Corporate social and environmental responsibility in relation to the agricultural sector and the food supply chain : a Case Study of Waitrose

Waitrose has a strong commitment to organic farming but also uses products from 'conventional' farms. At the production stage, Waitrose own-label products are fully traceable, GM-free and all suppliers undergo a detailed assessment programme based on current best practice. Crop suppliers to Waitrose operate an authenticity programme to certify that each assignment is GM-free and produce is screened for pesticide residues. Waitrose sources conventional crops grown from 'Integrated Crop Management Systems' (ICMS) using best horticultural practices. The 'Assured Product' scheme regulates all UK produce to ICMS standards and these audits are being extended worldwide. Business is withdrawn from suppliers who fail the audit. In relation to this, Waitrose has increased its Fairtrade range as in its view 'Buying these products provides direct additional benefit to workers in the developing countries where they are produced and assists marginal producers by giving them access to markets they would not otherwise have'. Currently, Waitrose is developing its own sustainable timber assessment criteria. For livestock, protocols are in place to ensure that animals are reared under the 'most natural conditions possible' and free range produce is offered where animals have access to open space although some produce is not from free-range animals. Waitrose also use a 'Hazards Analysis Critical Points' system to identify food safety hazards that occur at any stage from production to point of sale and to ensure that full measures are in place to control them. In addition, mechanisms have been implemented to reduce fuel use and hence reduce CO2 emissions in the transport of products and staff, and to increase the energy use efficiency of refrigeration systems which account for approximately 60% of Waitrose energy use.

A molecular survey of Eimeria in chickens across Australia

Coccidiosis is a costly enteric disease of chickens caused by protozoan parasites of the genus Eimeria. Disease diagnosis and management is complicated since there are multiple Eimeria species infecting chickens and mixed species infections are common. Current control measures are only partially effective and this, combined with concerns over vaccine efficacy and increasing drug resistance, demonstrates a need for improved coccidiosis diagnosis and control. Before improvements can be made, it is important to understand the species commonly infecting poultry flocks in both backyard and commercial enterprises. The aim of this project was to conduct a survey and assessment of poultry Eimeria across Australia using genetic markers, and create a collection of isolates for each Eimeria species. A total of 260 samples (faecal or caecal) was obtained, and survey results showed that Eimeria taxa were present in 98% of commercial and 81% of backyard flocks. The distribution of each Eimeria species was widespread across Australia, with representatives of all species being found in every state and territory, and the Eimeria species predominating in commercial flocks differed from those in backyard flocks. Three operational taxonomic units also occurred frequently in commercial flocks highlighting the need to understand the impact of these uncharacterised species on poultry production. As Eimeria infections were also frequent in backyard flocks, there is a potential for backyard flocks to act as reservoirs for disease, especially as the industry moves towards free range production systems. This Eimeria collection will be an important genetic resource which is the crucial first step in the development of more sophisticated diagnostic tools and the development of new live vaccines which ultimately will provide savings to the industry in terms of more efficient coccidiosis management.

Comportamiento prooxidante y antioxidante de hierbas aromáticas en queso

Los quesos de cabra, con mejores cualidades funcionales provienen de leche de cabras en pastoreo, esto obedece al mayor contenido de ácidos grasos ω-3 y ω-6 en una relación óptima para la salud, sumado a un menor contenido de grasa y colesterol. Saborizar quesos con especias, otorga beneficios sensoriales y saludables al producto. Las especias son usadas para realzar el flavor de los alimentos además presentan beneficios antioxidantes. Sin embargo, se reportaron evidencias del doble papel de los flavonoides como antioxidantes o prooxidantes en función de la concentración de uso. El objetivo del trabajo es evaluar el efecto de distintas concentraciones de especias aromáticas con capacidad antioxidante, frente a las reacciones de deterioro que ocurren en el almacenamiento de quesos de cabra. Se estudió la actividad antirradicalaria (AAR) de 18 especias. Para evaluar la actividad antioxidante (AA0) se usó la técnica de desaparición de un radical libre estable el 2,2-difenil-1-picril hidrazilo (DPPH) y se calculó la AAR porcentual. Definido el queso base estándar (control), se ensayaron tres variedades con especies, elegidas de entre las de mayor AAR (orégano, romero y tomillo) y se adicionaron con las concentraciones 0,4 – 1 % p/p. Estos, fueron madurados 30 días y almacenados 7 meses a 4 °C. Se analizaron cada 4 semanas. Se realizaron pruebas sensoriales de aceptabilidad con 60 consumidores de queso (condición), usando planillas, con escala hedónica. Se trabajó sobre los lípidos extraídos de los quesos. El rancidez y deterioro fueron evaluados con análisis de acidez; índice peróxido y sustancias reactivas al ácido TBA. Los resultados se compararon con el comportamiento sensorial del producto en el tiempo de almacenamiento. En los quesos adicionados al 1 %, la acidez se incrementó con el almacenamiento. El máximo valor corresponde al queso con orégano (3,72 % de ac. láctico a los 126 días). En el control, la acidez inicial fue inferior y alcanzó 1,05 g de ác. láctico % a los 166 días. El IP más alto corresponde a los quesos con orégano al 1% , resultado que se contrapone a la actividad antirradicalaria de esta especia. Al 0,4 %, tanto el IP como el número de TBA son menores en quesos adicionados, respecto del control. En los quesos de cabra analizados las especias agregadas al 1% ejercieron acción prooxidante, mientras que al ser agregadas al 0,4% la acción es antioxidante, lo que indica la importancia de la selección de concentraciones adecuadas.

