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Abstract

The aim of this study was to evaluate the effect of algal oil with very high level of docosahexaenoic acid (DHA, C22:6n-3) used as fat source in the diet for laying hens, on egg yolk lipids fatty acid composition, as well as egg production and egg quality indices, in comparison with other dietary fat sources. The experiment was carried out on 168 ISA Brown hens (25 to 60 wks of age), allocated to 7 groups of 12 replicates (cages), with two birds in each cage. The experimental diets were supplemented with 2% of different fat sources, i.e. soybean oil (SO), coconut oil (CO), rapeseed oil (RO), linseed oil (LO), camelina oil (CAO), fish oil (FO), or algal oil (AO). Laying performance indices, i.e. egg production, mean egg weight, feed intake, feed conversion ratio, or egg and eggshell quality parameters were not affected by used fat sources (P>0.05). Dietary fat sources significantly influenced on egg yolk lipids fatty acids composition. Thus, AO addition caused some changes in the yolk lipid profile that were favorable from the dietary perspective, i.e., increased concentration of eicosapentaenoic acid (EPA) and DHA (P<0.05). However, boiled eggs from hens fed a diet with AO were characterized by an inferior flavour and taste to those from other groups. In conclusion, the results of this experiment, have shown that the use of AO in the laying hens nutrition is an efficient way to increase the deposition of n-3 long chain polyunsaturated fatty acids (n-3 LCPUFAs) in eggs, without negative effect on egg performance, however further researches, aiming to establish optimal AO dietary level that does not adversely affect the organoleptic properties of eggs, are needed.

Abstract

The knowledge of the existing levels and the interrelationships between various blood and milk parameters is very useful for the analysis and monitoring of homeostasis high-yielding dairy cows. The aim of the study was to evaluate these values and correlations for selected blood markers of liver function aspartate aminotransferase (AST), alanine aminotransferase (ALT), gamma-glutamyl transferase (GGT), bilirubin, albumin, glucose, cholesterol) and selected milk parameters: somatic cell count (SCC), colony-forming units (CFU), fat, protein, lactose, dry matter (DM), fat-free dry matter (FDM), and milk production in cows during late lactation period. At the same time blood and milk samples were collected from 11 clinically healthy milking cows in later lactation period. The 11 selected cows were examined once a day for 3 days resulting in 33 sets of blood and milk samples for laboratory and statistical analysis. Significant positive correlations were observed between: ALT and albumin, ALT and cholesterol, GGT and glucose, albumin and cholesterol, CFU and fat, CFU and DM, SCC and protein, fat and DM, protein and FDM, lactose and FDM, GPT and FDM, albumin and protein, albumin and FDM, glucose and fat, as well as significant negative correlations between: AST and ALT, AST and GGT, AST and albumin, CFU and lactose, fat and lactose, fat and FDM, lactose and DM, DM and FDM, AST and SCC, AST and protein, AST and FDM, ALT and fat, ALT and DM, glucose and DM, cholesterol and CFU. The results obtained may be important for detecting of different biochemical pathways and helpful in estimating, predicting or determining trends, the direction of changes in liver functions and assessing the risk of alert levels for liver blood markers, when only daily results of milk parameters are available.

Abstract

The aim of the study was to determine meat quality in cockerels of two multipurpose breeds reared to different ages. The study involved 30 cockerels each of two native breeds: Yellowleg Partridge (Ż-33) and Rhode Island Red (R-11). The results showed that cockerels of the native breeds Rhode Island Red (R-11) and Yellowleg Partridge (Ż-33) represent a good starting material for niche production of poultry meat R-11 cockerels exhibited a better rate of weight gain and their carcasses had higher yellowness and redness values compared to Ż-33 birds. The carcasses of both cockerel breeds had lower breast and higher leg muscle percentage, and their meat contained more collagen and protein and less fat. As birds aged, body weight and abdominal fat percentage increased, and giblets percentage decreased in the cockerels of both breeds, whereas in the R-11 breed dressing percentage increased, leg bone percentage decreased, yellowness (a*) increased and redness (b*) decreased. Neither genotype nor slaughter age had a significant effect on chemical composition of the breast and leg muscles. In both breeds, the breast and leg muscle quality traits were more affected by age than genotype.

