The European Union livestock sector is a major player of the agricultural economy and its land use, and livestock is one of the fastest-growing sectors in agriculture, potentially presenting opportunities for economic growth and poverty reduction in rural areas. In Latvia, the year 2014 was quite difficult for the dairy industry both due to Russia’s embargo on dairy product import and low milk purchase prices and due to concerns that milk quotas had been exceeded. It is therefore important that cows are healthy and no additional losses are suffered from mastitis. Mastitis is a complex disease involving many factors, which is mainly caused by bacteria and there is no simple model that encompasses different possible aspects. Therefore, the research aim is to assess the effects of mastitis in cow herds for farms in Latvia. The research study proceeds in two stages or phases: firstly, to review the scientific literature on mastitis problems and solutions to the problems in other countries, secondly, to survey dairy farms of various sizes in the regions of Latvia in order to examine the real situation concerning mastitis and its effects on the economy of farms. A survey results of 74 farms in Latvia revealed that 90.5% of the farms had problems with mastitis. Consequently, if sick cattle are timely culled, it is possible to keep the herd milk yield without a significant drop. In case of cows with mastitis, farms suffer losses from smaller quantities of milk produced depending on farming intensity and due to cows culled with mastitis.

Advances in milk production and the expansion of dairy herds have increased the need for improved manure management and whole farm nutrient balance. It is well known in dairy management that the balanced feeding and holding technology is an important level by which milk production and milk composition can be modified. The objective of this study was to evaluate urea content and urea yield in different farms with different holding technologies. Four farms represent three cow breeds (Holstein Black and White, Latvian Brown, and cross breed XP). Individual cow milk samples (n=2740) were collected monthly from September 2009 to November 2010. Milk samples were analyzed for total protein, casein, fat, lactose, and urea content with instrumental infrared spectroscopy method. The average milk yield per cows in farms was significantly different (from 27.9 to 17.0 kg per control day). The urea content in cow milk was between 20.3 to 46.6 mg dLE-1. The average urea content in farms A, B and D was up to standard (from 15.0 to 30.0 mg dLE-1). In the farm C, average urea content ranged between 17.4 and 79.9 mg dLE-1, which indicated problems in feeding or management in the farm. It was established that milk urea content and yield significantly (p is less than 0.05) varied in farms with different dairy cow holding and feeding technologies. Urea content can be used to evaluate feed protein utilization in farms and predict environmental pollution.

The present study describes situation of antimicrobial resistance of animal pathogens and resistance trends in Estonia in years 2006-2009. Bacterial strains isolated during period 2006-2009 were Escherichia coli (E. coli), Enterococcus faecium (E. faecium), Enterococcus faecalis (E. faecalis), collected from healthy pigs faeces as well as from diagnostic submissions of pig samples. Staphylococcus aureus (S. aureus) isolates originated from cows with clinical mastitis and Staphylococcus pseudointermedius (S. pseudointermedius) isolates from dogs with pyoderma or otitis externa. Antimicrobial susceptibility was detected by microdilution method. Normal enteric microflora from health y pigs had resistance against streptomycin, tetracyclin, sulfametoxazol and trimethoprim. E. faecalis and E. faecium were resistant to erythromycin, tetracyclin, streptomycin and kanamycin. Multiresistance occured mainly against kanamycin, streptomycin and tetracyclin. E. coli strains isolated from pathological material showed high resistance to ampicillin, tetracycline, streptomycin, sulphonamides and trimethoprim. Multiresistance was detected between 60–73% during study years. In 2009, one ESBL (extended spectrum betalactamase) producing isolate was observed. S. aureus strains isolated from clinical mastitis samples were mainly penicillin resistant (58–86%). Meticillinresistant S. aureus was not found during the study. In 2009, resistance to lincomycin (30%) and fucidinic acid (22%) was detected. In S. pseudointermedius strains isolated from canine skin samples the prevalence of resistance to penicillin as high as 53–81% was found. Multidrug resistance was relatively stable being 38% in 2006, 29% in 2007 and 25% in 2009. In conclusion, antimicrobial resistance of animal pathogens in Estonia was high. Further improvement of prudent use of antimicrobials and infection control is needed.

