We hypothesised that copper nanoparticles (NanoCu), because of their high physicochemical reactivity and bioavailability, could be used in much smaller quantities than bulk Cu, consequently reducing excretion of Cu into the environment. The objective of the study was to evaluate the effects of various levels of NanoCu on the development and growth of broiler chickens, in order to establish an optimum level of NanoCu dietary supplementation. Broiler chickens were randomly divided into five groups of 10 birds each. The control group received 7.5 mg Cu/kg feed (standard level) as CuSO₄, while groups fed with complexes of NanoCu and starch received 25%, 50%, 75% and 100% of the standard level of Cu used in the control group. Chicken growth and excretion of Cu, Fe and Zn were measured during the growth period from d 7 to 42. At d 42, the slaughter characteristics, the content of Cu, Fe and Zn in the breast muscle and liver, and the oxidative status were analysed. The results indicate that using NanoCu can reduce the standard level of Cu from CuSO₄ supplementation by 75% without jeopardising animal growth, and at the same time significantly decreasing Cu excretion into the environment.

This paper presents the results of an interdisciplinary study aimed at assessing the possibility of using duckweed to purify and recover nutrients from the effluent remaining after struvite precipitation and ammonia stripping from a liquid fraction of anaerobic digestate in a biorefinery located at a Dutch dairy cattle production farm. The nutritional value of duckweed obtained in a biorefinery was assessed as well. Duckweed (Lemna minuta) was cultured on a growth medium with various concentrations of effluent from a biorefinery (EFL) and digested slurry (DS) not subjected to the nutrient recovery process. The study’s results showed that duckweed culture on the media with high contents of DS or EFL was impossible because they both inhibited its growth. After 15 days of culture, the highest duckweed yield was obtained from the ponds with DS or EFL contents in the medium reaching 0.39% (37.8 g fresh matter (FM) and 16.8 g FM per 8500 mL of the growth medium, respectively). The recovery of N by duckweed was approximately 75% and 81%, whereas that of P was approximately 45% and 55% of the growth media with EFL_0.39% and DS_0.39%, respectively. Duckweed obtained from the biorefinery proved to be a valuable high-protein feedstuff with high contents of α-tocopherol and carotenoids. With a protein content in duckweed approximating 35.4–36.1%, it is possible to obtain 2–4 t of protein per 1 ha from EFL_0.39% and DS_0.39% ponds, respectively.

Modern poultry production looks for feed and water additives that improve the welfare of chickens. The utilization of herbs as additives in feed or drinking water is becoming increasingly well known. The aim of this study was to determine the effect of milk thistle extract (Silybum marianum), administered in drinking water, on chickens’ welfare, production results, selected physicochemical properties of the breast muscles, the activity of selected enzymes, and the antioxidant potential of blood serum and breast muscles. A total of 102 one-day-old male ROSS 308 chicks were allocated into three treatment groups. The material was an infusion of dried milk thistle seeds in two doses, administered in drinking water for chickens (group: C = 0; E1 = 0.24; E2 = 0.36 g/day/animal) under standard rearing conditions. As a result of adding the milk thistle to the drinking water, there was an improvement in the welfare of the chickens and in the production results, enzymatic capacity of selected enzymes, and antioxidant capacity in the blood serum and in pectoral muscle (p ≤ 0.05). The addition of a milk thistle seed infusion for chickens can be used in poultry production to improve the rearing performance antioxidant capacity and welfare of chickens.

Purpose: It was hypothesized that heparan sulfate (HS) as an essential compound for myogenesis and nanoparticles of gold (nano-Au) as highly reactive compounds can affect muscle development as a consequence of molecular regulation of muscle cell formation, and that these effects may be enhanced by a complex of HS conjugated with nano-Au. The objective of the present study was to determine the effect of administration of nano-Au, HS, and a nano-Au+HS complex on the morphological and molecular characteristics of breast muscle during embryogenesis. Methods: Chicken embryos were used as in vivo model. Fertilized chicken eggs (n = 350) were randomly divided into the control group and the groups treated with nano-Au, HS, and nano-Au+HS. The experimental solutions were given in ovo on the first day of incubation and the embryos were evaluated on day 20 of incubation. The methods included biochemical indi- ces in blood, immunohistochemistry, microscopy (transmission electron microscopy, scanning electron microscopy, confocal), and gene expression at the messenger ribonucleic acid and protein levels. Results: The treatments did not adversely affect mortality, organ weight, and homeostasis of the embryos. HS stimulated the development and maturation of breast muscle by increasing the number of nuclei, satellite cells, and muscle fibers and affected the expression of basic fibroblast growth factor-2 and paired-box transcription factor-7. Furthermore, the nano-Au+HS complex contributed to the increased number of myocytes and nuclei in chicken embryo muscles. Conclusion: The results indicate that the administration of HS and nano-Au affects muscle development and that this effect is enhanced by conjugating HS with nano-Au.

Effect of Pasture or Maize Silage Feeding on the Nutritional Value of Beef: The objective of this study was to evaluate the nutritional value of beef from different production systems. The study was conducted with Hereford bulls on organic and conventional farms. On the organic farm, fattening was mainly based on roughages, including pasture forage in the summer season, when the end of fattening occurred. On the conventional farm the bulls were fed maize silage and concentrate. On both farms, the animals were aged 7-9 months at the beginning of fattening. The bulls were fattened to a final body weight of 550-600 kg. Samples oflongissimus thoracismuscle were collected from half-carcasses of slaughtered bulls originating from each farm to analyse fat content, fatty acid profile, and content of selected minerals and vitamin E. Muscle samples were additionally analysed for the concentration of thiobarbituric acid-reactive substances 3 and 7 days after slaughter. Analyses showed a lower fat content inlongissimus thoracismuscle of bulls from the pasture feeding system. The fatty acid profile was also characterized by a lower content of C 14:0, and a higher content of polyunsaturated fatty acids (PUFA), including C18:3n-3, conjugated linoleic acid, C 20:5n-3, and C 22:5n-3, as well as by a lower ratio ofn-6/n-3 PUFA. The total content of monounsaturated fatty acids was significantly higher in animals fed maize silage and feed concentrate. In turn, the muscle of pasture fed animals had higher levels of Na, Zn and Fe as well as of vitamin E.