P), magnesium (Mg), sodium (Na) and potassium (K) for sheep hair growth. Experimental diets contained different levels of metabolizable energy [ME; 0.96, 1.28, 1.72, 2.18 and 2.62 Mcal/kg of dry matter, (DM), corresponding to 4.23, 5.64, 7.58, 9.61 and 11.55 MJ/kg DM]. The lambs' hair (n = 48) at 2 months of age presented an average body weight (BW) of 12.05 ± 1.81 kg. At the beginning of the experiment, eight animals were slaughtered as a reference group to estimate the initial empty body weight and body composition. Net mineral requirements (g/day) ranged from 0.73 to 0.71 g of Ca, 0.51 to 0.49 g of P, 0.026 to 0.026 g of Mg, 0.16 to 0.19 g of Na and 0.15 to 0.13 g of K for animals with a BW ranging from 15 to 30 kg and a daily gain of 100 g. The results of this study indicate that the net macromineral requirements for weight gain in Morada Nova lambs are different from the values commonly recommended by the Agricultural and Food Research Council.     

Effects of dietary Tenebrio molitor meal inclusion in free‐range chickens

Insects are currently being considered as a novel protein source for animal feeds, because they contain a large amount of protein. The larvae of Tenebrio molitor (TM) have been shown to be an acceptable protein source for broiler chickens in terms of growth performance, but till now, no data on histological or intestinal morphometric features have been reported. This study has had the aim of evaluating the effects of dietary TM inclusion on the performance, welfare, intestinal morphology and histological features of free‐range chickens. A total of 140 medium‐growing hybrid female chickens were free‐range reared and randomly allotted to two dietary treatments: (i) a control group and (ii) a TM group, in which TM meal was included at 75 g/kg. Each group consisted of five pens as replicates, with 14 chicks per pen. Growth performance, haematological and serum parameters and welfare indicators were evaluated, and the animals were slaughtered at the age of 97 days. Two birds per pen (10 birds/treatment) were submitted to histological (liver, spleen, thymus, bursa of Fabricius, kidney, heart, glandular stomach and gut) and morphometric (duodenum, jejunum and ileum) investigations. The inclusion of TM did not affect the growth performance, haematological or serum parameters. The morphometric and histological features were not significantly affected either, thus suggesting no influence on nutrient metabolization, performance or animal health. Glandular stomach alterations (chronic flogosis with epithelial squamous metaplasia) were considered paraphysiological in relation to free‐range farming. The observed chronic intestinal flogosis, with concomitant activation of the lymphoid tissue, was probably due to previous parasitic infections, which are very frequently detected in free‐range chickens. In conclusion, the findings of this study show that yellow mealworm inclusion does not affect the welfare, productive performances or morphological features of free‐range chickens, thus confirming that TM can be used safely in poultry diets.     

Being exposed to low concentrations of pirimiphos-methyl and chlorfenapyr has detrimental effects on the mobility of Trogoderma granarium

BACKGROUND

Sublethal effects of insecticides may negatively affect several biological and behavioral traits of insects. The lethal effects of pirimiphos-methyl and chlorfenapyr have been previously showed on Trogoderma granarium, but little knowledge is available about their sublethal effects at low concentrations on both sexes. Herein, the sublethal effects of pirimiphos-methyl and chlorfenapyr on the mobility of T. granarium males and females were investigated.

RESULTS

Lethal concentration (LC) values of pirimiphos-methyl and chlorfenapyr were lower for T. granarium females than males. LC values on males were LC₁₀ = 0.000788 and 0.00139 mg active ingredient (a.i.) cm⁻², LC₃₀ = 0.00350 and 0.00535 mg a.i. cm⁻², and LC₅₀ = 0.00986 and 0.0136 mg a.i. cm⁻² for pirimiphos-methyl and chlorfenapyr respectively. LC on females were LC₁₀ = 0.000704 and 0.00110 mg a.i. cm⁻², LC₃₀ = 0.00323 and 0.00428 mg a.i. cm⁻², and LC₅₀ = 0.00925 and 0.0110 mg a.i. cm⁻² for pirimiphos-methyl and chlorfenapyr respectively. The walking duration of beetles exposed to LC₃₀ of pirimiphos-methyl was significantly lower than the individuals exposed to LC₁₀ and LC₃₀ of both insecticides and control ones. Pirimiphos-methyl LC₃₀-exposed males remained more time on their back (101.7 s) than females (46.9 s), while the latter stayed immobile longer than males (381.7 s versus 371.9 s). The highest speed was recorded for control beetles (14.17 mm s⁻¹ females vs. 12.44 mm s⁻¹ males), while the lowest speed was observed in pirimiphos-methyl LC₃₀-treated males (8.36 mm s⁻¹) and females (9.66 mm s⁻¹).