Nutritional value and shelf life of milk and dairy products depend on the composition and stability of their constituents. The aim of the present study was to evaluate the effects of carrots as cow feed carotenoid source on butter oil fatty acid (FA) composition and oxidative stability. Milk was obtained from one trial group (TG; n=5) and one control cow group (CG; n=5) in a conventional dairy farm in Latvia. TG cows received carrots 7 kg per cow per day; the length of the supplementation period was 39 days. The stability of butter oil exposed to sunlight (3h) and held for 14 days in the temperature of 60 °C was analyzed by peroxide value method. The changes of the FA content and ratios in TG milk fat were more positive with respect to the fat nutritional value as observed in CG – stronger increase in the content of polyunsaturated FA (p is less than 0.05), and in the ratio between stearic and palmitic acids (p is less than 0.05); also a tendency was seen of increasing content of short and monounsaturated FA, as well as decreasing the ratio between ω6 and ω3 FA groups. Oxidative stability of the carrot supplemented cow group’s milk butter oil samples that were collected after 25- day trial period, exposed to sunlight (3h) and stored at a temperature of 60 °C was significantly (p is less than 0.05) higher compared to CG samples. After the 39-day long trial period stability difference was not significant, despite the tendency that average polyunsaturated FA content in TG samples was higher compared to the control.

The objective of the study was to examine how the circumstances of different bull daughters – Latvian Brown cow - group productivity levels correlate with the blood biochemical composition indices in Latvian conditions. The daughters of seven bulls, selected for our research trial, were kept in the same barn and under rearing conditions. Their blood samples were taken in a single sampling activity and analyzed for blood serum biochemical averages. Also Cu, Fe, Zn, Mn and Mg were detected in blood serum and the values found were compared with values fixed in regulatory documents. There were changes in Cu levels (daughter groups of four bulls), in Zn levels (one group); Mn level was lower in all groups and Mg level was higher in 6 groups. The altered biochemical parameters of blood were assessed from the pathogenetical point of view and compared with productivity averages in the progeny groups. The correlation factors suggested that there exist a strong positive correlation (p is less than 0.05) among a number of indicators, such as aspartate aminotransferase (ASAT) and protein r = 0.823; ASAT and somatic cell count (SCC), r = 0.737; blood protein and milk protein r = 0.903 - 0.917; albumins and protein r = 0.964; blood urea and milk protein r = 0.931 - 0.984 along with additional correlations. The correlation factors for the progeny group of each bull differed. The data obtained shows that the Latvian Brown cows crossed with other breeds produce cows with new genetic traits.

The treatment of ketosis with glycerol was first introduced in the 1950s. Currently, the availability of glycerol as a feed supplement for dairy cattle has increased due to the rapid expansion of the biodiesel industry. It has been suggested that glycerol can be used as a dietary glucose precursor for dairy cows in a similar way to propylene glycol. This study examined the effect of orally administrated crude glycerol on milk production and composition, and energy-status related blood metabolites of primiparous (n=4) and multiparous (n=4) Holstein dairy cows in the first three weeks of lactation. The treatment group cows were given an oral drench of 500 mL of crude glycerol once a day before the morning feeding. Long-term oral drenching of crude glycerol had no effect on dry matter intake (DMI), but there was a positive effect on milk yield. Most milk composition values were not affected by the treatment, but treatment groups had lower milk protein levels. Blood glucose and insulin concentrations were declined with glycerol administration.

Milk production and milk composition are of prime economic importance for farmers. It is well known in dairy management that the balanced feeding and holding technology is an important lever by which milk production and milk composition can be modified. The objectives of this work are to establish relation among milk protein and urea content in different farms. Four farms represent three cow breeds (Holstein Black and White, Latvian Brown, and cross breed XP). Individual cow milk samples (n=8400) were collected monthly from September 2009 to November 2010. Milk samples were analyzed for total protein, casein, fat, lactose, and urea content with instrumental infrared spectroscopy method. The average milk yield in farms was significantly different (from 26.8 to 16.0 kg per control day), and average protein content varied from 3.32 g kgE-1 to 3.62 g kgE-1. The urea content in cow milk was between 21.3 to 42.6 mg 100 mLE-1. The average protein content was higher and significantly (p is less than 0.05) different in first yield level (up to 15 kg) for all farms. Overall, in different farm and milk yield levels correlation between protein and urea was low or very low. In the farm C, average urea content ranged between 30.0 and 60.0 mg 100 mLE-1, which indicated problems in feeding or management in the farm. It was established that milk productivity traits significantly (p is less than 0.05) varied in farms with different dairy cow holding and feeding technologies and milk protein and urea content significantly (p is less than 0.05) varied for cows with different milk yield per day.

