Volume 21 (2021): Issue 3 (July 2021)

The development of effective approaches for not only the in vitro maturation (IVM) of heifer/cow oocytes and their extracorporeal fertilization (IVF) but also the non-surgical collection and transfer of bovine embryos has given rise to optimizing comprehensive in vitro embryo production (IVP) technology and improving other assisted reproductive technologies (ART s), such as cattle cloning by embryo bisection, embryonic cell nuclear transfer (ECNT) and somatic cell nuclear transfer (SCNT). The primary goal of the present paper is to demonstrate the progress and achievements in the strategies utilized for embryonic cell cloning and somatic cell cloning in cattle. Moreover, the current article is focused on recognizing and identifying the suitability and reliability of bovine cloning techniques for nutritional biotechnology, agri-food and biopharmaceutical industry, biomedical and transgenic research and for the genetic rescue of endangered or extinct breeds and species of domesticated or wild-living artiodactyl mammals (even-toed ungulates) originating from the family Bovidae.

Bile acids are used for better emulsification, digestion and absorption of dietary fat in chicken, especially in early life. Similarly, exogenous lipases have also been used for the improvement of physiological limitation of the chicken digestive system. Owing to potential of both bile acids and lipases, their use has been increased in recent years, for better emulsification of dietary fat and improvement of growth performance in broilers. In the past, pancreatic lipases were used for supplementation, but recently, microbial lipase is getting attention in poultry industry as a hydrolysis catalyst. Bile acids strengthen the defence mechanism of body against bacterial endotoxins and also play a key role in lipid regulation and sugar metabolism as signaling molecules. It has been demonstrated that bile acids and lipases may improve feed efficiency by enhancing digestive enzyme activity and ultimately leading to better fat digestion and absorption. Wide supplemental range of bile acids (0.004% to 0.25%) and lipases (0.01% to 0.1%) has been used in broiler diets for improvement of fat digestibility and their performance. Combinations of different bile acids have shown more potential to improve feed efficiency (by 7.14%) even at low (0.008%) levels as compared to any individual bile acid. Lipases at a lower level of 0.03% have exhibited more promising potential to improve fat digestibility and feed efficiency. However, contradicting results have been published in literature, which needs further investigations to elucidate various nutritional aspects of bile acids and lipase supplementation in broiler diet. This review focuses on providing insight on the mechanism of action and potential application of bile acids and lipases in broiler diets. Moreover, future implications of these additives in poultry nutrition for enhancing nutrient utilization and absorption are also discussed.

Recently, microalgae, natural marine resources, have gained increasing interests as a feed for animals. Chlorella vulgaris microalgae are single-cell microorganisms that have been used to provide nutrition to humans and animals for centuries. In the present review, we unveil the composition and nutritive value of C. vulgaris microalgae as a feed for ruminants. Research has shown that inclusion of C. vulgaris microalgae in diets improved feed utilization, milk production and quality, growth performance, and meat quality in ruminants, as a result of improved diet nutritive value. Very low doses of C. vulgaris in feed enhance growth and lactational performance of ruminants. Additionally, C. vulgaris showed very promising results as an alternative to corn and soybean meal; however, it is an expensive protein feed. Therefore, the main constraint to use of C. vulgaris as a feedstuff is its high cost of production, making improvement of cultivation technology to reduce the production costs a critical issue in the near future.

