Volume 19 (2019): Edizione 2 (April 2019)

Unlike classical microbiology which focuses on bacteria capable of growing in vitro, metagenomics is a study of genetic information originating from microflora which aims to characterise the microbiome, namely the common genome of bacteria, archaea, fungi, protozoa and viruses living in the host. Metagenomics relies on next-generation sequencing (NGS), a large-scale sequencing technique which allows millions of sequential reactions to be carried out in parallel to decode entire communities of microorganisms. Metagenomic analyses support taxonomic analyses (involving gene fragments encoding ribosomal RNAs 5S and 16S in bacteria) or functional analyses for identifying genes encoding proteins that participate in the regulation of metabolic pathways in the body. New metagenomics technologies expand our knowledge of the phylogenetic structure of microflora in the gastrointestinal tract of poultry, and they support the identification of previously unknown groups of microbiota, mainly those occurring in small numbers. Next-generation sequencing also provides indirect information about the quantitative structure of the genes of gut microorganisms, but microbial activity and changes in the proportions of microbial metabolites that affect the host’s intestinal integrity and metabolism remain insufficiently investigated. Therefore, research studies are undertaken to investigate the proportions of the key microbial metabolites in the intestinal contents of poultry relative to changes in the population size of the most important bacterial groups, including those determined by cheaper techniques.

The aim of this study was to determine the possibility of using duckweed in sustainable livestock production and aquaculture. Duckweed is a small plant which grows in water and is exploited in biotechnology, dietetics, phytotherapy, and ecotoxicology. It is also used for biological waste-water treatment, and for biogas and ethanol production. This study provides the characteristics of duckweed and presents results indicating its applicability in livestock feeding. Duckweed is a rich source of proteins and amino acids, and contains many macro- and micronutrients as well as vitamins and carotenoids. Unfortunately, it accumulates considerable amounts of toxic metals and compounds from the aquatic environment, which may limit its use as a feed ingredient. Fresh or dried duckweed is willingly consumed by animals (poultry – laying hens, broiler chickens, ducks; cows, sheep, goats, swine, fish) and is a valuable protein source to them. It has been scientifically demonstrated that its use in moderate amounts or as a partial replacement of other protein feed materials, including soybean meal, has a beneficial effect on the productivity, fattening, and slaughter performance of livestock and poultry as well as on the quality of their meat and eggs. Research addressing duckweed use as a feed ingredient should focus on developing various growth media technologies, including the use of slurry digestate, to obtain high biomass yields. Another research direction should be to determine risks in the production chain (collection, processing), which limit its use in monogastric and ruminant diets.

The aim of this review was to define the most important factors that affect the reproductive success of farmed mink. The biology of mink reproduction is unique when comparing it with other farmed fur animals. The article emphasizes the importance of optimal environmental conditions in prevention of reproductive disorders. The novel attempts to the mating schedule, optimal diet and body condition of dams, kits transfer between dams, these are only examples of advantageous procedures used in mink farming to increase the effectiveness of reproduction.

This review discusses the thermal conservative and heat dissipating roles of one of the most sensitive thermoregulatory variables (respiratory rate) with the aim of enhancing its application in evaluating both cold and heat adaptation. During cold exposure, livestock enhance the economy of body heat through reduction in respiratory rate with the extent of reduction being greater and commencing at relatively higher ambient temperature in poorly adapted phenotypes. This is accompanied by an increase in tidal volume and alveolar oxygen uptake, but a decrease in partial pressure of oxygen. On the other hand, heat stress induces increase in respiratory rate to enhance evaporative heat loss with the magnitude of such increase being greater and commencing at relatively lower ambient temperature in phenotypes that are poorly-adapted to heat. This is accompanied by a decrease in tidal volume and the development of hypocapnia. The increase in respiratory rate is observed to be greater, moderate and lesser in livestock that are mainly (pigs, rabbits and poultry), moderately (sheep, goats and Bos taurus) and less (Zebu cattle) dependent on respiratory evaporative heat loss, respectively. The changes during chronic heat stress may cause acid-base crisis in all livestock, in addition to reduction in eggshell quality in birds; due to marked decrease in partial pressure of carbon dioxide and a compensatory increase in elimination of bicarbonate. Within and between breed variations in sensitivity of respiratory rhythm to both cold and heat stress has shown high applicability in identifying phenotypes that are more susceptible to thermal stress; with some cellular and metabolic changes occurring to protect the animal from the consequences of hypo- or hyper-thermia. The information in this review may provide basis for identification of genes that support or suppress thermoregulation and may also be of great use in animal breeding, genomics and selective thermal stress mitigation to provide maximum protection and comfort to poorly-adapted phenotypes.