Abstract

Increased interest in the production of rabbit meat justifies the need to assess and improve the welfare of these animals not only during the production cycle but also at slaughter. Therefore, the aim of this study was to assess the effects of different stunning methods on the level of blood biochemical parameters (stress indicators), and meat quality of slaughter rabbits. Rabbits of the Hycole line (n = 60), were subjected to the following stunning methods: mechanical with a non-penetrating captive bolt (group I; n = 20), mechanical by hitting a narrow rod on the head (group II; n = 20), and electrical stunning (n = 20). In the stunning groups there were no differences found in the blood level of insulin, cortisol, glucose, total cholesterol, triglycerides, non-esterified fatty acids, and protein content (P>0.05). The stunning method did not affect the pH of rabbit meat (P=0.768), but significantly influenced the L* and b* colour parameters. The muscles of longissimus thoracis et lumborum, from group of rabbits mechanically stunned by hitting a narrow rod on the head, were the darkest (L * = 58.4), with the lowest yellowness values (b* = 4.04). The meat of electrically stunned rabbits was characterised by higher drip loss (P<0.001), lower plasticity (P=0.043), and higher free water content (P=0.043). From the analysed texture measures, only the Warner Bratzler Shear Energy values of the cooked meat were affected by the stunning method. These values were higher in the meat of the mechanically stunned groups compared to the electrically stunned rabbits (P=0.042). The percentage of dry matter, crude protein, extractable fat and water to protein ratio, were affected only by the muscle type (P<0.001). To conclude, the rabbit meat was characterised by good quality, with only slight differences between the groups. No differences were found in the stress reaction of rabbits subjected to the examined stunning methods.

Abstract

Organophosphate insecticides are known to inhibit the activity of enzyme acetylcholinesterase. They affect olfactory learning and memory formation in honeybees. These insecticides cause mushroom body inactivation in honeybees, but their influence on other brain regions involved in olfactory perception and memory is unknown. The goal of this study was to study the effects of organophosphate insecticide diazinon on carnolian honeybee (Apis mellifera carnica) acetylcholinesterase activity in the olfactory brain regions of antennal lobe, mushroom body and lateral procerebrum (lateral horn). The lamina, medulla and lobula of optic lobes were also analyzed. The level of acetylcholinesterase activity was visualized using the histochemical staining method. Densitometric analysis of histochemical signals indicated that diazinon inhibited acetylcholinesterase activity only in the lip of calyces of mushroom body, but not in other analyzed olfactory regions, antennal lobe and lateral procerebrum. The visual brain system optic lobes were also unaffected. This is in accordance with the literature reporting that mushroom body is the main brain center for olfactory learning and memory formation in honeybees.

Abstract

An alternative to natural food shortage for honeybees is the provision of supplements. The objective of this research was to develop a method with ideal conditions for the fermentation of a protein supplement for honeybees. The microorganisms used were Lactobacilli, Bifidobacteria and Saccharomyces and the inulin prebiotic. There was an increase in lactic acid and a decrease in pH over a five-day fermentation period. The amount of acid bacteria present was 108–109 CFU/g of supplement. In the first phase the temperature and the humidity had significantly affected the fermentation but the variables inulin and probiotic didn’t. In the second phase, the lower temperatures and higher humidity produced the best effects on the fermentative responses. It was concluded that an ideal environment with temperature, humidity, inulin and probiotics could be created which allowed the fermentation of the protein supplement in five days obtaining final product fermentative characteristics close to bee bread.

Abstract

The slaughter value of cattle and beef quality are influenced by many factors, which can generally be divided into antemortem (breed, sex, age, housing system, diet, preslaughter handling) and postmortem (post-slaughter processing, chilling temperature, packaging). Studies of many authors have shown that meat quality traits can be also influenced by the individual genetic background of an animal. Numerous studies have been conducted worldwide to determine the functions of various genes as well as polymorphisms with potential effects on fattening and slaughter value of cattle and on beef quality. This study reviews the most important research done on the associations of polymorphisms in the calpain, calpastatin and myostatin genes with carcass traits and beef quality. Knowledge about the genes and chromosome regions associated with desired meat quality characteristics may prove very helpful when selecting pairs for mating and estimating the breeding value of offspring, mainly because it is difficult to improve meat quality traits based on conventional selection methods due to their low heritability and polygenic regulation. Furthermore, meat quality evaluation is expensive and can only be carried out after slaughter.