Étude de l'impact de deux traitements, dont un sans antibiotiques, sur la santé digestive et les populations de Clostridium perfringens dans des élevages de poulets de chair.

Le problème grandissant de l’antibiorésistance remet en question plusieurs pratiques reliées à l’utilisation des antibiotiques, dont l’usage à grande échelle pour des fins de promotion de la croissance chez les animaux de consommation. Depuis 2006, le retrait des antibiotiques dans les élevages de poulets de chair en Europe a été associé à la résurgence d’entérite nécrotique, une maladie intestinale causée par la bactérie Clostridium perfringens. Alors que la pathogénie de la maladie semblait bien comprise, le retrait des antibiotiques a montré que peu de solutions de remplacement sont disponibles afin de prévenir cette maladie. Très peu d’études se sont intéressées à mieux caractériser la dynamique des populations de C. perfringens dans les élevages avicoles et l’effet que pouvait avoir le retrait des antibiotiques sur l’évolution de ces populations. La présente étude a évalué l’impact du remplacement des antibiotiques promoteurs de croissance et des anticoccidiens pendant une période de 14 mois, dans huit élevages commerciaux de poulets de chair au Québec. Un protocole d’élevage alternatif, combinant des stratégies telles que des produits à base d’huiles essentielles, des acides organiques et inorganique, une vaccination contre la coccidiose ainsi qu’une amélioration des conditions de démarrage des poussins, a été utilisé en remplacement des antimicrobiens. Les performances zootechniques, la santé digestive ainsi que l’occurrence d’entérite nécrotique pour les lots de poulets soumis au protocole d’élevage alternatif ont été comparées avec celles de lots de poulets de chair recevant une ration conventionnelle. Des analyses moléculaires basées sur la PCR et le PFGE ont été utilisées afin de documenter l’impact de la mise en place du protocole d’élevage alternatif sur les populations de C. perfringens. Les résultats obtenus montrent qu’aucune différence entre les groupes soumis aux deux types de protocoles n'est observée en ce qui a trait à la viabilité en élevage, à l'âge d'abattage et aux taux de condamnations à l'abattoir. Toutefois, les lots soumis au traitement alternatif ont eu des performances moindres pour le poids moyen à l'abattage, le gain moyen quotidien et la conversion alimentaire. Un peu plus de 27% des lots soumis au protocole alternatif ont connu un épisode d’entérite nécrotique clinique. Les analyses ont aussi montré que l’un ou l’autre des protocoles ne semble pas exercer d’influence particulière sur la dynamique temporelle des populations de C. perfringens. Pour les lots soumis au protocole d’élevage alternatif, une forte diversité génétique pour C. perfringens a été liée à un risque augmenté de vivre un épisode d’entérite nécrotique. À l’opposé, les lots alternatifs ayant vécu des épisodes récurrents de la maladie ont montré une diminution significative de la diversité génétique, ainsi qu’une augmentation marquée du nombre de souches de C. perfringens transportant plusieurs gènes de virulence. La présente étude a permis de mieux documenter, d’un point de vue économique et scientifique, la production de poulets de chair élevés sans antibiotiques ni anticoccidiens au Québec. Cette étude est la seule du genre s’étant intéressée à la caractérisation et à la comparaison dans le temps des flores de C. perfringens retrouvées dans les deux types d’élevages. Elle a révélé que la production à grande échelle de poulets de chair élevés sans antibiotiques ni anticoccidiens est possible au Québec, mais que celle-ci présente des impacts sur les performances zootechniques des oiseaux, sur leur santé digestive et sur la dynamique des populations de C. perfringens. Mots-clés : poulets de chair, antibiotiques, huiles essentielles, acides organiques, vaccination coccidiose, performances zootechniques, santé digestive, entérite nécrotique, Clostridium perfringens, dynamique populationnelle