Feed contamination is a major cause of diseases outbreak in the poultry industry. There is a direct relationship between feeding, the intestinal microbiota and how the immune system responds to disease infestation. Cereals which form the bulk of poultry feed are mostly contaminated by mycotoxins of Fusarium origin. Adequate knowledge of mycotoxins and their effects on animals is necessary. Deoxynivalenol (DON) is a major contaminant of poultry feed. DON has the ability to bind with a large number of eukaryotic ribosomal subunits because of the presence of an epoxide group and these disrupt the activity of peptidyl transferase and the elongation or shortening of peptide chains. Deoxynivalenol has varying effect ranging from acute, overt diseases with high morbidity and death to chronic disease, decreased resistance to pathogens and reduced animal productivity. Deoxynivalenol also impairs the intestinal morphology, nutrient absorption, barrier function, and the innate immune response in chickens. This review highlights the impacts of deoxynivalenol on the immune system, intestinal microbiota composition and the morphology of chicken.

The objective of the study was to determine the relationship between polymorphism in the RYR1 gene (rs344435545) and on-farm test results (fattening, slaughter and reproductive traits) of pigs maintained in conservation herds. the experiment covered 76 boars and 291 gilts kept in 33 herds. animals aged 150–210 days were weighed and P2 and P4 backfat thickness as well as P4 loin muscle depth (P4m) were measured with an ultrasonic device. standardised daily gain (g/day) of the animals and carcass meat percentage (%) were determined. the following reproductive traits of sows were also collected: number of teats, age at first farrowing, dates of next farrowing, number of piglets born alive and weaned at 21 days of age. Hair roots were sampled from the gilts, sows and boars to determine the RYR1 gene polymorphism. it was found that only 3% of the animals in the analysed population had TT genotypes, whereas 28.34% were heterozygous (CT). this polymorphism (CT) was carried by 28.34% of the animals. when analysing the effect of this polymorphism on fattening and slaughter traits in live animals, it was found that sows with TT genotype, compared to the others, were characterised by higher backfat thickness only (P≤0.05). In the boars with CC and CT genotypes, no significant differences were noted between the values of the analysed traits. for reproductive traits of the sows, it was observed that females with TT genotype weaned more piglets until 21 days of age (P≤0.05).

The coding sequences (CDS) of TFAM and TFB2M genes from Jiaxing Black Pig (JBP) were first obtained by RT-PCR and DNA-seq in the present study. Sequence analyses showed that the TFAM gene contains a 741-bp CDS region encoding 246 amino acids sharing a 100% homology with the sequence on NCBI, while TFB2M gene contains a CDS region of 1176 bp encoding 391 amino acids with two missense mutations. The results of quantitative Real-Time PCR for TFAM and TFB2M revealed that transcripts of the genes were both presented at the highest levels in spleen tissue followed by liver tissue, while the least levels in longissimus dorsi muscle (LDM), and obviously the higher levels in two adipose tissues than those in LDM tissue (P<0.01). Meanwhile, a total of forty-two JBPs were employed in this experiment to investigate the effect of these two genes on the carcass, meat quality traits and flavor substances such as fatty acids, intramuscular fat (IMF) in LDM. As expected, some strong correlations of gene expression abundance of TFAM and TFB2M mRNA in particular tissues such as liver and LDM with carcass and meat quality traits including marbling score, as well as the content of saturated fatty acid (SFA), in JBP were found.

