Уточнить поиск
Результаты 1-9 из 9
Welfare assessment of two hybrids of laying hens housed in conventional cages
2018
H.D.H. Mahboub | I.M. Fares | R.A. Darwish
The aims of this study were twofold: to assess the welfare of two hybrids of laying hens in conventional cages and to investigate the effects of tier’s level on the integument condition and fearfulness. Two commercial hybrids, white Lohmann Selected Leghorn (LSL) and brown Lohmann Traditional (LT) at about 18 weeks of age were used in the current study and were housed at three hens / cage. No birds were beak-trimmed. External appearance of the body (scoring of plumage condition and skin injuries at body parts and comb), heterophil-lymphocyte (H-L) ratios and duration of tonic immobility (TI) were used as indicators of well-being. LSL birds showed better plumage condition and low H-L ratios than LT birds while no significant difference was recorded in TI test between the two hybrids. Hens housed in the top tier showed worse feather condition and more wounds than birds in middle and bottom tiers whereas for fear levels, no significant difference was revealed for hens from different tiers of cages. These results suggest that the welfare of LSL birds was relatively good compared to LT. Therefore, conventional cages can be used by the hens to a large extent if birds are properly selected to be specifically adapted to cages.
Показать больше [+] Меньше [-]Application of two staining methods for sperm morphometric evaluation in domestic pigs
2017
Kondracki, Stanisław | Wysokińska, Anna | Kania, Magdalena | Górski, Krzysztof
Introduction: The effect of two smear staining methods on the dimensions and shape of sperm cells in the semen of domestic pigs was evaluated. Material and Methods: The studies were carried out on 30 ejaculates collected from 15 boars, which included five Duroc boars, five Pietrain boars, and five hybrid Duroc × Pietrain boars. Each ejaculate was next sampled to make two microscopic slides, of which one was stained with eosin-nigrosin and the other with eosin-gentian dye. In total, 600 measurements of sperm cells were made. Each sperm was measured for the following morphometric parameters: head length, head width, head area, head perimeter, tail length, and the total sperm length. Results: Sperms measured on slides stained with eosin-nigrosin showed lower dimensions as compared with those stained with the eosin-gentian dye method. Sperm stained with eosin-nigrosin had shorter and narrower heads than sperm stained with eosin-gentian dye. The method of staining, therefore, affected not only the dimensions of the sperm, but also the proportions of the dimensions defining the shape of the sperm. Conclusions: The size and shape parameters in porcine sperm may take on different values depending on the method of semen staining. Sperm cells stained with eosin-nigrosin are smaller than the sperm stained with eosin-gentian dye. The sensitivity of the sperm to the type of dye used for the fixation may be associated with genetic factors.
Показать больше [+] Меньше [-]Quantitative comparison of the stress response of striped bass (morone sacatilis) and hybrid striped bass (Morone saxatilis X Morone chrysops and Morone saxatilis X Morone americana)
1994
Noga, E.J. | Kerby, J.H. | King, W. | Aucoin, D.P. | Giesbrecht, F.
Striped bass (Morone saxatilis) exposed to a standardized confinement stress had markedly different clinical and endocrinologic responses, compared with hybrid striped bass exposed to the same stress. Plasma cortisol concentration increased at a faster rate and appeared to reach a higher value in striped bass than in hybrid bass. Mean plasma cortisol concentration was 742 +/- 43 ng/ml in striped bass, compared with 490 37 and 531 +/- 40 ng/ml in striped bass x white perch (M americana) and striped bass x white bass (M chrysops) hybrids, respectively, after a 45-minute net confinement. Plasma cortisol concentration also remained significantly (P = 0.003) higher in striped bass for at least 48 hours after the net confinement. These hormonal differences were associated with a markedly lower survival and resistance to infection in striped bass, compared with the hybrids.
Показать больше [+] Меньше [-]Assessment of blood pool, soft tissue, and skeletal uptake of sodium fluoride F 18 with positron emission tomography–computed tomography in four clinically normal dogs
2012
Valdés-Martínez, Alejandro | Kraft, Susan L. | Brundage, Cord M. | Arceneaux, Billie K. | Stewart, Jeffrey A. | Gibbons, Debra S.
