Volume 19 (2019): Issue 4 (October 2019)

The aim of the paper was a review of the scientific achievements in physiological stunning and slaughtering mechanisms, control methods of consciousness and their effect on meat quality. Special attention was paid to neurophysiological phenomena that accompany the process of depriving consciousness before animal deaths using mechanical, electrical and gas stunning methods. These mechanisms are associated with cerebral hypoxia or ischemia or depolarization, acidification and the destruction of cerebral neurons. Such effects can be caused by shock waves, bleeding, electric fields, reduction or arrest of the circulation of blood in the brain, high CO₂ level or low O₂ level in inhaled air or by the mechanical damage of neurons. Some of the stunning methods cause immediate and some gradual consciousness loss. An important factor in the animals’ slaughtering process is the estimation of their consciousness level before bleeding. The indicators of consciousness during mechanical, electrical and gas stunning are discussed within this paper. It is pointed out that at least 2 indicators should be used when estimating animals’ consciousness after stunning, e.g. phonic and clonic limb movements and lack of breathing. Ten indicators to control the consciousness were described. The effect of stunning on meat quality is also discussed. It was found that the impact of this process on the quality is not clear. However, the prevailing view is that electric stunning causes effusions and blood haemorrhages in meat. Whereas gas stunning with a CO₂ mixture diminishes the risk of PSE meat. Despite numerous scientific research on the slaughter process there is still deficiency in knowledge on losing consciousness mechanisms and feeling pain. It might be useful to extend the knowledge concerning neurotransmitters and use of magnetic resonance in future studies.

Procedures that result in poor welfare of animals are unacceptable to many people. Consumers have become demanding about the quality of meat, but are also concerned about animal welfare during the production, transport, and slaughter stages. There is a well-known, clear relationship between animal welfare and the quality of animal products. Improper handling of farmed animals contributes to low meat quality. This rule refers to all animals raised for meat, including rabbits. Fasting, loading for transport, long distance transport in difficult environmental conditions, improper stocking density, lying down during transport, lairage, and stunning methods may negatively affect the quality of rabbit meat. A general conclusion from reviewed scientific articles is that many pre-slaughter factors influence the physiological and productive measurements of rabbits, through the effect on their welfare. Because of the complexity of the rabbit meat production chain, the possibility of excluding all the defined stressors is limited.

Development of the skeletal muscle goes through several complex processes regulated by numerous genetic factors. Although much efforts have been made to understand the mechanisms involved in increased muscle yield, little work is done about the miRNAs and candidate genes that are involved in the skeletal muscle development in poultry. Comprehensive research of candidate genes and single nucleotide related to poultry muscle growth is yet to be experimentally unraveled. However, over a few periods, studies in miRNA have disclosed that they actively participate in muscle formation, differentiation, and determination in poultry. Specifically, miR-1, miR-133, and miR-206 influence tissue development, and they are highly expressed in the skeletal muscles. Candidate genes such as CEBPB, MUSTN1, MSTN, IGF1, FOXO3, mTOR, and NFKB1, have also been identified to express in the poultry skeletal muscles development. However, further researches, analysis, and comprehensive studies should be made on the various miRNAs and gene regulatory factors that influence the skeletal muscle development in poultry. The objective of this review is to summarize recent knowledge in miRNAs and their mode of action as well as transcription and candidate genes identified to regulate poultry skeletal muscle development.

The complicated epidemiological situation of avian influenza viruses (AIV) caused by continuous emergence of new subtypes with failure of eradication, monitoring and vaccination strategies opens the door to alternative solutions to save the status quo and prevent new disasters for the poultry industry. Using of synthetic antiviral drugs such as neuraminidase and hemagglutinin inhibitors has been limited due to development of drug resistance and expensive commercial application. One of the most promising alternatives is herbal products and botanicals. This review presents a comprehensive and specialized view of in vivo studies of herbal plants in poultry species. Many herbal extracts as Nigella sativa oil, Astragalus, Cochinchina momordica and Sargassum pallidum polysaccharides proved very effective as adjuvants for AIV vaccines. Another beneficial role of herbs is enhancement of host response to vaccination with further better prevention of infection and easier control. For enumeration not inventory, this is best achieved with the use of virgin coconut oil, Echinacea purpurea, Ginseng stem-and-leaf saponins (GSLS), Astragalus polysaccharides (APS), Myrtus communis oil, Garlic powder, Turmeric, Thyme and Curcumin. This review aimed to evaluate most of the in vivo studies performed on poultry species as a step and a guide for scientists and field practitioners in establishment of new effective herbal-based drugs for prevention and control of AIV in poultry.

