Vasconcelos et al 2020). Animal's body temperature is traditionally estimated through rectal and vaginal measurements; however, alternative methods like tympanic temperatures (TT) also constitute a reliable measure since some studies reported no statistical difference with rectal temperatures (Sellier et al 2014;Shu et al 2021) and high correlation with vaginal temperature (r = 0.77; Bergen and Kennedy, 2000). The differences associated with the anatomical sampling point and its response time were also validated in other studies (Scharf et al 2011;Sellier et al 2014;Godyń et al 2019). TT is an attractive alternative measure Abstract The present study aimed to analyze large volumes of tympanic temperature (TT) data to identify its use as a physiological indicator of climatic conditions and its relationship with milk production in grazing cows under tropical lowland conditions. Three dairy farms and 21 multiparous early lactation cows were included in the study. Seven animals were equipped with tympanic temperature wireless sensors within each farm, and permanent information was collected hourly for 22 days on average. Ambient temperature (AT), relative humidity (RH), wind speed (WS), precipitation (PP), and THI information were obtained from meteorological stations located close to each farm. Statistical analyses included Spearman correlations and random coefficient regression models (P < 0.05). TT presented moderate and significant correlations with AT (0.35 to 0.49), SR (0.25 to 0.32), THI (0.35 to 0.49), and RH (-0.35 to -0.49). Climatic variables like AT, PP, SR, and WS were the most contributing factors to TT prediction (R 2 =0.42 to 0.86). Grazing dairy cows in tropical scenarios accumulate heat during the day and dissipate it at nighttime, although higher producing animals deal with more problems to reach thermal homeostasis. Correlations between TT and daily milk production varied according to animal yield; however, higher TT values were related to the most productive cows. The effect of TT on milk production prediction was not conclusive among farms, possibly by animal management or others characteristics of the systems. TT determination through remote sensors allows a reliable diagnosis of the physiological temperature response to climatic conditions.

<p>Después de evaluar la adaptación de 25 especies arbustivas en fincas ubicadas en zonas de ladera del trópico medio de los departamentos de Cauca y Valle del Cauca, se realizó el estudio de consumo y caracterización bromatológica e las tres especies con mayor potencialidad en sistemas productivos mixtos (ganadería doble propósito-agricultura): <em>Malvaviscus arboreus</em>, <em>Cratylia argentea </em>y <em>Codariocalyx gyroides</em>. La evaluación de calidad y consumo se realizó en ovejos africanos utilizando jaulas metabólicas que, para facilitar el manejo, fueron ubicadas en instalaciones del Centro de Investigaciones de CORPOICA en Palmira, 3° 31I N, 76° 19I W; 1.000 m.s.n.m.; 1.014 mm/año de precipitación, 24° C, brillo solar 5.8 h/d, humedad relativa 75%. Se ofreció una ración básica de heno de <em>Brachiaria dictyoneura </em>de baja calidad nutritiva, 3.6% de proteína cruda, equivalente a 100 g M.S./ kg0.75, junto con 80 g M.S./kg0.75 de follaje de cada una de las tres leguminosas fraccionadas en dos ofertas durante siete días de medición y previo acostumbramiento. De acuerdo con el índice predictivo de valor relativo (RFV = 88.9 – (0.119 * %FDA) (120 / %FDA) / 1.29), según Mertens (1993), la leguminosa arbustiva <em>Malvaviscus arboreus </em>reportó el consumo más alto, 94.53 g MS/kg0.75; seguido de <em>Cratylia </em>argentea, 83 g MS/kg0.75,; por último, <em>Codariocalyx gyroides</em>, 81.82 g MS/kg0.75. DIVMS y DTCIA correlacionaron positivamente en forma significativa mientras que FDN, FDNe, FDA correlacionaron negativamente con los valores encontrados para consumo.</p><p><strong><br /></strong></p><p><strong>Nutrition quality of shrub species <em>Malvaviscus arboreus</em>, <em>Codariocalyx gyroides </em>and <em>Cratylia argentea </em>in the hillside area of the Departments of Cauca and Valle</strong>, <strong>Colombia</strong>.</p><p>A study was conducted in order to evaluate the nutritional composition and intake of the shrub species <em>Malvaviscus arboreus</em>, <em>Cratylia argentea </em>and <em>Codariocalyx gyroides</em>, growing under hillside conditions in the Cauca and Cauca Valley regions of Colombia. In a previous evaluation of the nutritional quality of 25 shrub species, these three species showed the highest forage potential in mixed productive systems. The present evaluation was carried out using African sheep housed in metabolic chambers and was conducted at the Palmira CORPOICA Research Center, located at 3° 31I N, 76° 19I W, 1.000 masl with 1014 mm of precipitation/year, 24° C, 5.8 h/d solar bright and 75% of relative humidity. For seven days, after diet animal adaptation to the diet, animal received a basal diet of a low nutritive quality (3.6% of raw protein) <em>Brachiaria dictyoneura </em>hay, at an equivalent of 100 g DM/ kg0.75 per day. Additionally, animals received 80 g DM/ kg0.75  per day of one of the three legumes divided in daily portions. According to the relative feeding value predictive index (RFV=88.9 - (0.119*%FDA)(120/ %FDA)/1.29, Mertens, 1993), the shrub legume <em>M. arboreus </em>showed the highest intake index, (94.53) followed by <em>Cratylia argentea </em>(83) and <em>Codariocalyx gyroides </em>(81.82) g DM/kg0.75. IVDMD and DTCIA had a significant positive correlation, while NDF, eNDF and ADF correlated negatively with the observed intake values.</p>