Obesity is a serious problem in numerous dog breeds, but knowledge of its hereditary background is scarce. On the contrary, numerous DNA polymorphisms associated with human obesity have been identified, with the strongest effect being demonstrated for FTO gene. We used targeted next-generation sequencing (tNGS) to search for polymorphisms in the region harboring FTO and IRX3 in 32 Labrador dogs. Moreover, we investigated the selected regions of FTO and IRX3, orthologous to the human regions associated with obesity, in 165 Labradors. For all dogs, the following information was available: age, sex, gonadal status, body weight, and body conformation score (BCS). The use of tNGS revealed 12,217 polymorphisms, but none of these obtained significance when lean and obese dogs were compared. Study of two SNPs in the 5’-flanking region of FTO in 165 dogs – creating two upstream reading frames (uORFs) – also showed no association with body weight and BCS but suggested the need for improvement in FTO annotation. No polymorphism was found in the 5’UTR of IRX3. Additionally, no differences of CpG islands methylation status between lean and obese dogs were found. Our study suggests that FTO and IRX3 are not useful markers of obesity in Labrador dogs.

Dermal fibroblasts are commonly used as donors of genetic material for somatic cell nuclear transfer in mammals. Basic fibroblast growth factor (bFGF) is a cytokine that regulates proliferation and differentiation of different cell types. The study was aimed at optimizing the cell culture protocol for cat dermal fibroblasts by assessing the influence of culture media and different doses of bFGF on proliferation of fibroblasts and their viability in terms of cell banking and somatic cloning of felids. In Experiment I, skin biopsies of domestic cats were cultured in DMEM (D) and/or DMEM/F12 (F), both supplemented with 5 ng bFGF/ml (D-5, F-5, respectively). After the primary culture reached ~80% of confluency, the cells were passaged (3–4 times) and cultured in media with (D-5, F-5) or without (D-0, F-0) bFGF. To determine the optimal doses of bFGF, in Experiment II, secondary fibroblasts were cultured in DMEM with 0 (D-0), 2.5 (D-2.5), 5 (D-5) or 10 (D-10) ng bFGF/ml. The results showed that in D-5 the cells proliferated faster than in D-0, F-5 and F-0. Due to their poor proliferation, passages IV were not performed for cells cultured in F-0. In experiment II, a dose-dependent effect of bFGF on proliferation of cat dermal fibroblasts was found. In D-5 and D-10, the cells exhibited higher (P<0.05) proliferation compared with D-0. In D-2.5 the cells showed a tendency to proliferate slower than in D-5 and D-10 and at the same faster than in D-0. In conclusion. DMEM supplemented with bFGF provides better proliferation of domestic cat dermal fibroblasts culture than DMEM/F12. Supplementation of culture medium with bFGF has a beneficial effect on cat dermal fibroblast proliferation and could be recommended for addition to culture media.

Reproduction is one of the most important factors affecting the efficiency of animal production. Within the scope of uterine capacity and other morphometric parameters, the objective of this study was to evaluate the size variability of uterus dissected from prepubertal gilts. The research was conducted on 100 PLW gilts and 100 PL gilts at a pig testing station. After slaughter, the reproductive tract was dissected, and each element was measured and weighed. The obtained results were combined and analyzed in three groups differentiated by uterine capacity: I, II and III. Group I consisted of gilts with a uterine capacity below 115 cm³ (n=69); group II comprised gilts with a uterine capacity between 115 and 175 cm³ (n=85); uterine capacity in group III was above 175 cm³ (n=46). Ontogenesis of the reproductive tract showed great variability with respect to the uterine capacity of gilts of both breeds. Uterine weight with and without ligament was different between the analyzed groups of PLW gilts (P<0.01), and also between the groups of PL gilts (P<0.01; P<0.05). The uterine horns of the PLW gilts in group I were slightly longer than in the PL gilts (90.76 cm vs. 84.20 cm; P<0.05). A slightly higher variability of uterine capacity was observed with respect to the PLW gilts (80.92 cm³ to 243.13 cm³), as compared with the PL gilts (92.61 cm³ to 235.23 cm³). The determined uterine capacity was significantly correlated with all parameters of uterine size (P<0.01), apart from the length of the uterus and cervix in PLW gilts. The proportion between the uterine weight and the length of its horns, which characterizes the thickness of uterine walls, was significantly correlated with the length of uterine horns only in PL gilts (r=0.382**). This study may be used to forecast the potential fertility of related females (littermate gilts and their daughters); it may also be used in sow selection for litter size.