The present study was undertaken to analyse the genetic variation in coding sequences, splicing sites and regulatory sequences of FABP4, PPARγ and SCD genes in five breeds of sheep raised in Poland with different purposes: meat (Suffolk, Ile de France), dairy/prolific (Olkuska sheep, Kołuda) and primitive breeds (Polish Mountain Sheep). To identify genetic variability HRM-PCR, sequencing and PCR-RFLP method were used. Determining the genetic structure of the mentioned genes revealed six SNPs: FABP4 – c.73 + 13A>T and c.348 + 85G>A, PPARγ – c.391 – 66C>T (c.481 – 66C>T) and c.529 + 27G>C (c.619 + 27G>C), SCD – c.*945G>A and c.*1116A>G. For the c.*1116A>G SNP, a potential association with specific sheep body type and breeding purpose was found. In turn, the substitution c.*945G>A located in the regulatory region of the 3'-UTR of the Ovis aries SCD gene was identified for the first time. Based on the relationship demonstrated between sheep body constitution and productive type (dairy, meat) and the polymorphism of the SCD gene, further research is needed. The correlation between c.*1116A>G polymorphism and growth rate, slaughter and carcass value as well as meat quality of lambs needs to be studied in more detail. Such studies may lead to more effective selection processes in sheep breeding in the future.

The aim of the study was to analyse the genetic basis of piebald coat colour in Hucul horses and to verify their coat colour in breeding records. Tests were performed with DNA purified from the whole blood samples of 242 Hucul horses with different coat colour patterns. DNA was analysed to identify an inversion in ECA3 (PCR). The results confirmed that the inversion on ECA3 is a direct factor determining piebald (tobiano) colour in the analysed Hucul horses. No inversion was observed in any of the solid coloured horses, but it was present in all the piebald ones. It was also identified in 18% (11 of 61) of the horses from the group of horses qualified in the passport as solid coloured with white markings. In fact, these horses had the tobiano gene that is phenotypically identifiable as crypto-tobiano, which may give the false impression of having white markings and lead to error when describing a horse. This is an important issue, in particular with regard to the breed standard, which eliminates Hucul horses with white markings from breeding.

The objective of the present study was to determine the seasonal changes in boar semen quality by the assessment of sperm membrane integrity, analysis of chromatin structure, assessment of oxidative stress and of apoptotic changes in spermatozoa. Semen from 16 boars (172 ejaculates) was investigated. The males were aged between 7 months and 7 years. Semen was extended with BTS diluent and stored at +17°C. During seven days of storage, the semen was subjected to standard evaluation and novel methods for semen assessment. In the autumn-winter period, the semen had higher evaluations than in the spring-summer period, but only sperm membrane integrity examination showed significantly lower (P≤0.01) percentage of moribund spermatozoa and the semen had a significantly (P≤0.05) lower (by 0.5%) percentage of sperm with damaged chromatin. Examination performed after 7-day storage showed significantly (P≤0.01) higher percentage of live spermatozoa and with high mitochondrial membrane potential for the autumn-winter period. The level of apoptotic cells was significantly (P≤0.01) lower for the autumn-winter period. Examination of sperm membrane integrity after 7 days of storage showed a lower (P≤0.05) percentage of moribund spermatozoa for the autumn-winter period. In our opinion, novel methods for sperm assessment may be used to monitor new parameters of sperm function.

