The fatty acid profile and the quality of breast and leg muscles in female and male pearl gray guinea fowl (Numida meleagris).

The aim of this study was to evaluate the fatty acid (FA) profile and the quality of breast and leg muscles in male and female guinea fowl. In comparison with leg muscles, breast muscles had a higher content of dry matter and total protein, and contained less fat and total collagen (P ≤ 0.05). Sex had no effect on the chemical composition of the studied muscles or the FA profile of intramuscular fat (IMF) (P > 0.05). The IMF of breast muscles was characterized by higher proportions of total saturated fatty acids (SFAs) and polyunsaturated fatty acids (PUFAs), and lower proportions of total unsaturated fatty acids (UFAs) and monounsaturated fatty acids (MUFAs) (P ≤ 0.05) than the IMF of leg muscles. The physicochemical properties of guinea fowl meat were significantly influenced by muscle type (P ≤ 0.05), but not by sex (P > 0.05). Leg muscles were characterized by a higher pH, higher cooking loss, lower lightness (L*), lower drip loss, a higher contribution of redness (a*), and a lower contribution of yellowness (b*) than breast muscles (P ≤ 0.05). The experimental factors had no effect on the sensory attributes or the shear force values of the analyzed muscles (P > 0.05). The unique sensory attributes, high protein content, and low fat content of the analyzed muscles indicate that guinea fowl meat can be a dietary supplement and an addition to other types of meat consumed, especially that most guinea fowl are reared in extensive farming systems that contribute to sustainable food production.

Effect of Variety and Sex on the Carcass and Meat Quality Traits of Guinea Fowl (Numida meleagris L.).

The aim of this study was to evaluate selected parameters of carcass and meat quality in 16-week-old pearl gray and lavender guinea fowl. The birds were raised in summer and fall, in an extensive system. Until 4 weeks of age, the birds were kept indoors, and from week 5 until slaughter they could use outdoor space enclosed by a fence, adjacent to the building. Guinea fowl were fed complete chicken diets: starter (weeks 0−6), grower (weeks 7−12), and finisher (weeks >13). In comparison with lavender guinea fowl, pearl gray birds had higher live weight at slaughter (p = 0.001) and higher carcass weight (p = 0.001). Females, compared with males, had a higher carcass dressing percentage (p ˂ 0.001), lower liver weight (p = 0.008), lower heart weight (p ˂ 0.001), and lower total weight of giblets (p = 0.004). The leg muscles of pearl gray guinea fowl, compared with those of lavender birds, had a higher content of dry matter (p ≤ 0.029). The breast muscles (p ˂ 0.001) and leg muscles (p = 0.017) of lavender guinea fowl contained less fat than the muscles of pearl gray birds. The breast muscles of females had a higher content of dry matter (p = 0.044) and ash (p = 0.016), and lower total collagen content (p = 0.028) than the breast muscles of males. The leg muscles of females were characterized by a higher pH (p ˂ 0.001), and lower cooking loss (p = 0.004) and drip loss (p = 0.005) than the breast muscles of males. The breast muscles of lavender guinea fowl, compared with those of pearl gray birds, were characterized by a higher chroma value (p ˂ 0.001), and a higher contribution of redness (p ˂ 0.001) and yellowness (p = 0.002), and their leg muscles were lighter in color (p ˂ 0.001), with a higher contribution of yellowness (p = 0.041) and a higher hue angle (p = 0.037). The value of chroma (p = 0.004) and the contribution of yellowness (p = 0.002) were higher in the breast muscles of females, compared with males. Neither variety nor sex affected (p > 0.05) the evaluated sensory properties of guinea fowl meat or the proportions of total SFAs, total UFAs, total MUFAs, and total PUFAs in the intramuscular fat (IMF) of breast and leg muscles. Meat from guinea fowl of both analyzed varieties can be an excellent alternative to more popular types of poultry meat due to its high nutritional value and eating quality.

Effects of Garlic (Allium sativum L.) and Ramsons (Allium ursinum L.) on Lipid Oxidation and the Microbiological Quality, Physicochemical Properties and Sensory Attributes of Rabbit Meat Burgers.

