RESUMO
An experiment was carried out to verify the response to the Ca reduction levels of diets with different vitamin D sources on performance, bone mineral deposition, serum concentrations, digestibility, carcass characteristics, and meat quality of broiler chickens in the period from 1 to 42 days reared in thermoneutral environment. A total of 504 male broilers with one day of age and average weight of 43.27±1.08 g were housed in climatic chambers and distributed in a completely randomized design. The study consisted of a 4 × 2 factorial, with four Ca reduction levels (0, 10, 20, and 30%) and two vitamin D sources (2760 IU of D3 or 25-OH-D3). The performance of animals at 21 and 42 days of age was not affected by Ca reduction by up to 30%, regardless of the vitamin source used. Dietary reduction from 10% decreased serum Ca concentrations. The use of vitamin D3 provided a serum P level greater than the 25-OH-D3. Calcium reduction decreased serum 25-OH-D3 levels. No effect of vitamin source or Ca levels on broiler carcass characteristics was observed at 42 days. The vitamin source did not influence meat quality, while Ca reduction of the diet provided lower losses by thawing and cooking and higher initial pH values. The b* color was reduced in diets with lower Ca levels of the diet. Reducing Ca up to 30% does not affect the performance and carcass characteristics, regardless of the vitamin D source used. The quality of broiler meat is improved with the Ca reduction in the diet, but the vitamin used has no effect on such characteristics. We can conclude, based on the results of performance, blood, and bone, that the performance variables are not adequate to determine the actual requirement of Ca, since as it is a priority to maintain performance, bone mineral mobilization occurs, which may compromise the carcass quality of the birds.(AU)
Assuntos
Animais , Galinhas/fisiologia , Cálcio/administração & dosagem , Ração Animal/análise , Calcificação Fisiológica , Colecalciferol/análogos & derivados , Fenômenos Fisiológicos da Nutrição AnimalRESUMO
Two trials were conducted to determine the non-phytate phosphorus (nPP) requirement for broiler under heat stress. In both trials, birds were distributed in a completely randomized 4 × 2 factorial design with four nPP concentrations: 0.25, 0.35, 0.45, and 0.55%, and two Ca supply techniques: Ca fixed at 0.899% (CaF) or varying along with nPP aiming a 2:1 Ca to nPP ratio (CaV). Both trials had eight pens/treatment, with nine and five birds/pen for exp. 1 and exp. 2, respectively. nPP concentration had no effect on feed intake (FI), body weight gain (BWG), feed conversion ratio (FCR), nor fat deposition ratio (FDR). nPP levels showed a linear effect on protein deposition ratio (PDR) only for CaF diets. The nPP levels had a significant effect, regardless the technique adopted, on tibia phosphorus (TibP), which varied quadratically, on tibia calcium (TibCa) that increased quadratically and linearly, respectively, on CaF and CaV diets, and on tibia ash (TibAsh) that showed a quadratic effect for both. No effect was observed on Ca to P ratio in the tibia (TibCa:TibP). The nPP levels showed a linear increase effect over phosphorus intake (PI), phosphorus excreted (PE), and phosphorus retained (PR), and a linear decrease effect on phosphorus retention coefficient (PRC). Therefore, the nPP requirement for broilers from 8 to 21 days of age that provided better performance and bone variables were 0.250 and 0.484%, respectively, for CaF diets and 0.250 and 0.511%, respectively, for CaV diets.
