ISSN 1644-0714 e-ISSN 2300-6145

Zootechnica

Volume 15(4), 2016

Review Articles

Genetic background of chondrodysplasia in domestic dog (Canis lupus familiaris) – in silico analysis 

Patrycja Florczuk, Joanna Gruszczyńska

Abstract. Chondrodysplasia is a type of genetic skeletal disorder associated with abnormalities in the development of cartilage tissues. Affected dogs suffer from disproportionate short-limbed dwarfism and/or hyperplasia of the skull bones. Visible symptoms occur only during growth period. Early studies demonstrated that chondrodysplasia in domestic dog is an autosomal recessive disease. Therefore, the only way to detect carriers in the population without performing test matings is a genetic test. Current knowledge of the genetic background of chondrodysplasia is limited to Norwegian Elkhound and Karelian Bear Dog. In case of other breeds, for example Labrador Retriever, known research only excludes participation of certain genes in the origin of the disease. Therefore, the authors of this article decided to develop diagnostic genetic tests that will detect carriers on the basis of previously identified mutations, causing chondrodysplasia.

Original Research Articles

The level of selected milk performance traits of imported and home-bred Montbéliarde cows born in different seasons and calving at different ages 

Ewa Januś

Abstract. The aim of the study was to analyse milk performance traits of Montbéliarde cows imported from France as pregnant heifers and born in Poland, taking into account season of birth and age at first calving. Daily yield (in kg and converted to kg FPCM), content of fat, protein and lactose, the fat-to-protein ratio, and somatic cell count in the milk were analysed. Born in Poland cows have higher daily milk yield and a better fat-to-protein ratio than cows imported from France. The imported cows produced milk with a more favourable chemical composition. In terms of daily yield, calving ages at 855–915 days were most beneficial in the case of both imported and born in Poland cows. Age at first calving had a greater influence on the yield of born in Poland cows than on that of imported ones. In each range of age at first calving, higher fat and protein contents in the milk of imported cows as compared to cows born in Poland were noted. The somatic cell count in the milk may indicate somewhat better udder health in the born in Poland cows. In the case of both imported and home-bred cows, the spring/summer season of birth was associated with higher somatic cell count. In conclusion, the acclimatization process may have had a negative effect on the performance of cows imported as pregnant heifers from France.

Meat quality of broiler chickens fed mixtures with varied levels and varieties of faba bean 

Anna Milczarek, Maria Osek, Magdalena Pachnik

Abstract. The material were leg muscles collected from 40 broiler chickens from 5 feeding groups (I, II, III, IV and V). The differentiating factor of the groups were the seeds of faba bean added to starter/grower feed, according to the following design: group I (control) – without faba beans, group II – 8%/15% high-tannin faba beans, group III – 16%/22% high-tannin faba beans, group IV – 8%/15% low-tannin faba beans, group V – 16%/22% low-tannin faba beans addition. It was found that the addition of high- or low-tannin faba beans to compound broiler feeds did not affect the basic composition of leg muscles. More linoleic acid, C18:2(n-6), and linolenic acid, C18:3(n-3), as well as total polyunsaturated fatty acids (PUFAs), were found in the muscles of chickens fed on faba beans mixes, however, the difference was significant (P  ≤  0.05) only between the muscles of group III and control birds. In the lipids of the treated chickens, the proportion of saturated fatty acids (SFAs) decreased significantly (P  ≤  0.01). Significantly lower (P  ≤  0.01) atherogenic index (AI) and thrombogenic index (TI) were found in leg muscles of faba bean treated chicken, particularly with its higher feed content. Moreover, a high content of faba beans in the feed had a positive effect on the sensory qualities.

Effect of age and sex of slaughtered cattle on dressing percentage and EUROP classification results 

Marek Janiak, Anna Sawa, Mariusz Bogucki

Abstract. The effect of bovine carcass category on dressing percentage and EUROP classification results was determined on 2627 head of slaughtered cattle, using the FREQ and GLM procedures of SAS. The largest categories of slaughter cattle were bulls (30%) as well as young bulls and cows (each around 28%). The most numerous carcass conformation class in all the categories was class O (71.91%), followed by R (15.07%), P (11.88%) and U (1.14%). Moderate fatness of bull carcasses was observed for both A and B age categories. Young bull carcasses generally contained less fat than heifer carcasses. Dressing percentage coefficients were similar for young bulls (category A) and heifers (category E) (P  ≤  0.01), as a result of which no statistically significant effect of sex on dressing percentage was found for young slaughter cattle. The age factor caused much greater differences (P  ≤  0.01) in dressing percentage values for the slaughtered females (categories D and E) than for the slaughtered males (categories A and B).

Classification of calving difficulty scores using different types of decision trees 

Daniel Zaborski, Witold S. Proskura, Wilhelm Grzesiak

Abstract. The aim of this study was to classify the cases of calving difficulty using selected data mining methods (Classification and Regression Trees, CART, Chi-square Automatic Interaction Detector, CHAID, and Quick, Unbiased, Efficient, Statistical Trees, QUEST) and generalized linear model (GLZ) and to identify their most important predictors. A total of 1699 records of Polish Holstein-Friesian Black-and-White cows were used. Calving difficulty had three categories (easy, moderate and difficult). Percentages of calvings correctly classified by CART, CHAID, QUEST and GLZ, respectively, were as follows: 60.20, 65.31, 68.88 and 66.33% (easy), 71.36, 69.01, 64.79 and 69.01% (moderate) and 0, 0, 0 and 0% (difficult). The most influential predictors of calving difficulty were the rank of the dam’s sire, calf sex, calving age, previous calving difficulty, lactation number, daily milk yield and average milk yield of the farm. The tree models and GLZ were of moderate quality. None of them could correctly indicate dystocia.

Laying performance, egg quality and hatching results in geese fed with dry apple pomaces 

Lesia Fiialovych, Iaroslav Kyryliv

Abstract. The article provides the results of the studies on the efficiency of using dry apple pomaces with and without chelate copper and zinc addition in diet of breeding geese. The experiment demonstrated the effective level of these additives and their influence on the morphological qualities of eggs and on the level of productivity was examined. It is found that the usage of non-traditional feed additives improves the process of egg laying, and increases hatchability and vitality of goslings. Thus, it is obvious that inexpensive, practically dry apple pomaces can significantly increase the income of a poultry farm. Besides, it was shown that the highest level of hatchability and survival was present at a content of 7% of dry apple pomaces, enriched with chelate copper and zinc forage supplementation. This implies that such feed additives meet the high physiological needs – not only in nutrients, but also in biologically active matter, which satisfy the needs of the organism and provide appropriate level of realization of the genetic potential of breeding geese performance, especially promote more intensive usage of substrates for synthesis of the main components of the eggs.