The aim of this study was to evaluate the quality of rabbit meat burgers with the addition of garlic (Allium Sativum L.) powder (G), ramsons (Allium ursinum L.) powder (R) or their combination (GR). The effects of additives on lipid oxidation, color parameters, microbiological quality and organoleptic properties of raw and oven-baked burgers were analyzed before and after refrigerated storage. Four meat formulations were prepared: control (C)-without additives, with the addition of G (0.35 g/100 g of meat), R (0.35 g/100 g of meat) and GR (0.35 g/100 g of meat each). The addition of GR induced an increase in pH and TBARS values in raw and oven-baked burgers. The pH of raw and oven-baked burgers was also affected by storage time (ST), and it was lower after 7 days of storage (ST7) than before storage (ST0). TBARS values were higher at ST7 only in raw burgers. The addition of R and GR decreased the values of color parameter L* (lightness) relative to G and C in raw and oven-baked burgers. The greatest changes in parameter a* (redness) were observed after the addition of R and GR, both before and after heat treatment. The values of parameter b* (yellowness) increased after the addition of R, GR (raw and oven-baked burgers) and G (raw burgers). In raw burgers, color saturation (C*) was higher in groups R and GR than in groups C and G, and the value of hue angle (h°) was lower in burgers with GR than in those with G and R. In oven-baked burgers, the values of C* and h° were lower in group GR than in the remaining treatments (C, G and R). In raw burgers, ST had no effect on the values of L*, whereas the values of parameters a*, b*, C* and h° were lower at ST7 than at ST0. In oven-baked burgers, the values of L* were higher at ST0 than at ST7, and the values of a*, b*, C* and h° were higher at ST7 than at ST0. The tested additives had no influence on the presence of off-odors in raw burgers. This parameter was affected by ST, and its value was lower at ST0 than at ST7. The appearance and overall acceptability of burgers were affected only by additives, and raw burgers containing GR received the lowest scores. After heat treatment, control burgers scored lowest for all attributes, whereas burgers with the addition of R and GR received the highest scores. The analyzed additives had no effect on the growth of Enterobacteriacea, Pseudomonas spp., lactic acid bacteria or total aerobic psychrotrophic bacteria. However, the counts of all identified bacteria increased at ST7. In conclusion, garlic powder and ramsons powder can be added to rabbit meat burgers to extend their shelf life and improve their eating quality.

Performance and Egg Quality of Laying Hens Fed Diets Containing Raw, Hydrobarothermally-Treated and Fermented Rapeseed Cake.

The present study was conducted to investigate how raw rapeseed cake (RRC), hydrobarothermally-treated rapeseed cake (HRC) and fermented rapeseed cake (FRC) fed to laying hens over a period of 12 weeks affected their performance, and the quality, fatty acid (FA) profile and oxidative stability of eggs. A total of 304 Hy-Line Brown laying hens at 36 weeks of age were distributed in a completely randomized design to four treatment groups with 38 replicates per treatment and two hens per replicate. The birds had ad libitum access to feed and water throughout the study. During the experiment, the birds were fed isonitrogenous and isocaloric diets in mash form, with various protein sources. In the control group (C), soybean meal (SBM) was the main source of dietary protein, whereas the experimental groups were fed diets containing 20% of RRC, HRC or FRC. Hydrobarothermal treatment and fermentation decreased the glucosinolate (GLS) content of RC, and fermentation reduced the concentration of phytate phosphorus (PP). In comparison with the RRC group, layers from the HRC and FRC groups were characterized by higher laying performance, comparable with that in group C. Irrespective of its physical form, RC added to layer diets adversely affected eggshell quality in all experimental groups, whereas albumen quality was highest in the FRC group. In comparison with group C, diets containing RRC, HRC and HRC led to a significant decrease in the content of saturated fatty acids (SFAs), an increase in the proportion of n-3 and n-6 polyunsaturated fatty acids (PUFAs) in the total FA pool in egg yolks, and a decrease in the n-6/n-3 PUFA ratio. The inclusion of RRC, HRC and FRC in layer diets decreased the activity of superoxide dismutase (SOD) in egg yolks, relative to group C. Group FCR eggs were characterized by the highest activity of catalase (CAT) and the lowest lipid peroxides LOOH concentration, compared with the remaining groups. The addition of RC to layer diets did not compromise the sensory quality of eggs, and eggs produced in group FRC received the highest overall score. It can be concluded that the inclusion of 20% RRC, HRC and FRC in layer diets does not compromise the sensory quality of eggs and has a beneficial influence on the FA profile and antioxidant potential of egg yolks. The use of FRC is recommended because it contributes to the highest laying performance, superior albumen quality and the highest sensory quality of eggs, relative to RRC and HRC.

Effects of inclusion level and source of dietary sodium on performance and meat characteristics of broiler chickens.

The effect of different concentrations of dietary Na from three Na salts (NaCl, NaHCO3 and Na2SO4) was assessed in two experiments carried out on broiler chickens aged from 1 to 35 days. In Exp. 1, diets were supplemented with 0.15, 0.20 and 0.25% Na, which increased the average Na content of the diets to 0.19, 0.24 and 0.30% respectively. In Exp. 2, the amounts of selected Na salts (NaCI and Na2SO4) were reduced and the estimated Na contents of experimental diets amounted to 0.10, 0.13, 0.15 and 0.19%. In view of the risk factors for the development of foot pad dermatitis, our aim was to find an optimum source of Na and to keep dietary Na intake at the minimum level sufficient to support normal growth and acceptable slaughter quality. The present results suggest that the amount of Na required for the undisturbed growth of broilers and adequate feed conversion is not less than 0.15% of additional Na in the starter period (1-14 d), and not less than 0.11% in the grower period (until day 35). Higher dietary Na levels did not lead to further production advantages, and were found to increase the moisture content of droppings. Dry matter concentration of excreta was also affected by Na source. In comparison with NaHCO3, Na2SO4 seemed to be a better alternative for NaCl. Na2SO4 also tended to surpass NaHCO3 as a dietary alternative for NaCl in terms of feed utilisation during the starter period. The applied additional Na levels (0.25 and 0.15%) and Na sources had no effect on the sensory profile and composition of breast meat.