The aim of this study was to determine the epidemiological behavior of bovine paralytic rabies (BPR) in Mexico during the period 2017-2023. Case information was obtained through the National Epidemiological Surveillance System (SIVE), from which the prevalence rate at the state level was estimated at the state level and clusters were identified using the SaTScan statistic. Temporal behavior was evaluated using endemic channels and a Seasonal Integrated Moving Average Autoregressive Model developed in the Python environment. During the study period, 2,791 cases of BPR were reported, the states with the highest prevalence rates were Nayarit (47.61), Quintana Roo (32.62), and Campeche (31.24). Spatial scanning detected three significant clusters; the one located in Nayarit had 13 times higher risk of presenting BPR cases. Temporally, a seasonal pattern was observed with endemic peaks in February and October. The SARIMA specialIntscript (2,1,0)12 model forecasted 320 cases for 2024. BPR in Mexico shows variations across northern, central, and southern regions. Nayarit was the state with the highest prevalence and relative risk. This information could be used to strengthen prevention and control strategies in high-risk periods and areas.
The effects of changes in house temperature and relative humidity (RH) and their relationship on broiler production indicators in a commercial system with manual control of temperature and humidity were evaluated. Four production cycles were analyzed (26,000 birds/cycle; 10 broilers/m2). Each cycle consisted of four production phases (pre-starter, starter, grower and finisher). Feed and water were provided ad libitum. Six samples were taken from 120 birds per cycle in each phase, and body weight and daily weight gain were determined, as well as feed consumption and feed conversion ratio 1, phase 1 were estimated. The information was analyzed under fixed effects, principal components (PC) and response surface analysis (RSA) models. Temperatures and humidity were different (P<0.05) between cycles within each phase. Temperature and humidity affected (P<0.001) the productive indicators per cycle across phases. This was corroborated by the PC analysis (P<0.001). Meanwhile, the optimization process of the regression equations showed that the best combination of temperature and relative humidity was 29 degrees C/31%, 26 degrees C/35%, 25 degrees C/35%, 30 degrees C/44%, 14 degrees C/64% y 18 degrees C/50% and for weeks 1, 2, 3, 4, 5 y 6, respectively.
Small ruminants mastitis affects the economy by decreasing milk production and lamb development. To determine the frequency of mastitis in meat sheep and its associated agents, 38 family-farmed sheep flocks in municipalities in central Mexico were studied. A total of 822 individual sheep milk samples were obtained to perform the California mastitis test and microbial isolation. Results were evaluated using the Chi-square test (p<0.05). Isolations were achieved in 21.9% of the samples evaluated, with 19.89% in animals with subclinical mastitis and 2.79% in animals with clinical mastitis. The most isolated agents were Staphylococcus aureus 34.18%, coagulase-negative Staphylococcus (CNS) 21.94%, and coliform bacteria 16.33% (p<0.001); followed by non-agalactiae Streptococcus 8.68%, Mannheimia haemolytica 4.60%; noncoliform bacteria 2.04%, Pasteurella multocida 2.04%, and Streptococcus agalactiae 0.51% (p<0.05). The least frequently isolated pathogens were Bacillus spp., Corynebacterium spp., Truperella pyogenes, and yeast. Subclinical and clinical mastitis was associated with Staphylococcus aureus and coagulase-negative Staphylococcus (CNS) infection (p<0.001), showing a widespread distribution in meat sheep flocks in the central region of the State of Mexico.
Xylazine has been used to immobilize domestic and wild animals for the purpose of applying technologies aimed at reproduction, acquiring this drug special relevance in the veterinary field, for this reason, a literature review was carried out based on scientific publications related to the physiological effects of xylazine on reproductive aspects of animals, with the aim of describing its action and impact on the reproductive physiology of female and male domestic and wild animals, specifically, in assisted reproduction techniques. Xylazine, when interacting with receptors in different tissues and organs, has both adverse and favorable effects on reproductive processes. In females, xylazine can cause hypoxia and uterine contractions, while in males, when used in semen collection processes by electroejaculation, it can improve the amount of ejaculate as a factor that allows reducing stress levels. For the use of xylazine, it is important to consider that, in pregnant females, it can have adverse effects, and in males it is feasible to have beneficial effects in semen collection programs. Additionally, it is very important to know the desired effect to determine the dose to be used.
The tick Rhipicephalus microplus represents a highly relevant pest in Neotropical livestock systems due to its negative effects on cattle health and productivity. Its control constitutes a constant challenge for producers, primarily due to frequent resistance to conventional acaricides, the environmental damage associated with their use, and economic losses resulting from reduced herd profitability. This study documents the effectiveness of rotational grazing in Neotropical regions as a strategy to control R. microplus in cattle. Evidence indicates that pasture rest periods shorter than 30 days are insufficient to reduce parasitic loads, whereas rest periods exceeding 45 days, and even over 100 days, decrease infestations. Rotational pasture management with adequate recovery intervals constitutes a sustainable and effective alternative to control R. microplus, reduce conventional acaricide use, and enhance livestock system productivity.
