The aim of this study was to determine the genetic effect of cow breed on the yield and quality of cow's milk. On the selected dairy farm, cows of two different breeds Montbeliarde and Polish Holstein-Friesian between 45th -100 th days of lactation, were managed under the same environmental conditions. Milk samples were collected twice (in May and June 2008) from 97 (n = 51 and 46 for Montbeliarde and Polish Holstein-Friesian, respectively) cows. Montbeliarde cow's milk was characterized by significantly lower milk yield and somatic cell count. Higher level of C18: 2 cis-9 trans-11 and almost 2-fold C20:5 n-3 (P ≤ 0.01) was also recorded. However, Polish Holstein-Friesian cow's milk had a better composition of protein fraction (higher concentration of lactoferrin, α-lactoalbumin and β-lactoglobulin) and higher concentrations of vitamins D and E. Moreover, milk of Polish Holstein-Friesian breed was characterized by more favorable fat fraction with significantly lower concentrations of saturated fatty acids (C14:0, C18:0) as well as lower atherogenic and thrombogenic indexes and higher concentration of C18:2 trans-10 cis-12, C20:3 n-6 and C 22:6 n-3. This study was the first one comparing biological quality of Polish Holstein-Friesian and Montbeliarde milk under the same environmental conditions in Polish production systems. Cattle, somatic cell count, fatty acid, whey proteins, vitamins soluble in fat

Genetic parameters for somatic cell score (SCS) for Polish Black-and-White cattle were estimated using 52,599 test day records from the first six lactations of 8,418 cows, and the Bayesian method via Gibbs sampling. The two-trait random regression (RR) model included fixed herd-yearmonth of test effect, fixed regressions within genetic group by age at calving by season of calving subclasses, and random regressions for additive genetic and permanent environment effects. First and subsequent lactations were treated as separate traits. Fourth-order Legendre polynomials were used for regressions. There were 200,000 samples of (co)variances for random effects generated with the first 20,000 samples as the burn-in period.Genetic variances were in the range of 0.37 to 0.76 throughout first parity and 0.43 to 0.91 throughout later parities, with averages of 0.41 and 0.48, respectively. Variances for permanent environment increased from 1.04 to 1.37 throughout the first, and from 1.11 to 2.00 throughout subsequent parities. Estimates of heritabilities were from 0.11 to 0.20 for first and 0.13 to 0.22 for subsequent lactations, indicating stronger genetic resistance to mastitis in later parities. The highest values of heritability were observed at peripheries. Genetic correlations for SCS between first and later parities for different days in milk (DIM) were all less than 0.5, with the highest values in midlactation.

Genetic parameters for lactose percentage in the milk of Polish Holstein-Friesian cows were estimated using 48,859 test day records from six lactations of 8,418 cows and the Gibbs sampling method. The multiple-trait random regression model was applied for data from the first and subsequent (up to the sixth) lactations treated as two traits. Variance components and heritabilities changed in a similar way through the first and subsequent lactations, reaching the highest values at peripheries and relatively stable values in the middle of lactations. All estimates were smaller in the first than in the later parities. Heritabilities of daily lactose percentage ranged from 0.17 to 0.31 with a mean of 0.24 (SD=0.034), and from 0.23 to 0.36 with a mean of 0.28 (SD=0.026) in first and subsequent lactations. Genetic correlations for lactose percentage between the same days of the first and subsequent parities were less than 0.30, with the average equal to 0.26 (SD=0.047) and the minimum (less than 0.15) occurring in the first days after calving.

No abstract

Certified organic farm area in Poland increased 8.5 fold during the 2003-2010 time period to 518 thousand ha, which constituted 2.8% of the arable land. The production costs and profitability of the organic fruit production of apples, strawberries, and sour cherries were evaluated and compared to conventional production of those fruits. The research was based on data from thirty-two commercial fruit farms; twenty farms with conventional production, and twelve with organic production. The main problems associated with organic production were the costs of weed control and soil cultivation. The conventional production of apples turned out to be slightly more profitable than the organic production. The organic production of sour cherries was not profitable. In the case of strawberries, it was the opposite - the organic production gave a better financial outcome than the conventional one