Bovine colostrum is a mammary gland secret which, due to its high immunoglobulin concentration, is necessary for the transfer of passive immunity to the calf, preventing diseases caused by microbial infections in the newborn ruminants. Colostrum, however, may contain pathogens and can be an infection transmitter, affecting morbidity and mortality rates of calves in the farms. Total plate count and immunoglobulin concentration are two main factors affecting colostrum quality, therefore the aim of the study was to analyse Latvian dairy herd colostrum quality. Colostrum was collected from Holstein Black cows within the first six hours after calving, lactation period of animals ranged from 1 st to 4 th lactation. Colostrum samples (n=51, 50 mL) were collected from December 2018 to February 2019. Immunoglobulin concentration (n=51) was defined by colostrometer (COLOSTROMETER tm Biogenics, USA), total solids content by optical refractometer (Model BX, UK). Staphylococcus spp. colony-forming unit (CFU) (LVS EN ISO 6888-1+A1:2007), the presence of Listeria spp. (LVS EN ISO 11290-1+A1:2007) and Salmonella spp. (LVS EN ISO 6579-1:2017) were examined in the colostrum samples (n=20). Despite the high immunoglobulin concentration in the analysed samples, our research findings demonstrate suboptimal colostrum quality received by calves. That indicates the necessity for regular colostrum quality control and better management practise providing on the farm.

Bovine colostrum is an important source of different biologically active compounds: immunoglobulins, lactoferrin, lysozyme, lactoperoxidase etc., therefore vital for a dairy calf's ability to survive. There is the lack of information about microbiological quality of colostrum. Still it is very important parameter, which can be significant for calf mortality and antibodies absorption rate, the aim of the study was to evaluate microbiological quality of colostrum obtained from Latvian cows. Colostrum samples (n=20, 50 mL-1) were collected in conventional farm with 500 cows (Zemgale, Latvia) during December 2018 to January 2019 one hour after calving. Samples were immediately frozen (-19±1 °C, within 30 min) and delivered to the laboratory. The colony forming units (LVS EN ISO 4833-1:2013) and presence of β-glucuronidase positive Escherichia col (LVS EN ISO 16649-2:2007) were detected in colostrum samples. Descriptive statistics were used for data analysis. The average total plate count of analysed colostrum samples was 5.62 log CFU mL-1 , colony forming units ranged from 4.97 to 5.90 log CFU mL-1. In the current research β-glucuronidase positive Escherichia coli CFU ranged from >1 to 8300 mL-1 in colostrum sample. Research results associated with low antibodies absorption rate by calf and high risk of diarrhoea in the farm.

Body condition scoring (BCS) refers to the relative amount of subcutaneous body fat or energy reserve in the dairy cow. BCS is an important management tool for maximizing milk production and reproductive efficiency while reducing the incidence of metabolic and other peripartum diseases. The threedimensional BCS camera, made by the Swedish company "DeLaval" was used in the research. This camera is connected to the cow identification system. According to the camera location place, the cow is evaluated 2 to 10 times per day. The obtained information is sent to the computer. DeLaval 3D camera has been developed for three different cow breed types. The research was done at the Latvia University of Agriculture research and study farm "Vecauce" and the results of 10 primiparous and 10 multiparous Holstein breed cows in the robotic voluntary milking system were analysed. The data were collected from February to December 2016. The research shows that milking cow BCS during 120 lactation days was reduced from 3.5 till 2.7 units and the correlation among the parameters average tight (r =-0.72). The research cows were with a high productivity, in 120 lactation days it was 41.7 kg in average. The largest BCS during 120 lactation days was noticed to primiparous cows and the correlation between the BCS and milk yield was r =-0.71. The parameters among older lactation cow BCS and yielding were less (r =-0.22). The fastest increase of all age cows has been in the first lactation month, where the milk yield increase of primiparous cows was 13.5 %, but the BCS decrease was 5.7 %. The milk yield increase of multiparous cows was 10 %, but the BCS decrease was 5.7 %. Primiparous cows, which become pregnant in the first insemination time, were inseminated in the 89 ± 8.9 day and their BCS was 3.0 ± 0.12 units. Multiparous cows, which become pregnant, were inseminated in the 84 ± 3.5 lactation day and their BCS was 2.7 ± 0.3 units.