The effect of rations containing hulled or hull-less barley on the slaughter parameters and the quality of broiler chicken meat

Original scientific paper Journal of Central European Agriculture, 2020, 21(3), p.508-516 DOI: /10.5513/JCEA01/21.3.2699 The effect of rations containing hulled or hull-less barley on the slaughter parameters and the quality of broiler chicken meat Wpływ mieszanek zawierających jęczmień oplewiony lub nagoziarnisty na wyniki poubojowe i jakość mięsa kurcząt brojlerów Alina JANOCHA (✉), Anna MILCZAREK, Daria PIETRUSIAK, Kamil ŁASKI Institute of Animal Science and Fisheries, Faculty of Agrobioengineering and Animal Husbandry, Siedlce University of Natural Sciences and Humanities, Siedlce, Poland ✉ Corresponding author: Received: November 18, 2019; accepted: February 16, 2020 ABSTRACT The studies aimed to determine the effect of feed rations containing hulled or hull- less barley meal on the slaughter parameters and the quality of muscles in broiler chickens. The experiment involved 120 broiler chickens of Ross 308 split into 3 groups (K, DI, DII), each consisting of 40 birds. Until the 21st day of life the birds were fed ad libitum with ground starter rations, and from day 22 to day 42 they received grower rations based on wheat, soybean meal, and soya oil with an admixture of minerals and vitamins. In the control rations the second cereal was corn, and the experimental rations contained 30% hulled barley (DI) or hull-less barley (DII). The best slaughter parameters were recorded for chickens from group DI. They had the largest share of total muscles including thigh and drumsticks as well as the smallest share of abdominal fat and skin with subcutaneous fat compared to others. The intramuscular fat of experimental birds contained significantly less PUFA than that of the control birds. In terms of taste, the best note the muscles of chickens fed mixtures containing husked barley were rated. The mean of the traits of breast muscle of chickens in this group was higher (P≤0.05) compared to others. The slaughter parameters obtained in the study provide grounds for recommending the use of hulled barley in rations for broiler chickens accounting for 30% of the ration weight. Keywords: barley, broiler chickens, dressing percentage, meat quality, nutrition STRESZCZENIE Celem badań było określenie wpływu mieszanek zawierających śrutę z jęczmienia oplewionego lub nagoziarnistego na wyniki poubojowe i jakość mięśni kurcząt brojlerów. Doświadczenie wykonano na 120 kurczętach brojlerach Ross 308 podzielonych na 3 grupy (K, DI, DII) liczące po 40 ptaków Do 21. dnia życia ptaki żywiono systemem ad libitum sypkimi mieszankami Starter, a od 22. do 42. dnia mieszankami Grower wyprodukowanymi na bazie pszenicy, poekstrakcyjnej śruty sojowej, oleju sojowego oraz dodatków mineralno – witaminowych. W mieszankach kontrolnych jako drugie zboże zastosowano kukurydzę, a do mieszanek doświadczalnych wprowadzono jęczmień oplewiony (DI) lub nagoziarnisty (DII) w ilości 30%. Najlepsze wskaźniki poubojowe uzyskały kurczęta z grupy DI. Miały one największy udział mięśni ogółem, udowych i podudzi oraz najmniejszy udział tłuszczu sadełkowego i skóry z tłuszczem podskórnym w porównaniu do pozostałych grup.W tłuszczu śródmięśniowym ptaków doświadczalnych stwierdzono istotnie mniej PUFA w porównaniu do ptaków kontrolnych. Pod względem walorów smakowych najlepiej oceniono mięśnie kurcząt żywionych mieszankami zawierającymi jęczmień oplewiony. Średnia ocen mięśnia piersiowego kurcząt tej grupy była wyższa (P≤0,05) w porównaniu do pozostałych grup. Uzyskane wyniki poubojowe dają podstawę do zalecania stosowania jęczmienia oplewionego w udziale 30% w mieszankach dla brojlerów. Słowa kluczowe: jakość mięsa, jęczmień, kurczęta brojlery, wydajność rzeźna, żywienie 508 Original scientific paper DOI: /10.5513/JCEA01/21.3.2699 Janocha et al.: The effect of rations containing hulled or hull-less barley on the slaughter... INTRODUCTION Cereal grains are the main concentrate feed in poultry feeding. The feed usability of respective species of cereals is varied and depends on the content of nutrients and anti-nutrients (Osek et al., 2010; Janocha, 2011). Corn and wheat are used without limitations in the production of feed rations for slaughter chickens, but the feed range is more and more often extended by other cereal meals (Kwiecień and Winiarska- Mieczan, 2010; Osek et al., 2010; Perera et al., 2019). The emerging new varieties of (hull-less) barley and (naked) oats must be evaluated in terms of nutritional value and suitability for poultry feeding (Osek et al., 2003; Sharifi et al., 2012; Krajewski et al., 2013). Electric lighting was used throughout the rearing period (24 h/day). During the first week of the experiment, the birds were kept at 32 °C. The temperature was reduced by 1–2 °C every week until the final temperature of 21–23 °C was reached. Until the 21st day of life the birds were fed ground starter rations, and from day 22 to day 42 with grower rations based on wheat, soybean meal (SBM), soya oil and mineral and vitamin additives. In the control rations (group K) the second cereal was corn, while in the experimental rations corn was replaced with a 30% share of hulled barley Rubinek (group DI) or hull-less barley Rastik (group DII). In both ration types for all groups an enzymatic preparation of 0.6 g/kg with a declared activity of endo- Knowing their effect on the slaughter value and 1,3(4)- β-glucanase (50FBG/g) and pectinase (5000 quality of poultry meat is an important element of such an PSU/g), endoxylanase (8250 EXU/g) and the activity of evaluation. According to Pietrzak et al. (2013) the values accompanying hemicellulase and pentosanase was used. of poultry meat may vary depending on the method of The hulled and hull-less barley used in the experiment nutrition, origin of birds, rearing scheme (intensive, was analysed for the content of fundamental nutrients semi-intensive, ecological), age, sex and the slaughtering and minerals and β-glucanes. procedure. Its quality is a product of many properties such as texture, colour, juiciness, water absorption and nutritional value that is primarily determined by the whole protein content. This characteristic, in combination with a high content of unsaturated fatty acids, a lower content of connective tissues and collagen in poultry meat can testify to its high dietary quality (Zdanowska-Sąsiadek et al., 2013). The studies aimed to determine the effect of feed rations containing hulled or hull- less barley meal on the slaughter parameters and the quality of thigh and breast muscles in Ross 308 broiler chickens. Feed rations produced by own means were balanced according to the nutritional recommendations (Nutritional recommendations and nutritional value of feed, Feeding Standards for Poultry, 2005) for the needs of isoprotein and isoenergetic diets (Table 1). The raw materials and feed rations were subjected to chemical analysis according to AOAC(2005).The content of β-glucanes in the grain of hulled barleyRubinek and hullless barley (...truncated)