Objective: To determine the ideal interval to image acquisition after IV injection of sodium fluoride F 18 (18F-NaF) and evaluate biodistribution of the radiopharmaceutical in clinically normal skeletally immature dogs. Animals: 4 female dogs. Procedures: Each dog was anesthetized for evaluation with a commercial hybrid positron emission tomography (PET)–CT instrument. A low–radiation dose, whole-body CT scan was acquired first. An IV injection of 18F-NaF (0.14 mCi/kg) was administered, and a dynamic PET scan centered over the heart and liver was acquired during a period of 120 minutes. Uptake of 18F-NaF in the blood pool, soft tissues, and skeletal structures was evaluated via region of interest analysis to derive standardized uptake values and time-activity curves, which were used to determine the optimal postinjection time for skeletal image acquisition. Biodistribution was also assessed from a final whole-body PET-CT scan acquired after the dynamic scan. Results: Time-activity curves revealed a rapid decrease in the amount of radiopharmaceutical in the blood pool and soft tissues and a rapid increase in the amount of radiopharmaceutical in bones soon after injection. At 50 minutes after injection, the greatest difference in uptake between soft tissues and bones was detected, with continued subtle increase in uptake in the bones. Uptake of 18F-NaF was slightly increased at growth plates and open ossification centers, compared with that at other parts of the bone. Conclusions and Clinical Relevance: At 50 minutes after IV injection of 18F-NaF at the dose evaluated, PET-CT yielded excellent bone-to-background ratio images for evaluation of the skeletal system in dogs.
Показать больше [+] Меньше [-]Preliminary study on factors influencing rabbit doe reproductive efficiency: Effect of parity, day of mating, and suckling on ovarian status and estrogen levels at day 6 of pregnancy
2013
Marongiu, Maria Laura | Dimauro, Corrado
The rabbit corpus luteum becomes an estradiol-dependent tissue by day 6 of gestation, and adequate estrogen is critical to avoid pregnancy failure. The aim of this study was to investigate the effect of parity (primiparous or multiparous), day of mating (11 or 21 d postpartum), and suckling status (suckling or nonsuckling) on various reproductive traits in hybrid rabbit does (n = 96). Ovarian structures on day 6 after coitus were evaluated by means of ultrasonography. Blood samples were collected that day, and the serum was analyzed for estradiol-17β by radioimmunoassay (RIA). Parity and suckling had significant effects on mating rate (P < 0.01 and P < 0.05, respectively). More does accepted the male on day 11 than on day 21 (P < 0.05). Ovulation frequency was significantly affected by parity (P < 0.05), day of mating (P < 0.01), and suckling (P < 0.01). Fewer ovarian large follicles and lower estradiol-17β levels were detected in suckling compared with nonsuckling rabbits (P < 0.01). Since estrogen concentrations are commonly used to assess follicular growth and steroidogenic capacity, the lower hormonal levels in the suckling rabbits may reveal poorer ovarian activity, which could result in reduced reproductive efficiency. Our observations confirm the existence of a partial antagonism between lactation and reproduction in rabbits. Further research is needed to elucidate these phenomena, including when artificial insemination is done. Ultrasonography could represent a noninvasive and reliable method for studying several reproductive functions and dysfunctions in rabbits.
Показать больше [+] Меньше [-]Biomechanical and computational evaluation of two loading transfer concepts for pancarpal arthrodesis in dogs
2012
Rothstock, Stephan | Kowaleski, Michael P. | Boudrieau, Randy J. | Beale, Brian | Piras, Alessandro | Ryan, Mark | Boure, Ludovic | Brianza, Stefano
Objective: To evaluate 2 plate designs for pancarpal arthrodesis and their effects on load transfer to the respective bones as well as to develop a computational model with directed input from the biomechanical testing of the 2 constructs. Sample: Both forelimbs from the cadaver of an adult castrated male Golden Retriever. Procedures: CT imaging was performed on the forelimb pair. Each forelimb was subsequently instrumented with a hybrid dynamic compression plate or a castless pancarpal arthrodesis plate. Biomechanical testing was performed. The forelimbs were statically loaded in the elastic range and then cyclically loaded to failure. Finite element (FE) modeling was used to compare the 2 plate designs with respect to bone and implant stress distribution and magnitude when loaded. Results: Cyclic loading to failure elicited failure patterns similar to those observed clinically. The mean ± SD error between computational and experimental strain was < 15% ± 13% at the maximum loads applied during static elastic loading. The highest bone stresses were at the distal extent of the metacarpal bones at the level of the screw holes with both plates; however, the compression plate resulted in slightly greater stresses than did the arthrodesis plate. Both models also revealed an increase in bone stress at the proximal screw position in the radius. The highest plate stress was identified at the level of the radiocarpal bone, and an increased screw stress (junction of screw head with shaft) was identified at both the most proximal and distal ends of the plates. Conclusions and Clinical Relevance: The FE model successfully approximated the biomechanical characteristics of an ex vivo pancarpal plate construct for comparison of the effects of application of different plate designs.
