Saulo da Luz e Silva

Desempenho e características de carcaça de novilhos alimentados com dietas contendo diferentes fontes de lipídios

The objective of this trial was to evaluate the animal performance, carcass characteristics and meat tenderness of 36 crossbred steers averaging 14 months old and 320 kg body weight. The animals were fed high concentrate-based diets: control - without additional fat (CO); diet with 5% calcium salt of fatty acids (AG); and diet with 21% whole cottonseed (CA). Dry matter intake of AG treatment was lower (P=0,05) than CA, that differ from CO diet. No significant differences of treatments on daily weight gain and feed efficiency were observed. Blood urea nitrogen was greater (P=0,01) for CA treatment than AG treatment. Carcass dressing, rib eye area, fat thickness, kidney and pelvic fat, liver weight, pH and temperature did not show significant difference. No difference on water loss during cooking and tenderness measured by shear force at different aging times was detected. Diets with 5% calcium salt of fatty acids or 21% whole cottonseed can be used for feedlot with no change on animal performance or carcass characteristics.

Utilização do Bagaço de Cana-de-Açúcar em Dietas com Elevada Proporção de Concentrados para Novilhos Nelore em Confinamento

The objective of this work was to evaluate the performance and carcass characteristics of cattle fed high concentrate diets containing 15, 21 or 27% of sugarcane bagasse in the dry matter. Twenty-four Nellore steers with 279 kg of shrunk body weight and 24 months of age, two per pen, were fed for 98 days. No significant effects were observed for average daily gain (mean =1.461 kg) and feed efficiency among the treatments. It was observed a linear effect between dry matter intake and levels of bagasse, with greater intake in treatments with lower proportion of bagasse. Consistent with intake, the liver weight presented linear association with bagasse levels, with higher weight in treatments with more concentrate. The hot carcass weight, kidney, pelvic, heart and inguinal fat, ribeye area and fat thickness were no different between treatments. However, it was observed a linear association between dressing percentage and bagasse levels, with higher percentage in treatments with more concentrate, consistent with the energy level of the diet. The results showed the viability of the use of 15 or 21% of sugarcane bagasse as the only roughage in high concentrate diets with corn, citrus pulp and soybean meal for Nellore steers in feedlot.

Predicting pork quality using Vis/NIR spectroscopy

Visible and near-infrared reflectance spectroscopy (Vis/NIRS) was used to predict the ultimate pH (pHu), color, intramuscular fat (IMF) and shear force (WBSF) of pork samples and to build classifiers capable of categorizing the samples by tenderness (tender or tough) and juiciness (juicy and dry). Spectra were collected from 400 to 1495nm, and 200 data points were generated for every sample (n=134). Sixty-seven percent of the sample set was used for calibration, and 33% was used for validation. Partial least squares (PLS) calibration models were developed for each characteristic measured. A coefficient of determination (R(2)) and residual prediction deviation (RPD) were used to evaluate the accuracy of the calibration models. The pHu and color prediction models developed in this study fit this classification, indicating that these predictive models can be used to predict quality traits of intact pork samples. The Vis/NIRS offered great potential for correctly classifying pork Longissimus into two tenderness and two juiciness classes.

Fontes de lipídeos e monensina na alimentação de novilhos Nelore e sua relação com a população de protozoários ciliados do rúmen

ABSTRACT - Four ruminally and duodenally cannulated Nellore steers were assigned to a 4 x 4 latin square to study the effectsof feeding monensin (M) and different sources of fat on the ruminal population of ciliate protozoa and ruminal pH. The experime ntaldiets contained (DM basis) 19% of sugar cane and were supplemented with M [control (CTRL)], M plus calcium salts of fatty acids(CSFA), M plus whole cottonseed (MWCS), or only WCS. Ruminal contents were sampled at 0, 2, 4, 6, and 8 hours post-feeding. Inorder to identify the ciliate protozoa a Sedgwick-Rafter count cell and an optic microscope with slide area of 0.4362 mm 2 were used. Nosignificant differences in ruminal pH were observed among diets. Both cottonseed treatments (MWCS and WCS) reduced the ruminalpopulation of the ciliate protozoa investigated, mainly the Entodinium , possibly because of the slow release of fat. Ruminal counts of Diplodinium, Epidinium, Eudiplodinium , and total protozoa were all affected by time post-feeding. Calcium salts of fatty acids seemedto be inert in the ruminal environment because no significant changes were observed in the protozoa counts. Moreover, feeding C RTLand MWCS diets to Nellore steers did not change the ruminal population of ciliate protozoa in this trial.Key Words: calcium salt of fatty acid, cattle, cottonseed, ionophores, protozoology

