Volume 16 (2016): Issue 4 (October 2016)

This review updates the current state of technologies available for turkey semen storage (hypothermic- liquid storage and cryopreservation), with special attention paid to cryopreservation. Liquid semen can be stored for up to 24 or 48 h at temperatures around 5°C, while cryopreservation allows long-term storage at -196°C. The possibility of using frozen turkey semen for artificial insemination (AI) would have practical benefits for turkey production. Reported fertility rates in response to AI using frozen/thawed semen range from 15.8 to 84.3%. Unsatisfactory fertility may be attributed to an inability of turkey spermatozoa to successfully survive the freezing/thawing process, and this, along with the high variability observed, makes this technique unacceptable for commercial breeding programs. There is therefore a need to standardize the whole freezing and thawing process to improve the post-thaw quality of turkey semen and minimize variability in results. Finding an efficient freezing protocol for turkey semen will allow for the creation of a sperm cryobank, improving current prospects for the commercial use of frozen turkey semen and also for the long-term conservation of the genetic diversity of this bird.

The conservation of farm animal genetic resources and their protection against genetic erosion requires knowledge of biodiversity status. Genetic variation in populations can be estimated using both traditional pedigree-based methods and molecular techniques. SNP microarrays are a new generation of molecular genetic tools, which have found application in analysis of biodiversity in populations of domestic and wild sheep, in studies of resistance to intestinal parasites and foot rot, and in searching for markers associated with meat and milk yield, or colour inheritance traits. The aim of the study is the review of recent literature on the biodiversity and the use of molecular markers for population genetics in different breeds and populations of sheep.

Animal cell chimerism denotes the presence of two or more cell lines of different genetic origin. The most common form of chimerism, which occurs spontaneously in mammals, is the presence of two or more cell populations in animals derived from dizygotic twin or multiple pregnancies. The aim of this review is to present extensive information on XX/XY chimerism in cattle, sheep and goats from the Bovidae family. Additionally, it will discuss a methodology for a quick and accurate diagnosis of cell chimerism and make an analysis of cells obtained from gonads of animals derived from twin pregnancies which underwent an exchange of hematopoietic tissue as a result of anastomoses. The studies reviewed here led the authors to conclude that XX/XY chimerism is generally undesirable in livestock breeding. Females (freemartins) are infertile, whereas in male carriers of chimerism, the impact of this abnormality on sperm parameters is still under discussion, therefore every case of different-sex twin or multiple births should be analyzed individually.

Myostatin (MSTN), a negative regulator of skeletal muscle development, acts as a potential candidate gene used to increase muscle mass. Likewise, sheep MSTN gene has an important role in meat production. MSTN is made up of 376 amino acids, and is synthesized as a precursor protein. To investigate the MSTN in Iranian native Makuei sheep, a polymerase chain reaction-single strand conformational polymorphism (PCR-SSCP) analysis was used. Genomic DNA was isolated from the blood samples. A 417-bp of MSTN intron I segment was amplified using locus-specific primers. Four SSCP patterns were identified and nucleotide sequencing of the Makuei sheep MSTN gene was done and registered in the NCBI GenBank with “KJ526625” number. Three novel single nucleotide polymorphisms (SNPs) were found in the samples. These SNPs are found in 224bp, 226bp and 242bp locations. Accordingly three substitutions (c.224C>T; c.226A>G; c.242G>T) were observed in the intron 1 region of MSTN gene. The effects of the observed SNPs on breeding values of some biometric traits were investigated and the substitution of c.226A>G was found to be associated with heart girth (HG) and leg circumference (LC). Phylogenetic analysis, based on the nucleotide sequences indicated similar evaluation with the GenBank reference sequences. It seems that the observed polymorphisms of the ovine MSTN gene are associated with HG and LC traits.

The aim of this study was to evaluate genetic variability of five pig populations maintained in Poland with the usage of model based clustering method (MCMC approach) on microsatellite data. A high degree of genetic diversity with the values corrected for sample sizes was observed for four breeds: 0.740 for Polish Landrace, 0.697 for Pietrain, 0.692 for Polish Large White and 0.688 for Puławska. Duroc breed, however, was characterized by the lowest genetic diversity (0.589), allelic richness and number of effective alleles. As for Structure software results, each breed was represented by their own cluster while maintaining a possible small admixture of other breeds. The results obtained suggest a moderate gene flow between breeds, especially between Polish Landrace and Polish Large White has occurred. The lowest admixture was presented for Duroc breed, which confirms its high purity. The presented results can be used to study the structure and as a genetic information for the preservation and further genetic improvement of the pig breeds maintained in Poland. It seems also advisable to conduct further studies with a larger number of microsatellites and by analysis of mitochondrial DNA.

