Juliana de Oliveira Santos Marcatto

Climate change has intensified the need to reduce greenhouse gas emissions, particularly methane (CH ₄ ) from enteric fermentation. Genetic selection has emerged as a promising mitigation strategy; however, studies on Bos taurus indicus , especially Nellore cattle, remain limited. This study aimed to estimate heritabilities and genetic correlations for CH ₄ emission traits and their relationships with feeding behaviour, feed efficiency, and performance, as well as to evaluate the direct and correlated responses to selection for lower CH ₄ emissions. Data were from 2418 Nellore cattle evaluated in feed efficiency trials. Traits included dry matter intake (DMI), feeding time per day (FTd), feed events per day (FEd), and feeding rate (FR), residual feed intake (RFI), average daily gain (ADG), and mid‐test body weight (MBW). Methane emissions were measured in 1153 animals using the SF ₆ tracer technique, providing daily CH ₄ emission (g/day), CH ₄ per unit of DMI (CH ₄ DMI, g/day), and residual CH ₄ (CH ₄ res). Variance components were estimated using the single‐step genomic BLUP (ssGBLUP) method through Bayesian inference. Heritability estimates were moderate for CH ₄ (0.25), CH ₄ DMI (0.14), CH ₄ res (0.14), and performance traits such as DMI (0.35), ADG (0.36), and MBW (0.40). Higher estimates were observed for feeding behaviour traits FTd (0.49) and FR (0.42). Genetic correlations between CH ₄ and production traits were high, particularly with DMI (0.79), ADG (0.90), and MBW (0.91), indicating that selection for reduced CH ₄ emissions may affect growth. Direct selection for CH ₄ led to a modest annual reduction in emissions but also a correlated decline in MBW. These results demonstrate that while CH ₄ emissions are heritable, their strong genetic association with productivity traits indicates that isolated selection for reduced emissions may lead to undesirable outcomes in feed intake and performance. Therefore, strategies aiming to reduce CH ₄ emissions should consider the genetic relationships with growth and efficiency traits to avoid compromising animal productivity.

The pyrolysis process of residues has emerged as a sustainable method for managing organic waste, producing biochars that offer significant benefits for agriculture and the environment. These benefits depend on the properties of the raw biomass and the pyrolysis conditions, such as washing and drying. This study investigated biochar production through slow pyrolysis at 300 °C, using eight biomass types, four being plant residues (PBR)—sugarcane bagasse, filter cake, sawdust, and stranded algae—and four non-plant-based residues (NPBR)—poultry litter, sheep manure, layer chicken manure, and sewage sludge. The physicochemical properties assessed included yield, carbon (C) and nitrogen (N) content, electrical conductivity, pH, macro- and micronutrients, and potentially toxic metals. Pyrolysis generally increased pH and concentrated C, N, phosphorus (P), and other nutrients while reducing electrical conductivity, C/N ratio, potassium (K), and sulfur (S) contents. The increases in the pH of the biochars in relation to the respective biomasses were between 0.3 and 1.9, with the greatest differences observed for the NPBR biochars. Biochars from sugarcane bagasse and sawdust exhibited high C content (74.57–77.67%), highlighting their potential use for C sequestration. Filter cake biochar excelled in P (14.28 g kg⁻¹) and micronutrients, while algae biochar showed elevated N, calcium (Ca), and boron (B) levels. NPBR biochars were rich in N (2.28–3.67%) and P (20.7–43.4 g kg⁻¹), making them ideal fertilizers. Although sewage sludge biochar contained higher levels of potentially toxic metals, these remained within regulatory limits. This research highlights variations in the composition of biochars depending on the characteristics of the original biomass and the pyrolysis process, to contribute to the production of customized biochars for the purposes of their application in the soil. Biochars derived from exclusively plant biomasses showed important aspects related to the recovery of carbon from biomass and can be preferred as biochar used to sequester carbon in the soil. On the other hand, biochars obtained from residues with some animal contributions are more enriched in nutrients and should be directed to the management of soil fertility.