Early diagnosis of pregnancy is important in livestock production, but there is no reliable technology used for pregnancy diagnosis within the first three weeks after insemination. During early pregnancy, the expression of interferon-stimulating genes (ISGs) in peripheral blood leukocytes (PBL) is significantly increased. However, due to different strains, detection sample types, detection methods, threshold value, etc. the specific effectiveness of early pregnancy diagnosis using ISGs is worth further study. The purpose of this study was to test interferon-stimulated protein 15 (ISG15), 2'–5'-oligoadenylate synthetase 1 (OAS1) and radical S-adenosyl methionine domain containing 2 (RSAD2) for early pregnancy diagnosis in dairy cows. The expression of ISG15, OAS1, and RSAD2 in PBL of pregnant and non-pregnant heifers on days 0, 14, 18, 21 and 28 after artificial insemination (AI) was detected by fluorescence quantitative polymerase chain reaction (PCR). The sensitivity and specificity of the pregnancy diagnosis was analyzed using expression of these three genes separately or in combination by receiver operating characteristic curve. The combination with the highest accuracy used probe primers and duplex fluorescence quantitative PCR. The single quantitative PCR results showed that expression of ISG15, OAS1 and RSAD2 on day 18 after AI was significantly higher in pregnant than in non-pregnant cows. When these three genes were used separately, or in combination, for early pregnancy diagnosis, the sensitivity for the RSAD2 gene was 100%, and the combination of ISG15 with RSAD2 was 94.7%. The duplex quantitative PCR showed that, although the sensitivity of ISG15 alone was 100%, its specificity was only 88.2% (cut-off value 1.402). The sensitivity of RSAD2 alone was 89.5%, and the specificity was 88.2%; however, when the two genes were used in combination, the sensitivity, specificity and diagnostic cut-off value were consistent with the results of single quantitative PCR. These results indicated that a duplex quantitative PCR assay system for early pregnancy diagnosis in cows using ISG15 and RSAD2 was established. Simultaneous detection of expression of ISG15 and RSAD2 by duplex quantitative PCR can effectively improve the diagnostic accuracy for dairy cows.

Fumonisins are strongly toxic metabolites of Fusarium proliferatum and Fusarium verticillioides commonly present in corn-based feed. The aim of the study was to evaluate bone homeostasis in experimental fumonisins B1 and B2 intoxication of rats, a vertebrate animal model of toxicological studies, as still little is known about the possible disturbing effect of fumonisins on bone homeostasis. Adolescent (5-week-old) male Wistar rats were randomly assigned into a control group and a group FB intoxicated with fumonisins by daily intragastric administration of fumonisins at the dose of 90 mg/kg of body weight per animal in the FB group for 21 days. The fumonisin intoxication did not affect body and bone mass, although the mechanical and geometric properties were decreased in fumonisin-intoxicated rats. Bone volumetric and mineral density did not differ between groups, but bone mineral content and bone ash percentage was lower in the FB group. Detailed analysis showed that Ca, Cu, Fe, Mn, Sr, and Zn bone content significantly decreased in fumonisin intoxicated rats and the alterations in structure of bone mineral phase (reduction of the apatite-bone crystals size) were noted. While the negative structural alterations in growth plate and articular cartilages were also observed, fumonisin intoxication improved histomorphometrical parameters of trabecular bone. Concluding, the dose of fumonisins used in the present study caused hepatotoxic effect, which was sufficient to trigger the disturbance in mineral homeostasis resulting in altered bone metabolism and decreased mechanical endurance.