Respostas fisiológicas e produtivas de vacas holandesas em lactação submetidas a diferentes ambientes

This work was carried out during the summer of 2002 to evaluate the influence of some cooling systems on the milk yield and animal thermoregulation. Ten heifers and seventeen milking cows were assigned to the control housing (ICO), mist & fan housing (ICL) and shade cloth (80%) (IT). The milk yield and the individual intake were daily measured for each animal. The rectal temperature was measured three times a day with three animals from each treatment. The skin surface temperature was collected three times a day for all the animals and the respiratory frequency two times a day for all the animals. The climatic data of each housing were registered to calculate the temperature humidity index (ITU) and the black globe humidity index (ITGU). Twenty six days of high enthalpy were selected and analyzed. The study showed that temperature humidity index from 75 to 76 was not associated with stress conditions for the animals, although many researches propose this situation as stressing. The milking cows in the mist & fan treatment showed respiratory frequency and skin surface temperature significantly lower than the cows in the other treatments. The heifers presented respiratory frequency and rectal temperature higher than the cows in all the registration times. The higher milk yield of the cows was observed in the shade cloth treatment.

Milho grão seco ou úmido com sais de cálcio de ácidos graxos para novilhos Nelore em confinamento

The aim of this work was to evaluate the effects of dry corn grain or high moisture corn and calcium salts of fat acids on the performance and carcass traits of feedlot fed Nellore steers on finishing phase. Forty eight animals with 431 ± 29.8kg of initial mean body weight were fed during 70 days, with one of the four diets: MGS - basal diet containing corn silage (40%), dry corn grain (48.4%), soybean meal (7.6%), urea, amonium sulphate, mineral salt, limestone and monensin (4%); MGU - basal diet with high moisture corn replacing MGS; MGS-SCAG basal diet with 45% of MGU and 4% of calcium salts of fatty acids; MGU-SCAG - basal diet with 45% of MGS and 4% of calcium salts of fatty acids. The average daily gain was not affected by grain type. However, dry matter intake of animals of MGU treatment was smaller than MGS treatment, with a greater feed efficiency for MGU treatment. A greater number of ruminal ciliate protozoa was found in MGU treatments. Dressing percentage, renal, pelvic and inguinal fat and backfat thickness were greater in animals fed MGS diet. Average daily gain was not different between animals fed with or without SCAG, although, dry matter intake was greater in diets with SCAG, with no effect on feed efficiency. Protozoa number was smaller in diets containing SCAG and carcass traits were not affected by SCAG.

Estimativa do peso e do rendimento de carcaça de tourinhos Brangus e Nelore, por medidas de ultra-sonografia

The objective of this work was to obtain equations to estimate hot carcass weight (PCQ) and dressing percentage (RC) from ultrasound measurements (US) of 48 young bulls of the Brangus and Nellore breeds, fed diets with 20, 40, 60 or 80% of concentrate. Ultrasonic measurements made with a PieMedical Scanner 200 Vet equipment, with linear array transducer of 178 mm coupled with standoff guide, were ribeye area (AOLU), backfat thickness (EGSU) between 12a and 13a ribs and the fat thickness over the Biceps femoris (EGPU) muscle and live weight were collected on intervals of approximately 28 days. Regression equations for each breed and an overall equation were established. The best equations were selected through the Cp statistics. Correlations between measurements taken by ultrasound and after slaughter were 0.83 between AOLU and carcass area and 0.86 between EGSU and carcass backfat. Equations to estimate PCQ showed greater accuracy when measurements were taken closer to slaughter. However, equations to estimate RC showed lower accuracy and showed no improvement closer to slaughter. The overall equation showed the same or less accuracy for both characteristics if compared to equations of each breed. Predictions of PCQ and RC using ultrasound measurements showed results similar to those using the same measurements taken directly on carcass. The EGPU measurement did not increase the accuracy of predictions when EGSU already in model.