The assignment of an individual to the true population of origin is one of the most important applications of genomic data for practical use in animal breeding. The aim of this study was to develop a statistical method and then, to identify the minimum number of informative SNP markers from high-throughput genotyping data that would be able to trace the true breed of unknown samples in indigenous sheep breeds. The total numbers of 217 animals were genotyped using Illumina OvineSNP50K BeadChip in Zel, Lori-Bakhtiari, Afshari, Moqani, Qezel and a wild-type Iranian sheep breed. After SNP quality check, the principal component analysis (PCA) was used to determine how the animals allocated to the groups using all genotyped markers. The results revealed that the first principal component (PC₁) separated out the two domestic and wild sheep breeds, and all domestic breeds were separated from each other for PC₂. The genetic distance between different breeds was calculated using F_ST and Reynold methods and the results showed that the breeds were well differentiated. A statistical method was developed using the stepwise discriminant analysis (SDA) and the linear discriminant analysis (LDA) to reduce the number of SNPs for discriminating 6 different Iranian sheep populations and K-fold cross-validation technique was employed to evaluate the potential of a selected subset of SNPs in assignment success rate. The procedure selected reduced pools of markers into 201 SNPs that were able to exactly discriminate all sheep populations with 100% accuracy. Moreover, a discriminate analysis of principal components (DAPC) developed using 201 linearly independent SNPs revealed that these markers were able to assign all individuals into true breed. Finally, these 201 identified SNPs were successfully used in an independent out-group breed consisting of 96 samples of Baluchi sheep breed and the results indicated that these markers are able to correctly allocate all unknown samples to true population of origin. In general, the results of this study indicated that the combined use of the SDA and LDA techniques represents an efficient strategy for selecting a reduced pool of highly discriminant markers.

In the present study, two missense variants within ATGL (rs331307082) and MYOM1 (rs326001585) genes were tested for their potential usage as genetic markers related to pig production traits. The genotyping was performed on 519 pigs representing 990 synthetic sire line. The association analysis indicated that ATGL gene affected the panel of fattening parameters (test daily gain, age at slaughter), meatiness traits (meat percentage in the carcasses; the weight of loin, ham and primary cuts, and loin eye area), and meat quality characteristics (water exudation). In turn, MYOM1 polymorphism was related to loin weight, the weight of primary cuts and weight of loin backfat. Pigs with AA genotype were characterized by significantly higher loin and primary cut weights compared to opposite homozygotes GG (P<0.05). The observed differences were 2.29 kg and 1.2 kg, respectively. Moreover, despite higher meatiness, AA animals together with AG were characterized by lower weight of loin backfat (P<0.05) and average backfat thickness (P<0.1) compared to GG pigs. The MYOM1 polymorphism did not affect pork quality traits. The results allowed us to propose the new genetic markers which may be used in pig selection to obtain appropriate meatiness and fatness level in carcasses without decreasing meat quality.

The aim of the study was to estimate the genetic parameters for reproductive performance in native breed sows covered by genetic resource conservation programmes in Poland. The study used data on reproductive performance of 1,182 Złotnicka White sows, 1,648 Złotnicka Spotted sows and 1,180 Puławska sows. The following traits were analysed: age at first farrowing, number of piglets born alive, number of piglets at 21 days of age and farrowing interval. Covariance components and genetic parameters were estimated using an REML animal model with different combinations of fixed and random effects. Convergence of the iterative process was achieved by the selection of the AIREML algorithm. The estimated values of the coefficients of heritability for the number of piglets born ranged from h² = 0.09 in the Puławska breed to h² = 0.30 in the Złotnicka White breed. For the number of piglets reared, they varied between h² = 0.09 in the Złotnicka Spotted breed to h² = 0.27 in the Puławska breed. The heritability values for age at first farrowing and farrowing interval were higher, and ranged from 0.4 to 0.5. The significant positive and negative coefficients of phenotypic correlation, estimated between age at first farrowing and farrowing interval with the number of piglets born alive and reared per litter, suggest that the native pig breeds should be bred in keeping with their breed predispositions.

The European Regional Focal Point for Animal Genetic Resources (ERFP), is the European regional platform of National Coordinators (NCs) supporting management of animal genetic resources (AnGR). To assess the performance of the ERFP platform/network and consider options for its further development, a survey was performed among NCs. Twenty-five NCs responded to the survey on the roles, values and future of the platform. The paper provides an analysis of the results of the survey, including a ERFP SWOT analysis. NCs indicated high value of the support of the ERFP in fulfilling their functions at the national level. They highlighted the well-established network and facilitated communication and collaboration among NCs and other AnGR experts in Europe. The NCs appreciated the efficient organizational structure of the ERFP (Working Groups, Task Forces, Ad hoc Actions), and the well-functioning Secretariat. Indicated weak points included discontinuity of NC positions in some countries, and low levels of activities in some countries. NCs saw new opportunities for ERFP development in the context of the EU policy and regulatory framework related to AnGR management, and in strengthening the role of the Secretariat. No immediate threats were identified, however potential future threats included insufficient financing and lack of continuity. The NCs highly appreciated the substantial progress achieved by the ERFP over the last 20 years.

