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The aim of this study was to assess the significance of body condition scoring and metabolic profile test for estimation of energy status of healthy high-yielding dairy cows. Twenty one healthy cows (primiparous and secundiparous) were divided into three groups: dry cows, early puerperal cows and early lactating cows. Cow's energy status was estimated by the analysis of blood samples for beta-hydroxybutirate (BHBA) and glucose. Additionally, urea, total bilirubine and total protein were measured in blood serum samples. According to body condition scores (BCS) results dry cows were overweight (4.03±0.29 points). Immediately after calving, cows lost their weight significantly, since BCS was 2.85±0.46 points at puerperal period and 3.12±0.33 points at day 60 of lactation (p<0.001 compared to dry period, respectively). Glucose concentration did not change significantly between dry and puerperal period, while BHBA increased significantly (0.46±0.14 mmol/l at dry period to 1.08±0.21 mmol/l at puerperal period; p<0.001). Urea concentration did not change significantly during examined period. Total bilirubin concentration significantly increased from dry (6.31±0.37 mmol/l) to puerperal period (7.63±2.52 mmol/l; p<0.001 compared to dry period) and remained high until day 60 of lactation (7.62±0.13 mmol/l; p<0.001 compared to dry period). Total protein concentration decreased from dry to puerperal period (69.59±6.14 g/l to 58.87±3.29 g/l; p<0.001). According to obtained results it can be concluded that cows were not in adequate energy status during transition period. Our results also indicate that, body condition scoring, BHBA and total bilirubin concentrations can be used as reliable indicators of cow's energy status even when there are not clinically visible health disorders.

Piglets that nurse anterior mammary glands grow faster than those suckling posterior mammary glands. The underlying mechanisms are not known. The purpose of this study was to investigate if there is a difference in composition in colostrum and milk secreted by anterior and posterior mammary glands. Seven healthy sows were used. The first three pairs of mammary glands were defined as anterior mammary glands (AMG) and the rest as posterior mammary glands (PMG). Additionally, the total of 87 born piglets from 7 litters derived from the sows involved in the experiment was analyzed. Piglets from each litter that nursed AMG were defined as AMG group while the rest of piglets from the litter were defined as PMG group. Colostrum and milk were collected at days 1, 2, 3 and 7 after parturition. Samples taken from anterior and posterior mammary glands were pooled, respectively. Results showed that total protein, IGF-I and insulin concentrations were significantly higher in the colostrum of anterior than posterior glands and IGF-I concentration remained significantly higher in milk of anterior compared to posterior glands. There were no significant differences in fat, dry matter and lactose among anterior and posterior glands during all examined periods. Additionally, blood samples from nursing sows were obtained at days 1 and 7 after parturition. Results showed that concentrations of Ca, glucose, total protein, albumin, globulin, total bilirubin and insulin significantly increased from day 1 to day 7 of parturition while concentrations of P, BUN, CK and IGF-I did not significantly change during this period. Initial body weight of pigs nursing the anterior gland was higher but not significantly that those suckling posterior glands. Pigs that nursed anterior glands gained 538 weight faster then those which suckled posterior glands resulting with significantly higher body weigh of piglets nursing anterior compared to posterior glands at day 8 of neonatal life (p < 0.05). Therefore, it may be concluded that the priority of anterior glands milk secretion in total protein and grow stimulating factors may have an impact on increased body weight gain of nursing pigs.

The aim of this study was to compare the concentrations of blood variables obtained simultaneously from the jugular and mammary veins of dairy cows. Eighty Holstein cows were divided into four equal groups: dry, low-(LY), medium-(MY) and high-yielding (HY). Blood insulin, glucose, non-esterified fatty acid (NEFA), beta-hydroxybutyrate (BHBA) and urea concentrations were measured. The jugular and mammary vein (J/M) ratio between concentrations of each variable was calculated. Differences between the groups of cows in concentrations of variables in the jugular vein were not in accordance with those obtained for the mammary vein. J/M values for insulin and glucose concentrations were above 1.0 in all groups of cows. The ratios for NEFA and BHBA concentrations were under or equal to 1.0 in dry and LY cows but above 1.0 in the MY and HY groups, indicating that in MY and HY cows those metabolites are apparently utilised by the mammary gland. J/M values for urea were above 1.0 in dry and LY cows but less than 1.0 in groups MY and HY, indicating that in the latter case urea is apparently released by the mammary gland. In conclusion, J/M for NEFA, BHBA and urea may be useful for estimation of the critical point when the mammary gland receives insufficient energy precursors for its current activity.Key words: Energy balance, mammary vein, jugular vein, dairy cow, milk yield Energy balance (EB) is calculated as the difference between energy consumption in the diet and energy use by the body to support maintenance, growth, milk