The present study investigated the effect of an emulsifier with very high hydrophilic-to-lipophilic balance (HLB) value (18) on growth performance and fat digestibility in turkeys. A total of 1120 day-old female Hybrid Converter turkeys were randomly divided into four treatment groups with 7 replicates (pens) of 40 birds each. Control group (T1) turkeys were fed a basal diet (BD), while turkeys from experimental groups received different levels of the commercial emulsifier VE added to diets with standard or reduced metabolizable energy (ME) content: T2 – BD + 500 ppm of VE; T3 – BD + 500 ppm of VE until 8 weeks of age, and 250 ppm from 9 to 16 weeks; T4 – BD – 3% ME + 500 ppm of VE until 8 weeks of age, and 250 ppm from 9 to 16 weeks. Regardless of its dietary inclusion level (500 g/ton and 500/250 g/ton feed), the emulsifier positively influenced the body weights (BW) and body weight gains (BWG) of birds. On days 56 and 112, significant differences in the values of these parameters were noted between the control treatment (T1) vs. groups T2 and T3. Emulsifier addition even contributed to an increase in the BWG and BW of birds receiving diets with 3% lower ME content, as compared with turkeys fed control diets. This shows that the emulsifier more than compensated the reduction in ME in T4. The turkeys from group T3 were characterized by significantly higher feed efficiency than T1 and T4 birds. The highest fat digestibility was noted in turkeys fed diets with a standard ME level and emulsifier addition (T2 and T3). In conclusion, the use of dietary emulsifier positively influences the growth performance of turkeys, and improves fat digestibility.

The aim of the study was to select a dosage and time of administration of a probiotic preparation containing live cultures of Bacillus subtilis and enriched with choline to obtain the most beneficial effect on the antioxidant and biochemical status of the blood of chickens and to improve their growth performance. A total of 980 one-day-old Ross 308 chickens (7 replications of 20 individuals each) reared until their 42nd day of life were used in the experiment. The chickens were divided into seven groups of 140 each. The control group did not receive any additives. The T1 groups received a probiotic in the amount of 0.05 g/L (T1-0.05), 0.1 g/l (T1-0.1) or 0.25 g/l (T1-0.25) throughout the rearing period, while the T2 groups received the same doses of the probiotic, but only during days 1–7, 15–21 and 29–35 of rearing. Administration of a preparation containing Bacillus subtilis bacteria was shown to increase the level of ferric reducing ability of plasma (FRAP), vitamin C, and uric acid (UA), while reducing the level of peroxides (LOOH), malondialdehyde (MDA), non-esterified fatty acids (NEFA), the share of low-density fractions of cholesterol (LDL), and activity of alanine aminotransferase (ALT), asparagine aminotransferase (AST), γ-glutamyltransferase (GGT) and creatinine kinase (CK). An increase in the high-density fractions of cholesterol (HDL) and a decrease in lactate dehydrogenase (LDH) and alkaline phosphatase (ALP) were noted as well. The results of the study indicate that 0.25 g/l of the probiotic, administered continuously (T1), clearly has the most beneficial effect in terms of enhancing antioxidant potential and reducing the level of stress indicators, without disturbing overall metabolism in the body. During the 42 days of rearing each chicken received 33.3 CFUx10¹¹Bacillus subtilis from the probiotic preparation. The body weight gain of chickens from T1-0.1, T1-0.2 and T2-0.25 groups was higher (P≤0.027) and more favourable compared to G–C group.