There are several findings indicating that the endocannabinoid system (ECS) is an important factor, acting in multiple ways in regulating reproductive function but changes of this system in the bovine endometrium have rarely been investigated; therefore, this study was designed to consider an association between endometrial ECS expression and different stages of the estrous cycles. MRNA expressions of the ECS were investigated during the late luteal phase and estrus using real-time PCR. Following estrous synchronization of sixteen Holstein dairy cows (34±1.3 kg/day of milk production), using two PGF2α injections given 14 days apart, at 30 and 44 days in milk (DIM), blood samples and ultrasonography (US) were performed every other day from the day of second PGF2α injection (44 DIM) until the start of the next estrous cycle (67±2 DIM) to verify CL development and ovulation. Based on blood and US results endometrial tissue was collected on days 16 (late luteal phase) and 21 (estrus) of the synchronized estrous cycle (ovulation = d 0). Real-time PCR analysis of ECS mRNA expression revealed endocannabinoid receptor (CNR2), diacylglycerol lipase (DAGL), cyclooxygenase-2 (COX-2), fatty acid amide hydrolase (FAAH) and monoglyceride lipase (MGLL) had significant fold differences when comparing two different stages of the estrous cycle (late luteal phase vs. estrus). CNR2 and DAGL showed 2.01 and 2.57 fold increase, respectively (P=0.04 and P=0.02), in estrous cows. Among the analyzed genes FAAH (P=0.01) and MGLL (P=0.02) were significantly down-regulated in estrous cows, with a 5.01- and 2.44-fold difference in mRNA expression, respectively. Overall, this study highlights an association between the expression of the ECS in the bovine endometrium and stage of the estrous cycle.

The aim of the study was to determine the effect of caponisation on the morphometric traits and mechanical parameters of tibial and femoral bones in Greenleg Partridge cocks. The experiment involved 200 cocks. At the age of 8 weeks, 100 birds were subjected to surgical castration. At week 24, the birds were slaughtered and tibial and femoral bones were collected from 10 non-caponised cocks and 10 capons. The caponisation surgery had no effect on the weight and length of any of the long bones but resulted in reduction (P≤0.05) of the ash content in both bones and Ca in the femur. It also influenced the geometric structure of the bones, i.e. there was an increase (P≤0.05) in the second moment of inertia in the tibial bone and the cross-sectional area and mean relative wall thickness in the femoral bone of the capons. The three-point bending test revealed a negative effect of caponisation on the mechanical strength of the bone. Values characterising the highest bone material strength, i.e. yielding load (femur), maximum force moment (tibia) and yielding deformation, bending point resistance, and load-to-deformation (both bones), declined in the capons. The investigations demonstrated a negative effect of caponisation on the quality of long bones. The tibial bone seems to be slightly more sensitive to the caponisation effects than the femoral bone. It can be assumed based on the analysis of biomechanical traits that the bones of capons are more susceptible to deformations or fractures due to their modified geometry and mechanical brittleness.

The aim of the study was to evaluate the effect of different levels of dietary hybrid rye on eggs laid by Isa Brown laying hens and their quality, such as physical parameters, nutritional value (basic chemical composition, cholesterol content, fatty acid profile) as well as safety (microbiological purity). A total of 72 Isa Brown hens aged 26 weeks were allocated to 3 groups fed with 0%, 15% and 25% levels of hybrid rye in their diet up to week 50. At week 50, 72 eggs per group were collected for analysis. The 25% rye level had no significant effect on most of the examined physical parameters; however, a tendency to heavier eggs in this group was noted. An increased rye level resulted in lighter yolks with a lowered share of redness and yellowness compared to those obtained from hens fed a control diet. The administration of 25% of rye in the diet influenced the basic chemical composition of the yolks by increasing the water content and reducing the fat content, but with no significant effect on the contents of ash, chlorides and cholesterol. The sum of saturated fatty acids in yolks decreased along with the increase in dietary rye level while the sum of mono- and polyunsaturated fatty acids increased. Moreover, a lowered ratio of ω-6: ω-3 fatty acids was found with dietary rye level increases.