The aim of the study was to compare morphometric indices and the mineralization level of humerus, femur and tibia in Leghorn (H-22), Sussex (S-66) and Rhode Island Red (R-11) hens at different age (weeks 6, 16, 45 and 64), as well as some blood parameters. The material for the experiment was one-day old chicks of breeds: Leghorn (H-22), Sussex (S-66) and Rhode Island Red – RIR (R-11), which were separated into three groups. At 6, 16, 45 and 64 weeks of the study, 10 birds selected from each group were weighed, slaughtered, and their right femurs, tibiae and humeri were dissected. After removing soft tissues, the bones were weighed and measured for length, diameter, and the Seedor index (SI) was calculated. The bones were analysed for the content of calcium (Ca), phosphorus (P) and crude ash (CA). At 64 weeks, blood was collected from the hens and analysed for the concentration of Ca, P, pyridinoline and deoxypyridinoline. The study showed that hen breed had an effect mostly on morphometric indices of the bones such as bone weight and diameter, and the Seedor index (SI), while the age of birds had an effect on the bone mineralization level up to 45 weeks of age. The bone mineralization did not decrease in the studied breeds of hens at the end of the laying period. It was also found that heavier birds (RIR) had greater diameter bones and a higher SI, but the content of ash and minerals in the bones of that breed was generally similar to the Leghorn and Sussex hens. RIR hens exhibited higher plasma phosphorus concentration compared to Sussex hens. This may suggest that RIR birds have a slightly stronger bone system compared to Leghorn and Sussex hens.

Testing blood and milk parameters as well as analysing the relationships among these markers is very useful for monitoring the internal homeostasis and health in high-yielding dairy cows during various production periods. The aim of the study was to assess the correlations (relationships) among macro-minerals, such as calcium (Ca), inorganic phosphorus (P), magnesium (Mg), other selected bone profile markers, such as total protein (TP), albumin, activity of alkaline phosphatase (ALP) measured in serum and selected milk components such as number of somatic cells (SCC), colony-forming units (CFU), milk fat (MF), milk protein (MP), milk lactose (ML), solids, solids non-fat (SNF) and milk production in late-lactation cows. Both blood and milk samples were collected from 11 clinically healthy milking cows during the late-lactation period. The cows were examined once a day for 3 consecutive days resulting in 33 sets of blood and milk samples for laboratory and statistical analysis. Significant correlations were observed between: Mg and MP, Mg and SNF, ALP and SCC, TP and SCC, TP and MP, TP and SNF, albumin and MP, albumin and SNF, P and Mg, Mg and albumin, and between TP and albumin. When monitoring macro-mineral homeostasis and mammary gland health, especially in intensively fed high-yielding dairy cows correlations between these markers should be considered. The revealed correlations can allow for deeper comparative laboratory diagnostics of homeostasis and can be especially useful for laboratory monitoring of the potential risk of subclinical macro-mineral deficiency in high-yielding dairy cows.

The present study was performed to determine the effect of melatonin on cadmium accumulation and haematological parameters changes in females of Prussian carp (Carassius gibelio B.). The fish were exposed to a sublethal concentration of cadmium (0.4 and 4.0 mg/L) without or with melatonin implant (containing 18 mg melatonin hormone) for 1, 4, 7, 10 and 13 weeks. After the 7th week, Cd-exposed fish were divided into two groups. The first group of fish were subjected to depuration in clear water, while the second group remained exposed to the same concentrations of cadmium. After the 10th and 13th weeks of exposure the kidney, spleen, heart and blood were taken in order to determine the cadmium concentration and to analyse haematological parameters. The results of this study showed an increase in the concentration of cadmium in the tissues and blood in fish exposed to the highest dose (4.0 mg/L) of cadmium in water with a dependence on the exposure duration. Additionally, it was shown that melatonin administration reduced the cadmium concentration in the tissues and blood, and melatonin had a protective effect against cadmium accumulation. Moreover, the results showed a significant increase in blood parameters (RBC, Ht and Hb) in fish treated with the highest dose of cadmium. However, implantation of melatonin in cadmium-treated fish resulted in marked improvements in haematological parameters. Thus, melatonin can be a good implementation to alleviate, at least partially, the toxicity of cadmium.