The economic viability and potential of a novel poultry agroforestry system

Investigating agroforestry systems that incorporate poultry is warranted in Northern Europe as they may offer benefits including: improved welfare and use of range; reduced feed costs; price premia on products; reduced payback periods for forests; and, greater returns on investment. Free-range egg production accounts for 27% of the United Kingdom egg market and demand for outdoor broilers is increasing. No research has been conducted recently on the economic viability of agroforestry systems with poultry. An economic model was constructed to: assess economic viability of a broiler agroforestry system; and, investigate the sensitivity of economic performance to key factors and interactions, and identify those which warrant attention in research and management. The system modelled is a commercial trial established in Southern England in 2002 where deciduous trees were planted and broilers reared in six- or nine-week periods. The model uses Monte Carlo simulation and financial performance analyses run for a 120-year period. An Internal Rate of Return (IRR) of 15.5% is predicted for the six-week system which remains viable under a 'worst case' scenario (IRR of 12.6%). Factors which affect financial performance most (decreasing in magnitude) are prices achieved for broilers, costs of brooding houses, chicks, arks, feed and timber prices. The main anticipated effects of biological interactions on financial performance (increased ranging on feed conversion and excess nutrient supply on tree health) were not supported by analysis. Further research is particularly warranted on the welfare benefits offered by the tree component and its relation to price premia.

Marker placement to describe the wrist movements during activities of daily living in cyclical tasks

Objective. To describe the wrist kinematics during movement through free range of motion and activities of daily living using a cyclical task. Design. The wrist angles were initially calculated in a calibration trial and then in two selected activities of daily living (jar opening and carton pouring). Background. Existing studies which describe the wrist movement do not address the specific application of daily activities. Moreover, the data presented from subject to subject may differ simply because of the non-cyclical nature of the upper limbs movements. Methods. The coordinates of external markers attached to bone references on the forearm and dorsal side of the hand were obtained using an optical motion capture system. The wrist angles were derived from free motion trials and successively calculated in four healthy subjects for two specific cyclical daily activities (opening a jar and pouring from a carton). Results. The free motions trial highlighted the interaction between the wrist angles. Both the jar opening and the carton pouring activity showed a repetitive pattern for the three angles within the cycle length. In the jar-opening task, the standard deviation for the whole population was 10.8degrees for flexion-extension, 5.3degrees for radial-ulnar deviation and 10.4degrees for pronation-supination. In the carton-pouring task, the standard deviation for the whole population was 16.0degrees for flexion-extension, 3.4degrees for radial-ulnar deviation and 10.7degrees for pro nation-supination. Conclusion. Wrist kinematics in healthy subjects can be successfully described by the rotations about the axes of marker-defined coordinates systems during free range of motion and daily activities using cyclical tasks.

Expression of cyclooxygenase-2 in intestine of pigs of different ages and hygiene status

