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The objective of the present study was to determine metabolic status in late pregnant (n = 15) and puerperal (n = 15) Simmental dairy cows. The various blood metabolites and serum enzyme activities were determined by photometric methods. The early lactation cows had the indicative values of the beta-hydroxybutyrate (BHB) (> 1.20 mmol/l) but did not display any clinical signs, which means that they had a typical subclinical condition. The lipomobilization markers, serum BHB and non-esterified fatty acids (NEFA) concentrations, were markedly enhanced (P<0.05) in early lactation cows. Liver steatosis compromised hepatocyte metabolism, leading to significantly weaker (P<0.05) circulating concentrations of glucose, triglyceride (TG) and urea, and induced some cellular lesions as evidenced by significant increases (P<0.05) in the serum bilirubin concentrations and theaspartate transaminase (AST) enzyme activities in early lactation cows. On the basis biochemistry estimation, early lactation cows had metabolic disturbances which were associated with ketosis, and some degree of hepatic lesions, probably due to fat infiltration. [Projekat Ministarstva nauke Republike Srbije, br. TR31001]

The objective of the present study was to investigate nutritional and metabolic status in Simmental cows during early and mid-lactation. Fifteen early lactation cows and 15 mid lactation cows were chosen for the analysis. Blood samples were collected to measure beta-hydroxybutyrate (BHB), non-esterified fatty acids (NEFA), triglycerides (TG), glucose and the activity of aspartate transaminase (AST). Blood metabolites, milk yield, dry matter intake (DMI) and energy balance (EB) were recorded. Correlation analysis showed that DMI was significantly negatively correlated with NEFA, BHB and AST, and positively with glucose and TG. EB was significantly negatively correlated with NEFA, BHB and AST, and positively with glucose. Early lactation as compared to mid lactation cows were found to have significantly higher blood serum concentrations of NEFA, BHB and AST activities and lower blood serum concentrations of glucose and TG, but not significant. These metabolic changes were in correlation with DMI and EB, but not with milk yield. Suggest that they can serve as useful indicators of the nutritional and metabolic status of dairy cows during lactation.

As generally known, broiler meat quality is a very complex issue that can be looked at from several aspects. In terms of the meat processing industry and consumers' interests, fattened chicks should be characterised by good dressing percentage, desired conformation, as much meat on the carcass as possible, optimal distribution of fat tissues, appropriate skin colour and least damage possible occurring during fattening, loading and unloading. With respect to that, the proportions of major basic carcass parts (breast, drumstick and thigh) as well as the presence of certain tissues in them are regarded as vital parameters determining broiler meat quality (Lewis et al., 1997;Sütö et al., 1998;Holcman et al., 2003;Ristic, 2003). The above-mentioned quality traits depend on a number of factors. Of the biological ones, the greatest impact is produced by genotype, sex and age (Lewis et al., 1997;Bokkers and Koene, 2003;Hellmeister et al., 2003).Among numerous non-genetic factors that may have a considerable effect on meat quality, a broiler rearing system has been recognised over the past years by a large number of authors as being particularly important (Lewis et al., 1997;Bokkers and Koene, 2003;Hellmeister et al., 2003;Ristic, 2003). ABSTRACT:The objective of this study is an analysis of meat quality in broilers of standard fast-growing hybrid Hybro G, reared in two different non-industrial systems (extensive rearing in a poultry house or "extensive indoor" system and rearing in a poultry house using a free range or "free-range" system). Quality parameters, i.e. proportions of basic carcass parts (breasts, drumsticks and thighs), abdominal fat, and proportions of basic tissues (muscles, bones and skin) in more valuable carcass parts, were investigated. The aim of the investigation was to analyse the effect of the two non-industrial rearing systems and broiler sex on the above-mentioned traits of broiler meat quality. The used rearing systems (free-range and extensive indoor ones) did not have a statistically significant effect on the proportions of major basic carcass parts and of abdominal fat in broiler chickens (P > 0.05). Heavier carcasses at slaughter (on the 56 th day of fattening) were recorded in the male broilers compared to the female ones, the differences being statistically significant (P < 0.01). The drumstick proportion in the male broiler carcasses was statistically significantly higher (P < 0.05) than the proportion in the female broilers. The interaction between the investigated effects (of sex and rearing system) did not exert a statistically significant effect on the proportions of major basic carcass parts and abdominal fat in broiler chickens (P > 0.05). The rearing system (free-range and extensive indoor) and the interaction between the investigated effects (of sex and rearing system) did not affect statistically significantly the differences expressed in the meat, skin and bone proportions in breasts, drumsticks and thighs of the broilers (P > 0.05). The sex effect on the skin proportions in b...

