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Little is known about the performance, carcass, and meat traits of locally adapted cattle in Brazil. This study aimed to compare the growth, slaughter, and carcass traits as well as meat quality of two local breeds (Curraleiro Pé-Duro and Pantaneiro) with the Nelore breed. Fifteen 30-month-old steers of each breed were weighted (Curraleiro Pé-Duro = 264.80 kg; Nelore = 346.80 kg; Pantaneiro = 316.20 kg) and raised in a feedlot condition for 112 days, with measurements to assess growth and slaughter, visual and carcass and meat traits. Data were submitted to variance and multivariate analyses. Nelore and Curraleiro Pé-Duro had similar Gluteus medius depths. Pantaneiro and Curraleiro Pé-Duro were superior for leg compactness index (P < 0.05) and had higher eye muscle area than Nelore (P < 0.05). Although there was no difference in daily weight gain and slaughter weight between breeds, Curraleiro Pé-Duro had a lower initial weight (264.80 kg) when compared to Nelore (346.80 kg; P < 0.05). Nelore and Curraleiro Pé-Duro deposited more fat than Pantaneiro (P < 0.05), while Curraleiro Pé-Duro and Pantaneiro had more muscle than Nelore (P < 0.05), which also had more bone and a higher percentage of second-quality cuts (P < 0.05). Meat from Nelore also showed lower succulence than Pantaneiro (P < 0.05) and higher shear force than the other breeds (P < 0.05). Pantaneiro's meat had the most capacity to retain water (P < 0.05), lower shear force (P < 0.05), and was more succulent (P < 0.05) when compared to the other breeds. Multivariate analysis showed that Pantaneiro, Curraleiro Pé-Duro, and Nelore breeds can be considered distinct in growth, carcass, and meat traits, with the local breeds showing superior meat traits. The local breeds Curraleiro Pé-Duro and Pantaneiro presented characteristics similar or better to those of the Nelore, proving to be animals with great productive potential and generate high meat quality under feedlot conditions., (© 2023. The Author(s), under exclusive licence to Springer Nature B.V.)

Uterine histological analysis by serial biopsies are an important tool not only for a better understanding and evaluation of physiological events involved in the process of uterine involution, but also for the identification and monitoring of pathological process that may compromise reproductive life. This study describes a temporal histological changes in endometrial tissues from multiparous Nelore cows in Southeast Brazil treated or not treated with Cloprostenol sodium 1 and 4 days postpartum (DPP), to determine if the treatment promotes histological endometrial involution. Cloprostenol sodium was administered on 1 and 4 DPP and endometrial biopsies were collected 1, 7, 14, 28, and 42 DPP using a Yomann's biopsy instrument. The presence or absence of myometrial and endometrial tissue and its integrity, number of endometrial glands (classification 0 to 3), edema, hemorrhage, vascular congestion and type of epithelial cell was assessed. The average number of leukocytes was recorded. There was observed difference between groups on the number of endometrial glands (P≤ 0.05) at one-time point. In addition, the degree of inflammation was reduced (P≤ 0.05) on time points. Cloprostenol sodium did not alter the histological appearance of uterine tissue during the postpartum period or reduce the period of uterine involution. Additionally, serial biopsies did not affect the fertility of the animals. [ABSTRACT FROM AUTHOR]

Abstract: To investigate why the preferred means to produce bovine embryos in Brazil has changed from in vivo to in vitro, we compared these two approaches in the same Nelore cows (n =30) and assessed total embryo production and pregnancy rates. Without a specific schedule, all cows were subjected to ultrasound-guided ovum pick up (OPU)/in vitro production (IVP) and MOET, with intervals ranging from 15 to 45 d between procedures, respectively. To produce in vivo embryos, cows were superovulated and embryos were recovered nonsurgically from 1 to 3 times (1.4±0.6), whereas OPU/IVP was repeated from 1 to 5 times (3.2±1.2) in each donor cow during a 12-mo interval. Embryos obtained from both methods were transferred to crossbred heifers. On average, 25.6±15.3 immature oocytes were collected per OPU attempt. The average number of embryos produced by OPU/IVP (9.4±5.3) was higher (P <0.05) than the MOET method (6.7±3.7). However, pregnancy rates were lower (P <0.05) following transfer of IVP (33.5%) versus in vivo-derived embryos (41.5%) embryos. Embryonic losses between Days 30 and 60 and fetal sex ratio were similar (P >0.05) between in vivo and in vitro-derived embryos. We concluded that in Nelore cows, with an interval of 15 d between OPU procedures, it was possible to produce more embryos and pregnancies compared to conventional MOET. [Copyright &y& Elsevier]

Simple Summary: Monitoring animal activity in production systems is an important tool for obtaining information on health, production, and reproduction. In this study, we evaluated the use of accelerometers with different strategies to predict the grazing behavior of Nelore cattle. This research was conducted in an environment both more challenging and representative of the practices adopted in livestock production systems in Brazil. The results of this study showed that the use of the Random Forest algorithm, together with techniques for resampling the training data of the models, classified the studied behaviors with high accuracy, especially for important, and less frequent activities such as water consumption frequency. 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. [ABSTRACT FROM AUTHOR]

Simple Summary: Cattle that are fed high levels of concentrates may develop short-term rumen acidity that may occur frequently leading to necrosis of the rumen wall and reduced nutrient absorption, thereby decreasing animal productivity. This condition is known as subacute acidosis. Here, we evaluated an experimental model to induce such a condition in Nelore cattle, a Zebu breed widely used in Brazil, and assessed several clinical and feeding behavioral patterns of affected animals to better understand the disease pathogenesis and clinical outcomes. Subacute acidosis led to a reduction in food consumption and rumination time, and an increase was observed in the time spent in decubitus. Additionally, subacute acidosis caused different degrees of depression that was more pronounced with higher ruminal lactic acid concentrations. We evaluated the clinical aspects and feeding behavior of cattle with subacute ruminal acidosis (SARA) caused by short-chain fatty acids (SCFAs). Ten healthy Nelore heifers were subjected to an adjusted SARA induction protocol using citrus pulp (CP). Clinical examinations were performed at baseline and at 3, 6, 9, 12, 15, 18, and 24 h intervals after induction, with ruminal fluid, blood, and feces sampling. The animals' feeding behavior was evaluated on, before, and for 3 days after SARA by observing the animals every 5 min for 24 h. The dry matter intake (DMI) was recorded daily. The ruminal pH during SARA was always lower than baseline, with an acidotic duration of 547 ± 215 min, a minimum pH of 5.38 ± 0.16, and an average pH of 5.62 ± 0.1. SARA was mainly caused by SCFAs (maximum 118.4 ± 9.3 mmol/L), with the production of l-lactic acids (7.17 mmol/L) and d-lactic acids (0.56 mmol/L) 6 h after the experiment began. The DMI was reduced by 66% and 48% on days 1 and 2, respectively, and returned to normal levels on day 3. SARA caused a reduction in feed intake and rumination time, as well as an increase in the time spent in decubitus on days 1 and 2. These results were influenced by the ruminal pH, ruminal movement, and osmolarity. Furthermore, SARA caused different degrees of depression, which became more pronounced with higher ruminal lactic acid concentrations. [ABSTRACT FROM AUTHOR]