Prostaglandins (PG) are bioactive lipids derived from the metabolism of membrane polyunsaturated fatty acids (PUFA), and play important roles in a number of biological processes including cell division, immune responses and wound healing. Cyclooxygenase (COX) is the key enzyme in PG synthesis from arachidonic acid. The hypothesis of the present study was that expression of COX-2 in porcine intestine was dependent on the microbial load and the age of piglets. Piglets were obtained from sows raised either on outdoor free-range farms or on indoor commercial farms, and littermates were divided into three treatments: One group of piglets suckled the sow, a second group was put into an isolator and fed a milk formula, and a third group was put into the isolator fed milk formula and injected with broad spectrum antibiotics. Samples were collected from the 75% level of the small intestine at day 5, 28 and 56 of age. Tissue section from four piglets from each of these six treatment groups was analysed by immunofluorescence for COX-2 and type-IV collagen (basement membrane, defining lamina propria (LP)). Image analysis was used to determine the number of positive pixels expressing LP and epithelial COX-2. COX-2 expressing cells were observed in LP and epithelium in all porcine intestinal samples. When analysing images obtained on day 28, injection of antibiotics seemed to reduce the COX-2 expression in intestinal samples of piglets when compared to other treatments (P=0.053). No significant effect of farm, treatments or age of piglets was observed on COX-2 expressing data when analysing all data of images obtained at day 28 and 56. By double-labelling experiments, COX-2 was found not to be expressed on cell co-expressing CD45, CD16, CD163 or CD2, thus indicating that mucosal leukocytes, including dendritic cells, macrophages and NK cells did not express COX-2. Future research should investigate the role of COX-2 expression in the digestive tract in relation to pig health.

Modelling of control options for an outbreak of Mycoplasma gallisepticum in egg production: a decision support tool

Mycoplasma gallisepticum (MG) is a bacterium that causes respiratory disease in chickens, leading to reduced egg production. A dynamic simulation model was developed that can be used to assess the costs and benefits of control using antimicrobials or vaccination in caged or free range systems. The intended users are veterinarians and egg producers. A user interface is provided for input of flock specific parameters. The economic consequence of an MG outbreak is expressed as a reduction in expected egg output. The model predicts that either vaccination or microbial treatment can approximately halve potential losses from MG in some circumstances. Sensitivity analysis is used to test assumptions about infection rate and timing of an outbreak. Feedback from veterinarians points to the value of the model as a discussion tool with producers.

Impact of game bird release on the Adonis blue butterfly Polyommatus bellargus (Lepidoptera Lycaenidae) on chalk grassland

Polyommatus bellargus is a priority species of butterfly in the UK as a result of its scarcity and the rate of population decline over the last few years. In the UK, the species is associated with chalk grassland on hot, south-facing slopes suitable for the growth of the food plant Hippocrepis comosa. Shooting game birds is a popular pastime in the UK. Over 40 million game birds, principally Phasianus colchicus and Alectoris rufa, are bred and released into the countryside each year for shooting interests. There is a concern that the release of such a large number of non-native birds has an adverse effect on native wildlife. A study was carried out over a period of 3 years out to examine whether there was any evidence that A. rufa released into chalk grassland habitat negatively affects populations of P. bellargus. A comparison was made between sites where large numbers of A. rufa were released versus sites where no, or few, birds were released. The study involved the construction of exclosures in these sites to allow an examination of the number of butterflies emerging from H. comosa when the birds were excluded versus when the birds had free range across the area. Where birds were present the on-site vegetation was shorter than where they were absent indicating that the birds were definitely influencing habitat structure. However, the evidence that A. rufa was negatively influencing the number of adult butterflies emerging was not strong, although there was a largely non-significant tendency for higher butterfly emergence when the birds were excluded or absent.

Frequência da infecção por Toxoplasma gondii em galinhas caipira e frangos de corte em regiões dos Estados do Rio Grande do Norte e Paraíba

Toxoplasmosis is a zoonosis caused by Toxoplasma gondii, a protozoan that has a cosmopolitan geographic distribution and low host specificity. Usually a benign and selflimiting, infection can manifest itself in a severe systemic becoming overwhelming in fetuses and patients with immunosuppression. Domestic fowl are considered one of the most important hosts in the epidemiology of toxoplasmosis, since they are potential sources of infection for humans, in addition to playing the role of important indicators of environmental contamination by oocysts of T. gondii. We studied the prevalence of infection by the protozoan in chickens of different breeding systems mesoregions from the states of Rio Grande do Norte and Paraiba: broilers from commercial farms (200/PB) and free-range chickens of small farms (322/RN and PB). Were standardized IFAT and ELISA techniques for detecting specific antibodies in blood samples of birds, and commercial kit was used to determine the prevalence by IHAT. There was no seropositive reaction by T. gondii in the samples of broilers tested, indicating that the particularities of intensive management limit the chances of infection for these animals. Among the hens, the frequency of IgG anti-T. gondii diagnosed by the techniques of IHAT, IFAT and ELISA, respectively, were 3.73% (12/322), 37.88% (122/322) and 40.37% (130/322), for both young and adult animals. Amongst the seropositive samples by IFAT, 33 (27.05%) were positive at a dilution of 1:16, in 1:32, 31 (25.41%), in 1:64, 24 (19.67%), 15 (12.29%) in 1:128, and 19 presented titer greater than or equal to 1:256 (15.57%). The evaluation of the presence of anti-T. gondii should be careful, and reagents IHAT provided erratic results in this measure for the specie studied. This suggests the need for own standardization of the kit before the use in epidemiological studies in animal species. On the other hand, substantial agreement observed between IFAT and ELISA techniques (Kappa = 0.62) enables these methods as effective methodologies for the diagnosis of toxoplasmosis in chickens. The high prevalence of specific antibodies among poultry in the region studied attempts to the potential risk of transmission of toxoplasmosis to humans