The aim of this study was to determine the frequency of alleles and genotypes of four polymorphisms located in exons 2, 10 and 16 of the gene encoding insulin-like growth factor type 1 receptor (IGF1R) in the tested herd of 242 Simmental cows and to search for the relationship between these polymorphisms and selected milk production traits. The study applied the following methods: PCR-RFLP and combination of nested PCR and ACRS-PCR. The presence of three genotypes was found for all SNPs. The frequency of alleles was as follows: C - 0.29 and T - 0.71 (IGF1R/e2/MspI), A - 0.33 and G - 0.67 (IGF1R/e2/TaqI), C - 0.77 and T - 0.23 (IGF1R/e10/MspI) and C - 0.53 and T - 0.47 (IGF1R/e16/RsaI). In all lactations, cows with TT (IGF1R/e2/MspI) and GG genotypes (IGF1R/e2/TaqI) produced the highest amounts of milk, fat and protein (P≤0.01), particularly individuals with the combined TT/GG genotypes. As regards the IGF1R/e10/MspI and IGF1R/e16/ RsaI genotypes, the highest milk, fat and protein yields were observed in cows with separate and combined CC/CC genotypes, while the lowest in animals with combined TT/TT genotypes. Cumulative analysis of all genotype combinations showed that individuals with a potentially best combination of TT/GG/CC/CC might be characterized by the highest milk yield as well as fat and protein content in milk. Potentially unfavorable combinations (such as CC/AA/TT/TT and similar) have been almost completely eliminated from the herd tested. The IGF1R gene is proposed as a candidate gene for milk traits in cattle.

The objective of this study was to investigate whether dietary supplementation with different polyunsaturated fatty acids (PUFA s) affects expression of genes related to somatotropic axis and the plasma concentrations of insulin, glucose, non-esterified fatty acids (NEFA), beta hydroxyl butyrate acids (BHBA) and insulin-like growth factor 1 (IGF1) and milk fatty acids profile. Right after calving, Holstein cows (n=45) were randomly assigned to one of three diets supplemented with roasted whole soybean as a source of omega-6 PUFA (omega-6, n=15), linseed as a source of omega-3 PUFA (omega-3, n=15) or palm oil (control, n=15). Each cow was in the study over a period of 70 days. Blood samples were collected every two weeks from day 1 to 70 of lactation and plasma concentrations of insulin, glucose, NEFA, BHBA and IGF1 were determined. Liver samples were taken from a subset of 18 cows (6 per diet) at day 70 postpartum and hepatic mRNA level of total growth hormone-receptor 1A (GHR1A), insulin receptor (INSR), IGF1 and insulinlike growth factor binding protein (IGFBP2) was assessed. Experimental diets did not affect milk yield. Plasma glucose and insulin concentrations were greater for omega-3 treatment compared to omega-6 and control treatments. Cows fed diets enriched in omega-3 exhibited greater INSR and GHR1A mRNA expression, and a tendency for greater IGF1 mRNA expression in the liver compared to omega-6 and control cows. Plasma IGF1 concentration was significantly higher in omega-3 treatment compared with omega-6 and control treatments. Results of this study suggest that feeding omega-3 PUFA s during early postpartum couples with the somatotropic axis, leading to an increase in plasma IGF1 concentration in dairy cows.