Assuntos
Cálcio da Dieta/administração & dosagem , Galinhas/metabolismo , Temperatura Alta , Fósforo na Dieta/administração & dosagem , Estresse Fisiológico , Ração Animal/análise , Fenômenos Fisiológicos da Nutrição Animal , Animais , Dieta/veterinária , Masculino , Fósforo , Ácido Fítico , Distribuição Aleatória , Tíbia/química , Aumento de PesoRESUMO
This work was aimed to evaluate milk quality parameters according to three levels of specialization of milk production units in different districts of West Santa Catarina´s State, Brazil. Characterization of milk production units was carried out using a questionnaire in 29 farms as a tool for data collection, applied during a visit to the farm. At the time, 58 milk samples were collected from cooling tanks to determine the levels of fat, protein, lactose, somatic cell count (SCC) and total bacteria count (TBC). Considering the information obtained the milk production units were classified as specialized (E), semi-specialized (SE) and not specialized (NE). The database was subjected to multivariate methods of statistical analysis with the use of Principal Component Analysis (PCA) and Redundancy analysis (RDA). The results indicated that variables that most influence milk quality are: time in the activity, area with perennial pasture, gross income from milk activity, type of milking, teat washing and method of reproduction. Results showed that despite lower percentages of fat and protein, the increased level of specialization provides milk of better quality due to the low rates of SCC and TBC, which leads to higher income from this type of activity. In specialized farms where milk activity has a high economic importance, producers are encouraged to adopt better hygiene practices
O trabalho foi realizado com o objetivo de avaliar os parâmetros de qualidade do leite segundo três níveis de especialização das unidades de produção de leite de diferentes municípios do Oeste Catarinense. A caracterização das unidades de produção de leite foi realizada utilizando-se um questionário em 29 propriedades rurais como instrumento de coleta de dados, aplicado durante a visita à propriedade rural. Também foram coletadas 58 amostras de leite dos tanques de resfriamento para a determinação dos níveis de gordura, proteína, lactose, contagem de células somáticas (CCS) e contagem bacteriana total (CBT). Considerando-se as informações obtidas, as unidades de produção de leite foram classificadas em: especializado (E), semiespecializado (SE) e não especializado (NE). Os dados foram submetidos a métodos multivariados de análise estatística, com o emprego da Análise de Componentes Principais (ACP) e da Análise de Redundância (RDA). Os resultados das análises indicam que o tempo na atividade, a área com pastagem perene, a renda bruta com bovinos de leite, o tipo de ordenha, a lavagem dos tetos e o método de reprodução são as variáveis que mais interferem na qualidade do leite. O aumento do nível de especialização da atividade leiteira, mesmo produzindo menor porcentagem de gordura e proteína no leite, proporciona a obtenção de leite de melhor qualidade, devido aos menores índic
RESUMO
This work was aimed to evaluate milk quality parameters according to three levels of specialization of milk production units in different districts of West Santa Catarina´s State, Brazil. Characterization of milk production units was carried out using a questionnaire in 29 farms as a tool for data collection, applied during a visit to the farm. At the time, 58 milk samples were collected from cooling tanks to determine the levels of fat, protein, lactose, somatic cell count (SCC) and total bacteria count (TBC). Considering the information obtained the milk production units were classified as specialized (E), semi-specialized (SE) and not specialized (NE). The database was subjected to multivariate methods of statistical analysis with the use of Principal Component Analysis (PCA) and Redundancy analysis (RDA). The results indicated that variables that most influence milk quality are: time in the activity, area with perennial pasture, gross income from milk activity, type of milking, teat washing and method of reproduction. Results showed that despite lower percentages of fat and protein, the increased level of specialization provides milk of better quality due to the low rates of SCC and TBC, which leads to higher income from this type of activity. In specialized farms where milk activity has a high economic importance, producers are encouraged to adopt better hygiene practices
O trabalho foi realizado com o objetivo de avaliar os parâmetros de qualidade do leite segundo três níveis de especialização das unidades de produção de leite de diferentes municípios do Oeste Catarinense. A caracterização das unidades de produção de leite foi realizada utilizando-se um questionário em 29 propriedades rurais como instrumento de coleta de dados, aplicado durante a visita à propriedade rural. Também foram coletadas 58 amostras de leite dos tanques de resfriamento para a determinação dos níveis de gordura, proteína, lactose, contagem de células somáticas (CCS) e contagem bacteriana total (CBT). Considerando-se as informações obtidas, as unidades de produção de leite foram classificadas em: especializado (E), semiespecializado (SE) e não especializado (NE). Os dados foram submetidos a métodos multivariados de análise estatística, com o emprego da Análise de Componentes Principais (ACP) e da Análise de Redundância (RDA). Os resultados das análises indicam que o tempo na atividade, a área com pastagem perene, a renda bruta com bovinos de leite, o tipo de ordenha, a lavagem dos tetos e o método de reprodução são as variáveis que mais interferem na qualidade do leite. O aumento do nível de especialização da atividade leiteira, mesmo produzindo menor porcentagem de gordura e proteína no leite, proporciona a obtenção de leite de melhor qualidade, devido aos menores índic