No abstract

The aim of the research was to evaluate the factors influencing the productivity of rotary parlour milking equipment and the possibilities of their correction. Productivity of rotary parlour milking equipment is influenced by three main factors: the number of milking places on the rotary platform, the set rotation speed or the time of one revolution of the platform and cows with longer milking duration. Methodology for theoretical calculation of the cycle of rotary parlour operation according to the statistical indicators of the milk yield of the herd of the corresponding farm has been developed. To test the methodology also experimental research was performed in four farms, where rotary parlours with 32 to 80 milking places are used. The initial data necessary for the research were obtained in the result of timing the milking process and analysing the data obtained from the management on the milking process with MS EXCEL data analysis tool Descriptive Statistics. It has been stated in the research that the operation regimes of rotary parlour milking equipment used in practice and calculated theoretically have slight differences. Therefore, it is necessary to test the method of theoretical calculation additionally in the conditions of operation.

The preservation of local animal breeds is a topical theme in recent years. Latvian Brown (LB) and Latvian Blue (LZ) cow breeds are exhausting and must be preserved. It can be performed by the use of multiple ovulation and embryo transfer (MOET). The difficulties exist in choosing the gene-fond (GF) cows as donors caused by the small number of animals. Twenty-three cows were intended for donor cow's role from different herds until September 2018, and twenty of them were accepted. Anamnesis, clinical examination, blood morphology (13 parameters) and biochemical indices (19 parameters) were analyzed before MO induction. Three cows were rejected because of ovarian cysts or pyometra, negative energy balance (NEB) (glucose < 2.3 mmol L-1 simultaneously with elevated ß-hydroxybutyric acid > 1.4 mmol L-1) and elevated (p<0.05) number of leukocytes (28.20 x10 9 L-1). More than 52.6% of cows had a repeated artificial insemination before the last parturition, and 5.3% of cows had lifeless offspring in the last parturition. The 1 st and 2 nd lactation cows were healthier than older cows (p<0.05). The amount of albumins, cholesterol, triglycerides and Na, K, P, Cl, Mg was significantly different in donors with and without successfully obtained embryos (p<0.05). In conclusion, not only acceptable clinical health but also the cow metabolic status is a decisive factor for success of MOET.

. Robotic milking of cows began in Latvia in 2007, when it was introduced on two farms, including the training and research farm “Vecauce” of the Latvia University of Biological Sciences and Technology (then the Latvia University of Agriculture). These were the DeLaval VMS robots that are still in use on the farm “Vecauce”. A similar study was carried out already in 2009, but since then DeLaval milking robots have undergone technical and software updates and improvements. Therefore, a comparison of the operation indicators of these robots with the latest model of the same company, VMS V300, was made. Research shows that performing all technical maintenance intended for the VMS robot and replacing the original management system software can ensure successful operation of this robot even after 16 years of use. However, it has difficulties with accurately attaching the milking tubes to the respective cow’s teats. Because of this, the application of tubes is delayed and the average milking time of one cow reaches 8.25 minutes. When milking with the company’s latest generation VMS V300 robot, which uses a 3D camera to connect the milking tubes, the average milking time is only 6.6 minutes. Therefore, we can assume that the robots used on the farm “Vecauce” for milking cows are morally and physically obsolete.

The article discusses the experience of Latvian dairy farms in keeping cows in cubicle beds. It has been found that the number of cows kept in this way in the country is increasing every year. If in 2010 about 35% of the total number of dairy cows were kept in the cubicles, now it exceeds 50%. In addition, both high and deep cubicles are common. It was found that the highest milk yields and high milk quality (based on SCC) were obtained using deep cubicle beds in which the cows' beds were filled with sand. If high cubicle beds or deep cubicle beds with other bedding are used, the milk yield of cows is on average 15% lower. The number of SCC, on the other hand, increases by 50% with high cubicle beds and increases by 40% with deep cubicle beds with other bedding. However, this figure depends to a large extent on the frequency of cleaning the cubicle and the frequency of refilling the bedding material.