Estimation of the economic impact of heat stress on the Chilean dairy regions by using two comfort thermal indices.

The study aimed to estimate economic losses associated with heat stress in the eight dairy production regions (DPR), defined by the Dairy Chilean Consortium, using two comfort thermal indices, namely, the temperature-humidity index (THI) and the THI adjusted for solar radiation and wind speed (THIa). Hourly records from 19 weather stations (Nov - Mar 2017-2022) were collected to estimate the comfort thermal indices. The economic impact was estimated considering a critical threshold of 65 for both indices and the effect of higher values on loss in milk yield, days open, culling rate, and deaths. There were differences in the number of hours above the threshold among DPRs, independent of the thermal index used (P < 0.01). The greatest values were observed in DPRs I, II, and VIII, which concentrate most dairy cows. Average losses in milk yield were between 2.0 and 6.4 times higher when THIa was used instead of THI, which also depends on the DPR (P < 0.01). These estimations coincide with those observed empirically by producers. The lowest average economic losses per cow during the summer season (5 seasons average) occurred in DPR VI (US $ 91.5), and the highest losses were observed in DPR I (US $ 184.2) both using THIa. At the country level, economic losses fluctuate between US $ 29.0 and 108.4 million per summer season, depending on the comfort thermal index used. Finally, heat stress impacts negatively and significantly the Chilean dairy sector, which is highly dependent on the DPR.

Performance and carcass characteristics of steers fed with two levels of metabolizable energy intake during summer and winter season.

Climate change is producing an increase on extreme weather events around the world such as flooding, drought and extreme ambient temperatures impacting animal production and animal welfare. At present, there is a lack of studies addressing the effects of climatic conditions associated with energy intake in finishing cattle in South American feed yards. Therefore, two experiments were conducted to assess the effects of environmental variables and level of metabolizable energy intake above maintenance requirements (MEI) on performance and carcass quality of steers. In each experiment (winter and summer), steers were fed with 1.85 or 2.72 times of their requirements of metabolizable energy of maintenance. A total of 24 crossbred steers per experiment were used and located in four pens (26.25 m2/head) equipped with a Calan Broadbent Feeding System. Animals were fed with the same diet within each season, varying the amount offered to adjust the MEI treatments. Mud depth, mud scores, tympanic temperature (TT), environmental variables, average daily gain, respiration rates and carcass characteristics plus three thermal comfort indices were collected. Data analysis considered a factorial arrangement (Season and MEI). In addition, a repeated measures analysis was performed for TT and respiration rate. Mean values of ambient temperature, solar radiation and comfort thermal indices were greater in the summer experiment as expected (P<0.005). The mean values of TT were higher in steers fed with higher MEI and also in the summer season. The average daily gain was greater during summer v. winter (1.10±0.11 v. 0.36±0.06) kg/day, also when steers were fed 2.72 v. 1.85 MEI level (0.89±0.12 v. 0.57±0.10) kg/day. In summer, respiration rate increased in 41.2% in the afternoon. In winter, muddy conditions increased with time of feeding, whereas wind speed and rainfall had significant effects on TT and average daily gain. We conclude that MEI and environmental variables have direct effects on the physiology and performance of steers, including TT and average daily gain, particularly during the winter. In addition, carcass characteristics were affected by season but not by the level of MEI. Finally, due to the high variability of data as well as the small number of animals assessed in these experiments, more studies on carcass characteristics under similar conditions are required.

Eventos adversos en recién nacidos hospitalizados en una Unidad de Cuidados Intermedios / Adverse events among newborns hospitalized in an Intermediate Care Unit / Eventos adversos em recém-nascidos hospitalizados em una Unidade de Cuidados Intermediários

Resumen Introducción: Los recién nacidos (RN) conforman uno de los grupos poblacionales más vulnerables. El riesgo de ocurrencia de un evento adverso durante su hospitalización se incrementa por diversos factores. Objetivo: Identificar los eventos adversos en recién nacidos hospitalizados en una unidad de cuidados intermedios en 2018. Metodología: Estudio de tipo descriptivo, diseño transversal y retrospectivo, realizado en la Unidad de Cuidados Intermedios Neonatales del Instituto Nacional Materno Perinatal durante el 2018. Se elaboró una ficha de recolección de datos que constó de nueve ítems correspondientes a procedimientos realizados por el personal de enfermería. Se utilizó un análisis univariado de los datos, presentados en tablas y gráficos. Resultados: Fueron analizados 73 eventos adversos, la menor edad gestacional fue de 32 semanas, con un máximo de 28 días de hospitalización. 60% de eventos se produjo en los RN más lábiles y con situación de salud compleja, de los cuales, 58% fueron infecciones asociadas a catéter percutáneo o periférico, cuyo germen frecuente fue Sthapylococcus coagulasa negativo. Solo 20.5% de eventos adversos fueron reportados. Discusión: Los resultados obtenidos coinciden con otras investigaciones en que los factores intrínsecos de los recién nacidos contribuyen en la aparición de eventos adversos; de igual manera concuerdan en la necesidad de prevenirlos y notificarlos. Conclusiones: La prematuridad, el tiempo de hospitalización en una unidad crítica y de exposición a diversos procedimientos, incrementaron el riesgo de ocurrencia de eventos adversos en recién nacidos. Detectar oportunamente estos acontecimientos es importante, así como fomentar la cultura de reporte, con el fin de evitarlos.

