Rearing system, utility type and hens’ age as a factor modifying lysozyme's hydrolytic activity

<b>The aim of study was to analyze the impact of the utility type, age and rearing system of hens on egg quality traits and the enzymatic activity of egg albumen lysozyme (LA). The material consisted of 120 eggs from two genotypes of hens: Hy-Line Brown and parent stock of Ross 308. Laying-type hens were reared divided into 2 systems: intensive (litter, balanced feed) and extensive (open runs, farm fodders). The second source of material was hens age (29, 33, 41, 53 and 70 wks) of the parent stock.. Stocks were differentiated in terms of the hens age (29, 33, 41, 53 and 70 wks). Eggs quality traits and LA were evaluated. The LA of was higher in eggs from laying than from broiler breeder hens. It decreased with the hens’ age and increased with albumen mass, it was also positively correlated with albumen height and Haugh's units. The rearing system considerably modified mass of egg and albumen and the dense albumen height, but does not affect the LA.

The effect of straw based housing on selected quality attributes of pork – a meta-analysis.

<b>The aim of the research was to estimate the effect of straw-based housing on selected quality attributes of pork, using a meta-analytical approach. Meta-analysis is statistical procedure that combines the results of individual, independent studies into one common treatment effect, called the effect size. Data were extracted from 17 independent studies (20 experiments) and analysed using a random-effect model to estimate the effect of straw-based housing on the pH (initial pH at 45 min post mortem and ultimate pH), drip loss, colour (L*, a*, b*) and Warner-Bratzler shear force of pork loins. The meta-analysis of the available results showed that pigs from straw-based systems may produce pork with a faster early post-mortem pH decline (pH45), higher drip loss, and greater lightness than those reared under barren conditions with concrete (slatted) floors. A subgroup analysis showed that greater space allowance for straw-housed pigs had a greater negative effect on initial pH (pH45), drip loss, and lightness than straw housing with normal/minimal floor space requirements.

Effects of essential oils and their combinations added to broiler diets on the mineral contents of some tissues and bone breaking strength

At the end of the experiment, approximately 5 cc of blood was taken from broilers, and the serum was separated by centrifugation at 3000 rpm for 5 min. Serum mineral concentrations were determined directly in an atomic emission spectrometer (AX-ICP, Varian Vista). Subsequently, the tibia was removed from the slaughtered broilers, and the meat and bone marrow were cleaned and dried at 105°C for 24 h. Samples were taken from similar parts of each tibia (middle axis). The mineral content of the tibias was determined with an atomic emission spectrometer (ICP, VISTA AX CCD Simultaneous ICP-AES) after wet decomposition of the tibia in a microwave (Mars Xpress Technology Inside).

Influence of vegetable biostimulators on physical and chemical parameters of cows’ milk

<b>The results of a comparative study of the effectiveness of plant biostimulators “Biosvit” and “Megasvit” on changes in the physicochemical composition of milk, which was obtained from dairy cows of the Ukrainian black-and-white dairy breed, kept in Ltd “Renaissance +1881” Zolochivskyi district of Kharkiv region are reflected in the article. There were used 2 biological batches in our studies. One batch of the biological product was made on the basis of a dry mixture, which is called ‘11-Tigers by “Eleven Tigers Herbal Bar Energizer” and consists of seven species of plants of foreign origin. The other type is based on a dry mixture of 7 plants of domestic origin. Biologicals “Biosvit” and “Megasvit” experimental groups of animals (D 1) and (D 2) were injected subcutaneously at the rate of 3-4 mg of active substance per 1 kg of the body weight (on average 15 ml) per 1 animal. Biologicals were injected to the above animals five times, every 72 hours. Milk samples, taken from the formed groups of cows, were monitored for physico-chemical parameters. It was carried out that under the influence of two types of drugs “Biosvit” and “Megasvi” the productivity of cows in experimental groups increased, and in the milk samples from the cows in these groups (D 1) and (D 2), there was an increase in mass fraction: fat by 0,19 and 0,2%; protein by 0,15 and 0,16%; lactose by 0,13 and 0,14%; dry matter by 0,35 and 0,45%, skimmed milk powder by 0,15 and 0,19%, protein by 0,16 (P ≥ 0,95) and 0,28% respectively, compared with the control group of cows (K(controlled)). It can be noted that under the influence of the biological product “Megasvit” there was a more significant increase in the mass fraction of fat by 0,11%; protein by 0,25%, compared with similar indicators of the biological product “Biosvit”.