The success of cloning by somatic cell nuclear transfer depends on the efficiency of nuclear reprogramming, with the cycle stage of the donor cell playing a crucial role. Therefore, the aim was to evaluate three different approaches for cell cycle synchronization: (i) serum starvation (SS) for 1 to 4 days, (ii) contact inhibition (CI) for 1 to 3 days, and (iii) using cell cycle regulatory inhibitors (dimethyl sulfoxide, cycloheximide, cytochalasin B, or 6-dimethylaminopurine) for 1 and 2 days, in terms of their effects on synchronization in G₀/G₁ phases and viability of collared peccary skin fibroblasts. Flow cytometry analysis revealed that SS for 4 days (79.0% ± 1.6) and CI for 3 days (78.0% ± 1.4) increased the percentage of fibroblasts in G₀/G₁ compared to growing cells GC (68.1% ± 8.6). However, SS for 3 and 4 days reduced the viability evaluated by differential staining (81.4% ± 0.03 and 81.6% ± 0.06) compared to growing cells (GC, 95.9% ± 0.06). CI did not affect the viability at any of the analyzed time intervals. No cell cycle inhibitors promoted synchronization in G₀/G₁. These results indicate that CI for 3 days was the most efficient method for cell cycle synchronization in peccary fibroblasts.

Thirty-two lactating Boer goats (35.2 ± 1.4 kg body weight) were grouped into control and three treatment groups in completely randomised design. In treatment groups, supplementation was done as a mixture of 5 g Chlorella vulgaris + 4.5 mg of supplemental Cu/kg diet from CuSO₄ (Alg5 treatment), 10 g C. vulgaris + 9 mg of supplemental Cu/kg diet (Alg10 treatment), or a mixture of 15 g C. vulgaris + 13.5 mg of supplemental Cu/kg diet (Alg15 treatment). Treatments did not affect feed intake; however, Alg10 treatment increased (P<0.001) nutrient digestibility. Treatments did not affect ruminal pH, ammonia-N, butyrate; however, the Alg10 treatment increased (P<0.01) ruminal total volatile fatty acids, propionate and acetate concentrations. Without affecting other blood measurements, the Alg10 treatment quadratically increased (P<0.001) serum glucose and Cu. The Alg10 treatments increased (P<0.001) daily milk production and the concentration of fat, and enhanced milk (feed) efficiency. The Alg10 treatment decreased (P<0.05) milk saturated fatty acids and the atherogenic index, and increased the proportions of total conjugated linoleic acids, C18:1n9t, odd fatty acids and total unsaturated fatty acids compared with the control treatment. Present study concluded that inclusion of a mixture of 10 g C. vulgaris + 9 mg Cu/kg diet in the diet of lactating Boer goats enhanced nutrient digestibility, ruminal fermentation, milk production, feed efficiency as well as milk nutritive value. Increasing the dose of the mixture to 15 g C. vulgaris + 13.5 mg Cu/kg diet is not recommended in the diet of lactating Boer goats.

Six wether sheep with ruminal and duodenal cannulas were used in a replicated 3 × 3 Latin square to determine the effect of rye grain (from an open-pollinated or a hybrid cultivar) and maize grain from hybrid cultivar inclusion in the diet on ruminal fermentation parameters and nutrient digestion in different gastrointestinal tract compartments. The experimental diets consisted of meadow hay (800 g/day) and a concentrate mixture (300 g/day) that contained rye grain from an openpollinated cultivar (OPRG), rye grain from a hybrid cultivar (HRG), or maize grain from a hybrid cultivar (MG) as a main energy source. Each experimental period lasted 17 days and consisted of 10 days for diet adaptation and 7 days for data and sample collection. Ruminal fermentation (pH, short-chain fatty acids, and ammonia concentration) and nutrient digestion up to the duodenum (in reticulorumen, omasum, and abomasum), in the intestine, as well as in the total digestive tract was investigated. Mean ruminal pH was higher for MG compared to HRG and OPRG (P<0.01) but did not differ between HRG and OPRG (6.45, 6.35, and 6.29 for MG, HRG, and OPRG, respectively). Treatment did not affect short-chain fatty acid concentration in the rumen, except for the molar proportions of valeric acid and of isovaleric acid of the total short-chain fatty acids, which was or tended to be higher (P≤0.06) for MG compared to HRG and OPRG. Less starch was digested in the gastrointestinal tract up to the duodenum and more in the intestine for MG compared to HRG and OPRG (P=0.01); however, total tract nutrient digestibility did not differ between treatments. In conclusion, usage of rye grain in sheep diets resulted in a lower ruminal pH compared to maize grain usage. No differences for ruminal fermentation, nutrient digestion up to the duodenum, in the intestine, as well as in the total digestive tract between rye grain from open-pollinated and hybrid cultivar usage in sheep diets were found.

