Protein metabolism, feed energy partitioning, behavior patterns and plasma cortisol in Nellore steers with high and low residual feed intake.

The objective was to evaluate protein turnover, nitrogen balance, feed energy partitioning, behavior patterns and plasma cortisol in Nellore (B. indicus) cattle with high and low residual feed intake (RFI = actual minus expected dry matter intake). Seventy-two Nellore steers (16 to 21 months-old, 334±19 kg initial body weight) were fed a feedlot diet for 70 days ad libitum. Daily dry matter intake (DMI) and average daily gain (ADG) were recorded individually and RFI was calculated. The 12 steers of lowest (Low-RFI, most efficient) RFI and the 12 ones of highest RFI (High-RFI, least efficient) were evaluated with respect to their behavior patterns and plasma cortisol concentration. Urine was collected for determination of daily 3-methylhistidine excretion (3MH) and myofibrillar protein breakdown rates. Urinary, gaseous and fecal energy losses were determined as well as the N retention and excretion. High-RFI steers tended to have shorter lying and idle periods and greater feeding time and plasma cortisol levels than low-RFI cattle. No RFI effects were seen for urine 3MH excretion and for rates of protein degradation and synthesis. No effects of efficiency class were observed for N excretion or N retention. No RFI effects were observed for dry matter digestibility, digestible energy (DE) and metabolizable energy (ME) content and DE/ME ratio. Methane energy losses were lower for low- compared with high-RFI steers. Protein turnover seems not to affect feed efficiency in Nellore steers. Improved RFI in Nellore steers is probably associated with lower degrees of activity and responsiveness to stress and lower losses of dietary energy as methane

BENCHMARKING OF TWO SYSTEMS FOR TRANSMISSION OF MOTION FOR A DOUBLE ACTION STIRLING ENGINE

In a four-piston Stirling engine, Siemens configuration, the displacement of the pistons is governed by the motion transmission element, which converts the reciprocating motion of pistons into rotary motion. This study aimed to evaluate the influence of the geometry of the transmission element in the mechanical efficiency of a Stirling engine. Analyses were performed using a mathematical computer simulation that uses the geometric and operating data of the engine to calculate the mechanical power and efficiency through a first order thermodynamic mathematical model, also known as the Schmidtmodel. First, an analysis was performed to evaluate the mechanical efficiency of the transmission element with a sinusoidal curve surface. Later, it was implemented in the transmission mechanism a segment based straight plans surface, and then the same analysis was performed with this new transmission element. The results showed that using the transmission element with segment based straight plans the engine showed a significant increase in efficiency. Moreover, one can observe an increase in the vibration of the system, making it necessary to develop an appropriate system for balancing

Effect of flint corn processing method and roughage level on finishing performance of Nellore-based cattle

Citation: Caetano, M., Goulart, R. S., Silva, S. L., Drouillard, J. S., Leme, P. R., & Lanna, D. P. D. (2015). Effect of flint corn processing method and roughage level on finishing performance of Nellore-based cattle. Journal of Animal Science, 93(8), 4023-4033. doi:10.2527/jas2015-9051This study was conducted to evaluate the effects of flint corn processing method (CPM) and level of NDF from roughage (rNDF) on performance, carcass characteristics, and starch utilization by finishing Nellore-based cattle fed high-concentrate, flint corn-based diets. In this study, 112 Nellore type bulls (initial BW 384.07 +/- 29.53 kg and 24-36 mo of age) were individually fed using Calan gates or individual pens. The animals were used in a randomized complete block design in a 2 x 4 factorial arrangement with 2 CPM, high-moisture flint corn (HMC) or finely ground dry flint corn (FGC), with 1 of 4 levels of rNDF, 3, 8, 13, and 18% (DM basis), using sugarcane silage (SS) as roughage. Bulls were adapted to the finishing diet over a 21-d period and fed for a total of 81 d. Fecal starch (FS) concentration was determined on d 46 and 74 of the feeding period. There was a quadratic effect of rNDF on final BW (P < 0.01) and ADG (P = 0.01). Optimal concentrations of rNDF were estimated using the first derivative of second order polynomials, indicating that final BW and ADG were maximized with 13.3 and 13.0% rNDF, respectively. An interaction was observed between CPM and rNDF (P = 0.05) for DMI, with peak DMI occurring at 11.3 and 13.7% rNDF with FGC and HMC, respectively. Cattle fed HMC had 13.9% greater G:F (P < 0.01) compared with those fed FGC (0.172 vs. 0.151, respectively). There were quadratic effects of rNDF on HCW (P = 0.04) and ME intake (P < 0.01); heaviest carcass weights were estimated, in both cases, to be achieved with 12.8% rNDF. A quadratic effect of rNDF for renal, pelvic, and inguinal fat weight (P = 0.04) was observed, with a peak estimated to occur at 12.6% rNDF. An interaction between CPM and rNDF also was observed for FS (P < 0.05). Bulls fed FGC with 3% rNDF had greater FS content, and FS linearly decreased as concentration of rNDF increased. For bulls fed HMC, FS was 3.0% of DM and was unaffected by rNDF in the diet. Lower FS from bulls fed HMC suggests that availability of starch from flint corn was greater than that of FGC. For Nellore-based cattle fed a flint corn-based diet containing SS and 8% whole lint cottonseed, performance was optimized with 12.8% rNDF. In the absence of cottonseed addition to diets, optimal performance would be expected with about 14.5% rNDF

Monensin and functional oil addition in feed behavior and methane emission of Nellore bulls fed low-fiber diets.

