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Thickness of the skin and its layers at Degeress sheep of various stripes
2014
Alzhaxina, N., Kazakh National Agrarian Univ., Almaty (Kazakhstan) | Begembekov, K., Kazakh National Agrarian Univ., Almaty (Kazakhstan) | Kulmanova, G., Kazakh National Agrarian Univ., Almaty (Kazakhstan)
The article discusses the results of comprehensive studies histomorphological signs of skin and hair of sheep (Degeress) of various stripes, especially the thickness of the skin and its layers that are commonly identified indicators. Studies allow to bring the scientific basis for the proper development of activities aimed at increasing production of wool, quantity and quality of which skin microstructure largely depends on. Sheep of different colors have a specific feature on the histological structure of the skin, which is essential for the development of effective methods of selection that enhance productivity of sheep wool. The researches have established that brown suit sheep has thickened skin as compared to red and gray color (p is less than 0.01). In turn, pilar layer of the skin is also much thicker at brown coloration sheep (2029.7 ×10E-6 m) than in sheep red (1850.6×10E-6 m) and sulfur (1773.7×10E-6 m) suits, the difference is statistically highly significant (p is less than 0.001). The thickness of the pilar layer is up to 70% of the dermis, which varies depending on sheep lear ranging from 1773.7×10E-6 m to 2029.7×10E-6 m. Reticular layer thickness varies depending on sheep lear ranging from 743.5×10E-6 m to 826.4×10E-6 m.
Показать больше [+] Меньше [-]Environmental factors affecting performance traits in Latvian sheep population
2011
Puste, A., Latvia Univ. of Agriculture, Jelgava (Latvia) | Kairisa, D., Latvia Univ. of Agriculture, Jelgava (Latvia) | Sarma, R., State Agency Agricultural Data Centre, Riga (Latvia)
This study investigates different environmental effects on birth weight, weaning weight, and pre-weaning daily gain using different statistical models in the Latvian sheep population. The coefficients of determination (R2) were used to estimate the extent of different non-genetic factors influencing birth weight, weaning weight, and pre-weaning daily gain. Data were collected of 4460 lambs born in 36 herds during 2008 to 2010. The birth weight (on average 4.1 ± 0.01 kg), weaning weight (on average 21.0 ± 0.07 kg) and pre-weaning daily gain (on average 242.1 ± 0.93 g) was significantly affected by type of birth and sex, lambing age of dam (covariate) and herd, year, season of birth (p is less than 0.01). Coefficients of determination were estimated from 0.14 to 0.42 for birth weight, from 0.13 to 0.49 for weaning weight, and from 0.10 to 0.46 for pre-weaning daily gain. The results show that when the fixed effects of HYS (interaction between the herd, year, and season of birth) were included it improved the quality of the statistical model most of all, because higher determination coefficients were obtained for all traits: 0.42 for birth weight, 0.49 for weaning weight, and 0.46 for pre-weaning daily gain.
Показать больше [+] Меньше [-]Estimation of genetic parameters for growth traits of sheep population in Latvia
2013
Puste, A., Latvia Univ. of Agriculture, Jelgava (Latvia) | Kairisa, D., Latvia Univ. of Agriculture, Jelgava (Latvia) | Sarma, R., Latvia Univ. of Agriculture, Jelgava (Latvia)
The aim of the present study was to estimate variance and covariance components and genetic parameters for birth, weaning and yearling weights. The data were collected from lambs who born in period from 2007 to 2010 years and located in 58 pure-bred sheep herds in Latvia. Records of 11310 lambs from 160 rams and 4180 ewes for birth and weaning weight and on 3194 lambs from 134 rams and 2058 ewes for yearling weight were used in this study. The total number of individual pedigree was 18932. The fixed effects in the model were sex and type of birth, birth year and month and age of dam, because all growth traits were significantly affected by these fixed effects (p is less than 0.01, p is less than 0.05). Genetic parameters for growth weights were estimated by Restricted Maximum Likelihood (REML) procedure fitting three animal models including various combinations of maternal and herd effects. Based on the most appropriate fitted model which included additive genetic, maternal additive genetic and herd effect, direct heritability’s were estimated to be 0.26 ± 0.01, 0.29 ± 0.63, 0.29 ± 2.63, but maternal heritability’s 0.14 ± 0.00, 0.04 ± 0.19, 0.04 ± 0.94, respectively for birth, weaning and yearling weights. The results showed maternal and strong herd influence in this study, therefore inclusion of maternal and herd effects into the model for growth traits is necessary.