The objective of the present study was to investigate nutritional and metabolic status in Simmental cows during early and mid-lactation. Fifteen early lactating cows and 15 mid lactating cows were chosen for the investigation. Blood samples were collected to measure beta-hydroxybutyrate (BHB), nonesterified fatty acids (NEFA), triglycerides (TG), glucose and the activity of aspartate transaminase (AST). Early lactation as compared to mid lactating cows were found to have significantly higher (P<0.05) blood serum concentrations of NEFA, BHB and AST and lower blood serum concentrations of glucose (P<0.05) and TG (P>0.05). Significantly negative correlations were observed between BHB and glucose (P<0.01), BHB and TG (P<0.05), NEFA and glucose (P<0.05). Significantly positive correlations were observed between NEFA and BHB (P<0.05), NEFA and AST (P<0.05), glucose and TG (P<0.01). The results suggest that these parameters can serve as useful indicators of the nutritional and metabolic status of dairy cows during lactation. [Projekat Ministarstva nauke Republike Srbije, br. TR 31001]

The aim of the present study was to determine the degree of blood glucose utilization by peripheral tissue on the basis of changes in blood concentrations of glucose, insulin and inorganic phosphorus in healthy (n = 10) and ketotic cows (n = 10) after intravenous infusion of glucose solution. Blood samples were taken in both groups of examined cows at the following time intervals: just before (time 0) and 30, 60, 120, 180 and 240 min after intravenous infusion of a total of 500 ml of 50% of glucose solution. Glucose and insulin blood serum values in both groups of cows increased significantly within 30 and 60 min of the experiment (p < 0.05).Significantly lower values (p < 0.05) of insulin in blood serum of ketotic cows compared to the healthy ones were established within 30 and 60 min of the test. This indicated that the ability of beta cells of the endocrine pancreas to release insulin is reduced in cows suffering from ketosis. After intravenous infusion of glucose, it was established that values of inorganic phosphorus were decreased in blood in both groups of cows. Within 180 and 240 min of testing there was a significant decrease (p < 0.05) in the blood value of inorganic phosphorus in ketotic cows compared to the healthy ones. This is linked with the active entry of glucose into the glucolytic pathway of peripheral tissues. It can thus be concluded that there is a higher degree of blood glucose utilization by peripheral tissues in ketotic cows.

The objective of the present study was to determine a relationship among blood indicators of hepatic function and lipid content in the liver during transitional period in dairy cows. Late pregnant and calved cows (n= 40) were selected from a Holstein dairy herd and allocated to four groups: a late pregnant cows (n=10) from day 15 to day 5 before calving; late pregnant cows (n=10) from day 5 to day 1 before calving; clinically puerperal healthy cows (n=10) and clinically ketotic puerperal cows (n=10). Liver and blood samples were taken from all cows. The results of present investigation have shown that the lipid content in the liver and the blood non-esterificed fatty acids, β-hydroxybutyrate, total bilirubin concentrations and the AST activities were significantly higher (P<0.05) as well the blood glucose, total cholesterol, triglycerides and albumin concentrations were significantly lower (P<0.05) in puerperal ketotic cows as compared to the values of these parameters in the blood of healthy cows. The fat proportions in liver were positively (P<0.05) associated with the AST activities and with the serum NEFA and BHB concentrations, but negatively correlated (P<0.05) with the circulating triglyceride, total cholesterol and albumin concentrations, All these biochemical metabolites may be used as important biochemical indicators in the determination of the functional status of the liver in dairy cows during the transition period.

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