The aim of the study was to assess the biocompatibility of gold nanoparticles (Au-NPs) for chickens by investigating their effect on their growth, hematological parameters, markers of oxidative stress, and indicators of liver and kidney function. The experiment was carried out on 54 chickens assigned to 3 experimental groups of 18 birds each. The control group did not receive gold nanoparticles. The birds in group Au-NPs_2.0 received gold nanoparticles in a tube into a crop at a rate of 2.0 mg/kg body weight/day, while the birds in AuNPs_5.0 group at a rate of 5.0 mg/kg body weight/day. The blood for analysis was collected after 7, 14, 21 and 28 days of Au-NPs application. The obtained results indicate that short-term (7–14 day) exposure to lower dose (2.0 mg/kg b.w./day) of AuNPs had no toxic impact on chickens, but the extension of the duration time caused toxicological effects evidenced by growth inhibition as well as induction of oxidative stress and liver injury. The higher dose of AuNPs (5.0 mg/kg b.w./day) exerted toxic effects already after 7–14 days of supplementation.

The main objective of this study was to identify the influences of different climatic conditions and cow-related factors on the respiration rate (RR) of lactating dairy cows. Measurements were performed on 84 lactating Holstein Friesian dairy cows (first to eighth lactation) in Brandenburg, Germany. The RR was measured hourly or twice a day with up to three randomly chosen measurement days per week between 0700 h and 1500 h (GMT + 0100 h) by counting right thoraco-abdominal movements of the cows. Simultaneously with RR measurements, cow body postures (standing vs. lying) were documented. Cows’ milk yield and days in milk were recorded daily. The ambient temperature and relative humidity of the barn were recorded every 5 min to calculate the current temperature-humidity index (THI). The data were analyzed for interactions between THI and cow-related factors (body postures and daily milk yield) on RR using a repeated measurement linear mixed model. There was a significant effect of the interaction between current THI category and body postures on RR. The RRs of cows in lying posture in the THI < 68, 68 ≤ THI < 72 and 72 ≤ THI < 80 categories (37, 46 and 53 breaths per minute (bpm), respectively) were greater than those of standing cows in the same THI categories (30, 38 and 45 bpm, respectively). For each additional kilogram of milk produced daily, an increase of 0.23±0.19 bpm in RR was observed. Including cow-related factors may help to prevent uncertainties of RR in heat stress predictions. In practical application, these factors should be included when predicting RR to evaluate heat stress on dairy farms.

In this study, varying concentrations of polyunsaturated fatty acids in goat’s milk were obtained by supplementing goat feed rations with maize dried distillers grains with solubles (DDGS). In comparison to the control group, the milk of goats that received DDGS contained about 25% more polyunsaturated fatty acids, 30% more conjugated linoleic acid (CLA), and had more favorable values of the atherogenic and thrombogenic indices. The diverse composition of fatty acids present in the goat’s milk correlated with the olfactory perception of the milk and its volatile compound profile. The level of unsaturated fatty acids significantly affected the odors detected in the processed goat’s milk. The volatile compound profile of the milk was mostly differentiated by the concentrations of aldehydes (hexanal and furfural) and furanones (furaneol), which exceeded their odor threshold values. The total concentration of identified aldehydes was highest in pasteurized milk samples from the goats of the experimental group, as a result of heating. Furfural was found in pasteurized samples of both the control and experimental milk at concentrations exceeding its odor threshold (3 mg·kg⁻¹). Feeding goats with DDGS did not change the animal, cooked, dairy fat, lack of freshness, light-oxidized, or overall dairy flavors of the raw milk. After pasteurization, milk from goats fed with DDGS retained its characteristic animal odor and gained a very intense cooked flavor.