In the past, pigs were commonly fed with acorns, and this was of remarkable economic importance. Currently this habit is continued in some areas, especially for production of prime-quality Iberian ham. Mature acorns, after shedding and during storage in unsuitable conditions, can be quickly infected with spores of many moulds, which cause mummification, blackening, dehydration, and nutrient loss. This study aimed to evaluate the quality of acorns of pedunculate oak (Quercus robur L.). The samples were collected in 2017 in southern Wielkopolska (central part of Poland), as feed material. In mouldy acorns a very high number of fungi was found (2.6 × 10⁶ cfu/g), and 97% of them represented pathogenic Penicillium spp. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis showed in mouldy acorns high concentrations of mycophenolic acid (14580 μg/kg) and patulin (50 μg/kg). The dominant mould species, Penicillium expansum, showed a high cytotoxicity of swine kidney cells using assay based on the conversion of the tetrazolium salt, 3-(4,5, dimethylthiazol-2-yl)-2-5 diphenyltetrazolium (MTT). This raises the question if the pathogenic metabolites of moulds present in acorns can be dangerous for livestock, especially pigs, and people, as acorns are beginning to be seen as an interesting and functional part of their diet.

The aim of this study was to investigate the effect of hempseed cake on production traits, metabolic profile and antioxidant status of lambs. The research was conducted on 20 Merinolandschaf lambs of similar live body weight (24.03 kg ± 2.22 and 24.06 ± 1.84 kg in control and experimental group, respectively). The experiment started after the weaning of lambs at their average age of 70 days. Lambs were divided by gender (50% male: 50% female) and then allocated in two groups. The research lasted for 30 days during the fattening period. Lambs in the control group were fed with feed mixtures, where main protein source was soybean meal and extruded soybean (SB), while lambs in the experimental group were fed feed mixtures in which soybean was replaced by hempseed cake (HSC) at 12% of dry matter. Higher values of daily weight gain (P<0.05) compared to SB lambs were observed from days 15 to 30. HSC lambs showed no significant differences in hematology and biochemical blood parameters, except for lower (P<0.001) urea concentrations on days 15 and 30, as well as higher (P<0.05) Mg concentrations in serum on day 30. Hempseed cake in lambs’ diets did not influence (P>0.05) activity of the enzymes like AST, ALT, ALP, GGT and CK, as well as SOD and GPx enzymes, thus not affecting the antioxidant status of lambs’ blood. Concentrations of DHA and n-3 fatty acids were higher (P<0.05) in HSC group than in SB group. The present study confirmed that the inclusion of HSC as soybean replacement up to 12% in the lambs’ diet is justified when considering production traits, metabolic profile and antioxidant status of Merinolandschaf lambs.