Exigências de metionina + cistina digestível para aves de corte ISA Label criadas em semiconfinamento

Foram realizados três experimentos para determinação das exigências de metionina+cistina (met+cis) digestível para aves da linhagem ISA Label. As aves foram criadas em semiconfinamento nas fases inicial (1 a 28 dias), crescimento (28 a 56 dias) e final (56 a 84 dias). em cada experimento, foram utilizadas 480 aves (metade de cada sexo) alojadas em 24 piquetes. O delineamento experimental utilizado foi o inteiramente casualizado, em esquema fatorial 4 × 2 (níveis de met+cis e sexos) com três repetições de 20 aves. Os níveis de met+cis digestível avaliados foram: 0,532; 0,652; 0,772; 0,892% na fase inicial; 0,515; 0,635; 0,755; 0,875% na fase de crescimento; e 0,469; 0,589; 0,709; 0,829% na fase final. Foram avaliados o desempenho, as características de carcaça, a deposição de proteína e gordura corporal, o peso e o teor de proteína das penas. Na fase inicial, os níveis de met+cis digestível na ração recomendados para machos e fêmeas foram 0,76 e 0,80%, que correspondem a 0,252 e 0,268% de met+cis por Mcal de energia metabolizável da ração, respectivamente. Para aves ISA Label na fase de crescimento, recomenda-se 0,716% de met+cis digestível na ração, independentemente do sexo, que corresponde a 0,235% de met+cis por Mcal de em da ração. Na fase final, recomendam-se níveis de met+cis digestível de 0,756 e 0,597%, que correspondem a 0,244 e 0,193% de met+cis por Mcal de energia metabolizável na ração para machos e fêmeas, respectivamente.

Exigências de lisina digestível para aves de corte da linhagem ISA Label criadas em semiconfinamento

Foram realizados três experimentos para determinar as exigências de lisina digestível para aves da linhagem ISA Label, de ambos os sexos, criadas em semiconfinamento durante as fases: inicial (1 a 28 dias), de crescimento (28 a 56 dias) e final (56 a 84 dias). em cada experimento, foram utilizadas 480 aves, alojadas em 24 piquetes, cada um contendo abrigo coberto de 3,13m² e área de pastejo de 72,87m². O delineamento experimental utilizado foi o inteiramente ao acaso, em esquema fatorial 4x2 (níveis de lisina e sexo) com três repetições de 20 aves cada. Os níveis de lisina digestível avaliados foram: 0,850; 0,970; 1,090 e 1,210% na fase inicial; 0,750; 0,870; 0,990 e 1,110% na fase de crescimento e 0,640; 0,760; 0,880 e 1,000% na fase final. Foram mensuradas as variáveis de desempenho, característica de carcaça, deposição de proteína e gordura corporal, peso e teor de proteína das penas. Com base nos resultados de desempenho, recomendam-se 1, 041; 1,006 e 0,760% de lisina digestível em rações para aves ISA Label nas fases inicial, de crescimento e final, respectivamente.

