Effect of fast-, medium- and slow-growing strains on meat quality of chickens reared under the organic farming method

Abstract

The characteristics of meat quality, chemical and fatty acid composition, from fast-growing (FG) and medium-growing (MG) meat-type and slow-growing (SG) egg-type chickens reared under organic conditions were compared. Three-hundred and sixty 1-day-old male chicks, equally divided into three experimental groups represented by strains (FG: Cobb 700, MG: Naked neck Kabir and SG: Brown Classic Lohman) were housed into three poultry houses with outdoor pasture availability of 10 m 2 /bird located in the same Research Centre of the University of Perugia. All the birds were fed ad libitum the same diets formulated according to the European Union (EU) Regulations by using organic raw materials. Birds from the FG and MG groups were raised until 81 days, whereas birds from the SG group were raised until 96 days in order to achieve an acceptable market live weight. SG birds showed significantly ( P , 0.01) higher breast meat drip and cook losses, Allo-Kramer shear values and collagen content. In comparison with FG and SG, MG exhibited a higher breast meat pH (5.86% v. 5.79% and 5.78%, respectively; P , 0.01) and a lower lightness (54.88% v. 57.81% and 56.98%, respectively; P , 0.05). Genotype dramatically affected the lipid content as well as the fatty acid composition of both breast and thigh meat. SG exhibited the lowest content of lipid, both in breast and in thigh meat, the lowest proportions of monounsaturated fatty acids (MUFA) and the highest proportions of polyunsaturated fatty acids (PUFA). The total n-3 PUFA of SG breast meat was double that of FG meat and intermediate with respect to MG birds (8.07% v. 4.07% v. 5.14% total fatty acids; P , 0.01). The fatty acid composition of thigh meat is similar to that of breast meat, but the differences among genotypes are less pronounced. Total saturated fatty acids were not affected by the genotype. In conclusion, meat functional properties of FG and MG strains appeared much more attractive both for industry and consumer (lower drip and cook losses and higher tenderness), whereas from a nutritional point of view, meat from SG appeared healthier (less fat and higher content of n-3 PUFA) and thus might better fit with the consumer's expectations of organic products.

Qualidade Da Carne De Aves Da Raça Rodhe Island Red Criadas Em Sistema Alternativo

“…Resultados semelhantes foram encontrados por Sarsenbek et al (21) e Sirri et al (27) , que, comparando os cortes peito e coxa, observaram um maior teor de umidade em coxas. Com relação ao sexo, os machos apresentaram maiores teores de umidade (Tabela 3).…”

“…Sirri et al (27) , avaliando a linhagem Lohman Brown, de crescimento lento e criada em sistema semiintensivo, encontraram valor inferior para o índice de trombogenicidade (0,59) do peito. Isso pode ser devido principalmente aos menores teores de C16:0 (ácido palmítico) e C18:0 (ácido esteárico), encontrados neste trabalho, que são considerados como trombogênicos.…”

“…Dessa forma, quanto menores os teores destes ácidos graxos, menor será o índice de trombogenicidade. Ainda segundo Sirri et al (27) , o índice de aterogenicidade do peito de aves da linhagem Lohman Brown foi 0,32. Novello et al (30) , avaliando uma linhagem de frango comercial, observaram valores de índice de aterogenicidade e de trombogenicidade de 0,43 e 0,69 do peito, respectivamente, e para a coxa os valores foram 0,45 e 0,73, respectivamente.…”

Association of Chicken Fatty Acid Desaturase 1 and 2 Gene Single- Nucleotide Polymorphisms with the Fatty Acid Composition of Thigh Meat in Japanese Hinai-dori Crossbred Chickens

“…Sirri et al [23] compared fatty acid profiles of breast and thigh meat among fast-(Cobb 700), medium-(Naked neck Kabir), and slow-(Brown Classic Lohman) growing strain chickens slaughtered at the age of 81 d. The SA, ARA and DHA compositions of the slow-growing strain were significantly higher than those of the fast-and mediumgrowing strains, whereas the MA, POA, and oleic acid (OA, C18:1) compositions of the slow-growing line were significantly lower than those of the fast-and medium-growing lines both in breast and thigh Table 5: The primers and target position in chicken fatty acid desaturase 1 and 2 (FADS1 and FADS2) genes for the mismatch amplification mutation assay.…”

“…These reports may suggest that there is a significant strain difference in the fatty acid profile of meat; however, we would like to refer to sex differences of samples in these reports. Rikimaru and Takahashi [2] used Hinai-jidori females because almost 100% of the Hinai-jidori chickens sold commercially are females, whereas Sirri et al [23], Jayasena et al [24], and Boschetti et al [25] used males. In fact, Sirri et al [26] reported that the ARA, DPA, and DHA composition of breast and thigh meat of cocks were significantly higher than those of capons at the age of 180 d. To explain the difference between cocks and capons, the authors supposed that D6D activity is affected by testosterone, since Clejan et al [27] found a decrease of ARA and DHA in castrated rats owing to the lack of testosterone and showed that the administration of testosterone to castrated rats could bring the ARA content to normal values.…”