The starch content of triticale and oat grains provides much of their readily available energy. Synchronizing energy and nitrogen in the rumen is important in optimizing profitability; for this reason, ammonia processing of these grains was evaluated for its potential to modify ruminal fermentation and to improve milk production performance. A mixture of ground triticale and oats (CONG, at a ratio of 60:40 on a dry matter basis) was treated with urea (5 kg/1000 kg) and urease additive (20 kg/1000 kg) containing 200 g/kg of moisture, for 2 wk (UREG). The urea treatment enhanced the pH and CP content of grains by 34% and 52%, respectively. In a batch culture study, CONG or UREG as the only substrate was incubated in a buffered ruminal fluid. Compared to CONG, UREG increased pH, total VFA concentration, total gas, and disappearance of DM, while reducing CH₄ production, whereas NH₃ concentration increased and entodiniomorph counts tended to increase. In the in vivo study, cows were randomly allocated to two dietary groups (n = 24) and were offered TMR based on maize and grass silage, containing either 155 g/kg of CONG and 80 g/ kg of soybean meal (CONT) or 155 g/kg of UREG and 59 g/kg of soybean meal (URET) for 31 d. Ruminal fluid was collected (n = 10) using rumenocentesis. The relative abundances of Streptococcus bovis decreased, but Megasphaera elsdenii, methanogens, and ammonia-producing bacteria increased by URET. Entodiniomorph and holotrich counts were decreased by URET. Feeding with URET increased ruminal pH and concentrations of total VFA, acetate, branched-chain VFA, and NH₃. Feeding with URET also increased milk yield. These results demonstrate that replacing untreated triticale and oat grains with urea-treated grains can beneficially modulate ruminal microbiota and fermentation, consequently improving production performance and profitability.

The feasible strategies to keep up the growth and wellbeing of aquatic organisms by using beneficial dietary additives are highly recommended. Among these additives, β-glucan (BG) and mannanoligosaccharide (MOS) were examined on common carp performances in the current experiment. For 80 days, carps were fed four diets with 0%, 1%, 2%, and 3% BG/MOS (1:1) and distributed in four groups (triplicates). Higher final weight and weight gain (P<0.05) were detected in carps fed 1%, 2%, and 3% of BG/MOS than the control group. The feed conversion ratio showed lower values (P<0.05) in carps fed BG/MOS mixture at 2%, and 3% than 0% and 1% levels. The activities of amylase, lipase, and protease were higher in fish fed BG/MOS mixture than in the control group. Interestingly, fish fed BG/MOS mixture had markedly increased villi length and width with branched villi integrity. Further, the count of goblet cells was increased (P<0.05) in groups fed BG/MOS mixture than in carps fed the basal diet. The hemoglobin and hematocrit levels and the counts of red and white blood cells were higher in carps fed BG/MOS mixture than the control with the highest counts in 3% level. Additionally, the blood total protein, globulin, and phagocytic activity were higher (P<0.05) in groups that received BG/MOS mixture at 3% than the control. The lysozyme had a higher value in 1% group than the control (P<0.05). Therefore, using the mixture of BG/MOS at 2–3% is suggested for improving the growth rate, intestinal health, blood health, and immunity of common carp.

The study herein evaluated the effects of dietary supplementation with different yucca (Yucca schidigera) extract levels on rearing water quality, growth performance, protein utilization, hematological and immunological status, and economic benefits of cultured European seabass (Dicentrarchus labrax) juveniles. Yucca extract (YE) was incorporated in an experimental diet at levels of 0, 0.25, 0.50, and 1 g YE kg⁻¹, and offered to fish reared in 70-L glass aquaria (15 fish per aquarium; three replicates each). Dietary YE supplementation significantly (P<0.05) decreased ammonia-nitrogen levels in water. Compared with the control, groups fed 0.50 and 1 g YE kg⁻¹ diets showed improved growth performance (by 26.02% and 36.98%, respectively) and protein efficiency ratio (by 31.39% and 37.29%, respectively). In addition, hematological parameters (red blood cells, hemoglobin, hematocrit, white blood cells and neutrophil) and innate immune parameters (globulin fractions and lysozyme activity) improved with increasing dietary YE levels. Growth, hematological, and immunological parameters increased with a polynomial second-order regression models, with curves peak close to 1 g YE kg⁻¹ diet. The cortisol level decreased significantly (P<0.05) with increasing dietary YE levels. The groups fed the 0.50 and 1 g YE kg⁻¹ diets generated significantly (P<0.05) higher revenue than groups fed the 0.25 g YE kg⁻¹ and the control diets. The using of YE is recommended as a dietary feed additive at a level of 1 g kg⁻¹ for reducing the environmental footprint of fish protein production, accelerating growth, and improving health status of cultured seabass in a short-term feeding period.