The aim of the studies was to evaluate the effect of the diet in the final growth phase and slaughter age of poulards on productivity, dressing percentage, carcass colour and physicochemical properties of meat. The studies were conducted on 78 hybrids obtained by crossing Ross 308 broiler roosters with Rhode Island Red (R-11) dual-purpose laying hens (♂Ross 308 × ♀R-11). Birds were assigned to 3 groups: control group (K) fed starter, grower and finisher diets without addition of dairy products, experimental group S offered a finisher diet supplemented with 4% whey, and experimental group M receiving 4% milk powder supplement in the final growth phase. Spaying procedure was carried out at 8 weeks of age. Poulards were slaughtered at 18 and 20 weeks of age. The studies showed that by using hybrids of dual-purpose hens with broiler roosters for production of poulards, rearing period could be shortened to 18 weeks, and the obtained meat had comparable or even better quality traits compared with poulards slaughtered at 20 weeks of age. Supplementation of poulard diet with 4% whey or milk powder in the final growth phase had a beneficial effect mostly on improvement of sensory properties of meat. There were not many significant differences in meat quality between poulards fed the diet supplemented with milk and whey but instead there were differences between these groups and the control group fed the diet without these additives.

Fifty-two male Kivircik lambs were used to investigate the influences of finish weight (LOW: 25–26 kg, MEDIUM: 30–31 kg and HIGH: 35–36 kg) and production system (CON: concentrate-based system, PAS: pasture-based system) on carcass and meat quality characteristics. CON lambs (n=27) were weaned at 76 d of age and then finished on concentrate feed and alfalfa hay until slaughter. PAS lambs (n=25) grazed on native pasture in the day-time and sucked their dams until slaughter. CON group grew 30% faster during the experimental period; therefore significantly fewer days were required to reach the target weight. CON lambs had higher cold carcass weight, cold dressing percentage, and produced fattier carcasses compared with those of PAS system. PAS lambs had lower meat lightness values than CON ones. CON system produced more tender meat than PAS system in terms of shear force and sensory evaluation results. Intramuscular fat of the PAS lambs had higher percentage of ∑PUFA and ∑n-3 PUFA, and lower n-6/n-3 ratio than that of CON ones. Finish weight had no influence on dressing percentage and carcass fatness. Meat of HIGH lambs had lower L* value than other groups. Panellists gave lower scores to meat of MEDIUM lambs for tenderness when compared with other groups. In conclusion, CON system might be considered to obtain higher carcass dressing, lighter meat colour and more tender meat, while PAS system had an advantage of lower n-6/n-3 ratio and of higher ∑n-3 PUFA percentage. PAS lambs had lower fatness level than CON ones. Therefore, if priority is given to fatty acid composition and carcass with lower fat, PAS system might be considered. Finish weight of 35–36 kg might be preferred to increase lamb production, without any adverse effect on carcass and meat quality in both of the production systems.

Research on skeletal muscles includes chemical, sensorial, histopathological, microbiological analysis, and the influence of observed data on meat quality. The aim of this paper was to establish a point scale for analysing the fat concentration in breast and thigh muscles of birds during histological examination. The need for a point scale showing lipid localization arises during the experiment, including the castration of the bird. During necropsy, pectoral and thigh muscles were put into 30% saccharose solution with the addition of sodium azide. Then, frozen samples were cut into 8 µm sections and stained with Oil Red O (Bio-Optica, Milan, Italy) to detect lipids. Four main locations were evaluated: the area around vessels, perimysium between fascicles, endomysium between fascicles, and sarcoplasm of the fibres. Each location was separately evaluated for pectoral and thigh muscles. The percentage of tissue occupied by lipids in different locations was detected using Panoramic Viewer software (3DHISTECH, Budapest, Hungary). The results from the point scale analysis, similar in pectoral and thigh muscles, confirmed data from the chemical analysis. Significant differences were observed in all examined periods in chemical analysis (P<0.05) and were visible in the point scale with a higher number of birds with higher lipid concentration in all examined locations. Our scale analysis of lipid concentration, confirmed by chemical analysis, is an objective tool and can be used separately in muscle tissues in experiments where there is the need for lipid visualization. An established three-point scale can be a tool in poultry muscle tissue evaluation because not only accumulation but also lipid location is crucial in determining the usefulness of meat in culinary processing.