The main aim of the study was to evaluate the effect of two experimental feed additives based on kaolin clay on piglets’ health and microbiota status. The experiment was divided into 2 parts – from birth up to weaning (28 d) and later after weaning up to 70 d of age. Eighteen litters of piglets with sows were divided into 3 groups: control, A and B. The animals from experimental group A were supplemented with kaolin clay (100%), while the animals from group B received kaolin clay enriched with dried pomace of chokeberry and fructooligosaccharides. We noted an improvement in blood parameters related to anaemia, which were significantly better in the experimental group B in comparison to the control and A group (haematocrit; 37.67 and 37.40 vs 39.65%; P<0.0005). The dietary treatments during pre-weaning time influenced the increase of the E. coli strain in the colon and jejunum and had no effect on lowering the population of Salmonella and Shigella in the colon. However, it affected the quantity of Salmonella and Shigella in the jejunum in both A and B (-20%) groups. The rise of commensal bacteria Lactobacillus (+2.3 and +10%) and Bacteroides (+5.82 and +5.11%) was observed in groups A and B in the colon. This effect was not present in the jejunum.

The aim of the present study was to assess the effect of different levels of fermented soybean meal on growth performance, intestinal morphology, metabolic indicators, and immunity in turkeys. The material for the study consisted of day-old BIG 6 turkeys raised to the age of 112 days. The experiment was carried out on 800 turkey hens (10 replications of 20 individuals each), assigned to 4 experimental groups of 200 birds each. The feed for the control group (FSBM₀) was a standard mix without fermented soybean meal. For turkeys from groups FSBM₇, FSBM₉ and FSBM₁₀ the diet contained 70, 90 or 100 g fermented soybean meal (FSBM) per kg of feed, respectively. The study showed that including fermented soybean meal in feed for turkeys at 7% improved intestinal histology and stimulated the immune and antioxidant systems. The use of higher level of FSBM (9% and 10%) in the diet of the turkeys improved growth performance and had a beneficial effect on the histology of the small intestine. The dietary inclusion of 10% FSBM had beneficial effect on red-blood-cell parameters, but caused negative impact on liver and kidney function (an increase of aminotransferases activity, content of glucose and creatinine in turkeys’ blood). Ten percent share of FSBM in feed contributed to an adverse intensification of oxidation and inflammatory reactions which were reflected by an increase of malonyldialdehyde, lipid peroxides level and proinflammatory inteleukine-6 contents.

Fermented soybean meal (FSBM) has been widely investigated as a nutritional strategy for reducing the use of fish meal (FM) and antibiotic growth promoters. Microbial fermentation by using bacteria can increase the bioavailability of nutrients and reduce the levels of antinutritional factors in soybean meal (SBM). In this study, we evaluated whether FSBM produced from Lactobacillus species and Clostridium butyricum improves growth performance, diarrhea incidence, and fecal bacteria in weaning piglets. Eighty-four crossbred male piglets with an average initial body weight of 8.36±0.63 kg were randomly allotted to 3 dietary treatments consisting of 7 replicate stalls with 4 piglets each. The dietary treatments were: (1) 3% FM in the diet; (2) 5% FSBM in the diet; and (3) 3% FM in the diet plus 4 mg/kg antibiotic growth promoters (AGP). We determined that growth performance was unaffected in FSBM-fed weaning piglets compared with a FM group. Similar to the AGP group, FSBM supplementation significantly reduced diarrhea incidence in weaning piglets. The number of fecal Lactobacillus species significantly increased in 28-day-old FSBM-fed weaning piglets compared with the other groups. Compared with AGP, FSBM has the highest inhibitory effect on the number of fecal Enterobacteriaceae at 28 d old. Furthermore, serum immunoglobulin G and immunoglobulin A levels in FSBM-fed weaning piglets significantly increased at the same age. These results together indicate that FSBM can replace FM in the diets of weaning piglets without affecting growth performance. Furthermore, similar to AGP, FSBM could improve diarrhea incidence, fecal bacteria, and immunoglobulin levels in weaning piglets. Therefore, SBM fermented by Lactobacillus species and C. butyricum demonstrated high potential for development as swine feed ingredients.

