PRODUCTIVE QUALITIES OF HYBRID PIGS
INTERNATIONAL TRANSACTION JOURNAL OF ENGINEERING MANAGEMENT & APPLIED SCIENCES & TECHNOLOGIES
Authors: Krasnova, O. A.; Kazantseva, N. P.; Kudrin, M. R.; Khardina, E., V; Vasilieva, M., I; Pushkaryov, M. G.; Sannikova, N. A.
Abstract
This research focuses on the reproductive qualities of cross-breeding sows of different breeding options, growth rate and development of hybrid piglets during periods of suckling and nursery, and on the assessment of fattening and meat qualities with different genotypes. The best reproductive performance was observed when crossing crossbred sows (LW x L) with Duroc boars: multiple fertility reached 14 baby piglets, the weight of a piglet 1.6 kg, livability up to weaning 93.8%, live weight before weaning 6.5 kg. Hybrid piglets from the first and second groups were characterized with the best growth rate during suckling and nursery periods; they were obtained from a combination of sows of Large White x Landrace of Canadian and Danish breeding with Duroc boars. Best results in fattening and slaughter qualities of hybrid young animals were obtained with a combination of sows (LW x Y) with Canadian Landrace boars, and also with a combination of sows (LW x Y) with Danish Landrace boars: early maturity 145-146 days, average daily gain 990.4 g, slaughter yield 80.9% and 79.6%, respectively. The length of the carcasses of young animals of the third group in this experiment was larger in comparison to their herd mates in the second and first groups, respectively. Piglets from the second group (LW x L c.) xD had the smallest fat depth, and fattening livestock from the third and fourth groups had the largest one; these animals also had a higher pre-slaughter weight. Fat depth in the second (LW x L c.) xD group was less, compared to the third and the fourth groups. According to research results, for increasing the production of pork and for improving its quality under industrial conditions, it is recommended to use Canadian and Danish Landrace boars at the final stage of crossbreeding in a three-breed combination i.e., Large White x Yorkshire x Landrace. Disciplinary: Agriculture and Animal Sciences, Swine Science, Pig Husbandry, Pig Farming and Production, Biotechnology. (c) 2020 INT TRANS J ENG MANAG SCI TECH.
Accuracy analysis of different Laplacian models of incompressible SPH method improved by using Voronoi diagram
JOURNAL OF THE BRAZILIAN SOCIETY OF MECHANICAL SCIENCES AND ENGINEERING
Authors: Shobeyri, Gholamreza
Abstract
The purpose of this paper is to investigate the effect of employment of Voronoi diagram drawing as an alternative approach to estimate the particle or nodal volume on accuracy of three well-known Laplacian operator models of incompressible SPH method (Hu and Adams in J Comput Phys 227:264-278, 2007; Schwaiger in Int J Numer Methods Eng 75:647-671, 2008; Shao and Lo in Adv Water Resour 26:787-800, 2003). In addition to this, the numerical performance of these modified Laplacian models is compared with that of another newly developed higher-order Laplacian model proposed by Shobeyri (Iran J Sci Technol Trans Civil Eng 10.1007/s40996-018-0226-9, 2019). The numerical errors of the above Laplacian models for solving different 2-D elliptic partial differential equations are analyzed on a unit square computational domain discretized with highly irregular node distributions. In addition to this, the patch test for an arbitrary function is conducted to evaluate numerical behavior of the Laplacian models. The numerical results indicate that the three Laplacian models coupled with Voronoi diagram technique can get smaller errors compared with the standard models. The most significant finding of this study is that the Laplacian model proposed by Shobeyri (Iran J Sci Technol Trans Civil Eng 10.1007/s40996-018-0226-9, 2019) produces lower numerical errors even in comparison with the improved models. Voronoi diagram technique with simple implementation can significantly improve numerical accuracy of the presented higher-order Laplacian models for arbitrary and highly irregular node configurations, and it is expected that this strategy is applicable for other SPH Laplacian models to obtain higher-accurate results.