Beef production must combine the interests of both producers and consumers, taking into account the sustainable use of environmental resources. The aim of the study was to analyze and compare the slaughter results, meet chemical composition and pH value of three beef breeds – Aberdinangus (AA), Hereford (HF) and Limousin (LI) bulls. The bulls were fattened on Latvian and Lithuanian farms, mainly using grass forage. The breed and age of bulls before slaughter significantly affected all slaughter results, except for fat class. From the meat chemical composition traits, the bull breed and age before slaughter had a significant effect only on the protein content. LI bulls showed the highest carcass weight 301.1±6.8 kg (p<0.05), dressing percentage 58.2±1.1% (p<0.05) and conformation score 3.56±0.18 points. The best fattened carcasses were obtained from AA bulls - 2.43±0.20 points. Muscle samples of musculus longissimus (M. longissimus) bulls of LI breed showed higher content of moisture (72.0±1.0%), protein (23.0±0.2%), ash (1.1±0.0%) and cholesterol (56.7±6.6 mg 100 g⁻¹). AA breed bulls showed higher total fat (6.6±1.2%) and iron content (13.1±0.6 mg). The highest pH was observed in the meat obtained from AA bulls – 6.0±0.1, LI and HF breed bulls showed pH 5.8±0.0 and 5.8±0.1 respectively. Correlation analysis showed a significant, strong positive correlation between cold carcass weight and dressing percentage for AA and LI bulls, r=0.90 and r=0.88, respectively. For LI breed bulls, a strong positive correlation was also found between the cold carcass weight and the conformation score (r=0.98, p<0.01).

The aim of the study was to investigate the beef and dairy cow parasitosis epizootic situation in Vidzeme region. Research was done throughout Vidzeme territory during the period of the years 2013-2014. The total number of animals examined was: 273 dairy and 90 young beef cattle aged from 6 months to two years and 248 dairy and 29 beef cows older than two years. For the diagnosis of helminthes standardized ovoscopic and larvoscopic methods were used. For the diagnosis of protozoa flotation and modified Ziehl-Neelsen methods were used. The main species in the samples were Cryptosporidium spp., Eimeria spp. and Strongylus spp. In the young dairy and beef cattle aged from 6 months to two years and cattle older than two years Cryptosporidium spp. invasion accordingly was 32.6% and 19% (dairy cattle) and 62.2% and 65.5% (beef cattle); the invasion of Eimeria spp. 30% and 7.3% (dairy cattle) and 55.6% and 10.3% (beef cattle); and the invasion of Strongylus spp. was 17.6% and 13.7% (dairy cattle) and 43.3% and 27.6% (beef cattle). Both dairy and beef cattle were infected with Moniezia spp., Paramphistomum spp., Strongyloides spp. Dairy cows aged from 6 months to two years had Trichuris spp., Dictyocaulus spp. and Neoscaris spp. invasion.