Factors affecting acetone concentration in blood of dairy cows at the first stage of lactation.

The aim of this paper was to determine effects of selected genetic and environmental factors on the concentration of acetone in blood of cows in the first trimester of lactation. The study included 124 Polish Holstein-Friesian primiparous cows born, reared and managed on the same farm. The samples of blood were collected on day 2, 5, 30, 60 and 90 after calving. The highest serum acetone concentration in the animals examined was observed on day 5 after calving. The level of this compound was inversely related to the contribution of the original Holstein-Friesian breed in gene pool. Significantly higher serum acetone level was observed in cows calved in January-March period when compared to other months of the year. Besides, the level of acetone determined on day 5 after calving was associated positively with body weight determined at the same day and negatively with body weight changes between days 5 and 60 after calving.

The effects of genotype and selected environmental factors on colostrum production and intake in cattle.

The aim of this study was to determine effects of genotype and selected environmental factors on colostrum production, intake, and efficiency in the cattle. The investigations were conducted on 67 dam-calf pairs. All cows were of Polish Holstein-Friesian breed, the Black-and-White variety (PHF-HO), whereas calves were sired by bulls of the following breeds: PHF-HO, Polish Holstein-Friesian of the Red-and-White variety (PHF-RW), Jersey (JE), Montbéliarde (MB) and Limousine (LI). The colostrum was collected from cows and offered to calves "from bucket" thrice a day. The amount of produced colostrum considerably exceeded the ability of its consumption by calves. Low share of HF genes in the cow, older cow's age and calving in the period from January to April appeared to be favorable factors for colostrum production. Calves born to cows with low HF gene share drank more colostrum than calves originating from cows with higher gene share of this breed. Crosses with JE drank the highest amount of the colostrum in relation to body weight, while MB-sired calves drank the highest amount in absolute terms. Colostrum intake was positively correlated with the dam's age. Furthermore, it was shown that in case of the first colostrum intake the most favorable period was from May to September, while in cases of total intake in the first day of life and mean intake in the first 5 days of life it was the period from January to April. Crosses with JE were characterized by extremely high use of colostrum per unit of body weight gain.

Factors affecting somatic cell count in cow bulk tank milk--a case study from Poland.

The aim of this paper was a retrospective analysis of factors affecting the somatic cell count (SCC) in cow bulk tank milk. The investigations concerned the year 2000 and were conducted on 212 family dairy farms in the Wielkopolska region (Western Poland). The average herd size was 13.3 cows (ranging from 5 to 48), whereas the mean SCC was 269,000 in 1 cm3 of milk (ranging from 63,000 to 631,000). In the period from July to September a higher SCC (P < or = 0.01) was found than in the other months. In herds of more than 15 cows, higher SCC values (P < or = 0.05) were observed than in the smaller herds. The following management and technological factors significantly decreased SCC: a 7-8-week dry period (versus shorter period), foremilking with the use of a forestripper, practicing manual udder massage before milking, individual rationing of feeds according to production, and the application of MgO and beta-carotene additives to the feed ration.