Effect of short-term fasting on the expression of ACTH (cMC2) receptor in the adrenal glands of chicken (Gallus domesticus)

<b>Domestic hen is a full model in terms of stress and adrenal function. The main hormone produced by the hens’ adrenals is corticosterone, synthesized and secreted by stimulating the HPA axis during stress. Direct activation of adrenal activity is conditioned by ACTH, which binds to the melanocortin receptor cMC2 in adrenals. It stimulates the synthesis and release of corticosterone. One of the factors that stimulate the HPA axis activity is the starvation, to which the hen is very sensitive. The purpose of this study was to determine the ACTH receptor cMC2 expression in the hens’ adrenals during the short-term fasting and after restoring the proper level of nutrition (refeeding). The results of the experiment show that 24-hour of food deprivation is stressful for the hen, as indicated by increased concentrations of corticosterone in the adrenals and in blood plasma. Changes in cMC2R expression and level of corticosterone in the adrenals during fasting and refeeding indicate a rapid increase of HPA axis activity in response to differentiated levels of nutrition. The results of this experiment confirm the direct effect of ACTH on the avian adrenals in corticosterone release.

Preliminary biometric characteristics of Greyster dogs

<b>The aim of the study was to record and analyse selected biometric data based on the results of measurements of Greyster dogs actively involved in sports. The results of our study were compared with the biometric indices of other breeds of dogs, including the original breeds from which Greysters derive, and the indices of Polish native breeds. The study showed that the Greysters were characterised by intermediate height, as compared with their original breeds, i.e. they were shorter than Greyhounds and taller than German Shorthaired Pointers, and their height index was lower than one. This means that the height at the withers dominated over the diagonal body length in the rectangular shape of the Greyster body. The massiveness index showed that the advantage of the chest girth over the height at the withers was similar to that of the Polish Greyhound. The Greyster eurysomy index was also similar to that of the Polish Greyhound. The biometric parameters of Greysters incline them to run fast. This inclination was also indicated by the leg length index and the proportions of the length of the sections of the pelvic limb. Further research is necessary to obtain full biometric characteristics of Greysters. The results obtained at this stage of the research can be used as an auxiliary tool to select these animals for reproduction or sport competitions. If a breed standard is to be established for Greyster dogs and they are classified as an FCI breed, any information with biometric data may help to set this standard.

Acute toxicity of Siltac EC to the honey bee (Apis mellifera)

<b>Different types of pesticides are commonly used in modern agriculture. Honey bees (Apis mellifera) are sensitive indicators of environmental contamination with these substances. Exposure of honey bees to pesticides can lead to changes in their behaviour and increase mortality, so it is important to develop formulations that provide alternatives to common (‘chemical’) pesticides. The preparation Siltac EC, that has recently been developed (patent no. WO 2016/061259), shows promise as an effective substitute. This preparation is based on a physical interaction with the pest. It does not contain chemicals classified as pesticides. The aim of the current study was to evaluate the toxicity of Siltac EC to adult honeybee workers. The experiments showed that both contact and oral acute toxicity were very low and the preparation can be initially considered safe for honey bees.