Abstract Introduction: Newborns are one of the most vulnerable populations, and their risk of suffering an adverse event during their hospital stay is influenced by diverse factors. Objective: To identify the adverse events among newborns hospitalized in an Intermediate Care Unit in 2018. Methodology: This is a descriptive, transversal, and retrospective study carried out in a Newborn Intermediate Care Unit of the Maternal and Perinatal National Institute during 2018. A data gathering chart with 9 items related to the corresponding nursing procedures was designed. A univariate data analysis was calculated, and the results were shown in tables and graphs. Results: 73 adverse events were analyzed. The lowest gestational age was 32 weeks, and the longest hospitalization was 28 days. 60% of these events were related to the more delicate and with the more complex situation newborns; and 58% of these were related to percutaneous or peripheral catheter infections and the most frequent pathogen was Coagulase-Negative Staphylococcus. Only 28.5% of the events were reported. Discussion: These findings are in line with the results of other research studies. Addressing the diverse factors which contribute to the adverse events in newborns in Intermediate Care Units is suggested. Conclusions: Being premature and the length of the hospital stay increase the risk of adverse events in newborns. It is critical to promote a culture of events reporting.

Resumo Introdução: Os recém-nascidos (RN) constituem um dos grupos populacionais mais vulneráveis. O risco de ocorrência de um evento adverso durante sua hospitalização é incrementado por diversos fatores. Objetivo: Identificar os eventos adversos em recém-nascidos hospitalizados em una unidade de cuidados intermediários em 2018. Metodologia: Estudo de tipo descritivo, desenho transversal e retrospectivo, realizado na Unidade de Cuidados Intermediários Neonatais do Instituto Nacional Materno Perinatal durante 2018. Foi elaborada uma ficha de coleta de dados que constou de nove itens correspondentes a procedimentos realizados pelo pessoal de enfermagem. Utilizou-se uma análise univariáda dos dados, apresentados em tabelas e gráficos. Resultados: Foram analisados 73 eventos adversos, a menor idade gestacional foi de 32 semanas, com máximo de 28 dias de internação. 60% dos eventos produziram-se nos RN mais lábeis e em situação de saúde complexa, dos quais, 58% foram infecções associadas a cateter percutâneo ou periférico, cujo germe frequente foi o Sthapylococcus coagulase negativo. Apenas 20.5% de eventos adversos foram relatados. Discussão: Os resultados obtidos coincidem com outras pesquisas em que os fatores intrínsecos dos recém-nascidos contribuem no aparecimento de eventos adversos; aliás, concordam com a necessidade de preveni-los e notificá-los. Conclusões: A prematuridade, o tempo de hospitalização em uma unidade crítica e de exposição a diversos procedimentos, incrementaram o risco de ocorrência de eventos adversos em recém-nascidos. É importante detectar estes acontecimentos oportunamente, assim como fomentar a cultura de notificação, a fim de evitá-los.

Quantification of bovine albumin fraction V in cellular antigens of antileptospirosical Cuban vaccine vaxSpiral.

A solid phase immunoradiometric assay (IRMA) for quantification of bovine albumin fraction V (Bov.Alb.FV) in antileptospirosical Cuban vaccine vaxSpiral is described in the present work. Anti-Bov.Alb.FV IgG raised against rabbit purified by affinity chromatography was used as first antibody. Anti-rabbit IgG labeled by Chloromine-T reaction was used as a tracer and the method has demonstrated to be sensitive with high intra- and inter-assay reproducibility. Eight lots of vaccinal antigens were evaluated and in all of the cases, the bovine albumin fraction V concentration was lower than 1 microgram/mL, as the World Health Organization (WHO) establishes. This IRMA is a simple and sensitive assay and could be used as control method for all human vaccines that use Bov.Alb.FV in their production process, even cellular vaccines.

Immunological and virological markers of disease progression in HIV-infected children.