This study was conducted to evaluate the relationship among digestibility, residual feed intake (RFI), and enteric methane emission in growing Nellore cattle (Bos indicus) divergently classified based on RFI phenotype and breeding value (EBV-RFI). Animals (n = 122) subjected to performance testing (forage:concentrate ratio of 60:40) in two test groups were classified based on RFI. A sample of 80 animals classified as low (−0.748±0.076 kg DM/day) or high (0.775±0.075 kg DM/day) RFI was evaluated regarding feed compounds digestibility, fecal [...] ABSTRACT This study was conducted to evaluate the relationship among digestibility, residual feed intake (RFI), and enteric methane emission in growing Nellore cattle (Bos indicus) divergently classified based on RFI phenotype and breeding value (EBV-RFI). Animals (n = 122) subjected to performance testing (forage:concentrate ratio of 60:40) in two test groups were classified based on RFI. A sample of 80 animals classified as low (−0.748±0.076 kg DM/day) or high (0.775±0.075 kg DM/day) RFI was evaluated regarding feed compounds digestibility, fecal

BACKGROUND AND OBJECTIVES: Healthy newborns inevitably undergo painful procedures from the first hours of life and pain assessment is essential for choosing the right treatment. The objective of this study was to evaluate the agreement between evaluators of the Neonatal Facial Coding System (NFCS) pain scale in healthy newborns before, during and after hepatitis B vaccination performed in the first 48 hours of life. METHODS: This is an analysis of agreement between two evaluators, carried out as part of a quasi-experimental intervention study, developed in a maternity hospital in Belo Horizonte. Two researchers carried out an independent evaluation based on filming 2 minutes before, during and 2 minutes after the procedure. RESULTS: The study included 129 newborns between August and December 2022, 60 (46.51%) in the control group (facilitated restraint) and 69 (53.49%) in the intervention group (breastfeeding). There was substantial agreement between the researchers before (0.69) and after (0.70) vaccination. When the agreement between the groups was analyzed, it was substantial for the evaluations of newborns submitted to facilitated restraint before and after the procedure. In the breastfeeding group, agreement was almost perfect before and substantial after the procedure. CONCLUSION: There was substantial agreement between the researchers who used the NFCS scale before, during and after vaccination. This data validates the use of the scales when assessing the pain of newborns undergoing easy restraint and breastfeeding, even though it is an indirect method of assessment. It is important to highlight the importance of periodic staff training programs for the use of pain assessment scales at bedside.

BACKGROUND AND OBJECTIVES: Healthy newborns inevitably undergo painful procedures from the first hours of life and pain assessment is essential for choosing the right treatment. The objective of this study was to evaluate the agreement between evaluators of the Neonatal Facial Coding System (NFCS) pain scale in healthy newborns before, during and after hepatitis B vaccination performed in the first 48 hours of life. METHODS: This is an analysis of agreement between two evaluators, carried out as part of a quasi-experimental intervention study, developed in a maternity hospital in Belo Horizonte. Two researchers carried out an independent evaluation based on filming 2 minutes before, during and 2 minutes after the procedure. RESULTS: The study included 129 newborns between August and December 2022, 60 (46.51%) in the control group (facilitated restraint) and 69 (53.49%) in the intervention group (breastfeeding). There was substantial agreement between the researchers before (0.69) and after (0.70) vaccination. When the agreement between the groups was analyzed, it was substantial for the evaluations of newborns submitted to facilitated restraint before and after the procedure. In the breastfeeding group, agreement was almost perfect before and substantial after the procedure. CONCLUSION: There was substantial agreement between the researchers who used the NFCS scale before, during and after vaccination. This data validates the use of the scales when assessing the pain of newborns undergoing easy restraint and breastfeeding, even though it is an indirect method of assessment. It is important to highlight the importance of periodic staff training programs for the use of pain assessment scales at bedside.