Karla Paola Picoli

Use of Vitamin D3 and Its Metabolites in Broiler Chicken Feed on Performance, Bone Parameters and Meat Quality

The objective of this experiment was to assess the use of different vitamin D metabolites in the feed of broiler chickens and the effects of the metabolites on performance, bone parameters and meat quality. A total of 952 one-day-old male broiler chicks were distributed in a completely randomised design, with four treatments, seven replicates and 34 birds per experimental unit. The treatments consisted of four different sources of vitamin D included in the diet, D3, 25(OH)D3, 1,25(OH)2D3, and 1α(OH)D3, providing 2000 and 1600 IU of vitamin D in the starter (1 to 21 d) and growth phases (22 to 42 d), respectively. Mean weight, feed:gain and weight gain throughout the rearing period were less in animals fed 1α(OH)D3 when compared with the other treatments (p<0.05). No significant differences were noted among the treatments (p>0.05) for various bone parameters. Meat colour differed among the treatments (p>0.05). All of the metabolites used in the diets, with the exception of 1α(OH)D3, can be used for broiler chickens without problems for performance and bone quality, however, some aspects of meat quality were affected.

Dietary glycine+serine responses of male broilers given low-protein diets with different concentrations of threonine

Abstract 1. The objective of this study was to determine the optimum glycine+serine (Gly+Ser) concentration in low-crude protein (CP) diets that have adequate or high concentrations of dietary threonine (Thr) for broiler chickens in the initial growth phase. 2. Treatments consisted of four concentrations of dietary Gly+Ser (18.4; 19.8; 21.2 and 22.6 g/kg) and two concentrations of dietary Thr (9.3 and 10.7 g/kg, corresponding to 100 and 115% of the required Thr, respectively). 3. At 21d, interactions were observed between dietary Gly+Ser and Thr concentrations for the feed conversion ratio, creatine content in the pectoral muscles and serum concentrations of uric acid. There was a quadratic effect of the concentrations of Gly+Ser in the diets with 9.3 g Thr/kg on the feed conversion ratio and creatine content in the pectoral muscles, with an optimisation concentration of 20.8 and 21.1 g Gly+Ser/kg, respectively. 4. Diets containing 10.7 g Thr/kg negatively affected the feed conversion ratio, relative breast weight, creatine content in the pectoral muscles, serum concentrations of uric acid and ammonia in poultry compared to diets containing 9.3 g Thr/kg. 5. The need for Gly+Ser in diets with low-protein concentration (190 g CP/kg) and adequate concentration of Thr (9.3 g/kg) is 20.8 g/kg for broilers in the 1- to 21-d phase.

Effect of dietary restriction and hay inclusion in the diet of slow-growing broilers

The objective of this study was to evaluate the effect of dietary restriction and inclusion of alfalfa (Medicago sativa L.) and Bermudagrass (Cynodon dactylon cv Coastal) hays in the diets of ISA Label JA57 slow-growing male broilers on performance, gastrointestinal tract characteristics, and economic viability. A total of 272 broilers at 21 days old were distributed in a randomized experimental design with four treatments, four replicates, and 17 birds per experimental unit. The treatments consisted of ad libitum concentrated feed (control intake), feed restriction (80% of the control intake), and feed restrictions with supplementation of alfalfa hay (80% of the control intake+20% alfalfa) or Bermudagrass hay (80% control intake+20% Bermuda). Dietary restriction, with and without hay inclusion, negatively affected (P<0.05) the weight gain of the birds; however, feed conversion was improved (P<0.05) for animals that underwent only restricted feeding, which also had the best economic indices. Birds subjected to dietary restriction and inclusion of hays showed changes (P<0.05) in the gastrointestinal organs and intestinal morphology.

Utilização da vitamina D3 e seus metabólitos na alimentação de frangos de corte sobre parâmetros imunológicos e morfometria intestinal

Os efeitos da suplementacao da vitamina D3 e de seus diferentes metabolitos foram avaliados na resposta imune e na morfometria intestinal de frangos de corte. Foram utilizados 952 frangos de corte de um dia de idade, distribuidos em um delineamento inteiramente casualizado, com quatro tratamentos, sete repeticoes e 34 aves por unidade experimental. Os tratamentos foram constituidos por quatros diferentes fontes de vitamina D3: colecalciferol (D3), 25-hidroxicolecalciferol (25(OH)D3), 1,25-dihidroxicolecalciferol (1,25(OH)2D3) e 1α-hidroxicolecalciferol (1α(OH)D3). As diferentes fontes foram incluidas na dieta, fornecendo 2000 e 1600 UI de vitamina D, nas fases pre-inicial, inicial e de crescimento, respectivamente. O peso relativo do intestino delgado diferiu entre os tratamentos aos 7, 21 e 42 dias e o peso relativo do figado somente aos 42 dias de idade. Os demais orgaos e parâmetros imunologicos avaliados (peso dos orgaos linfoides, reacao de hipersensibilidade cutânea basofilica, avaliacao da atividade de macrofagos, dosagem de nitrito e perfil heterofilo: linfocito foram similares entre os animais alimentados com os diferentes metabolitos. Houve efeito (P 0,05) dos tratamentos. Os parâmetros imunologicos nao foram afetados pelos diferentes metabolitos de vitamina D. Os diferentes metabolitos de vitamina D afetaram positivamente a morfometria intestinal na altura de vilo na fase inicial, sendo os melhores resultados obtido pelos animais alimentados com 1,25(OH)2D3, contudo os parâmetros imunologicos foram similares entre os metabolitos estudados.