The aim of investigations was the estimation of nutritional value of currently cultivated yellow lupine cultivars in raw and extruded form, and their usefulness for broiler chickens. Two experiments were conducted with male Ross 308 chickens. In a digestibility trial 60 fifteen-day-old birds were randomly assigned to three dietary treatments (20 replications in each). Birds were kept in individual pens. Digestibility was calculated using the difference method. From day 16 to 21, diets contained lupine meal in raw or extruded form and the basal diet in the ratio 20:80. Subsequently, the total digestibility of dry matter and crude fat, also apparent nitrogen retention and AMEN value of lupine seeds were determined on chickens fed different forms of lupine. The ileal digestibility of crude protein and amino acids of lupine seeds was also analyzed. In the second experiment the one-day-old birds were randomly assigned to ten dietary treatments (10 replications in each) and were fed diets with increasing amounts of raw or extruded lupine from 10 to 30%. The chickens in control treatments were fed a diet without lupine. Extruded yellow lupine meal was characterized by lower phytic P content in comparison to raw yellow lupine meal. The content of remaining ingredients and antinutritional substances was similar. Yellow lupine seeds post extrusion were characterized by better total crude fat digestibility, nitrogen retention and AMEN values, compared to raw seeds. Higher ileal digestibility was confirmed in numerous amino acids, except lysine, threonine and valine (P≤0.05). By feeding the broilers with diets consisting of 10 to 30% of lupine seeds post extrusion (experiment II), improved apparent fat digestibility, apparent nitrogen retention and AMEN values were achieved in young chickens (P<0.01). Using 10 and 20% of lupine in the diets showed significant positive effects of extrusion on body weight gains, feed intake and feed conversion rate. The performance indices of chickens were drastically decreased by use of 25% ratio of both raw and extruded yellow lupine in the diet. This effect was heightened by a 30% share in feed mixtures.

In this study, we have attempted to analyse the impact of dietary fats on the liver transcriptome in pigs. Four nutritional groups were created. The animals’ diets differed among groups in terms of the presence of corn dried distillers’ grains with solubles (DDGS) (group I - no DDGS, groups II, III, IV - 20% DDGS) as well as the type of fat (rapeseed oil - groups I and II, beef tallow - group III, coconut oil - group IV) used. Using the RNA-Seq method we identified 39 differentially expressed genes (DEGs) as a result of Cuffdiff analysis of the differences among all groups. Analysis of these genes with Panther Gene Classification System revealed that among identified DEGs, genes responsible for lipid and fatty acids metabolism are overrepresented as well as the genes engaged in oxidoreductase and catalytic activity. The article presents for the first time the RNAseq analysis of the liver transcriptome in pigs fed with different sources of fats. The results may be useful for the elaboration of new therapies for cardiovascular diseases in humans as well as for the preparation of new nutrition strategies in animals.

Yarrowia lipolytica yeast can be a valuable component of feed compounds due to its high content of protein and essential amino acids, as well as minerals. The objective of the study was to verify the research hypothesis that Yarrowia lipolytica (YL) yeast, having a more valuable chemical composition than Saccharomyces cerevisiae (SC), can improve growth performance in piglets. An attempt was made to determine what proportion of YL yeast in a compound feed for piglets would produce measurable effects in terms of production and health. The experiment was carried out on 46-dayold piglets receiving experimental mixtures for 39 days. The piglets in the experimental groups were fed the same mixture as the control, but with 3% or 6% fodder yeast of the strain Yarrowia lipolytica A-101 in place of soybean meal. The YL fodder yeast had significantly higher content of alanine (by about 50%), lysine, isoleucine and tryptophan (over 30%), leucine, valine, glycine and glutamic acid (over 20%), and tyrosine (by about 17%) in comparison with SC yeast. Content of crude fat was three times higher than in SC yeast. YL yeast had significantly higher content of Na⁺, K⁺, Ca⁺², Mn⁺², S, Mg⁺² and Zn⁺² than SC, as well as significantly higher content of vitamins B2 and E. Yarrowia lipolytica fodder yeast introduced to compound feed in the amount of just 3% improved growth performance (an increase in daily weight gain and a decrease in feed conversion per kg weight gain). These results indicate that YL in the amount of 3% in compound feed can be successfully used in the diet of piglets in place of the commonly used SC.

It was postulated that naturally occurring phenolic compounds obtained from various plant species may have potential use as feed additives for poultry. Therefore the aim of the study was to compare extracts of hesperidin, diosmin, quercetin and resveratrol in terms of their health-promoting (particularly immunostimulatory) effect on turkeys at different ages. The experiment was conducted on 720 Big 6 turkey hens assigned to 6 experimental groups of 120 individuals (6 repetitions with 20 birds each). The turkey hens in group G-C were the control, receiving a basal compound feed with no experimental additives. The turkey hens in the remaining groups, from the first to the 16th week of life, received a basal diet containing hesperidin (group G-H), diosmin (group G-D), quercetin (group G-Q) or resveratrol (group G-R) in the amount of 200 g per tonne of feed. Ht, Hb, RBC, WBC, lysozyme activity, %PC, IgA, IL-6, GLU, TP and minerals were determined in blood samples. The addition of quercetin or resveratrol in the amount of 200 g per tonne of feed was found to have a beneficial effect on haemoglobin synthesis and phosphorus availability, and may also modulate immunity in turkey hens.