The effect of age at first calving on the milking performance of primiparous Jersey cows

<b>The aim of this study was to determine the effect of age at first calving on the milking performance of primiparous Jersey cows (261 cows). Analyses were conducted on 2461 test day milking samples from 17.09.2007 to 26.07.2016. The primiparous cows were divided into four groups according to their age at first calving (≤ 24, > 24–26, > 26–28, > 28 months), and their daily milk yields were compared. Fourfold contingency tables were prepared to investigate the distribution of the population of cows calving at different ages and the peak daily milk yield. The significance of the association between factors was estimated using Fisher's exact test. To illustrate the course of 305-day lactation in primiparous cows varying in age at first calving, linear graphs were plotted with linear trends for daily milk yields. Primiparous Jersey cows calving at the age of > 26–28 months of life had the highest daily milk yield. In terms of the contents of basic milk constituents in the first lactation, the most advantageous age at first calving was > 24–26 months of life. However, a younger age at first calving (≤ 24 months) was associated with a lower somatic cell count in milk as well as a more favourable lactation curve for daily milk yield. The results of the study may suggest that Jersey cows calving at an earlier age (up to 24 months) may have a longer productive life and thus better performance parameters.

Carcass characteristics of farmed fallow deer bucks

The average body weight of the 20-21-month-old bucks was 48,00 kg, with an average cold carcass weight of 24,08 kg (Table 1). Research by Żmijewski et al. (2020) showed an average body weight of more than 48 kg in 18-month-old deer bucks, with an average cold carcass weight of 26 kg. According to Volpelli et al. (2002), animals of the same age had an average body weight of 42 kg and a cold carcass weight of 24 kg. Those results are similar to the values presented in this study, which suggests that the body development of the animals studied was normal. null The average carcass weight of 24-month-old fallow deer acquired in natural hunting grounds has been found to be 36,2 kg (Dzierżyńska-Cybulko and Fruziński, 1997). It is worth noting that animals living in the wild are more physically active than farm-raised animals, which may be reflected in differences in their average body weight. The differences between values may be linked to many factors, e.g. health, activity, and/or the quality and amount of food in the diet. It should also be noted that deer body weight differs during the hunting season and off-season, while farmed animals can be slaughtered all year long. The measurements presented in Table 1 are an important element of carcass assessment. Both the carcass proportions and the animal’s individual development can be determined on the basis of these measurements. The average carcass length was 135,67 cm and was statistically significantly correlated (P ≤ 0,01) with body weight (Tables 1 and 2). Żmijewski et al. (2020) reported an average side length of 94 cm in fallow deer. This differs significantly from the data presented in our study, which can be explained by the use of different research methodologies. null A statistically significant relationship (P ≤ 0,01) was found between chest girth and body weight. Among height measurements, a significant relationship (P ≤ 0,05) was noted between height at the withers and body weight, and a highly statistically significant (P ≤ 0,01) relationship between rump height and body weight, as presented in Table 2. The cold dressing percentage was 50,09%, which is similar to the values obtained by Dzierżyńska-Cybulko and Fruziński (1997), ranging from 48,7% to 56,8%. According to Summer et al. (1997), 18-24-month-old fallow deer bucks can attain a dressing percentage of up to 56%, which is higher than the result presented here. Based on hot carcass weights, Stanisz et al. (2015) and Volpelli et al. (2002) estimated dressing percentages of 63,3% and 57,7%, respectively. The differences in the results may stem from differences in research methodologies, including the use of hot carcass weight rather than cold carcass weight to calculate dressing percentage. The combined percentage share of inedible elements (skin, head, and lower limbs) in fallow deer from the research farm was calculated to be 15,42%. Żmijewski et al. (2020) reported a value of 12,48%, while Stanisz et al. (2015) estimated the weight of the head, skin, and lower limbs to be 2,41 kg, 4,31 kg, and 1,44 kg, respectively. In our study, the head and lower limb weights were higher (2,89 kg and 2,06 kg respectively), while the skin weight was lower (2,44 kg). The difference may be attributed to differences in the age of the animals. The internal organs, i.e. the heart, liver, spleen, and kidneys, together constituted 2,86% of the animal’s body weight (Table 3). A statistically significant positive relationship (P ≤ 0,01) was shown between the weight of the liver and body weight (Table 4). Stanisz et al. (2015) reported heart, kidney and liver weight of 0,41 kg, 0,12 kg, and 0,95 kg, respectively. The corresponding values in the present study were 0,34 kg, 0,26 kg, and 0,62 kg. It is worth noting that the data used for comparison pertained to 32-month-old bucks, resulting in significantly different internal organ weights. null null Research by Czajkowska and Czaplejewicz (2020) showed that the average heart weight of 2-3-year-old fallow deer was 0,28 kg, while the heart weight in our research was 0,06 kg higher. The difference in heart weight can be attributed to different methods of extracting the organ, including different amounts of fat tissue left adhering to the heart. An important attribute of carcass quality is the percentage share of the various cuts. In the present study, the rump had the largest percentage share, amounting to about 37% of the total carcass weight, followed by the shoulders (19,49%) and the loin (16,60%). The combined weight of all cuts was 24 kg (98,97%). Stanisz et al. (2015), in 32-month-old fallow deer, found that the loin and the shoulders constituted 17,7% and 16,7%, respectively, of the carcass weight. Żmijewski et al. (2020) reported the rump, loin and shoulder cuts to be 38,42%, 14,42%, and 15,50% of the carcass weight. Those numbers confirm that the rump accounts for the highest percentage share of the carcass, amounting to more than 37% of the overall carcass weight. It should be noted that detailed comparison of the data obtained in the present study with the results of other research may be problematic due to differing dissection methods. The present study showed a highly significant (P ≤ 0,01) relationship between the shoulder, loin, and rump weights and carcass weight. The correlation coefficients ranged from 0,97 to 0,99. Łebacka and Gardzielewska (1975) noted similar relationships for loin and shoulder weights in red deer (r = 0,83 and r = 0,98, respectively). Similarly, Janiszewski (2009) found a highly statistically significant relationship between the weights of the cuts and carcass weight in red deer. For example, the correlation coefficients for the rump and shoulders were r = 0,82 and r = 0,84, respectively. A pronounced relationship between rump weight and carcass weight was also noted by Trziszka (1975), with a correlation coefficient (r = 0,95) very similar to that obtained in the present study. This confirms that calculating correlations between the weights of cuts can enable carcass assessment without the need for dissection. To conclude, the research results confirmed that there are clear relationships between the carcass parameters determined in the study (Table 5), which can serve as a basis for developing indirect methods of assessing the carcasses of farm-raised fallow deer. null Calculating linear regression equations made it possible to approximate the weight of the rump, shoulders, and loin based on the cold carcass weight. The results, presented in Table 6, indicate that the equations are useful and quite accurate, as the estimated and actual weights of the cuts differ by less than 0,13%. The equation used to estimate the weight of the shoulders had the smallest standard error and a high correlation coefficient. null