The present study aimed to identify the carotenoid content and evaluate the antioxidant activities of spirulina, Arthrospira platensis (in vitro), and the effect of its supplementation to a vegetarian diet on growth performance, feed utilization, body proximate composition and physiological status of Nile tilapia, Oreochromis niloticus (in vivo). The carotenoid content of spirulina was identified by UPLC-MS/MS and showed that trans and cis β-carotene were the major carotenoids (88.3%) followed by β-cryptoxanthin and zeaxanthin. The antioxidant activity of spirulina was determined in water and crude carotenoid extracts by 2,2-diphenyl-1-picryhydrazyl (DPPH) scavenging assay, both extracts showed a significant free radical scavenging capacity. In addition, Nile tilapia fry (0.83 ± 0.01 g) was fed a vegetarian diet supplemented with different levels of spirulina for 12 weeks. The results revealed that the highest growth performance and nutrient utilization were recorded with 0.5% spirulina and the peak response determined at 0.63%-0.65% using polynomial second order regression. Also, the hemoglobin content improved in a quadratic regression model with the peak at 0.67% spirulina. Plasma total protein and lipid contents increased significantly with spirulina levels over 0.50%. Moreover, the aminopeptidase activities and glucose level decreased significantly with increasing spirulina levels. The current study recommended the supplementation of the Nile tilapia vegetarian diet with spirulina at levels of 0.63-0.65% for better growth performance and physiological status.

The main objective of the study was to determine the effect of transition from a conventional milking system (CMS) to an automatic milking system (AMS) on survival of 6361 Polish Holstein-Friesian cows to second (SL2), third (SL3) and fourth (SL4) lactation as well culling reasons. The cows were born between 2002 and 2015 and calved between 2004 and 2018. All data for the survival analysis and culling reasons of cows in 17 herds during operation of CMS and AMS were extracted from the SYMLEK official milk recording system. Cow survival (SL2, SL3 and SL4) was analysed with multiple logistic regression using the following effects in the model: milking system (MS), first calving season (CS), age at first calving (AFC), ease of first calving (CE), birth of a dead calf at first calving (DC), milk yield (MY) for full first lactation (MY – this effect was ignored in SL2 analysis), herd (H), and MS × H interaction. In the next stage of the study, χ² test was used to analyse culling reasons of cows (udder diseases, low fertility – infertility and reproductive disorders, locomotor diseases, low milk yield, other diseases – metabolic, digestive and respiratory diseases, accidents and chance events) in the first, second and third lactation and collectively in the first three lactations. Logistic regression analysis indicated a significant effect of MS, AFC, DC on SL2 and SL3, and of MY on SL3 and SL4. Moreover, H and MS × H interaction had a highly significant effect on SL2, SL3, and SL4. Cows used in AMS barns were characterized by significantly worse SL2 and SL3 compared to CMS (odds ratio), by 27.8% and 31.0%, respectively. It was also observed that the effect of switching from CMS to AMS on cow survival was determined by herd membership – in most herds this effect was unfavourable. A distinctly positive effect of milking automation on cow survival (SL2, SL3, SL4) was noted in only one barn (herd) – it was a new barn with a considerably expanded number of milked cows, where the lying area was covered with straw. When analysing the reasons for culling in the first three lactations collectively, it was found that after the AMS system was introduced into the herds, there were increases in the rate of culling for locomotor diseases (by 0.85 percentage points (p.p.)), low milk yield (1.36 p.p.) and other diseases (3.01 p.p.). It was also observed that the automation of milking reduced culling due to udder diseases by 0.37 p.p., low fertility by 3.24 p.p., and accidents and chance events by 1.60 p.p.

