Teresa Nałęcz-Tarwacka

Effect of different fat supplements on the antioxidant capacity of cow’s milk

Abstract. This study examined the effect of different fat supplements on the antioxidants of cow’s milk. Thirty five Polish Holstein Friesian cows at 180±20 day of lactation and averaging 17.71±2.26 kg/d of milk were divided into five equal groups. There were five treatments groups: 300 g/d of fish oil, 500 g/d of Opal linseed, 500 g/d of Szafir linseed, 150 g/d of fish oil + 250 g/d of Opal linseed, 150 g/d of fish oil + 250 g/d Szafir linseed. Milk samples were collected five times during the 21 day of supplementation period: at the 1st, 14th and 21th day of the experimental period, and also at the 14th and 21st day after the supplement withdrawal. Diet supplementation with the Szafir linseed improved the chemical composition and milk yield at the 21st day of experiment. The highest level of malondialdehyde was recorded in fish oil, Opal linseed, fish oil + Opal linseed, and fish oil + Szafir linseed groups, and the lowest in the Szafir linseed group. After the 21st day of supplementation the concentration of α-retinol was significantly increased in all groups by 23 to 183 %. The highest level of α-tocopherol was found in fish oil + Opal linseed group at the 21st day of supplementation. Total antioxidative status increased in all experimental groups; however, the highest peak was recorded in fish oil + Szafir linseed and Szafir linseed group. The experiment confirmed that manipulation in cows’ diet may improve antioxidative capacity of milk.

Effect of supplementation of cows diet with linseed and fish oil and different variants of β-lactoglobulin on fatty acid composition and antioxidant capacity of milk

BACKGROUND The aim of this study was to determine the influence of polymorphic variants of β-lactoglobulin in cows supplemented with linseed and fish oil on the fatty acid composition and antioxidant capacity of milk. From the herd of 320 Polish Holstein Friesian cows three groups of cows were selected according to the variants of β-LG (β-LGAA, β-LGBB, β-LGAB). During the first 7 days (the initial period) all the cows were fed the same total mixed ration (TMR) diet. From day 8 to 28,150 g fish oil and 250 g linseed (FOL) was added to the TMR diet of each cow. RESULTS The results showed that the diet supplemented with FOL was effective in reducing atherogenic and thrombogenic indices. Introducing supplementation improved the antioxidant capacity: higher concentration of C18:2cis-9 trans-11, C20:5 n-3, C22:6 n-3, bioactive whey proteins and vitamin soluble in fat has been recorded. The results showed that β-LGAA was associated with lower levels of atherogenic and thrombogenic indices and higher concentration of C22:5 n-6, phospholipids and β-carotene. β-LGBB favours a higher content of C18:1trans-11, C18:2cis-9 trans-11 and lactoferrin. β-LGAB was associated with higher concentrations of C20:5 n-3, Lysozyme, α-retinol, α-tocopherol and total antioxidant status. CONCLUSION Modification of the diet of cows with fish oil and linseed significantly influenced fatty acid composition and antioxidant properties of milk. The effect of β-LG phenotype on the fatty acid composition and antioxidant capacity of milk is variable, which could partly be the result of a β-LG phenotype × diet interaction.

Influence of linseed variety on fatty acid profile in cow's milk

BACKGROUND The aim of this study was to examine the influence of linseed variety on the concentration of cows milk constituents, particularly fatty acids. The experiment was conducted on 30 Polish Holstein Friesian cows whose diet was supplemented with two varieties of crude linseed, Opal and Szafir. RESULTS After 21 days of linseed supplementation, the Szafir variety proved to be a better supplement than the Opal variety, particularly in relation to the concentration of saturated fatty acids, C20:5 (69.2% higher) and C22:6 (147.1% higher) and also because of improved chemical composition of the milk (19.7% higher fat, 2.9% higher protein and 39.9% higher casein content). CONCLUSION Linseed variety significantly influenced the lipid fraction level and the basic chemical composition of cows milk. Linseed variety should therefore be taken into consideration in subsequent experiments in addition to the quantity and physical form of linseed. The results showed that the use of a diet supplemented with linseed, especially the Szafir variety, was effective in reducing saturation, atherogenic and thrombogenic indices, yielding benefits for consumers by improving the nutritional quality of cows milk.

