Objetivou-se com este estudo avaliar o efeito da adição de complexo enzimático, composto por protease, xilanase e amilase, associado ou não a betaína em rações de frangos de corte sobre o desempenho e a análise econômica. Novecentos e vinte e quatro pintos machos da linhagem Cobb 500, com peso médio inicial de 45,8 g, foram distribuídos em um delineamento experimental inteiramente casualizado, com quatro tratamentos, sete repetições por tratamento e trinta e três animais por unidade experimental (boxe). Os tratamentos foram: Controle Tratamento controle dieta basal constituída por milho e farelo de soja; Enz Tratamento enzima ração com adição de enzimas (amilase, protease e xilanase); Bet Tratamento betaína ração com adição de betaína; Enz+Bet Tratamento enzima e betaína ração com adição de enzimas (amilase, protease e xilanase) e betaína. O período experimental foi dividido em quatro fases: pré-inicial, inicial, crescimento e final. Aos sete, 21, 35 e 41 dias de idade, as aves e as sobras de ração foram pesadas para avaliar o peso médio, o consumo médio de ração, o ganho médio de peso e a conversão alimentar dos animais. Além disso, foram determinados a viabilidade criatória, o fator de produção e o custo da alimentação. No período de 1 a 7 dias, não se detectou diferença significativa (P>0,05) para as variáveis de desempenho com a adição de betaína ou enzimas na ração. Para o período de 1 a 21 dias de idade, foi observado menor consumo médio de ração (P<0,05) para o tratamento Enz+Bet quando comparado com o tratamento acrescido apenas de enzimas, porém sem afetar o ganho médio de peso (P>0,05) e a conversão alimentar (P>0,05). Não houve diferença significativa (P>0,05) para as variáveis de desempenho analisadas quando os frangos de corte foram suplementados com complexo enzimático ou betaína. Com relação ao período de 1 a 35 dias, as aves que receberam os tratamentos Enz ou Bet apresentaram desempenho semelhante ao controle (P>0,05). No período total de 41 dias os frangos de corte recebendo rações formuladas com enzimas ou betaína tiveram desempenho muito próximo ao das aves do tratamento Controle, indicando que as substituições tiveram o efeito desejado. Não houve efeito significativo (P>0,05) entre os tratamentos para o custo da alimentação. A suplementação independente das rações com enzimas ou com betaína natural resultou em desempenho semelhante ao das aves do tratamento Controle. Entretanto, a associação entre os aditivos não se constituiu uma alternativa satisfatória para melhorar o desempenho das aves, embora tenha resultado em custo de alimentação mais baixo que os demais tratamentos. / The broiler of this study was evaluate the effects of an enzyme complex containing protease, xylanase and amylase, associated or not with betaíne, added to broiler diets on the performance of the birds and economic results. Day-old male Cobb 500 broiler chicks (924) with average weight of 45,8 g were distributed to four treatments and seven replicates per treatment in a completely randomized design. The experimental was a pen with 33 birds. The treatments were: Control unsupplemented diets based on corn and soy bean meal; Enz Diets containing enzymes (protease, xylanase and amylase); Bet Diets containing natural betaína; Enz+Bet association of the two previous treatments. The experimental period comprised the pre-starter, starter, grower and finisher pfases. At seven, 21, 35 and 41 days of age the chickens and feeders were weighed to determine the average weight, average feed intake, average weight gain, and feed conversion of the birds. Viability, productivity index, and feeding cost were also determined. On days 1 to 7 addition of enzymes or betaína to the feeds did not result in significant differences in performance (P>0,05). In the period from 1 to 21 days of age, the treatment Enz+Bet had a lower average feed intake (P<0,05) compared to Enz; however, average weight gain and feed conversion were similar (P>0,05). Compared to the Control, the performance of birds in the treatments Enz or Bet was not significantly affected (P>0,05). Linewise, the treatments Enz and Bet resulted in performance similar to the Control (P>0,05) in the period from 1 to 35 days. In the overall period of 41 days, the chickens receiving diets formulated to contain enzymes or betaína had a performance very similar to those fed the Control diet, indicating that the supplements used resulted in the expected effects. There were no differences among treatments in cost of feed per kg of chicken (P>0,05). These additives may be used as components of broilers diets depending on economic considerations.