The current study investigated the effects of stocking density (SD) on the performance, tibia mineralization, and the hypothalamic appetite genes expression in broilers. A total of 2,800 1-d-old male broilers (Cobb 500) were distributed in a completely randomized design to 1 of 5 SD treatments with 8 replicate cages for each treatment. The SD treatments were 12.5, 15.0, 17.5, 20.0, and 22.5 birds/m², corresponding to 50, 60, 70, 80, and 90 birds per cage (4 m²/cage), respectively. The concentration of tibia phosphorus was determined by the ammonium metavanadate colorimetric method and the mRNA abundance in different tissues was measured by the real-time quantitative PCR method. The data were analyzed by the one-way and/or two-way analysis of variance and polynomial contrasts were used to determine the effect of increasing SD. Feed intake linearly decreased (P < 0.05) with increasing SD during d 1-42 production period. On d 42, body weight and tibia breaking strength were significantly lower in the groups of 17.5, 20.0 and 22.5 birds/m² than in the groups of 12.5 and 15 birds/m² (P < 0.01). Concentrations of ash and phosphorus in the tibia of broilers linearly decreased (P < 0.03) with increasing SD on d 42. The SD of 22.5 birds/m² decreased the mRNA abundance of neuropeptide Y (NPY), NPY-receptor (NPYR) 1, and NPYR2 (P < 0.05), while it increased melanocortin receptor 4 mRNA abundance (P = 0.012) in the hypothalamus of broilers as compared with the SD of 12.5 birds/m² on d 21 and 42. The mRNA abundance of hypothalamic cocaine and amphetamine-regulated transcript (CART), corticotrophin-releasing factor (CRF), and CRF-receptor 1 (CRFR1) were higher (P < 0.05) in the group of 22.5 birds/m² than in the group of 12.5 birds/m² on d 21. We concluded that increasing stocking density beyond 15 birds/m² (corresponding to the 45 kg/m² at 42 days of age) suppressed final BW and bone mineralization of broilers raised in multitier cage system. Hypothalamic NPY and CRF signaling might be involved in the anorexigenic effect of HSD.

The objective of the study was to evaluate the quality of eggs laid by native breed hens of different ages (33 and 53 weeks of age), with particular consideration of the lysozyme parameters. Eggs were collected from 6 breeds/strains of laying hens under the genetic resources conservation in Poland, i.e. Greenleg Partridge (Z-11), Yellowleg Partridge (Ż-33), Rhode Island Red (R-11), Rhode Island White (A-33), Sussex (S-66) and Leghorn (H-22). The yolks of eggs from older hens had a more favourable, intense colour, but the freshness parameters (albumen height and Haugh units) of these eggs were lower. The albumen of eggs from older hens showed greater content and higher enzymatic activity of lysozyme in both thin and thick albumen. Among the six strains of hens, lysozyme content and enzymatic activity were highest in the egg albumen of strains Ż-33, Z-11 and R-11, and lowest in that of strain H-22. The analysed eggs showed statistically significant correlations between some interior egg quality traits (albumen weight, albumen height, Haugh units, yolk colour) and the discussed enzyme parameters. These traits are influenced by genotype and age of the hens.

Changes in the odor of meat during its storage are one of the basic indicators affecting its assessment and possible disqualification. The aim of the study was to determine whether the addition of essential oils may affect the composition and concentration of volatile compounds included in the aroma of stored turkey meat. We investigated the effect of adding essential oil (EO) of caraway (0.02% v/w), rosemary (0.02% v/w) and a mixture of the two (0.01% each) on the composition of volatile compound fractions formed during 10-day storage of vacuum-packed minced turkey meat. The EOs used were also evaluated for their influence on microbial contamination (total viable count and lactic acid bacteria count), sensory quality (odor and taste) and the level of fat rancidity (acid value, peroxide value and p-anisidine value) and pH in chill-stored samples. In terms of sensory indicators, the greatest beneficial effect of adding EOs was noted in the odor of raw meat. Use of the HS-SPME/GC-MS (headspace-solid phase microextraction/gas chromatography-mass spectrometry) method showed that the addition of essential oils significantly reduced the amounts of benzeneacetaldehyde, 2-octenal and ethyl 2-methyloctanoate compared with the control sample. In addition, in the presence of essential oils of rosemary and caraway, decreases were noted in benzaldehyde and 9-octadecenal, respectively. These changes may potentially affect the reception of the odor. There was a beneficial effect of the EOs in reducing the levels of fat oxidation indicators, including peroxides. However, the oils at applied concentrations had no significant effect on the total viable count and LAB count.