Promotion of the conservation and preservation of local breed’s biodiversity combined with the concept of sustainable agriculture and development of economically marginal areas are important policies to implement in modern society. The biometric characterization, contributing to maintain phenotypic traits, is a significant tool in breeding programs, which revaluate local breeds, allow the preservation of animal biodiversity and support consumer demands. This paper approaches the biometric characterization of the Portuguese poultry breeds through the study of sexual dimorphism and breed differentiation using six zoometric measures as differentiation criteria. A total of 429 fowl (66 males and 426 females) were studied and the parameters recorded were body weight, body length, chest circumference, shank length, shank diameter and wingspan. A highly sexual dimorphism was evident, in all breeds, with the “Branca” breed being the most zoometrically distant. Concerning Principal Component Analysis, the highly correlations observed between body length, wingspan and shank length, determined the generalized animal form and could be used as selection criteria for improving body size. Breeding programs aiming to preserve these local genetic resources should consider the dual purpose of these breeds: sustainability and cultural legacy, and the offer to urban consumers a source of differentiated high-quality products.

The purpose of this study was to estimate the growth curve parameters and carcass traits yields of three Portuguese autochthonous chicken breeds, Amarela (AM), Preta Lusitânica (PL) and Pedrês Portuguesa (PP). Birds (198) were individually weighed at pre-established time intervals (6682 records) and the study period lasted 30 months. The growth data were fitted to a mixed nonlinear model based on the Gompertz growth function. Fixed effects were breed, sex, lot, temperature and photoperiod. The adult weight estimated for males (females) were 2851.3 (1951.6) g for AM, 3047.5 (2147.7) g for PL, and 3243.7 (2344.0) g for PP, respectively. The males (females) estimated maximum daily growth were 22.7 (18.1) g at 77 (69) days for AM, 20.7 (17.5) g at 79 (72) days for PL, and 18.1 (16.3) g at 82 (74) days for PP, respectively. Within breed the males were heavier than females at 365 days but with lower maturity rates. Yields of carcass and noble meat pieces were evaluated on data collected from 10 males of each breed, sacrificed at 240 days. Traditionally, these breeds are commercialised whole and again the PP had the heaviest carcass with the highest yield. Growth of these autochthonous breeds after 240 days was minimal and may justify the decrease of the traditional slaughter age of approximately one year, in order to increase profitability. Establishing special market niches will also be a valuable complement for the rural economy of Portugal and an important contribution to the conservation of this genetic heritage.

Biodiversity concerns and the sustainability of agroecological systems, together with consumer demand for higher quality products from alternative and extensive farming methods, have reinforced interest in local breeds that are well adapted to low-input environments. The first reference to Portuguese poultry breeds appeared in the 1930s, with registration and breeding programs of native breeds only being implemented in the last ten years. Portuguese chicken breeds (Pedrês Portuguesa, Preta Lusitânica, Amarela, and Branca) are almost extinct and are currently bred on small-scale farms for egg and meat production. This study aimed to characterize the performance of laying hens, evaluating the influence of genotype, age, and season on egg production over four years in farm conditions. The results highlight the Pedrês Portuguesa as the most productive breed regarding egg production and reveal a tendency for an increase in egg production performance by the Branca in contrast with the lower productive capacity of the Preta Lusitânica. Older hens start laying earlier in consecutive laying periods, present a shorter peak, and an inferior number of total eggs/cycle. There is a need to establish breeding goals and to evaluate and revise breeding programs to increase productivity in autochthonous Portuguese chicken breeds.

The “Branca” breed is a dual-purpose Portuguese autochthonous chicken breed, produced in extensive systems and in small flocks, especially in the Entre Douro and Minho regions. A total of 40 birds (n = 20/sex) were slaughtered between 38 and 42 weeks (males) and 110 and 120 weeks (females), and carcass and meat quality parameters were evaluated. The results showed significantly higher weights and differences for males between sexes and pieces (p ≤ 0.05) in the meat physicochemical composition. Water holding capacity (WRC), moisture and ash contents were influenced by sex. They were higher in males in the breast and drumstick and lightness (L*) and lipid content were higher in females (p ≤ 0.05). The breast meat presented greater lightness, moisture, ash and protein contents, while the drumstick showed a higher pH value, redness (a*) and lipid content, in both sexes (p ≤ 0.05). Regarding the nutritional properties, “Branca” meat revealed a good proportion of minerals and the female meat showed, in both pieces (p ≤ 0.05), significantly lower values for total saturated fatty acids (SFAs) and higher values for monounsaturated fatty acids (MUFAs). Breast meat was richer in n-3-PUFAs (C22:5n-3 and C22:6n-3) in both sexes (p ≤ 0.05). Considering the results obtained, it can be concluded that “Branca” breed meat is a healthy food characterized by a good general nutritional profile.

Ten roosters produced according to “Barcelos Confraria” rules and ten roosters of autochthonous “Amarela” breed, reared on a similar traditional production system, were analyzed, and the chemical profile of two of the most significant meat portions, breast and drumstick, was determined. The results demonstrated that the “Barcelos” rooster raw meat is rich in proteins (22.3%) and fat (4.31%), particularly in monounsaturated fatty acids (39.1%). Significant differences (p ≤ 0.01) were observed, with the breast having a higher protein content (25.1 vs. 19.7%) and less fat (1.9% vs. 6.7%), compared to the drumstick. The fatty acid profile revealed (SFA 30.0%, MUFA 39.1%, and PUFA 24.6%) a similar composition to the roosters reared in the traditional or organic production systems, such as the “Amarela” autochthonous rooster. The “Barcelos” rooster can be regarded as a highly nutritional meat, with an interesting chemical profile ensuring a high-quality traditional product to consumers.