In order to minimize unwanted effects of high levels of grains in feedlot diet, antibiotic feed additives are used, but its security is challenged and the discovery of alternative natural substances becomes necessary. The aim of the study was to evaluate the effect of increasing levels of the forage neutral detergent fiber (NDFf) and additives in feeding behavior and enteric methane emissions. Seventy Nellore bulls, (408 ± 14.17 kg initial LW), were distributed in a factorial arrangement 2 x 3 + 1, where two additives (500 mg kg-1 DM, of a blend of castor oil and cashew nut shell liquid, Essential Oligo Basics, Brazil, or 30 mg kg-1 DM of monensin), three levels of NDFf (6, 9 and 15% in DM), and control group, without additive. The diet was composed by Brachiaria hay, ground corn, citrus pulp, soybean meal and mineral salt. The experiment lasted 105d, the enteric methane emission was estimated by indicator gas SF6 methodology, in two collections for five straight days, the intake behavior was performed through rumination sensors (Heatime® HR), evaluated in five animal per treatment. Data were analyzed using the SAS´s MIXED, 5% significance evaluated by contrasts. The monensina increased (P<0.05) the dry matter intake (DMI), final live weight (FLW), and methane emission compared to oil treatment, the averages 8.29 ± 0.06 kg d-1, 518.73 ± 5.7 kg and 183.22 ± 4.6 g d-1 for monensin and 7.48 ± 0.04 kg d-1; 489.8 ± 8.9 kg and 161.33 ± 4.83 g d-1 for functional oil. Regarding the NDFf levels, the DMI was higher for 15% of NDFf compared to other levels (P = 0.0156), the averages were respectively 8.69 ± 0.03, 7.10 ± 0.04 and 7.99 ± 0.05 kg d-1. The methane emission increased (P = 0.0006) as the NDFf level was increased (139.03 ± 4.97; 165.51 ± 3.4 and 213.72 ± 4.64 g d-1 for the 6 and 9% levels, respectively), with no changes when methane was analyzed by kg of DMI (P = 0.1308). There was an effect on NDFf levels on rumination time (P = 0.0106) with 23.25 ± 0.62; 21.30 ± 0.30 and 26.94 ± 0.43 kg of DM d-1 for 6, 9 e 15% levels, respectively. As well the monensina increased (P = 0.0030) the rumination time compared to the functional oil (25.56 ± 0.38 and 23.98 ± 0.49 kg of DM d-1 respectively). The diet with 15% of NDFf and the monensin were more effective in DMI, FLW and rumination, the functional oil contributed to the reduction of enteric methane emission

Correlations of visual scores and ultrasound carcass traits with economically relevant traits in Nellore cattle.

T17

Identificação de méis adulterados utilizando FT-NIR e quimiometria.

O mel é um produto alimentício que tem sofrido constantemente processos de adulteração devido ao seu custo e sua disponibilidade limitada. Desta forma, o presente trabalho tem como objetivo analisar amostras de mel não adulteradas e adulteradas com glicose, melado de cana-de-açúcar e água, em diferentes proporções, 10%, 25%, 40% e 50% (m m-1). As amostras foram analisadas utilizando espectrometria na região do infravermelho próximo com transformada de Fourier (FT-NIR) e os resultados obtidos foram analisados utilizando a ferramenta quimiométrica de análise de componentes principais (PCA). A partir dos resultados obtidos, foi possível verificar a viabilidade da técnica NIR para verificação da adulteração de méis com água

PHYSIOLOGICAL RESPONSES OF HOLSTEIN COW’S FACE TO RESOURCE OF FAN IN FREE-STALL

Este estudo teve como objetivo avaliar a influência do recurso de ventilação sobre a fisiologia de vacas Holandesas alojadas em free-stall, durante o verão do sudeste brasileiro. Foram utilizadas 20 vacas Holandesas submetidas a dois tratamentos: controle e ventilação. Os parâmetros ambientais registrados foram temperatura e umidade relativa do ar e temperatura de globo negro. As variáveis fisiológicas avaliadas foram temperatura retal e frequência respiratória. Para obtenção das estatísticas descritivas utilizou-se a metodologia de quadrados mínimos. Apesar das diferenças estatísticas obtidas para as variáveis fisiológicas, as mesmas não foram biologicamente efetivas e indicaram que os animais se encontravam em conforto térmico