The aim of this study was to investigate the effect of seven different levels (0, 25, 50, 100, 200, 400, and 600 mg/kg) of a phytogenic feed additive containing a mixture of essential oils from thyme, black cumin, fennel, anise and rosemary on performance, eggshell quality, bone biomechanical properties and bone mineralization in laying hens. This study consisted of a total of 112, 21-week-old Super Nick laying hens, which were randomly distributed into seven experimental groups. During the 12-week experimental period, each experimental group of four replicates of four birds each was fed with seven treatment diets. Egg weight and egg mass were positively linearly affected by essential oil mixture supplementation. Also, eggshell thickness was increased quadratically by essential oil mixture supplementation. The biomechanical properties and tibia mineral content were adversely affected by essential oil mixture supplementation at the level of 600 and 400 mg/ kg, respectively. These results demonstrated that dietary supplementation with a low or medium concentration of essential oils improved bone parameters, while at high levels were adversely affected in laying hens.

The effect of supplementing the standard piglet diet containing sodium butyrate with glutamine and/or glucose on the structure of the piglet digestive tract and the small intestine epithelium, acidity and volatile fatty acid content of its digesta was investigated. The free amino acids level, insulin and insulin-like growth factor-1 (IGF-1) concentration in the blood were also analysed. The experiment was performed on 156 piglets (15 litters) allocated to 5 experimental groups, 3 litters in each. Group I (C, negative control) received a basal mixture with no supplement. Group II (SB, positive control) was fed the same basal diet containing additionally 3 g of sodium butyrate per kg. Group III and IV, besides sodium butyrate, received additionally 10 g of glutamine (GT) or glucose (GC), respectively. The last group V received all these supplements, i.e. SB+GT+GC (3, 10, 10 g per kg, respectively). At 60 days of age, the piglets (6 animals from each group) were slaughtered and their intestines were measured and weighed. The piglets in group SB+GT+GC receiving all the supplements grew slightly faster than the others, and at the end of the experiment the differences in body weight were significant. The total intestinal mass of the piglets fed with glucose or all the supplements was significantly higher than that of the piglets receiving glutamine but there was no significant difference in the total length of intestines. There was also no significant difference in acidity of chyme along the entire length of the gastrointestinal tract. Digesta in the jejunum of both control groups (C, SB) contained significantly more SCFA than the remaining groups. In the caecum their content in the negative control and the group fed with all supplements was significantly higher when compared to the butyrate and glucose group. In the duodenum villus height was similar in all the groups but in the jejunum it was significantly higher in the group receiving all supplements than in other groups. Free amino acids level was lowest in the piglets receiving glucose but there was no difference between the remaining groups. The lowest level of IGF-1 was found in the same group and this difference was significant when compared with remaining groups, except C. It is concluded that glutamine and glucose, when given together with sodium butyrate, improve the structure of piglet jejunum epithelium and average body weight gains. A supplement of glucose significantly lowers free amino acid content and IGF-1 level in piglet blood.

The aim of the study was to evaluate the effects of dietary level of two types of inulin differing in the degree of polymerization (DP) on microbial activity in the large intestine of chicks. The experiment was performed on 70 one-day-old Ross 308 male chicks divided into 7 groups fed starter-type diets without inulin addition or supplemented with 0.2%, 0.4% or 0.6% of inulin with DP≥10 (IN10), or DP≥23 (IN₂₃). After 14 days of feeding birds were sacrificed to collect digesta samples from caeca and colon. Caecal digesta was examined for pH, concentrations of short-chain fatty acids (SCFA) and amines, activities of β-glucosidase and mucinase, and relative amount of selected bacterial populations, whereas in colonic digesta only pH, SCFA and amines were analysed. Regardless of DP, inulin level did not affect digesta pH, activity of bacterial enzymes and relative amounts of Clostridium spp., Lactobacillus spp., Bifidobacterium spp. and E. coli populations. Dietary level of IN₁₀ significantly affected propionic acid concentration, which was greater in caecal digesta of birds fed diet supplemented with 0.2% of IN₁₀ compared to other groups and feeding diets supplemented with all levels of IN₁₀ significantly reduced histamine concentration compared to the control. There were no effects of inulin on microbial activity indices in the colon. The present study indicates that, regardless of DP, inulin does not modify considerably microbial activity in the large intestine of chicks.