Live weight and body condition are indicators for dairy cow’s (Bos taurus) health, milk productivity and reproduction. Live weight and body condition are defined by genetic and non-genetic factors. These factors are dependent on dairy cows growing and welfare. The aim of research was to analyze body condition relationship with milk productivity and live weight. Data were collected from 49 different breed and lactation dairy cows. Research location was Latvia University of Agriculture Research and Study farm ‘Vecauce’. Data were collected from October 2013 to January 2014. Body condition score of all cows decreased from 2.8 ± 0.05 to 2.5 ± 0.04 points in research period. Milk yield increased from 35.6 ± 0.79 kg in the 1st recording to 40.9 ± 1.12 kg in the 2nd recording. Milk yield decreased in the 3rd recording (p is less than 0.05). Fat content was the lowest in the 2nd recording (35.5 ± 0.09 g kgE-1). Protein content was significantly different in the 1st and 2nd recordings (p is less than 0.05). Somatic cell changes were not significant. Body condition decreased of older lactation cows, but milk yield increased at the same time. Milk yield was significantly the greatest in red breed group, compared with Holstein black and white cows (51.1 ± 3.21 kg vs. 41.4 ± 0.78 kg; p is less than 0.05). Body condition score significantly affected live weight in such body condition score groups: less than 2.5 points, 2.75 to 3.0 points. Effect was not significant on live weight in body condition score 3.25 less than group. Milk productivity and quality traits were not affected by the body condition score (p is less than 0.05).

Estimating feed intakes of individual cows in a loose-housed system is difficult and unreliable. It is known that estimating intakes from the number of bites taken at grazing is unreliable. Feeding from a total mixed ration (TMR) is likely to have fewer confounding variables. All cows were over 30 months old, of three breeds: Holstein Friesian, Estonian Red and Estonian Native. There were 30 feeding bins and 66 cows. Cows were observed over the whole 24 hour period, from 1st July to October 22nd 2011, in Märja experimental farm, of the Estonian University of Life Sciences, and data from 37 cows were collected. Measures taken included: time spent at the feed bin, number of bites taken at each visit, weight lost from the bin, and evidence of stealing. Mean time spent at each visit to the feed bin with standard error was 4.4 + 0.68 minutes. The mean number of bites per visit was 7.1 + 1.01. There was a significant correlation between the number of bites and total time cows spent feeding (p is less than 0.001), with a regression R2 value of 79.8%. No correlation was found between the number of bites and feed removed at each visit (p=0.851) nor between the time per visit and amount of feed removed (p=0.681). Therefore, there is no evidence that either the number of bites taken per visit or the time spent at bin per visit is related to intakes. There was no effect of age. Stealing was evident and widespread.

The quality and nutritional value of milk and dairy products are considerably influenced by the stability of its constituents. The aim of the present study was to evaluate the possibility of enhancing oxidative stability of cow’s milk fat and vitamin B2 using carrots and palm oil feed supplement CAF 100 as sources of natural antioxidants in cow feed. Milk samples were collected after 25-day period of feed supplementation. The intensity of riboflavin losses during its photo oxidative degradation in sunlight was measured by the fluorometric method. A slight and significant (p is less than 0.05) difference in higher vitamin B2 stability was seen in carrot-supplemented group (TG1) milk, where the losses of vitamin B2 were by 3.01% less compared to CG (CG). The oxidative stability of butter oil samples stored in 60 °C temperature was analyzed by peroxide value (PV) method. The oxidative stability of samples initially affected by light from both trial groups was significantly (p is less than 0.05) higher compared to CG showing the good potential of the cow diet enrichment with carotenoid additives. The longest induction period (larger than 14 days) was observed in CAF-100- supplemented (TG2) cow milk fats, which can be explained by carotenoids and tocopherol presence and its possible synergism in fat protection. The induction periods of the TG1 and CG were 12.03 and 10.97 days, respectively.