In conclusion, feeding 1% SDP in the starter period to broilers resulted in improved performance and health under both good and bad management and biosecurity standards independent of the type of ventilation. nutritional density, containing zinc bacitracin and CuSO4 from 0 to 28?d. After 10?d, both groups were fed common commercial diets. Performance data were analyzed together or by type of ventilation system: positive pressure or negative pressure. Birds were sent to market as they reached 3.05?kg; therefore, age at slaughter (AS) was evaluated as a dependent variable along with other performance measures. From the 100 farms in the trial, 35 (16 control and 19 SDP farms) were selected for the assessment of broilers health, biosecurity, and local management. For that, 6 broilers per farm at 14 2?d of age 3,4-Dehydro Cilostazol were necropsied and ileum sampled for the ISI methodology evaluation. Biosecurity and management were also evaluated to obtain the influence of those parameters on animal RGS8 health. SDP-fed birds demonstrated improved feed conversion ratio, reduced mortality, and 1?d less for AS ( 0.05) vs. control group ( 0.05) regardless of the type of ventilation. During necropsy, birds fed SDP showed lower coccidiosis and locomotor system lesions as the overall ISI score compared to controls. Histologic intestinal alterations were also lower in SDP-fed broilers ( 0.05). In conclusion, feeding 1% SDP in the starter period to broilers resulted in improved performance and health under both good and bad management and biosecurity standards independent of the type of 3,4-Dehydro Cilostazol ventilation. Overall, there was good agreement between the ISI method and performance improvements observed. spp. oocysts. The final ISI score is calculated as the sum of all parameters evaluated. The higher the final ISI total score, the worse the intestinal health of the animal (Kraieski et?al., 2017; Belote et?al., 2018, 2019). Biosecurity and Management Biosecurity and local management practices were evaluated to obtain the influence of those parameters on animal health. During each visit, in the 35 farms used for the ISI evaluation, farms were classified according to their biosecurity standards as good or bad based on the following observations: presence of a farm gate, a functional vehicle disinfection system at the farm’s gate, farm’s appearance (organized and clean), presence of appropriate fencing, and presence of barn seals. If more than half of these items were in place, biosecurity was regarded as good or otherwise considered bad. Management practices were also evaluated and regarded as good or bad based on the following observations: quality of drinking water (clarity/water flow [mL/1?min/presence of leaks]), nipple height, ambience (temperature, ventilation), feed’s physical appearance, feeder height, and litter quality (compaction and moisture). If more than half of these parameters were regarded as acceptable, the farm was considered to have good management, or otherwise considered bad. Statistical Analysis Data on AS, ADG, weight at processing, FCR, FCRA, and MT were provided by the broiler integrator. Complete descriptive statistics of all variables in general is included in the Supplementary Material (mean, median, SD, minimum, maximum, and skewness calculation). Mean, median, SD, and interquartile range by group are presented in Tables 4 and 3,4-Dehydro Cilostazol ?and5.5. The Shapiro-Wilk test was used to evaluate the adherence of data to a normal distribution, which revealed that all the 6 performance variables tested were asymmetric to normal distribution (test, e.g.) cannot be used to compare groups and the Mann-Whitney U test (nonparametric approach) was used to verify differences between farms fed with or without SDP for each variable separated by the type of housing. All performance parameters were analyzed using SPSS 20.0 (IBM, 2011) software (IBM Corp., Armonk, NY). Table?4 Effect of adding SDP at 1% in the starter diet from 0 to 10?d of age on overall performance. 0.05) between them. ab Means with different letters in the same column are significantly different in Mann-Whitney U test ( 0.05). Abbreviations: AS,?age at slaughter; FCR,?feed conversion ratio; FCRA,?feed conversion ratio adjusted to 2.8?kg; M,?mean; MD,?median; MT,?mortality; SDP, spray-dried plasma; WP,?weight at processing. Table?5 Effect of adding SDP at 1% in the starter diet from 0 to 10?d of age on overall performance in birds raised in farms with different ventilation systems. 0.05) between them. ab Means with different letters in the same column are significantly different in Mann-Whitney U test ( 0.05). Abbreviations: AS,?age at slaughter; FCR,?feed conversion ratio; FCRA,?feed conversion ratio adjusted to 2.8?kg; M,?mean;.