The purpose of this paper was to assess the suitability of various protein feeds in broiler chicken feeding. The study covered 160 birds split into 5 equipotent groups (SBM, EFFS, RFFS, EL, DDGS). Four protein feeds were an experimental factor: extruded full-fat soybean (EFFS group), raw full-fat soybean (RFFS group), extruded lupine (EL group) and distillers dried grains with solubles (DDGS group) that were added to starter rations in an amount replacing 30%, and in grower and finisher rations 50% of extracted soybean meal protein. Results showed that after replacing an identical amount of extracted soybean meal protein with protein from extruded soybean or DDGS in chicken rations, the final body weight and feed conversion ratio were similar to those of birds from the control group. Deterioration (P≤0.01) in the above-mentioned parameters was observed for chickens fed with rations containing raw soybean or extruded lupine. Birds that were given rations containing raw soybean (RFFS group) were characterized by the lowest dressing percentage, and, compared to the control group, the difference was significant (P≤0.01). The type of protein feed contained in the rations did not affect the musculature of chickens, however it did impact their fat deposition. Fat deposition was the lowest in birds from RFFS and DDGS groups that reached the lowest final body weight. Microscopic images of all examined livers showed a normal histological structure. The results of the studies carried out provide a basis for recommending the use of extruded full-fat soybean or DDGS in broiler chicken rations as partial substitutes for extracted soybean meal protein.

The experiment was performed on 60 crossbred weaners with average initial body weight (BW) of 22 kg. The animals were divided into 4 groups, with 15 animals (10 males and 5 females) per group, based on the percentage content of the following components in complete diets: soybean meal, toasted full-fat soybeans, cold-pressed rapeseed cake with increased oil content, extruded rapeseed cake with increased oil content. The growth performance of pigs, carcass characteristics, meat quality and the fatty acid profile of depot fat were determined. The pigs fed complete diets containing toasted soybeans had higher average daily gain (ADG). The animals receiving cold-pressed rapeseed cake were characterised by lower ADG and higher FCR. The carcasses of pigs fed diets containing cold-pressed rapeseed cake and extruded rapeseed cake had lower lean content than the carcasses of pigs administered toasted soybeans. The analysed feedstuffs had no effect on back-fat thickness or meat quality. Cold-pressed and extruded rapeseed cake contributed to changes in the fatty acid profile of backfat, including an increase in the concentrations of monounsaturated fatty acids (MUFAs) and a more desirable n-6/n-3 PUFA ratio. The extrusion processing of rapeseed cake decreased the content of lysine and methionine with cystine by approximately 4%, and reduced total glucosinolate content by approximately 17%. The inclusion of toasted soybeans in pig diets contributed to higher BW gain and carcass dressing percentage. Rapeseed cake with increased oil content led to desirable changes in the fatty acid profile of backfat.

A feeding trial was conducted to evaluate the effects of plant extracts derived from Mentha arvensis (MA) and Geranium thunbergii (GT) on broiler performance, carcass yield, digestive organ weights, meat quality and odorous gas emissions from the excreta. A total of 210 one-day-old broiler chicks were randomly assigned to one of the following dietary treatments for five weeks: (1) control, (2) 0.1% MA, (3) 0.05% GT, (4) 0.1% GT and 0.1% mixed preparation with varying ratios such as (5) 0.1% 1MA:1GT, (6) 0.1% 1MA:4GT and (7) 0.1% 4MA:1GT. The weight gain (0–3 weeks) was significantly (P<0.01) increased in response to dietary inclusion of plant extracts; however, no significant differences were observed in breast and thigh meat yield (P>0.05). Additionally, no differences were observed in proventriculus, gizzard, pancreas, small and large intestine weight. When compared with the control group, birds fed plant extracts had the lowest meat TBARS value after 0 and 3 weeks of storage (P<0.05). Moreover, the pH value was significantly lower (P<0.05) in the plant extract supplemented groups at 0 weeks. The faecal H₂S emissions were significantly reduced at 0 h and 6 h in all supplemented groups relative to the control (P<0.05). Similarly, NH₃ emissions were reduced at 0 h and 6 h for all supplemented groups except the 0.1% 1MA:1GT group (P<0.05). Overall, the results of the present study indicate that plant extracts supplementation can be used to improve performance and meat quality of broiler chickens while reducing the emission of harmful gases from the excreta.