Abstract

The neuromodulatory effects of brain-derived neurotrophic factor (BDNF) on appetite regulation centre peptide gene activity in the sheep hypothalamus have not been examined yet. The aim of this study was to determine whether BDNF participates in modulation of neuropeptide Y (npy), agouti-related peptide (agrp), cocaine and amphetamine regulated transcript (cart), and proopiomelanocortin (pomc) mRNA expression and selected microRNAs in the sheep hypothalamic arcuate (ARC) nucleus. Animals (Polish Merino sheep, n=24) were divided into three groups. The control group received a central infusion of Ringer-Locke solution (480 µl/day) whereas the experimental groups were treated with BDNF in two doses: 10 or 60 μg/480 µl/day. All sheep received four intracerebroventricular infusions (performed from 08:40 a.m. to 01:30 p.m.; infusion scheme: 4 x 50 min infusions with 30 min intervals between them) on each of three consecutive days. Immediately after the last infusion, the sheep were slaughtered, and selected structures of the hypothalamus were frozen for further real-time qPCR analysis. Central infusion of BDNF evoked dose-dependent changes in npy, agrp, cart, pomc and peptidylglicine alpha-amidating monooxygenase (pam) mRNA expression in the sheep ARC nucleus. An increase in npy, agrp and pomc mRNA expression but also a decrease in cart mRNA expression in the ARC nucleus were detected. Moreover, a decrease in pam (gene encoding an enzyme that converts POMC into α-MSH) mRNA expression, was also noted. Furthermore, after central BDNF administration, changes in miRNA-33a-5p, miRNA-33b-5p, miRNA-377-3p, miRNA-214-3p, miRNA-485 and miRNA-488 expression were observed. Based on the presented results, it can be concluded that BDNF may affect the appetite regulating centre activity through modulation of npy, agrp, cart, pomc and pam mRNA expression in the ARC nucleus. It was also revealed that BDNF modulates miRNA expression in the sheep ARC nucleus.

Abstract

The aim of the study was to determine whether replacing soybean meal with 3% or 6% fermented soybean meal would positively affect blood metabolites and redox status of broiler chickens. The experiment was carried out on 600 broiler chickens assigned to three experimental groups of 200 chickens each (10 replications of 20 individuals each). In the control group, soybean meal (SBM) was the main source of dietary protein, whereas the remaining groups were fed diets in which soybean meal was partially replaced with 3% or 6% fermented soybean meal (FSBM-3%, FSBM-6%). The fermentation of the SBM contributed to an increase of lactobacillus, content of crude protein, methionine and lysine, and especially over a 30-fold increase in the concentration of lactic acid. The inclusion of 3% or 6% share of FSBM in the diet of chickens contributed to an increase in total antioxidant potential (FRAP) and plasma total glutathione content. In blood of chickens received FSBM an increase of total protein and HDL cholesterol content, aspartate aminotransferase activity and a decrease in urea content were noted. In addition to the positive effect on protein and lipid metabolism as well as antioxidant defense, the diet with a 6% share of FSBM improved body weight gain of chickens. In conclusion, it can be suggested that introducing 6% share of FSBM in place of FSM is more justified.

Abstract

It was hypothesized that dietary copper (Cu) nanoparticles, as a substitute for the commonly used copper sulfate, could contribute to lowering the dietary inclusion levels of Cu without compromising growth performance or reducing Cu digestibility and utilization in turkeys. An experiment was carried out on 648 one-day-old Hybrid Converter turkeys divided into 6 groups with 6 replicates per group in a two-factorial design with 3 dietary inclusion levels of Cu (20, 10 and 2 mg kg−1) and 2 dietary sources of Cu, copper sulfate and Cu nanoparticles (Cu-SUL and Cu-NPs, respectively). The apparent digestibility coefficients of minerals were determined after 6 weeks, and tissue samples were collected after 14 weeks of experimental feeding. A decrease in the dietary inclusion levels of Cu from 20 to 10 and 2 mg kg−1 did not reduce the body weights of turkeys at 42 and 98 days of age. In comparison with the remaining treatments, the lowest dietary inclusion level of Cu significantly decreased MDA concentrations in small intestinal tissue (P=0.002) and in the bursa of Fabricius (P=0.001). The replacement of Cu-SUL with Cu-NPs differentially modulated the redox status of selected tissues, i.e., enhanced SOD activity in small intestinal tissue (P=0.001) and decreased total glutathione levels in the bursa of Fabricius (P=0.005). In general, neither the different levels nor sources of additional dietary Cu (main factors) exerted negative effects on the histological structure of the duodenum and jejunum in turkeys. The intestinal digestibility of Cu increased with decreasing dietary Cu levels, and as a consequence, the highest apparent digestibility coefficient of Cu (and zinc) was noted in turkeys fed diets with the addition of 2 mg kg−1 Cu-NPs. Therefore, the environmental burden of excreted Cu was substantially reduced along with decreasing dietary Cu levels but it did not depend on the Cu source.