CONCLUSIONS

Overall, males and females exposed to low concentrations of pirimiphos-methyl and chlorfenapyr showed reduced motility. This knowledge can be exploited further to unlock behavioral effects of insecticides for effective pest management programs in warehouses. © 2023 Society of Chemical Industry.     

Gross anatomy,computed tomography,magnetic resonance imaging and bone mineral densitometry of the ovine metacarpo/metatarsophalangeal joint

This study was aimed to provide anatomical atlas of the ovine metacarpo/metatarsophalangeal joints using computed tomography (CT) scan and magnetic resonance imaging (MRI), as well as to investigate bone mineral density (BMD) and morphometric features of this joint. The limbs of twenty adult Sanjabi sheep were examined. Imaging was performed using a 16-slice multi-detector CT scanner and a 1.5 Tesla MRI scanner. The obtained images were correlated with corresponding anatomical sections. BMD was measured by Dual Energy X-ray Absorptiometry (DEXA) method. Also morphometric features included distance between metacarpal and metatarsal heads, width of metacarpal and metatarsal head, length, width and the height of the proximal sesamoid bones were measured. In MRI images, compact bones, ligaments and tendons showed less signal intensity (hypointense). The fatty tissue and bone marrow had more signal intensity (hyperintense), but articular cartilage and synovial fluid showed moderate signal intensity. BMD in the left hind limb was significantly higher than other three limbs (p ≤ 0.05). The length of proximal sesamoid bones in left forelimb was higher than right forelimb (p ≤ 0.05). The thickness of proximal sesamoid bones in left limbs was higher than those in their counterparts (p ≤ 0.05). The width of the medial head in the forelimbs was significantly greater than the hind limbs (p ≤ 0.05). The present results might be useful in managing the clinical techniques on this joint. Larger volume of the proximal sesamoid bones and wider medial head in the forelimbs compared to the hindlimbs impel this speculation that the centre of gravity is closer to the forelimbs.     

新农村视角下农民参与式小型水利

用水户参与式灌溉管理是我国近年来在总结本国管理体制基础上结合国际管理经验提出的一项重大改革。新时期倡导“坚持以人为本，构建和谐社会”的社会主义“新农村”建设与发展过程中，国家高度重视农村基础设施的建设发展特别是农村水利设施，那么农村小型水利工程参与式管理体制目前状况如何、今后如何围绕“新农村”发展将是新时期农村水利管理体制发展所面临和需要解决的。     

贫困地区农业技术推广新模式：发展小区域农业技术推广户 ——基于甘肃省部分贫困县的调查思考

（1甘肃农业大学经济管理学院，兰州 730070；2兰州资源环境职业技术学院，兰州 730020）     

Design for Precision Measurement System Based on Machine Vision

It is difficult to measure the geometric quantity of small parts in finishing, assembling and measuring, because it's easy to break the workpieces' surface and alter their position by means of traditional contact measuring methods.There are some non contact measurers, such as,light feeler pin and interference microscope etc., because of it's high price and strict working conditions,so it's difficult to promote them in widely use. Precision measurement system based on machine vision has the advantages of non contact measuring as well as high performance and low price. Some problems, such as light source, algorithm of edge fitting, auto focusing,are discussed.     

A Theoretical Analysis of Underpricing in IPOs Based on the Irrational Behavior of Investors

Employing the standpoint of irrational investors in the behavior finance, the authors study the relation on the irrational behavior of medium and small Investors and underpricing of IPO in our country. The paper premises that a revenue-maximizing issuer will be regarded as the target function, and the rational institutional investors can be delegated the task of holding the stocks in the after-market for resale to the irrational medium and small investors--thereby extracting surplus from them, finally the issuer can maximize their expected revenue. We model the process mentioned above and find that the high underpricing of IPO in our country has the direct relation with numerous the irrational medium and small investors existing in our country who cause the underpricing.