This study examines the impact of soybean meal (SBM) substitutes, including solvent-extracted 00 rapeseed meal (RSM), narrow-leaved lupin (LUPIN), and distillers dried grains with solubles (DDGS) (each used at a ratio of 250 g/kg⁻¹ in the diet), as well as administered probiotic (L. casei, L. plantarum, Rhodopseudomonas palustris, S. cerevisiae), on gut microbiota activity, diversity and performance. The experimental treatments were arranged in a 4 × 2 factorial design, with the factors being protein source in the diets (SBM only, RSM, LUPIN or DDGS) given from 8 to 35 days of age, and with or without a probiotic preparation administered in drinking water during the entire rearing period. The performance declined in birds fed with SBM substitutes (P≤0.01). The RSM diet decreased concentration of short chain fatty acids (SCFAs) (P<0.01) in ileal and caecal digesta as well as decreased bacterial enzymes activity in the caeca. The LUPIN diet increased viscosity and decreased SCFAs concentration in ileum, while the DDGS diet increased butyrate concentration in caeca. SBM substitutes and probiotic were involved in changing the Clostridiales and Lactobacillales diversity in the ileal and caecal digesta. Probiotic administration did not affect performance, but it did alleviate some negative effects of SBM substitutes on microbiota activity and diversity.

The aim of this study was to test the effect of the animal to feeding place ratio on behavior of meat goats during gestation. In one group (FP-1.0; n=10) every goat had a single feeding place while in the other group (FP-0.5; n=10) two goats had to share one feeding place. Behaviors were analyzed with the continuous sampling method for 24 h for each animal. Social dominance index was used by ranking individuals as low-, medium- and high-ranking according to withdrawal and displacement behaviors. Total daily feeding duration decreased (P=0.001) from 5.2 h to 4.2 h by reducing feeding place. Feeding duration was neither affected by social rank (P=0.362) nor its interaction with feeding place (P=0.159). Feeding frequency was higher in FP-0.5 than FP-1.0 (P=0.001). Low-ranking goats had a higher feeding frequency (P<0.001). Resting duration (lying and standing) decreased in medium- and low-ranking goats in FP-0.5 (P=0.001) while all rank categories were similar in FP-1.0. Competition behaviors increased (P=0.001) in medium- and low-ranked goats in FP-0.5 but were similar between rank categories in FP-1.0. Feeding place and social rank had an effect (P≤0.009) on some of the agonistic behaviors. Agonistic interactions such as displacement, butting and ignoring were affected by the interaction of feeding place and social rank (P≤0.005). In conclusion, the reduction of the number of feeding places from 1.0 to 0.5 per goat in pregnant hornless Boer goats negatively affected feeding, competition, resting and aggressive behaviors, whereas low-ranking animals suffered more from competition and aggression behaviors.

The viability of conventional goat farms, such as the native Payoya dairy goat, could be improved by switching to organic production, but product quality needs to be ensured. The present work assesses the carcass and meat quality of Payoya kids raised under conventional and organic grazing-based systems. Twenty-four kids (12 males, 12 females) were selected from each system (n = 48). The slaughter live weight (8.52 vs. 8.28 kg), cold carcass weight (4.44 vs. 4.29 kg) and farm dressing percentage (51.7 vs. 50%) of the conventionally raised kids were significantly higher than those of the organic kids. The shoulder (first category) (21.7 vs. 22.3%) and long leg (32 vs. 32.9%) percentages were lower in the conventional than in the organic kids. The percentage contribution of the intermuscular fat (10.70 vs. 8.11%) to the shoulder weight was greater in the conventional kids, while the percentages of muscle (59.7 vs. 57.2%) and bone (24.7 vs. 22.8%) were higher in the organic kids. For the chemical composition, there were only differences between the two sexes in the percentage of fat (6.64 and 7.99% on dry matter, for male and female, respectively). For rheological variables, only differences were found in the water holding capacity (% water expelled), the meat of the organic females had a higher value (17%) than that of the conventional females (14%). For the meat colour, the conventional male kids returned the highest values for C* and Hº (14.32 and 64.34, respectively). Farms following conventional grazing-based management could easily switch to organic production. Most of the meat and carcass quality variables studied were very similar across the systems.