Prolactin (PRL), secreted from the anterior pituitary, plays extensive roles in osmoregulation, corpus luteum formation, mammogenesis, lactogenesis, lactopoiesis, and production of crop milk. In birds, prolactin (PRL) is generally accepted as crucial to the onset and maintenance of broodiness. All the actions of prolactin (PRL) hormone are mediated by its receptor (PRLR), which plays an important role in the PRL signal transduction cascade. It has been well established that the PRL gene is closely associated to the onset and maintenance of broody behavior, and could be a genetic marker in breeding against broodiness in chickens. Meanwhile, the prolactin receptor (PRLR) gene is regarded as a candidate genetic marker for reproductive traits. PRLR is also an important regulator gene for cell growth and differentiation. The identified polymorphism of this gene is mainly viewed in terms of egg production traits. Due to different biological activities attributed to PRL and PRLR, they can be used as major candidate genes in molecular animal breeding programs. Characterization of PRL and PRLR genes helps to elucidate their roles in birds and provides insights into the regulatory mechanisms of PRL and PRLR expression conserved in birds and mammals.

The effects of age and sex of guinea fowl on their dressing percentage, carcass composition, pH value, water holding capacity, colour and sensory properties of meat was determined. At 16 weeks of age, males and females had significantly higher body weights and carcass weights compared to birds at 13 weeks of age. The carcasses of older birds contained more breast muscles, leg muscles and skin with subcutaneous fat, and less wings, with a significant difference for males. At both evaluation times, males compared to females had lower body weight, carcass weight, dressing percentage, content of breast muscles and abdominal fat, and a higher proportion of leg muscles. Older birds had significantly lower redness (a*) values for breast muscles in males and for leg muscles in females.KEYWORDS: guinea fowl, slaughter value, colour of meat, sensory property STRESZCZENIE Określono wpływ wieku i płci perlic na ich wydajność rzeźną i skład tuszki oraz wartość pH, wodochłonność, barwę i właściwości sensoryczne mięsa. Samce i samice w wieku 16 tygodni miały istotnie większą masę ciała i masę tuszki niż ptaki w wieku 13 tygodni. Tuszki starszych ptaków zawierały więcej mięśni piersiowych i nóg oraz skóry z tłuszczem podskórnym, a mniej skrzydeł, u samców istotnie. Samce, w porównaniu z samicami miały mniejszą masę ciała, masę tuszki, wydajność rzeźną, zawartość mięśni piersiowych i tłuszczu sadełkowego, a większy udział mięśni nóg. U starszych ptaków stwierdzono statystycznie istotnie mniejsze wartości a* mięśni piersiowych u samców, a w przypadku mięśni nóg u samic.SŁOWA KLUCZOWE: perlica, wartość rzeźna, barwa mięsa, właściwości sensoryczne DETAILED ABSTRACTOcenie podano 60 perlic perłowoszarych. Ptaki utrzymywano na głębokiej ściółce w budynku zamkniętym o regulowanych parametrach środowiska, bez dostępu do wybiegu. W pierwszych czterech tygodniach stosowano promienniki podczerwieni. Odpowiednią wymianę i ruch powietrza umożliwiła wentylacja mechaniczna. W pomieszczeniu z perlicami stosowano światło żarowe. Ptaki utrzymywano w dwóch kojcach, każdy o powierzchni 12 m 2 , po 30 sztuk w jednym kojcu. Perlice karmiono ad libitum przemysłowymi mieszankami dla indyków. Do 3. tygodnia życia włącznie ptakom podawano mieszankę paszową zawierającą 24,5% białka ogólnego i 12,15 MJ (2900 kcal) energii metabolicznej, od 4. do 8. tygodnia mieszankę zawierającą 22,6% białka i 12,35 (2950 kcal) EM, a od 9. tygodnia do końca badań mieszankę z udziałem 20,7% białka i 12,55 MJ (3000 kcal) EM. W 13. i 16. tygodniu wychowu wybrano po 10 perlic do uboju. Po uboju oznaczono pH 15 mięśni, wykonano rozbiór tuszki, pobrano próby mięśni piersiowych i nóg do oznaczeń właściwości fizykochemicznych i sensorycznych. Ptaki 16-tygodniowe miały istotnie większą masę ciała i masę tuszki. Obliczona wydajność rzeźna była większa u ptaków młodszych (w wieku 13 tygodni) oraz u samic w porównaniu z samcami. Wraz z wiekiem stwierdzono zwiększenie zawartości (%) mięśni piersiowych, mięśni nóg i skóry z tłuszczem podskórnym, a zmniejszenie udziału skrzydeł ...