Healthy dietary changes would be beneficial for society, as the economic burden of diet-related diseases is massive, and for the individual, who would reduce their risk of ill health. However, it is not easy to change dietary habits. Therefore, the aim of this thesis was to better understand dietary change, focusing on the barriers to and facilitators of healthy dietary change by i) examining changes in food choices when dietary change is imposed by a medical diagnosis, ii) examining experiences related to dietary change and its sustainability after participation in a study where healthy dietary changes were required, and iii) examining diet cost in relation to healthiness of the diet. Methods Eighty children aged 13 who were diagnosed with celiac disease (CD) by a screening study reported their food intake in a food frequency questionnaire before and 1,5 years after commencing a gluten-free diet. Changes in food intake and the healthiness of the diet were examined, controlling for societal changes through the use of an age- and sex-matched control group. Diet healthiness was assessed using the National Food Administration’s (NFA) food index and the Diet Quality Index-Swedish Nutritional Recommendations. Qualitative interviews were conducted with 14 individuals who participated in an intervention study five years earlier where they had been randomly selected to adhere to a Mediterranean-like diet for three months. Analyses of the transcribed interviews focused on their experiences of barriers to and facilitators of dietary change and its sustainability. The costs related to healthy diets were examined by comparing consumer food prices with dietary intake data collected in two separate studies. The first study collected dietary intake data through a diet history interview with participants who had been randomized to either a Mediterranean-like diet or to continue their normal diet. The second study collected dietary intake data from 4-, 8-, and 11-year-old children by means of food diaries and was conducted by the NFA. Diet healthiness was assessed using the Healthy Eating Index 2005. Results The screened CD group made relatively few changes to their diets. They decreased their intake of certain gluten-containing products, including pizza, chicken nuggets, fish sticks, and pastries. There were no changes in the healthiness of their diet. The narratives of the individuals changing their diets showed that social relationships were the main barrier to sustainability. Social relationships within the household were especially troublesome, and various coping strategies were required on an everyday basis. Dietary change also increased the burden of food work (e.g., planning, shopping, cooking), which was another major barrier to dietary change. Comparisons between consumer costs of healthy and less healthy diets showed that those consuming the healthier diets also had consumed more expensive diets. Conclusion More barriers to healthy dietary changes were found than facilitators of these transitions. For instance, the impact of social relationships on sustainability of dietary change was found to be high, indicating the importance of participation of other household members when dietary changes are implemented. The higher cost of the healthier diets may be another barrier for healthy dietary changes, especially for those with limited resources. Even though it is possible to eat healthily at a lower cost, such a diet would likely require both cooking skills and time, thus making the task more difficult. However, the finding that children diagnosed with CD only made minor changes in their consumption of, for instance, bread and pasta, indicates that one way of increasing the healthiness of a diet is to substitute healthier alternatives within the same food group for less healthy food items.

Objetivou-se com este estudo avaliar o efeito da adição de complexo enzimático, composto por protease, xilanase e amilase, associado ou não a betaína em rações de frangos de corte sobre o desempenho e a análise econômica. Novecentos e vinte e quatro pintos machos da linhagem Cobb 500, com peso médio inicial de 45,8 g, foram distribuídos em um delineamento experimental inteiramente casualizado, com quatro tratamentos, sete repetições por tratamento e trinta e três animais por unidade experimental (boxe). Os tratamentos foram: Controle Tratamento controle dieta basal constituída por milho e farelo de soja; Enz Tratamento enzima ração com adição de enzimas (amilase, protease e xilanase); Bet Tratamento betaína ração com adição de betaína; Enz+Bet Tratamento enzima e betaína ração com adição de enzimas (amilase, protease e xilanase) e betaína. O período experimental foi dividido em quatro fases: pré-inicial, inicial, crescimento e final. Aos sete, 21, 35 e 41 dias de idade, as aves e as sobras de ração foram pesadas para avaliar o peso médio, o consumo médio de ração, o ganho médio de peso e a conversão alimentar dos animais. Além disso, foram determinados a viabilidade criatória, o fator de produção e o custo da alimentação. No período de 1 a 7 dias, não se detectou diferença significativa (P>0,05) para as variáveis de desempenho com a adição de betaína ou enzimas na ração. Para o período de 1 a 21 dias de idade, foi observado menor consumo médio de ração (P<0,05) para o tratamento Enz+Bet quando comparado com o tratamento acrescido apenas de enzimas, porém sem afetar o ganho médio de peso (P>0,05) e a conversão alimentar (P>0,05). Não houve diferença significativa (P>0,05) para as variáveis de desempenho analisadas quando os frangos de corte foram suplementados com complexo enzimático ou betaína. Com relação ao período de 1 a 35 dias, as aves que receberam os tratamentos Enz ou Bet apresentaram desempenho semelhante ao controle (P>0,05). No período total de 41 dias os frangos de corte recebendo rações formuladas com enzimas ou betaína tiveram desempenho muito próximo ao das aves do tratamento Controle, indicando que as substituições tiveram o efeito desejado. Não houve efeito significativo (P>0,05) entre os tratamentos para o custo da alimentação. A suplementação independente das rações com enzimas ou com betaína natural resultou em desempenho semelhante ao das aves do tratamento Controle. Entretanto, a associação entre os aditivos não se constituiu uma alternativa satisfatória para melhorar o desempenho das aves, embora tenha resultado em custo de alimentação mais baixo que os demais tratamentos. / The broiler of this study was evaluate the effects of an enzyme complex containing protease, xylanase and amylase, associated or not with betaíne, added to broiler diets on the performance of the birds and economic results. Day-old male Cobb 500 broiler chicks (924) with average weight of 45,8 g were distributed to four treatments and seven replicates per treatment in a completely randomized design. The experimental was a pen with 33 birds. The treatments were: Control unsupplemented diets based on corn and soy bean meal; Enz Diets containing enzymes (protease, xylanase and amylase); Bet Diets containing natural betaína; Enz+Bet association of the two previous treatments. The experimental period comprised the pre-starter, starter, grower and finisher pfases. At seven, 21, 35 and 41 days of age the chickens and feeders were weighed to determine the average weight, average feed intake, average weight gain, and feed conversion of the birds. Viability, productivity index, and feeding cost were also determined. On days 1 to 7 addition of enzymes or betaína to the feeds did not result in significant differences in performance (P>0,05). In the period from 1 to 21 days of age, the treatment Enz+Bet had a lower average feed intake (P<0,05) compared to Enz; however, average weight gain and feed conversion were similar (P>0,05). Compared to the Control, the performance of birds in the treatments Enz or Bet was not significantly affected (P>0,05). Linewise, the treatments Enz and Bet resulted in performance similar to the Control (P>0,05) in the period from 1 to 35 days. In the overall period of 41 days, the chickens receiving diets formulated to contain enzymes or betaína had a performance very similar to those fed the Control diet, indicating that the supplements used resulted in the expected effects. There were no differences among treatments in cost of feed per kg of chicken (P>0,05). These additives may be used as components of broilers diets depending on economic considerations.