Inclusion of shrimp waste meal in diet of free-range chickens

Shrimp waste meal (SWM) is a by-product from the processing of shrimp for human consumption. The value of SMW in feeding poultry is not well documented. The objective of this study was to determine the energy value and optimal inclusion level of SWM in the diet of growing chickens. A total of 180 one-day-old broilers were randomly assigned to five treatments with 0, 50, 100, 150 and 200 g/kg of SWM included in their diet. There were six replicates of six birds for each treatment. Dry matter intake (DMI) was not affected by the level of SWM that was fed. Retained dry matter varied from 72.39% in the diet that did not contain SWM to 66.97% in the diet with 200 g/kg of SWM. Nitrogen retention (NR) ranged from 54.70% to 70.10%; N ingested was between 18.71% and 24.03%. Energy intake ranged from 73.57% to 69.33% for the control and the diet with 200 g/kg of SWM, respectively. NR improved with increasing SWM inclusion levels. The apparent metabolizable energy (AME) and corrected apparent energy metabolizable (AMEn) ranged from 2928 to 2527 kcal/kg and 2774 to 2329 kcal/kg, respectively, relative to the control and 200 g/kg SWM diets. The energy consumption, in kcal/kg, of SWM consumed was AME = 2332-6.971 x SWM and AMEn = 2113-8.128 x SWM. High levels of SWM reduce the dry matter metabolization coefficient and metabolizable energy values in broilers during the growing phase, so it is recommended that up to 100 g/kg should be included, which would provide an AMEn of 1300.2 kcal/kg for free-range chickens in dry matter

Níveis de cálcio e fósforo disponível em rações com fitase para frangos de corte nas fases pré-inicial e inicial Calcium and available phosphorus levels in diets with phytase for broilers in the pre-starter and starter phases

Dois experimentos independentes, um na fase pré-inicial (1 a 7 dias) e outro na fase inicial (8 a 21 dias de idade), foram realizados com frangos de corte para avaliar níveis de cálcio e fósforo disponível (Pdisp) em rações suplementadas com 500 unidades de atividade de fitase/kg de ração. Cada experimento constou de um ensaio de desempenho e outro de metabolismo e foi conduzido em esquema fatorial (3 × 4) + 1, sendo três níveis de Pdisp (0,42; 0,37; 0,32% na fase pré-inicial e 0,39; 0,34; 0,29% na fase inicial), quatro níveis de cálcio (0,94; 0,84; 0,74; 0,64% na fase pré-inicial e 0,88; 0,78; 0,68; 0,58% na fase inicial) mais uma ração controle. O controle correspondeu à única ração sem fitase e continha 0,47% de Pdisp e 0,94% de cálcio (fase pré-inicial) ou 0,44% de Pdisp e 0,88% de cálcio (fase inicial). Nos ensaios de desempenho, aos 7 e aos 21 dias de idade, foram avaliados o consumo de ração, o ganho de peso, a conversão alimentar e o teor de cinzas na tíbia. Nos ensaios de metabolismo, determinaram-se a energia metabolizável aparente corrigida pelo balanço de nitrogênio (EMAn) das rações e os coeficientes de digestibilidade da matéria seca (CMMS). Na fase pré-inicial, os níveis de cálcio influenciaram o consumo de ração, a EMAn e o CMMS e, na fase inicial, afetaram o conteúdo de cinzas ósseas, a EMAn e o CMMS. Os níveis de Pdisp influenciaram o teor de cinzas na tíbia, a EMAn e o CMMS na fase pré-inicial e as cinzas ósseas e o CMMS na fase inicial. Adicionando 500 unidades de atividade de fitase/kg de ração, é possível reduzir, respectivamente, os níveis de cálcio e Pdisp para 0,64% e 0,37% na fase pré-inicial e 0,58% e 0,29% na fase inicial, pois essa redução não tem efeito negativo sobre o desempenho e a mineralização óssea dos frangos de corte nessas fases.<br>Two independent experiments, one in pre-starter phase (1 to 7 days) and the other in the starter phase (8 to 21 days of age), were carried out with broilers to evaluate levels of calcium and available phosphorus (aP) in diets supplemented with 500 units of phytase activity/kg of diet. Each experiment consisted of a performance and a metabolic assay, and was conducted in a factorial schedule (3 × 4) + 1, with three aP levels (0.42, 0.37, 0.32% in the pre-starter phase and 0.39, 0.34, 0.29% in the starter phase), four calcium levels (0.94, 0.84, 0.74, 0.64% in the pre-starter phase and 0.88; 0.78, 0.68, 0.58% in the starter phase) plus a control diet. The control corresponded to the only diet without phytase and contained 0.47% of aP and 0.94% of calcium (pre-starter phase) or 0.44% of aP and 0.88% of calcium (starter phase). In the performance assays, at 7 and 21 days of age the feed intake, weight gain, feed conversion and the ash content in the tibia were evaluated. In the metabolic assays the apparent metabolizable energy corrected for nitrogen balance (AMEn) of the feed, and dry matter digestibility coefficients (DMDC) were determined. Calcium levels influenced the feed intake, AMEn and DMDC in the pre-starter phase, and in the starter phase they influenced bone ash, AMEn and DMDC. The aP levels influenced the content of tibia ash, AMEn and DMDC in the pre-starter phase, and bone ash and DMDC in the starter phase. By adding 500 units of phytase activity/kg of diet, it is possible to reduce, respectively, the calcium and aP levels to 0.64% and 0.37% in the pre-starter phase, and to 0.58% and 0.29% in the starter phase, since this reduction does not cause a negative effect on performance or bone mineralization of broilers in the evaluated periods