Показать больше [+] Меньше [-]Concentrate distribution to sheep using automatic feeding station
2017
Senfelde, L., Latvia Univ. of Agriculture, Jelgava (Latvia) | Kairisa, D., Latvia Univ. of Agriculture, Jelgava (Latvia)
The research was conducted with the aim of studying the possibility of using automatic feeding stations for individual sheep (Ovis aries) feeding. The research was organized in 3 periods, in which 10–13 months old sheep – female only (1st research period), 6–10 months old sheep – female only (2nd research period) and 8–12 months old sheep – female only (3rd research period) were used. Part of the sheep did not visit the feeding station at all. Sequentially, over the research periods the percentage was 13%, 37% and 49%. Upon setting the concentrate daily ration 400 g per sheep, on the average the number of visits to the particular feeding station was 6.1 and 4.7 (sequentially in the 1st and 2nd research period). Upon increasing the concentrate ration amount up to 700 g per day, the average number of feeding station visits was 6.9 (in the 3rd research period). The number of visits to the automatic feeding station was varied (V is greater than 10%). Over the research period live weight of the sheep increased significantly (p ≤ 0.05) for the subgroups of animals which made visits to the feeding station regularly during the entire research period. In all research periods, the average daily concentrate intake (373.5 g in the 1st research period, 333.1 g in the 2nd research period and 581.2 g in the 3rd research period) was 93%, 83% and 83% respectively, of the maximum established feeding standard.
Показать больше [+] Меньше [-]Pratiques d'alimentation pour l'engraissement des agneaux dans des systèmes d'élevage agropastoraux de la région d'El-Guedid-Djelfa
2015
Kanoun M. | Huguenin J. | Yakhlef H. | Kanoun Meguellati A. | Julien L. | Taugourdeau S. | Bellahrache A.
Les pratiques d'engraissement des agneaux sont étudiées dans les systèmes d'élevage ovins agropastoraux de la zone d'El-Guedid située au Nord-Ouest de la Wilaya de Djelfa. L'élevage de cette région est reconnu et approvisionne en viande rouge ovine les grandes agglomérations algériennes, voire au-delà. En quelques décennies, cet élevage, son système de production et sa filière, ont connu de nombreuses transformations pour s'adapter aux changements : démographique, socioéconomique, biophysique, d'utilisation des terres. Malgré les adaptations de conduite d'élevage, certains savoir-faire ont pu être préservés, notamment en matière d'alimentation. Ainsi la viande de Djelfa reste très appréciée. Les élevages ayant recours à certaines pratiques anciennes, associées à de nouvelles conduites, continuent d'assurer des produits de qualité toute l'année. Les évolutions du contexte et des modes d'élevage ont rendu le contexte favorable au développement de pratiques d'engraissement par les éleveurs. La diversité des conduites alimentaires notamment des pratiques d'engraissement et des stratégies des éleveurs selon leurs systèmes d'élevage sont le coeur de notre questionnement. Nous l'avons abordé selon une méthodologie comprenant plusieurs étapes : i) entretiens chez 86 éleveurs et observations dans des ateliers d'engraissement au sein des exploitations agropastorales ; ii) exploitation de la base de données des suivis du marché ovin de Djelfa pour évaluer les prix des animaux ; iii) traitements des données obtenues à l'aide d'outils statistiques (ACM ; PCOA Gower ; traitements graphiques). Cette étude apporte deux enseignements majeurs, d'une part l'utilisation des territoires steppiques n'est pas exclusif aux élevages naisseurs et d'autre part il ressort une dominance des élevages mobiles (transhumants et semi-transhumants). Les éleveurs sédentaires ne représentent que 15 % de notre échantillon. En outre, nous avons caractérisé quatre types d'éleveurs selon leurs mobilités, s
Показать больше [+] Меньше [-]Features and likenesses of information models of animals registration
2007
Smirnova, J., Latvia Univ. of Agriculture, Jelgava (Latvia) | Arhipovs, S., Latvia Univ. of Agriculture, Jelgava (Latvia)
The process of creation of the informative systems based on the account of such animals as horses, sheep and goats is analyzed in the work. Three structural models are created and their comparative analysis is conducted. As a result of analysis the general elements of structures, characteristic to each model were found. The Meta modelling approach to facilitate the system was used. The system has a more abstract structure and allows dynamically to adding not only the animal specimens but also new types of attributes in fly during runtime. Recompilation of the system is not required there is no necessity of the analytical restructuring of the model, the absence of type explosions is guaranteed in a database because not a new table-type, but a new record in one or two tables is added.
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