Associations between the breeding values of Holstein-Friesian bulls and longevity and culling reasons of their daughters.

Taking into account functional traits in the breeding practice should lead to a longer productive life of cows. However, despite the increased contribution of these traits in bull selection indices, their daughters are frequently culled as early as the 2nd or 3rd lactation. The problem is whether and to what extent the genetic potential of animals is realized in the production practice. Therefore, the purpose of this study was to determine the associations between the breeding value (BV) of bulls and their daughters for cow longevity and culling reasons in the Holstein-Friesian cattle population in Poland. Data for 532 062 cows culled in 2012, 2015, and 2018 were analyzed. A majority of 5 045 cow sires originated from Poland, Germany, France, the Netherlands, and the United States. The highest variation in the contribution of culling reasons was for the cows culled at the age of 2-4 years. The contribution of the culling reasons, analyzed in relation to the cow culling age, remained similar and the only exception was culling because of old age, for which a significant increase was observed only for the culling age of at least 9 years (13.8%), which was reached by only 7.3% of the cows. The sires were characterized by generally high BV for conformation and reproductive traits. However, they had, at most, the average genetic potential for functional longevity. There were a number of beneficial associations found between the BV of bulls and the distribution of culling reasons in their daughters. For example, it concerns relations between the somatic cell score in milk and culling due to udder diseases and low milk yield, between the interval from calving to first insemination and low milk yield, between the protein yield and old age, or between the BV for certain conformation traits (size, udder) and cow culling due to age. In these cases, as the BV increased for a given trait, the contribution of the corresponding cow culling reason tended to decrease. Our study showed that it seems reasonable to consider Holstein-Friesian cows aged at least 9 years at culling to be long-living animals. This is primarily evidenced by the rapid increase in the culling due to old age in relation to younger cows. Nowadays the above age limit can be suggested as a criterion of longevity for Holstein-Friesian cows but the criterion should be updated to the relation genotype-environment-economy that tends to change over time.

Associations between strain, herd size, age at first calving, culling reason and lifetime performance characteristics in Holstein-Friesian cows.

Cow longevity and lifetime performance traits are good indicators of breeding effectiveness and animal welfare. They are also interrelated with the economics of dairy herd. Unfortunately, a high milk yield is often associated with deteriorated cow health and fertility and, consequently, with an increased culling rate. This situation, observed also in the Polish population of Holstein-Friesian cattle, inspired us to undertake a study on the associations between some factors and lifetime performance characteristics. The data set consisted of the records on 135 496 cows, including 131 526 of the Black and White strain (BW), and 3970 of the Red and White strain (RW) covered by performance recording and culled in 2012. It was found that cows of the BW strain and those from the largest herds (>100 cows) reached higher lifetime and mean daily energy-corrected milk (ECM) yields than cows of the RW strain and those from smaller herds culled at a similar age. Cows youngest at first calving (<2.0 years) were characterised by the highest lifetime ECM yield. It indicates that heifers can be bred even when they are younger than 15 to 16 months with no significant negative effect on their later performance. Infertility and reproduction problems (39.6%) and udder diseases (15.5%) constituted the most frequent reasons for cow culling. Cow longevity and lifetime productivity were considerably affected by the interactions between the studied factors.

Application of GC-FID and GC-MS for assessing PAHs in suspended dust.

The social concern about polycyclic aromatic hydrocarbons (PAHs) is due to the awareness that several of them are carcinogens and are present in polluted air. Several epidemiological investigations have tried to assess the influence of air pollution on the incidence in the population (1). Some authors have suggest that 1-10% of the incidence of lung cancer is caused by air pollution (2, 3). Several sources, e.g. traffic, oil heating, wood stoves, industry may contribute PAHs to the air pollution. Therefore continuous air pollution control applying selective and precise analytical procedures is needed. The submitted work presents results of examination of sixteen polycyclic aromatic hydrocarbons [naphthalene, acenaphthylene, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, chrysene, benzo(a)anthracene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(a)pyrene, indeno(1,2,3-cd)pyrene, dibenzo(a, h)anthracene, benzo(ghi)perylene] settled on particles of 10 microns fractions of ashes, emitted from industrial and communication sources. Samples of suspended dust were collected at twelve measuring points, from May to June 1998, in 24-hour cycles, in accordance with US EPA methodology. PAHs were extracted from suspended dust in a Soxhlet apparatus and then exposed to extraction in a liquid-solid system (solid extraction-SPE) to eliminate redundant pollution, which may interfere with compounds by determined analysis. Samples were then analyzed using by capillary gas chromatographs "Varian" model 3400 with FID and MS detectors. Results of analysis make it possible to determine the influence of industry and traffic on atmospheric pollution, to compare results of two analytical methods (GC-FID and GC-MS).

[Thoracic radiation myelopathy]. / Popromienna mielopatia piersiowa.

In a 62-year-old patient 8 month after radiotherapy for right pulmonary hilus carcinoma signs of thoracis cord involvement with ascending course from Th10 to Th7. Cerebrospinal fluid and myelogram were normal. The patient died after about 12 months. Radiation myelopathy was confirmed by neurohistological examination. The results of experimental studies are quoted which could predict the possibility of early diagnosis of radiation myelopathy by rising level of basic myelin protein in cerebrospinal fluid.