ABSTRACT This paper aims to describe and evaluate FiT, a software that streamlines the process of analysing animal growth curves. It is characterized as a web-based software, developed using the Python and R languages, that adjusts the parameters of the classical nonlinear models Brody, Von Bertalanffy, Logistic and Gompertz. These parameters are estimated using the nlsLM function from the minpack.lm package of R. For model comparison, FiT calculates the mean square of the residuals, coefficient of determination, Akaike information criterion, […]

ABSTRACT Mothers must allocate limited resources between raising their offspring and maintaining their own biological functions. In both wild and livestock populations, food availability fluctuates with climate, soil fertility, and rainfall, challenging mothers and calves when environmental quality declines. This study evaluated whether maternal investment is influenced by progeny sex and environmental conditions, using coefficients of variation as a measure of evolvability. We analyzed three pre-weaning growth traits in cattle: birth weight (BW), body weight at 120 days (BW120), and […]

ABSTRACT This study investigated the diet of laying hens containing selenium in organic, inorganic, and Se-Met complex encapsulated with chitosan was investigated in order to enrich eggs and their oxidative stability. The microencapsulation process was performed using two molecular weights of chitosan (150 and 250 kDa) and the ratio of chitosan to Se-Met (1:1.5 and 1:2) in order to achieve the best encapsulated selenium according to evaluation of particle size, zeta potential, and encapsulation efficiency. Subsequently, 450 Hy-Line W36 laying […]

ABSTRACT This study aimed to investigate whether the beef cattle production system enhances the commercial value of beef carcasses. We assessed which characteristics of the production system most significantly influence the carcass grade and consequently the value generated, using a database from a commercial property analyzed through mixed factor analysis. The dataset included information on 3,612 cattle slaughtered commercially from a property in Mato Grosso do Sul in 2019. Qualitative explanatory variables considered were breed, sex, type of finishing, slaughterhouse, […]

ABSTRACT Five bagger configurations were evaluated for their effects on physical characteristics, fermentation, and starch degradability in corn (Exp. 1) and sorghum (Exp. 2) grain silages. Both experiments were conducted using five treatments, involving baggers with different nominal power ratings (60, 75, and 90 hp; designated as M-60, M-75, and M-90). The treatments consisted of the following configurations: M-60 equipped with a standard roll; M-75 and M-90 equipped with intermediate and coarse rolls for corn; and fine and intermediate rolls […]

ABSTRACT The use of digital technologies and wearable sensors has advanced in precision livestock farming. However, there is still no clear definition of the most suitable models for the use of sensors in grazing animals, especially under tropical systems. Thus, we aimed to compare the performance of six predictive models for grazing cattle behavior and to evaluate different testing strategies. The study was conducted in a pasture area, using nine Tabapuã heifers monitored by triaxial accelerometers attached to the nape, […]

ABSTRACT Three experiments were carried out to evaluate the effects of the following commercial inoculants: Lactiplantibacillus plantarum, Lacticaseibacillus rhamnosus, and L. buchneri (LP+LB) at 2.5 × 105 CFU g−1; as well as L. rhamnosus, L. buchneri, and L. diolivorans (LB+LD) at 2.5 × 105 CFU g−1; and the same inoculants at double dosage (2LB+2LD) at 5.0 × 105 CFU g−1. In Exp. 1, corn silage was uninoculated and inoculated with LP+LB and LB+LD and stored in 5-L jars for 15, […]

ABSTRACT The study evaluates the impact of feeding the same amount of corn grain at different times on animal production, carcass characteristics, and meat quality. At weaning, 60 steers (176 kg) were divided into six groups assigned to one of two dietary treatments (n = 3). In dietary treatment one (DT1), steers grazed an endophyte-free tall fescue pasture to 330 kg of LW and then (Phase-3) were fed a corn grain-based diet for 90 d before slaughter. In dietary treatment […]

ABSTRACT This study evaluated the effects of xylanase combined with increasing amylase levels in broiler diets containing protease and phytase on performance, intestinal histomorphology, cecal short-chain fatty acid profile, serum interleukin (IL) levels, and economic viability over a 28-d period. A completely randomized experimental design was adopted in a 2 × 3 + 1 factorial arrangement (100 or 200 U kg−1 amylase × 0, 1,000 and 2,000 U kg−1 xylanase + positive control (PC), without enzymes), with seven replicates of […]

ABSTRACT This study quantified production risks and economic feasibility in tropical pasture-based beef systems by integrating a rule-based Minimum Module (MM) framework with Monte Carlo simulation (@Risk 8.0) in Excel 365 using a Microsoft Visual Basic 6.0 algorithm. Twelve scenarios combining low (0.5 animal unit [AU] ha⁻1), medium (1.0 AU ha⁻1), and high (1.5 AU ha⁻1) stocking rates across 2017–2020 were each run with 10,000 stochastic iterations to identify the smallest viable herd size and pasture area that ensured non-negative […]

ABSTRACT The aim of the study was to evaluate the inclusion of carotenoids in the diet of layers on the production performance, quality and oxidative stability of eggs during storage. A total of 240 Dekalb White laying hens, 76 weeks of age, were used. The hens were allocated in completely randomized design with eight diets (control diet (CD); astaxanthin (AXT), 10 mg kg⁻1; lutein (LUT), 10 mg kg⁻1; lycopene (LYC), 10 mg kg⁻1; AXT + LUT, 10 mg kg⁻1 each; […]