The objective of this study was to evaluate the intake and digestibility of nutrients, emission of enteric CH4, and productive performance of Nellore bulls grazing Urochloa brizantha cv. Marandu palisade grass pastures during the rainy season, receiving an energy supplement or mineral supplement, with or without the inclusion of phytogenic additives. Forty-eight Nellore bulls were treated with: (1) energy supplement without the inclusion of phytogenic additives; (2) energy supplement with the inclusion of phytogenic additives; (3) mineral supplement without the inclusion of phytogenic additives; and (4) mineral supplement with the inclusion of phytogenic additives. Consumption of total dry matter (DM), crude protein (CP), apNDF, and energy; digestibility of DM, CP, and energy; average daily gain; stocking rate; and gain per area were higher in animals consuming energy supplements than those consuming mineral supplements. Digestibility of DM, NDF, and energy levels were lower in animals that consumed phytogenic additives. Compared with mineral supplements, the supply of energy supplements provides higher nutrient intake, increases enteric CH4 emission, and improves nutrient digestibility, providing a greater productive performance. The inclusion of phytogenic additives negatively affected nutrient intake and digestibility, did not reduce enteric CH4 emission, and influenced productive performance.

Knowledge of animal behavior can be indicative of the well-being, health, productivity, and reproduction of animals. The use of accelerometers to classify and predict animal behavior can be a tool for continuous animal monitoring. Therefore, the aim of this study was to provide strategies for predicting more and less frequent beef cattle grazing behaviors. The behavior activities observed were grazing, ruminating, idle, water consumption frequency (WCF), feeding (supplementation) and walking. Three Machine Learning algorithms: Random Forest (RF), Support Vector Machine (SVM) and Naïve Bayes Classifier (NBC) and two resample methods: under and over-sampling, were tested. Overall accuracy was higher for RF models trained with the over-sampled dataset. The greatest sensitivity (0.808) for the less frequent behavior (WCF) was observed in the RF algorithm trained with the under-sampled data. The SVM models only performed efficiently when classifying the most frequent behavior (idle). The greatest predictor in the NBC algorithm was for ruminating behavior, with the over-sampled training dataset. The results showed that the behaviors of the studied animals were classified with high accuracy and specificity when the RF algorithm trained with the resampling methods was used. Resampling training datasets is a strategy to be considered, especially when less frequent behaviors are of interest.

The objective of this study was to evaluate the effect of the addition of a phytogenic compound blend (PHA) containing hydrolyzable tannins, carvacrol, and cinnamaldehyde oil to mineral salt or energy supplementation on the rumen microbiota and nitrogen metabolism of grazing Nellore cattle. Eight castrated Nellore steers were distributed in a double-Latin-square 4 × 4 design, with a 2 × 2 factorial arrangement (two types of supplements with or without the addition of the PHA), as follows: energy supplement without the PHA addition (EW); energy supplement with the PHA addition (EPHA); mineral supplement without the addition of the PHA (MW); mineral supplement with the PHA addition (MPHA). Steers that received supplements with the PHA have a lower ruminal proportion of valerate (with the PHA, 1.06%; without the PHA, 1.15%), a lower ruminal abundance of Verrucomicrobia, and a tendency for lower DM digestibility (with the PHA, 62.8%; without the PHA, 64.8%). Energy supplements allowed for higher ammonia concentrations (+2.28 mg of NH3-N/dL), increased the propionate proportion (+0.29% of total VFA), and had a higher ruminal abundance of Proteobacteria and Spirochaetae phyla in the rumen. The PHA addition in the supplement did not improve nitrogen retention, reduced the ruminal proportion of valerate, and had a negative impact on both the total dry-matter digestibility and the abundance of several ruminal bacterial groups belonging to the Firmicutes and Verrucomicrobia phyla.

This study aimed to evaluate the forage mass and nutritional value (NV) of Guinea Massai grass (Megathyrsus maximus × Megathyrsus infestum) in an open pasture (OP) or the silvopastoral system (SPS) at different stages of development (SDs). The experimental design was completely randomized, with five replications. The treatments were distributed in a factorial scheme 2 × 4, corresponding to types of systems (OP and SPS) and four SD (vegetative stage—S1, pre-flowering—S2, full flowering—S3 and maturity after flowering—S4). There was no interaction of the system × stage of plant development in any of the variables evaluated. The production of forage mass and Guinea Massai grass morphological components did not differ (p > 0.05) between SPS and OP. However, they differed between the SDs (p ≤ 0.05), with an increasing linear effect for forage mass, percentage of the stem, and dead material, and decreasing for leaf percentage and leaf: stem ratio. Only protein content differed (p < 0.05) among the chemical composition variables between culture systems. The shading caused by the SPS did not decrease the forage mass, NV, and in vitro dry matter digestibility of Guinea Massai grass compared to the system in OP. The advance of the SD of Guinea Massai grass increases the forage mass, with higher proportions of morphological components of low NV, such as stem and dead material. Silvopastoral system of Guinea Massai grass and eucalyptus is effective to prolongate the grazing season, with a greater amount of green leaves in the sward and better NV, without compromising herbage mass production in the forage growing season.

The objective of this study was to evaluate the inclusion of different levels of 0.0%; 0.7%; 1.4% and 2.1% of Noni (Morinda citrifolia) in the feeding of lambs regarding ingestive behavior and physiological variables. The experiment was carried out in a double Latin (4x4) experimental design with eight animals, consisting of four periods and four experimental rations. Eight lambs with no defined racial pattern were used, with mean initial body weight (BW) of 23.74 ± 1.00 kg. The ingestive behavior was performed during 24 hours, always on the last day of each experimental period. The physiological variables and the environmental variables were measured during three days of each period. Data were submitted for analysis of variance and, when significant, regression equation was applied at 5% of probability. Statistical analysis was performed considering the subdivision of the plot, which consisted of the diurnal and nocturnal evaluation times for the ingestive behavior and the morning and afternoon periods for the physiological variables. The inclusion of Noni in fed lambs did not change (p > 0.05) the time spent with ingestive behaviors for dry matter intake (DMI), rumination (RUM), idleness (IDL), water intake (WIN) and other activity (OAC). However, the daytime During the period there was gr eater (p < 0.05) time use for DMI, WIN and OAC. Inclusion of Noni to diets provided higher (p > 0.05) time use during the night time for RUM and IDL. The physiological variables were not influenced (p > 0.05) by the inclusion of Noni in the diets of lambs. However, higher mean (p < 0.05) body temperature of the front and rear, rectal temperature and respiratory rate of the lambs were observed during the afternoon. The inclusion of up to 2.1% of Noni in lamb feed does not alter ingestive behavior and physiological variables. However, the consumption of dry matter and water is higher during the diurnal period, while rumination and idleness are more active during the night period.