Показать больше [+] Меньше [-]Рост и развитие чистопородного и помесного молодняка шаролезской породы в послеотъемный период в условиях комплекса
2009
Zyl, V.M. | Letkevich, V.I. | Sidunov, S.V. | Loban, R.V. | Yurenya, A.S., National Academy of Sciences. Scientific and Practical Center of Animal Breeding (Belarus)
Growth and development of mixed bred Charollais x white-and-black young stock and black-and-white bull-calves since 8-month old age till and 15-month old age were studied in the conditions in the Republic of Belarus. In course of studied there were analyzed linear growth; young stock growth intensity; forage consumption; efficiency of experimental results. On the basis of obtained data there was determined the absolute growth rate of bull-calves at certain growing periods. Research results showed that dramatic changing of technology of management and feeding of mixed bred Charollais x white-and-black young stock bulls after weaning period caused the decrease of daily average live weight gain from 8-month old age till and 15-month old age in comparison with white-and-black cattle on 99 grams or 14%. Analysis of exterior of experimental animals confirmed the priority of mixed bred young cattle over white-and-black herdmates. They were characterized by massive corpus, wider and deeper barrel, wide withers, back and coupling
Показать больше [+] Меньше [-]Характеристика качества яиц кур кросса Беларусь аутосексный
2009
Sviridova, S.N. | Makhnach, V.S. | Dmitrieva, T.V., National Academy of Sciences. Scientific and Practical Center of Animal Breeding (Belarus). Belarus Regional Experimental Poultry Station
Into the programme hen selection of Belarus Autoseksnyj cross there was introduced the indeks of the so-called quality of eggs which is defined by removal defective on quality of a shell of eggs in 30 and 52-week age. The size of variability of an indicator of 16,0-25,4% and hehtability 0,3-0,4 allows to lead selection on increase in an exit of qualitative eggs. Influence on quality of eggs with defects of a shell of age of hens, intensity eggs, weights of eggs, a linear accessory is established
Показать больше [+] Меньше [-]Воспроизводительные особенности маточного поголовья помесей герефорд х черно-пестрой породы в сравнении с чистопородными черно-пестрыми сверстницами
2008
Linnik, L.M. | Zhdanova, A.A., Vitebsk State Academy of Veterinary Medicine (Belarus)
Beef production in the Republic of Belarus could be competitive only in case of development of the specialized beef cattle breeding. Therefore, for the increasing of beef production and improvement of its quality in Belarus there was noted the necessity to use cattle beef breeds both in case of straightbred breeding, and in crossing with low income-earning Black-and-White cow stock. Research results showed that hybrid Gereford x Black-and-White breeds of the first and second filial generations showed higher reproductive abilities which were manifested in 105-120 days age reduction at the stage of the first insemination, 18-44 days reduction of service period, 0,07-0,1 times increasing of breeding efficiency index, 9,8-14,4% increasing of calf crop per 100 dams, and 14,4-16,4% increasing of young stock livability in comparison with the Black-and-White breeds calves. Research results showed that the non-heating season of the mongrel Gereford x Black-and-White heifer breeds of the first and second filial generations was 396-400 days, breeding efficiency index (rate of fertilization) - 1,29-1,32, breeding performance index - 85,4-90,0%, while for the at Black-and-White heifer breeds the same indices were 425 days, 1,29 and 75,6%, respectively
Показать больше [+] Меньше [-]