ABSTRACT This study evaluated the technical and economic feasibility of long-acting progesterone (P4LA) supplementation in Nellore cows by assessing conception rates, pregnancy loss, cost per pregnancy, and progeny performance. A total of 452 cows (with a body condition score, BCS, ranging from 2.25 to 3.75) underwent a conventional three-handling timed artificial insemination (TAI) protocol. After TAI (D0), cows were allocated to a control group (n = 234; saline solution) or a P4LA group (n = 218; 150 mg, intramuscular, IM, […]

ABSTRACT Condensed tannins and α-tocopherol are important antioxidants produced by forage plants, with potential benefits for grassland sustainability and ruminant productivity. The objective of this study was to quantify the concentrations of phenolic compounds in Desmodium incanum DC. and Paspalum notatum Flüggé in subtropical grasslands of the Brazilian Pampa and Atlantic Forest. Pasture samples were randomly collected from eight sites selected to represent different climatic conditions of the southernmost grasslands of Brazil. Six sites were located in the Pampa biome […]

ABSTRACT This survey was conducted to assess the fermentation profile and nutritional composition of tropical grass silages on beef farms. Grass silage samples were collected from 51 beef cattle operations located in four Brazilian states (MT, MS, SP, and PR). Additionally, a questionnaire about silage production and utilization was completed. The lack of correlation between the concentration of n-butyric acid and the IVDMD (P = 0.368) indicated that fermentation pattern and nutritional value were independent and therefore required separate grouping […]

ABSTRACT The aim of this study was to predict pregnancy in beef heifers, identifying the most impactful variables using computational modelling. Developmental data of 98 heifers up to 480 days (16 months) of age (Charolais, Nellore, and their crossbreeds) were used. At the beginning and end of the mating season initial body weight (IBW), initial body condition score (IBS), final body weight (FBW), and final body condition score (FBS) were assessed. The age at the start of the mating season […]

ABSTRACT The objective of this study was to evaluate how male age, semen extender, cooling (equilibration) time and freezing method influence the quality of Brahman bulls’ sperm after cryopreservation, as measured by Computer-Assisted Sperm Analysis (CASA) parameters. Six Brahman bulls, with an average age of 48.6±11.5 months, were used. Two ejaculates were collected for each animal on different days, with an interval of approximately one week between collections. Semen was diluted with three extenders: Andromed®, BioXcell®, and OptiXcell®. The samples […]

ABSTRACT This study aimed to evaluate commercially purified essential oil compounds to assess molecule-specific effects when applied as additives to rehydrated corn grain silage (RCGS). Dry ground corn grains were rehydrated to 350 g/kg moisture and packed (>1,000 kg/m3) in 5-L plastic buckets. Treatments were prepared as a factorial arrangement of two storage lenghts (30 and 60 d) × fifteen strategies (compound × application rate), being: control RCGS; carvacrol at 200, 600 and 1,000 mg/kg fresh matter (FM); cinnamaldehyde at […]

ABSTRACT This study evaluated increasing dietary levels of Black wattle bark extract (BWE) on broiler performance, nutrient digestibility, intestinal histopathological score, and bone quality. A total of 240 male Cobb 500 broilers, eight days old, were distributed into five dietary treatments (0, 300, 500, 700, or 900 mg kg−1 BWE) in a randomized block design, housed in metabolic cages, with eight replicates of six birds each. Performance was evaluated from 8 to 28 days of age, nutrient digestibility from 18 […]

ABSTRACT The experiment aimed to assess the impact of exogenous protease in diets formulated with soybean meal (SBM) or black soldier fly larvae meal (BSFLM) on nutrient retention and broiler performance. Forty-eight female Ross 308 chicks were assigned to a randomized block design study using a 2 × 2 factorial arrangement, with four treatments in total. The main factors considered were the protein source and the presence or absence of protease. Each experimental diet was fed to six pens of […]

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 […]