A group of 98 Czech Fleckvieh cows (one section) was observed over the period of one year with the aim to determine the variation in their milk performance and behaviour at different cowshed temperatures. Behaviour and milk yield were recorded once a week (on the same day) at 10:00. Periods of 8 weeks with the highest temperature (hot period - H) and of 8 weeks with the lowest temperature (cold period - L) were then compared. The cows were housed in one section (1/4 of the total capacity) of the free-stall cubicle shed and where the cubicles were distributed into three rows. Row A (32 cubicles) was close to the feeding plateau, row B (33 cubicles) was in the centre and row C (38 cubicles) was peripheral, close to the side wall. The cowshed temperature was monitored on a daily basis and the mean temperature was 23.2°C in the hot period and -1.7°C in the cold period, relative humidity 60.2% (H) and 74.6% (L), and THI 69.4 (H) and 33.4 (L). The behaviour of the cows was recorded 1568 times, showing them mostly lying down (1037) or standing (531). The cows tended to prefer lying down on their left sides (594 observations) as opposed to their right sides (443). Row A was favoured by the cows (418) and row B was the least popular (377). The cows produced significantly more milk in H period than in L period (0.3 kg per day). The cows lying down were older (3.18 lactations) than the standing cows (2.99 lactations) and they tended to produce more milk per day (by 0.6 kg) but the difference was found to be insignificant. The cows lying resting on their left side produced more milk per day (0.9 kg) and were older (0.02 lactations). The cows in row C were the youngest (2.94 lactations) and the cows in row B were in the last days in milk (144.1 days).

Observations were made concerning active species protection of the Roman snail. Samples were collected from three natural plots in which 3,000 marked hatchlings of farmed origin, aged 1+ (three individuals per m²), were placed in mid-May 2011. The hatchlings originated from breeding snails of the park, or ‘source’ plot. The other plots were a forest, or ‘inhabited’ plot, occupied by a foreign population and a cultivated ‘empty’ plot, which had been emptied of its natural population. By the end of June 2012, the introduced snails were aged 2+, when snails of this species reach maturity. During this period, as part of the analysis of collected samples, the snails in their final maturation period in this age group were divided into mature and immature groups. After thirteen months of observations, a greater density was observed for the farm-originated, naturalised population in the ‘empty’ plot than in the total populations for the other two plots. In the ‘empty’ plot the percentage of somatic and sexually mature farmed snails aged 2+ was significantly higher than in the same snail groups from the other two research plots. There were no statistically significant differences between the shell diameters of the mature farmed snails in all the research plots. The Roman snails of farmed origin considerably extended their territorial range, maintaining their high percentage share in the local natural populations.

Breeding value of sport horses in Poland is estimated on the basis of, among others, results of the 100-day performance test of young stallions in the training centres. However recently, a drastic decrease has been reported in the number of stallions undergoing this way of assessment in Poland with an increase in foreign breeds in equestrian competitions. The objective of the study was to determine variability level of stallion traits evaluated in the training centres and to identify factors affecting stallion performance value assessment during the stationary performance test. The study included 503 stallions subjected to the 100-day training followed by the performance test in the years 2004-2013 at the training centres. There were computed statistical characteristics of 16 performance traits which were scored by the trainer of the training centre, judging commission and test riders. Influence of identified factors on each evaluation was established using the GLM procedure. The rank correlations served to estimate phenotypic interdependencies between the scores and performance value indices. It was stated that the studied group of stallions showed low variation within the body basic measurements and the conformation correctness evaluated on the 100-point scale was also found within an average value (78.86 pts), quite close to minimum value for young stallions in Poland (78 pts). The highest variation was observed for the scores given by the test riders and the main factor differentiating the performance value of horses was their origin-breed group. The horses of the German breeds (HANN, OLDBG, HOLST) earned the highest scores, while Wielkopolska horses got the lowest scores for performance test. Insufficient consistency between the individual evaluation made by the trainer of training centre and the judging commission may imply completely different period of assessment (trainer - 100 days, judging commission - 2 days) or unsatisfactory competencies of examiners.

