Digestible Threonine Levels in the Starter Diet of Broilers Derived from Breeders of Different Ages Laboissiere M III Racanicci AMC I Café MB II,IV

ABStRACt The aim of this study was to evaluate the effect of digestible threonine supplementation in the starter diet on the performance, intestinal parameters, and nutrient metabolism of broilers derived from breeders of different ages. In total, 480 one-day-old Cobb chicks, derived from 38-or 49-week-oldbreeders, were housed in experimental battery cages until 21 days of age and fed four different threonine levels (800, 900, 1,000, or 1,100 mg/kg) in the starter feed. A completely randomized experimental design in a 2x4 factorial arrangement (breeder age x threonine levels) was applied, totaling eight treatments with five replicates of 12 birds each. Broilers from older breeders fed 800 mg digestible threonine/kg of diet presented higher weight gain, with a positive linear effect. There was also an interaction between breeder age and threonine levels for the weight gain of 21-d-old broilers supplemented at maximum level of 1,003 mg Thr/kg diet during the starter phase. There was no effect of breeder age or threonine levels on nutrient metabolism during the period of 17-21 days. There was no influence of breeder age or threonine levels in the starter diet on intestinal morphometric measurements, absorption area, or percentage of goblet cells

Digestible Threonine Levels in the Starter Diet of Broilers Derived from Breeders of Different Ages

ABSTRACT The aim of this study was to evaluate the effect of digestible threonine supplementation in the starter diet on the performance, intestinal parameters, and nutrient metabolism of broilers derived from breeders of different ages. In total, 480 one-day-old Cobb chicks, derived from 38-or 49-week-oldbreeders, were housed in experimental battery cages until 21 days of age and fed four different threonine levels (800, 900, 1,000, or 1,100 mg/kg) in the starter feed. A completely randomized experimental design in a 2x4 factorial arrangement (breeder age x threonine levels) was applied, totaling eight treatments with five replicates of 12 birds each. Broilers from older breeders fed 800 mg digestible threonine/kg of diet presented higher weight gain, with a positive linear effect. There was also an interaction between breeder age and threonine levels for the weight gain of 21-d-old broilers supplemented at maximum level of 1,003 mg Thr/kg diet during the starter phase. There was no effect of breeder age or threonine levels on nutrient metabolism during the period of 17-21 days. There was no influence of breeder age or threonine levels in the starter diet on intestinal morphometric measurements, absorption area, or percentage of goblet cells

Back surface measurements by rasterstereography for adolescent idiopathic scoliosis: from reproducibility to data reduction analyses

Purpose: Aim of this cross-sectional study was to evaluate the reproducibility of back surface measurements obtained by rasterstereography (RS) in adolescents with idiopathic scoliosis (AIS), and to identify the most informative RS parameters through a multi-step reduction analysis approach. Methods: Sixty-six AIS were assessed with a RS scanner. The assessment was repeated in the same day 15 min after the first scan and after 1 week. Intraclass-correlation analyses were conducted to verify the consistency of the measurements. A multi-step reduction technique including correlation, principal component analysis (PCA) and regression was employed to extract a core-set of key RS parameters. Results: Back surface measures were obtained from 66 AIS aged 10–17 years (median 13), with a mild Scoliosis angle < 25 (median 20). The reliability over the 3 sessions proved high to very high, with all the intraclass correlation coefficients ≥ 0.8 and 32 out of 48 coefficients ≥ 0.9. Only 8 of the 12 parameters provided by the RS device showed significant inter-item correlations and were therefore considered for further analyses. PCA extracted 4 of them, which entered the final regression analysis. High beta coefficients were found for 2 predictors: “Surface rotation-rms” and “Side deviation-rms,” which were found to be significantly associated with the dependent variable “Scoliosis angle.” Conclusions: Data showed that RS measurements are reliable in AIS with mild severity of scoliosis. “Surface rotation” and “Side deviation” were the best descriptors of the Scoliosis angle and should be considered as key parameters when surveilling AIS with mild curves by RS surface topography. Graphical abstract: These slides can be retrieved under Electronic Supplementary Material. [Figure not available: see fulltext.