Evaluación de diferentes niveles de inclusión de plantas nativas de sabanas inundables sobre una dieta basal de Brachiaria humidicola y su efecto sobre la producción de metano in vitro resUMen Se evaluó el efecto sobre la producción de metano de la inclusión creciente (25, 50 y 75 %) de cinco plantas nativas de sabanas inundables (Senna occidentalis, Enterolobium schomburgkii, Galactia jussiaeana, Belencita nemorosa y Ambrosia peruviana), sobre una dieta base de Brachiaria humidicola. Los tratamientos fueron incubados anaeróbicamente con fluido ruminal a 39°C por 24 h y después del proceso de fermentación, se determinó la producción de gas, metano, ácidos grasos volátiles (AGV), amonio y degradación de la materia seca (MSD). La inclusión en la dieta de 50 y 75% de todas las plantas, incrementaron el contenido de amonio ruminal, con valores entre 189 -282 mg/L. Ninguna de las plantas modificó la concentración de AGVT (44-62 mmol/L). La producción de metano no se redujo significativamente con ningún tratamiento (p>0,05), aunque con S. occidentalis (75%) este parámetro fue inferior en un 18%, además, se incrementó la MSD y los niveles de butirato, isobutirato y valerato. Con E. schomburgkii (75%), la metanogénesis también se redujo en un 15%, sin embargo, este efecto estuvo acompañado de una disminución en la MSD y producción de gas. En conclusión, ninguna de las plantas mostró potencial para reducir la producción de metano, no obstante, las especies se convierten en alternativas nutricionales útiles para complementar el aporte proteico de la dieta en los sistemas ganaderos ubicados en condiciones de sabanas inundables. The effect on methane production of increasing levels (25, 50 and 75%) of five native plants from the floodable savannas (Senna occidentalis, Enterolobium schomburgkii, Galactia jussiaeana, Belencita nemorosa y Ambrosia peruviana), on a Brachiaria humidicola based diet were evaluated. The treatments were anaerobically incubated with ruminal fluid at 39 °C for 24 h, after the incubation period, gas production, methane, volatile fatty acids (VFA), ammonia and dry matter degradation (DMD) were determined. The inclusion of 50 and 75 % of all plants in the diet, increased the ruminal ammonia content, with values between 189-282 mg/L. None of the plants modified TVFA concentration (44-62 mmol / L). Methane production was not significantly reduced with any treatment (p>0.05), although with Senna occidentalis (75%) this parameter was an 18% lower, in addition, DMD and butyrate, isobutyrate and valerate levels were increased. With Enterolobium schomburgkii (75%), methanogenesis was also reduced by 15%, however, this effect was accompanied by a decrease in DMD and gas production. In conclusion, none of the plants showed potential to reduce methane production, nevertheless, they become useful nutritional alternatives to supplement the dietary protein in the livestock systems located under floodable savanna conditions. additional keYwordsIn vitro fermentation. Antimethanogenic plants. Dose. Ruminants.Arch. Zoot...

The objective of this study was to evaluate and compare the erosion rates generated by two types of hand tools for small-scale tillage on a hillslope, using experimental tests and the Universal Soil Loss Equation (USLE). The hand tools evaluated were a conventional hoe and a redesigned furrowing hoe. The experimental work was conducted in a 145 m2 plot with an average slope of 45% in Colombia. Three treatments were evaluated: a) Zero tillage and no herbicide (control); b) tillage with a conventional hoe plus herbicide; c) tillage with a furrowing hoe plus herbicide. Each treatment was represented by a sedimentation plot, using three repetitions in blocks (lower, middle, and upper parts of each plot), according to the maximum slope gradient. Both hand tillage tools generated high to extremely high erosion rates with differences of up to 8.1 times between them. Both types of tools accelerated soil erosion rates, being higher in furrowing hoe tillage. The USLE method showed no differences in erosion rates between the tillage methods, while differences were found in the experimental tests. This is explained by the lower sensitivity of the USLE to detect small-scale changes in factors such as soil type, cover, and slope.