Broiler breeders hens (meat-type hens) have lower reproductive potential than laying-type hens. Statistical models for predicting potential laying pattern are important for economically optimal breeding strategy of egg production in a poultry flock. The aim of the study was to find the most suitable function for describing the egg-laying rate and egg weight during the broiler breeders’ production period and to characterize laying pattern in groups of hens with different egg production. The following four mathematical models were used: gamma, Narushin-Takma, logistic-curvilinear, and compartmental. The daily recorded egg production data from 100 broiler breeder hens were used. Hen-weekly egg production was described using laying rate during successive weeks after reaching sexual maturity (26 weeks of age) and daily recorded egg weight. On the basis of the total number of eggs laid (NEggs), groups of hens with low (21%), intermediate (52%), and high (27%) egg production were created. The differences between the goodness-of-fit criteria values (AIC, R² MSE) were small, with all the examined models having the same quality of curve fitting for egg-laying rate and egg weight. The logistic-curvilinear model was able to fit well both egg-laying rate and egg weight of the whole broiler breeder hens’ flock, and also when hens were divided into three egg production groups. This model could be considered in a long-term prediction of the reproductive potential in the commercial management. Moreover, the presented model could be useful in the research on different reproduction parameters of individual hens.

In 50 fattening pigs representing two Polish native breeds: 24 Złotnicka Spotted, 10 Puławska and 16 F₁ ♀ (Polish Large White × Polish Landrace) × F₁ ♂ (Duroc × Pietrain) crosses microstructure of muscle, carcass and meat quality were studied. Puławska pigs had the thickest backfat, but the loin eye area was smaller only in comparison to crossbreds. Compared to the Puławska breed, the meat of Złotnicka Spotted pigs was darker, which was associated with a greater percentage of type I fibres and a smaller percentage of type IIB fibres. Puławska pigs distinguished themselves from the other groups under study by the greatest density of fibres per mm². Smaller diameter of type IIA and IIB fibres and higher total number of fibres were found in Puławska breed pigs compared to Złotnicka Spotted, despite the absence of differences in the loin eye area. Smaller thickness of the fibres favourably affects meat quality, and might be considered an indicator of a delicate structure of meat.

The aim of this study was to determine the fatty acid (FA) profile of Simmental cow milk in relation to lipid intake in feeds and their composition, and to compare it with FA composition of milk from cows of Polish Holstein-Friesian (PHF) breed. To this end, 104 milk samples were collected from Simmental cows and 52 milk samples derived from PHF breed were taken over a 2-year period. The season significantly influenced both contents of lipid, dry matter and crude protein as well as FA content in lipids extracted from forages. Winter and autumn seasons were characterized by a significantly higher intake of lipids with forages resulting from the intake of fresh silages, compared with the other seasons when the animals were fed stored silages. This was reflected in the highest content of conjugated linoleic acid (CLA) c-9 t-11 C18:2 in milk from the autumn season. Compared with PHF, milk from Simmentals had a higher content of short-chain saturated FAs (SCSFAs) and was characterized by great differences in FA contents determined in the group of odd- and branched-chain FAs (OBCFAs). Milk from Simmental cows had the butyric acid C4:0 and iso C15:0 content of 4.99 and 1.20 g/100 g FA on average, respectively, which have been associated with benefits for human health.

The analysis of slaughter yield and meat quality was performed on a total number of 96 birds from four medium-heavy weight pedigree strains. Based on their strain, cockerels were divided into the following groups: group I - strain N88 (originating from New Hampshire), group II - strain R55 (Rhode Island Red), group III - strain S11 (Sussex) and group IV - strain P55 (Plymouth Rock). Each group consisted of 24 birds. At 12 weeks of age, half of the cockerels from each group was caponised. In total, 48 birds were caponised (12 birds in each strain). Based on the strain, capons were then divided into groups V (N88), VI (R55), VII (S11) and VIII (P55). It was noted that the strain and caponisation had influence on differences in such traits as the weight of eviscerated carcass with neck and slaughter yield. On the other hand, it was observed that caponisation did not affect significantly the total weight, percentage share of breast and drumstick muscles in carcasses of birds from analysed strains. No significant differences were observed between groups in terms of physicochemical properties of meat. The highest content of water in breast and drumstick muscles was observed among cockerels and capons from strain N88 (groups I and V). Protein content in cockerels’ breast muscles differed depending on their strain whilst among capons (groups V-VIII) it was similar. It was also noted that capons originating from strains S11 (VII) and P55 (VIII) stood out significantly with higher fat content in breast muscles compared to cockerels from the same strain (groups III and IV). The effect of caponisation on higher fat content in drumstick muscles was confirmed in all observed groups. Capons from all strains had more fat in drumstick muscles compared to cockerels of the same origin.