Abstract. The aim of the study was to compare Muscovy ducks and mule ducks for proximate analysis, colour attributes, sensory properties of the meat, and concentration of some minerals in the meat and liver, with consideration of the effect of sex on the analysed traits. The study used 46 Muscovy and 44 mule ducks. At the end of the rearing period, 40 birds (10 males and 10 females of each genotype) were selected for slaughter. Meat and liver samples were collected from the slaughtered birds to determine quality traits. The analysed ducks of different genotypes differed significantly in the water content, sodium content, and redness of breast muscles; in the water, fat, and zinc content of leg muscles; and in the sodium, iron, and copper content of liver. Regardless of genotype, males had a higher sodium content in breast muscles; contained more protein, sodium, phosphorus, and magnesium and less potassium and copper in leg muscles; and had a significantly higher content of sodium, potassium, phosphorus, magnesium, zinc, iron, and copper in liver compared to females. The genotype–sex interaction was significant for the sodium and potassium content of breast muscles, for the water, protein, sodium, potassium, phosphorus, magnesium, and copper content of leg muscles, and for the copper content of liver. Our study provided information about differences in the quality of meat and liver in Muscovy and mule ducks.

The aim of the study was to analyze the effect of a blend of phytogenic additive on nutritional and mineral composition of breast, thigh muscles and liver in fattening turkeys. A total 300 female turkeys were monitored in the trial. 1-day old broadbreasted white turkeys hybrid XL were randomly divided into two groups (150 pcs per each). Turkeys in control group were fed by standard diet for fattening and in experimental group from the 1st to the 12th week by complete feed mixture with supplementation of a blend of essential oils from origanum, anise and citrus fruits as well as a prebiotic rich fructooligosaccharides in dosage 1 kg per 1000 kg of feed mixture. Turkeys were housed in group on deep litter. Experiment lasted 18 weeks. Samples of breast and thigh muscles, and liver for nutritional analysis were collected during turkey's dissection (10 samples per each group). After the determination of nutrients, there were found significant (P ˂ 0.05) differences between control and experimental samples of breast muscles in content of crude protein and fat. Statistically significant (P ˂ 0.05) differences in all analyzed nutrients in thigh muscles were observed. The phytoadditive supplementation markedly (P ˂ 0.05) increased content of crude protein in breast (from 91.13 to 93.7% of DM) and thigh muscles (from 79.78 to 85.73% of DM) and ash in thigh muscle (from 4.25 to 4.61% of DM). Tendency of higher (P ˃ 0.05) content of DM and fat was recorded in liver. After analysis the macro and microelements, significant (P ˂ 0.05) differences in all minerals except potassium and manganese were found. Compare to the control group, in the experimental group were detected significantly (P ˂ 0.05) higher amounts of zinc in breast, magnesium and copper in thigh muscle samples. In the 1664 case of liver, there was found higher (P ˃ 0.05) concentrate only in content of manganese in experimental group. Occurrence of manganese was not observed in both muscles. 25Journal of Central European Agriculture, 2016, 17(1), p.25-39 DOI: 10.5513/JCEA01/17.1.Keywords: minerals, muscle, nutrients, phytogenic additive, turkeys Abstrakt Cieľom štúdie bolo analyzovanie vplyvu zmesi fytogenného aditíva na živinové a minerálne zloženie v prsnom svale, stehennom svale a pečeni výkrmových moriek. V pokuse bolo monitorovaných celkovo 300 jedincov samíc moriek. Morky plemena mäsový medzilíniový úžitkový kríženec morka širokoprsá biela, hybrid XL, vo veku 1 deň boli rozdelené do dvoch skupín (150 kusov v každej skupine). Morkám v kontrolnej skupine bola skrmovaná štandardná kompletná kŕmna zmes pre výkrm a v experimentálnej skupine od 1. do 12. týždňa bola skrmovaná kompletná krmná zmes s prídavkom zmesi esenciálnych olejov z oregana, anízu, citrusových plodov a prebioticky obohatená o fruktooligosacharidy v dávke 1 kg na 1000 kg kŕmnej zmesi. Morky boli ustajnené skupinovo na hlbokej podstielke. Pokus trval 18 týždňov. Vzorky prsného svalu, stehenného svalu a pečene, určené na analýzu živín, boli odobrané počas jatočnej rozrábky (10 vzoriek ...