Effect of fish oil and linseed supplementation on the protein composition of milk from cows with different β-lactoglobulin phenotypes.

BACKGROUND The objective of this study was to determine the impact of fish oil and linseed (FOL) supplements on the protein fraction levels of milk from cows with different phenotypes of β-lactoglobulin. RESULTS After 21 days of supplementation the study showed significantly higher concentrations of whey proteins, especially lysozyme (144% increase) and lactoferrin (45.5% increase), compared with milk from control cows (total mixed ration with no supplemented FOL). A reverse trend was demonstrated for casein, casein index and casein number (lower level). The most favourable change (higher level), in terms of lactoferrin, α-lactalbumin and bovine serum albumin contents in milk, was recorded in cows with the BB variant of β-lactoglobulin. The highest level of lysozyme was recorded in the milk of cows with the AB variant of β-lactoglobulin. CONCLUSION The combined supplementation of fish oil and linseed had a positive impact on whey proteins in cows milk. In addition, the phenotype of β-lactoglobulin also played a role in milk protein composition. There is therefore a clear indication that nutritional experiments should take into account not only food supplements but also the genetic variants of β-lactoglobulin.

Comparison of calves' rearing parameters in two different housing systems: indoor versus outdoor hutches

Abstract. The main aim of the study was to compare the rearing effect of calves kept outdoor in individual hutches and indoor in group pens. During the experiments, the following measure ments were carried out: body weight, daily gains, feed intake, morbidity and mortality. The study was conducted on 90 calves from 5th to 90th day of age; all calves were fed the same feed and according to the same schedule. Results revealed that during the first month, the calves from both groups achieved the same daily gains. However, older calves kept indoor were characterised by better daily gains, feed intake and as a result, body weight. The outdoor system has positive effect on morbidity, especially in case of pneumonia and diarrhoea. During the experiment, only two calves were lost (mortality rate – 2.2 %).

Effect of Dairy Cow Crossbreeding on Selected Performance Traits and Quality of Milk in First Generation Crossbreds: Crossbreeding in dairy cattle…

The main goal of crossbreeding Holstein-Friesian (HF) cows with bulls of other dairy or combined breeds is to improve their performance traits. Thus, the aim of this investigation was to compare the dairy performance traits of first generation crossbreds produced by crossbreeding Polish HF cows with bulls of other breeds (Norman, Norwegian Red, Danish Red, Brown Swiss, Montbeliarde, and Simmental). This was done by analyzing the fatty acid profile and technological quality of the milk from these first generation crossbreds. The investigation showed that crossbreeding greatly influenced the performance parameters and technological quality of the milk of the first generation crossbreds obtained from crossbreeding Polish HF cows with bulls of other dairy or combined breeds. The crossbreed cows characterized by the highest both quantity and quality of milk. Also, the best parameters of milk fat dispersion (that is, the highest values of these parameters) that are useful in the production of hard ripening cheeses and butter were found in the milk of crossbreed cows. Health beneficially, saturated fatty acids level in milk of crossbreeds was by 25.96% lower in crossbreds milk when compared to purebred cows. The most beneficial content of whey proteins was found in the milk of Polish HF and Norwegian Red crosses, where it was 19.04% higher than in pure breed Holsteins. F1 cows tend to express better functional traits than Holstein (PHF) cows. Effect of heterosis was larger and gave better results when there was a greater genetic distance between the animals used for crossbreeding. PRACTICAL APPLICATION The effects of heterosis are opposite to the effects of inbreeding depression, and it extends the lifespan and use of animals as well as improves their fertility and health. The main goal of crossbreeding Holstein-Friesian cows with bulls of other dairy or combined breeds is to improve their performance traits. F1 cows tend to express better functional traits than Holstein (PHF) cows. Effect of heterosis was larger and gave better results when there was a greater genetic distance between the animals used for crossbreeding.