Effect of the use of flaked maize in diets with reduced metabolic energy on performance, egg quality, and serum parameters in layer quails

<b>The research was conducted to determine the effects of substituting raw maize with flaked maize in diets containing different levels of metabolic energy on the performance, egg quality, and serum parameters of layer quails. In the experiment, 120 female quails at ten weeks of age were randomly allocated to six treatment groups with four replicates, each consisting of five quails. The quails were fed six diets, with two forms of maize (raw or flaked) and three metabolic energy levels (2750, 2825 or 2900 (control) kcal/kg) during a ten-week trial. Compared with the control group, reducing the metabolic energy level of the diet to 2750 kcal/kg negatively affected egg production (P < 0,01), egg mass (P < 0,01), feed conversion ratio (P < 0,01), and serum cholesterol concentration (P < 0,05). Eggshell thickness decreased significantly in the group receiving 2750 kcal/kg metabolic energy in the diet, and the yolk b* value increased significantly (P < 0,01). The use of flaked maize in the diets significantly increased egg production (P < 0,05), egg mass (P < 0,05), eggshell thickness (P < 0,05), and yolk L* value (P < 0,01) and significantly decreased the feed conversion ratio (P < 0,05) and b* value of the yolk (P < 0,05). Although the effects of the interactions of the metabolic energy levels and forms of maize on the egg yolk b* value were significant (P < 0,01), this effect was not significant for the other parameters. The results indicate that layer quails can be fed diets containing 2825 kcal/kg metabolic energy and that replacement of raw maize with flaked maize in the diet positively affects performance and egg quality.