Основные хозяйственно полезные признаки коров заводских линий Букем 66636657 и Блитц 17013604 голштинской породы молочного скота отечественной селекции

The Holstein breed of dairy cattle is the most widespread due to its high productivity (7000–11000 kg of milk with 3.6–3.8 % of fat and 3.0–3.2 % of protein), good adaptability to a variety of climatic, feed and technological conditions, as well as a high feed conversion ratio. In this regard, the breeding of animals of this breed, including the pedigree breeding and the creation of optimal conditions for directional rearing of young animals, is of great importance for the economy of the Republic of Belarus. Any breed is characterized by a distinctive quality, a certain structure, and specific morphological and economically useful traits. The goal of our work was to analyze the main economically useful traits of two new factory lines Bukem 66636657 and Blitz 17013604 of the Holstein breed of dairy cattle of domestic selection. To achieve this goal, we used the UE “GIVC Minselhozproda” information database of pedigree dairy cattle bred at basic farms. It has been established that cows of new factory lines are characterized by high milk productivity rates, good reproductive performance and sufficient development regardless of breed line. The effective use of animals of new factory lines will increase the genetic potential of milk productivity of herds, allowing for obtaining high-value young pedigree cattle of domestic origin.Голштинская порода молочного скота является наиболее распространенной, благодаря высокой продуктивности (7–11 тыс. кг молока при содержании жира 3,6–3,8 % и белка 3,0–3,2 %), хорошей приспособляемости к разнообразным климатическим, кормовым и технологическим условиям, высокой оплате корма молоком. В связи с этим разведение животных этой породы, включающее племенную работу и создание оптимальных условий для направленного выращивания молодняка, имеет большое значение для экономики Республики Беларусь. Любая порода характеризуется качественным своеобразием, определенной структурой, специфическими морфологическими и хозяйственно полезными свойствами. Целью нашей работы было проанализировать основные хозяйственно полезные признаки двух новых заводских линий Букем 66636657 и Блиц 17013604 голштинской породы молочного скота отечественной селекции. Для достижения поставленной цели использовали информационную базу данных племенного молочного скота УП «ГИВЦ Минсельхозпрода». Установлено, что коровы новых заводских линий характеризуются высокими показателями молочной продуктивности, отличаются хорошими воспроизводительными качествами, достаточным развитием независимо от линейной принадлежности. Эффективное использование животных новых заводских линий позволит повысить генетический потенциал молочной продуктивности стад, а также получать высокоценный племенной молодняк отечественного происхождения

Reduction of Subtask Dispersion in Fork-Join Systems

Abstract. Fork-join and split-merge queueing systems are well-known abstractions of parallel systems in which each incoming task splits into subtasks that are processed by a set of parallel servers. A task exits the system when all of its subtasks have completed service. Two key metrics of interest in such systems are task response time and subtask dispersion. This paper presents a technique applicable to a class of fork-join systems with heterogeneous exponentially distributed service times that is able to reduce subtask dispersion with only a marginal increase in task response time. Achieving this is challenging since the unsynchronised operation of fork-join systems naturally militates against low subtask dispersion. Our approach builds on our earlier research examining subtask dispersion and response time in split-merge systems, and involves the frequent application and updating of delays to the subtasks at the head of the parallel service queues. Numerical results show the ability to reduce dispersion in fork-join systems to levels comparable with or below that observed in all varieties of split-merge systems while retaining the response time and throughput benefits of a fork-join system

Trading off subtask dispersion and response time in split-merge systems

Abstract. In many real-world systems incoming tasks split into subtasks which are processed by a set of parallel servers. In such systems two metrics are of potential interest: response time and subtask dispersion. Previous research has been focused on the minimisation of one, but not both, of these metrics. In particular, in our previous work, we showed how the processing of selected subtasks can be delayed in order to minimise expected subtask dispersion and percentiles of subtask dispersion in the context of split-merge systems. However, the introduction of subtask delays obviously impacts adversely on task response time and maximum sustainable system throughput. In the present work, we describe a methodology for managing the trade off between subtask dispersion and task response time. The objective function of the minimisation is based on the product of expected subtask dispersion and expected task response time. Compared with our previous methodology, we show how our new technique can achieve comparable subtask dispersion with substantial improvements in expected task response time