Polymerase chain reaction (PCR), virus culture and antigen detection assays are useful for early detection of vertically transmitted human immunodeficiency virus type 1 (HIV-1) infection in infants under 12 months of age. Sixty-four children born to HIV-1-seropositive mothers were evaluated. Thirteen children (20.3%) were repeatedly positive by PCR analysis. There was 100% concordance between the results obtained from PCR and culture assays. Measurement of p24 antigen in serum was, in contrast, a less sensitive marker of HIV infection: only 5/13 infants had positive p24 antigen results. We have investigated the relationship among the HIV-1 biological phenotype, replicative capacity of viral isolates, HIV RNA copy number in plasma, p24 antigenaemia, CD4 T lymphocyte counts and the clinical status in 13 HIV-infected infants. Six out of 13 HIV-1 isolates from these patients were classified as rapid/high and seven as slow/low. We have found a significantly positive correlation between the replication rate of HIV isolates and their capacity to induce syncytia in vitro. The HIV-1 isolates with rapid/high and syncytium-inducing phenotype, and isolates with slow/low and non-syncytium-inducing phenotype were obtained from infants who had HIV-1 RNA copy number ml(-1) plasma values of 27654-83520 and 1342-34321, respectively. Levels of HIV-1 RNA were measured in sequential plasma samples from three HIV-infected infants and their biological properties determined in vitro. Our findings indicate that infants who carried viruses with more cytophatic biological phenotype and who had higher viral RNA copy numbers in blood were more likely to have lower CD4+ T cell counts and more likely to develop full-blown AIDS.

Environmental factors affecting daily water intake on cattle finished in feedlots.

Records from 7 studies conducted during 1999 to 2005 were utilized to assess the effects of environmental factors on daily water intake (DWI) of finishing cattle. Data from unshaded feedlot pens (up to 24 pens utilized per study; 6 to 9 animals·pen(-1)) containing predominantly Angus crossbred cattle were obtained by dividing total water intake by the number of animals utilizing that waterer. Each waterer was shared by 2 pens; therefore, data were derived from a database containing 72 experimental units comprising 144 pen records. Climatic data were compiled from weather stations located at the feedlot facility. The database included daily measures of mean ambient (Ta), maximum (Tmax), and minimum (Tmin) temperature (°C), precipitation, relative humidity (%), wind speed (m•s(-1)), solar radiation (SR, W•m(-2)), and temperature-humidity index (THI), as well as DMI (kg•d(-1)) and DWI (L•d(-1)). Simple and multiple regression analyses were conducted by season and for the overall data set. Results confirmed that DWI increases during the summer (P < 0.01). When seasons were combined and analyzed by linear regression, the best predictors of DWI were THI (r(2) = 0.57), Ta (r(2) = 0.57), Tmin (r(2) = 0.56), and Tmax (r(2) = 0.54). In multiple regression analyses, smaller coefficients of determination (R(2) < 0.25) were found within summer and winter seasons. Across season, the largest R(2) (0.65) were obtained from the following prediction equations: 1) DWI = 5.92 + (1.03•DMI) + (0.04•SR) + (0.45•Tmin); and 2) DWI = -7.31 + (1.00•DMI) + (0.04•SR) + (0.30•THI). In conclusion, Ta, Tmin, and THI were found to be the primary factors that influence DWI in finishing cattle, whereas SR and DMI were found to have a smaller influence on DWI.

Effects of diet type and metabolizable energy intake on tympanic temperature of steers fed during summer and winter seasons.

A summer study and a winter study were conducted using an incomplete factorial structure in a complete randomized design. Within season, the factors studied were 1) type of diet, which included 2 levels of ME, classified as either concentrate (3.04 Mcal of ME/kg) or roughage (2.63 Mcal of ME/kg) diets, and 2) daily ME intakes (MEI) of 11, 18, and 25 Mcal of ME/d for the roughage diets and 18, 25, and 32 Mcal of ME/d for the concentrate diets. In Exp. 1 (summer study), 30 steers (5 steers/treatment combination) were used to collect tympanic temperatures (TT). In Exp. 2 (winter study), 24 steers (4 steers/treatment combination) were used to collect TT. Mean TT was 0.3°C greater for summer than winter (38.9 vs. 38.6°C, respectively; P < 0.05). Steers fed diets based on concentrate tended to display greater TT than steers fed diets based on roughage. Season × diet × hour interactions were found for TT (P = 0.01). In the winter, greater TT (P < 0.05) were found from 0900 to 1400 h when an equal amount of MEI was derived from a concentrate-based vs. roughage-based diet. In cattle fed roughage-based diets during the summer, TT = 38.63 + 0.0114•MEI, whereas for cattle fed concentrate-based diets, TT = 38.69 + 0.0114•MEI. During the winter, for cattle fed a roughage-based diet, TT = 37.65 + 0.0856•MEI - 0.0018•MEI(2), whereas for cattle fed a concentrate-based diet, TT = 35.37 + 0.2635•MEI - 0.0051•MEI(2). In summary, results demonstrate that increases in the energy of the diet resulted in increases in TT. However, the response was dependent on season of the year, with a linear response in TT for summer and a quadratic response during winter.