Níveis de cloreto de sódio para aves de corte da linhagem Colonial criadas em semiconfinamento

Objetivou-se determinar níveis de inclusão de cloreto de sódio (NaCl) em rações para aves machos e fêmeas da linhagem Colonial nas fases inicial (1 a 28 dias), de crescimento (28 a 56 dias) e final (56 a 84 dias) criadas em semiconfinamento. em cada ensaio, 480 aves com idade correspondente à fase de criação foram alojadas em 24 unidades experimentais contendo áreas de abrigo e de pastejo. O delineamento experimental utilizado foi o inteiramente casualizado, em esquema fatorial 4 × 2 (níveis de NaCl e sexos), totalizando oito tratamentos e três repetições de 20 aves. Os níveis de NaCl avaliados foram: 0,20; 0,40; 0,60 e 0,80% na fase inicial; 0,10; 0,30; 0,50 e 0,70% na fase de crescimento e 0,10; 0,25; 0,40 e 0,55% na fase final. Foram avaliados o ganho de peso, o consumo de ração, a ingestão de água, a conversão alimentar, o potencial hidrogeniônico, a pressão parcial de gás carbônico no sangue, a concentração de hematócritos e os teores de sódio e cloro no sangue. Para a fase inicial, o nível recomendado é de 0,53% de NaCl na ração para aves de ambos os sexos. Para a fase de crescimento, os níveis de 0,40 e 0,43% de NaCl, respectivamente, para machos e fêmeas e, para a fase final, de 0,25% para aves de ambos os sexos, atendem às exigências nutricionais.

Níveis nutricionais de fósforo disponível para aves de corte ISA Label criadas em semiconfinamento

Foram realizados três ensaios para determinar os níveis nutricionais de fósforo disponível (Pd) para machos e fêmeas da linhagem ISA Label nas fases inicial (1 a 28 dias), crescimento (28 a 56 dias) e final (56 a 84 dias) criadas em semiconfinamento. em cada ensaio, 480 aves com idade correspondente à fase de criação foram alojadas em 24 unidades experimentais contendo áreas de abrigo e de pastejo. O delineamento experimental utilizado foi o inteiramente casualizado, em esquema fatorial 4 × 2 (níveis de Pd e sexos) com três repetições de 20 aves. Os níveis de fósforo disponível avaliados foram: 0,25; 0,36; 0,47 e 0,58% na fase inicial; 0,18; 0,31; 0,44 e 0,57% na fase de crescimento; e 0,14; 0,27; 0,40 e 0,53% na fase final. Foram avaliados o ganho de peso, consumo de ração, consumo de Pd, conversão alimentar, teores de fósforo, cálcio e cinzas na tíbia e resistência à quebra óssea. de acordo com os resultados, o nível ótimo de Pd na ração na fase inicial, para machos e fêmeas são de 0,39 e 0,49%, que correspondem ao consumo de 3,94 e 3,96 g de Pd/ave, respectivamente. Para a fase de crescimento, recomenda-se 0,35% de Pd na ração para aves de ambos os sexos, que correspondem a consumo de 8,45 e 6,70 g de Pd/ave. Na fase final, recomendam-se os níveis de 0,32 e 0,30% de Pd, que correspondem a consumos de 12 e 9,5 g de Pd/ave para machos e fêmeas, respectivamente.

Crescimento e desempenho de linhagens de aves pescoço pelado criadas em sistema semi-confinado

Este trabalho foi realizado para avaliar o crescimento e desempenho de duas linhagens de aves pescoço pelado. Foram utilizadas 400 aves, distribuídas em um delineamento inteiramente casualizado, os tratamentos consistiram de um esquema fatorial 2 x 2 (linhagens x sexo), com cinco repetições de 20 aves cada. Foram utilizadas aves Pescoço Pelado das linhagens Sasso e ISA Label. As aves receberam rações formuladas à base de milho e de farelo de soja para atender às exigências nutricionais. Foi determinado o ganho de peso (GP), o consumo de ração (CR) e a conversão alimentar (CA) aos 28, 56 e 84 dias de idade e o rendimento de carcaça e de partes aos 84 dias de idade. Não foi observada interação entre sexo e linhagem (P>0,05) para nenhuma das variáveis de desempenho analisadas. Para CR e GP houve diferenças significativas (P<0,05) entre as linhagens e entre os sexos nos três períodos. As aves da linhagem Sasso apresentaram desempenho superior à ISA Label. em relação aos parâmetros descritos da equação de Gompertz, as aves da linhagem Sasso apresentaram maior peso à maturidade (Pm) e tempo em que a taxa de crescimento é máxima (t*) e menor taxa de maturidade (b), indicando que as aves da linhagem ISA Label foram mais precoces para atingir a idade de máximo crescimento. As fêmeas demonstraram melhor aptidão para rendimento de peito e os machos para o rendimento de coxa e de sobra-coxa.