Exigências líquidas de proteína e energia para ganho de peso de tourinhos Brangus e Nelore alimentados com dietas contendo diferentes proporções de concentrado

The energy and protein requirements for gain of Brangus and Nellore bulls were estimated using the comparative slaughter technique, in which the empty body as well as the gain composition were estimated through the 9th -10th -11th rib cut. Twenty-eight animals from each breed were used in this research. At the beginning of the trial four animals from each breed were slaughtered to determine the initial body composition while the remaining bulls had free access to diets containing 20, 40, 60 or 80% of concentrate (dry matter basis) during 145 days. The average initial and final shrunk body weights were 238 and 402 kg for Brangus and 230.7 and 361.9 kg for Nellore, respectively. Animals averaged eight months of age in the beginning of the trial. The final average shrunk body gain, empty body gain, and hot carcass gain differed between breeds and concentrate levels with greater values found for Brangus and 60% of dietary concentrate, respectively. Fat and energy contents in the empty body were greater for Brangus while water, protein, and ash were higher for Nellore bulls. Protein and energy requirements for empty weight gain differed between breeds averaging 0.161 and 0.188 kg of protein and 3.02 and 2.46 Mcal of energy per kg of empty weight gain for Brangus and Nellore, respectively. Although it was observed greater energy requirement for Brangus and greater protein requirement for Nellore, no effect of concentrate level was found probably because the age of the bulls prevented animals to reach a stage of greater fat deposition.

Características da Carcaça e Qualidade da Carne de Tourinhos Alimentados com Dietas de Alta Energia

Thirty six 3⁄4 European 1⁄4 Zebu bulls were fed diets containing 9, 15 and 21% of the dry matter as sugar cane bagasse in natura (BIN). The animals, with initial body weight of 257 kg, were slaughtered with 435 kg, after 138 days on feed. Measurements in the carcass and the 9-10-11th rib cut physical composition were taken. Samples of Longissimus dorsi and Supraspinatus muscles, aged 0, 7 and 14 days, were analyzed for texture and color. Renal, pelvic and inguinal fat was higher for treatments with 9 and 15% of BIN. There was a tendency for greater backfat thickness in the treatments with 9 and 15% of BIN. BIN level in the diets had no effect on physical composition or carcass characteristics. However, greater fat deposition in the inguinal and pelvic region was observed in treatments with greater energy. The objective texture (WB) was different with ageing in the two muscles, with greater tenderness after 14 days than after 7, or 0 day. No significant differences in meat color were observed due to the BIN levels, but affected this characteristic. The aged steaks (0 and 14 days) were more tender and brilliant and their colors enhanced. Results suggest aging has great benefits on tenderness in young intact males with carcasses of 230 kg and 4 mm of fat thickness.Thirty six ¾ European ¼ Zebu bulls were fed diets containing 9, 15 and 21% of the dry matter as sugar cane bagasse in natura (BIN). The animals, with initial body weight of 257 kg, were slaughtered with 435 kg, after 138 days on feed. Measurements in the carcass and the 9-10-11th rib cut physical composition were taken. Samples of Longissimus dorsi and Supraspinatus muscles, aged 0, 7 and 14 days, were analyzed for texture and color. Renal, pelvic and inguinal fat was higher for treatments with 9 and 15% of BIN. There was a tendency for greater backfat thickness in the treatments with 9 and 15% of BIN. BIN level in the diets had no effect on physical composition or carcass characteristics. However, greater fat deposition in the inguinal and pelvic region was observed in treatments with greater energy. The objective texture (WB) was different with ageing in the two muscles, with greater tenderness after 14 days than after 7, or 0 day. No significant differences in meat color were observed due to the BIN levels, but affected this characteristic. The aged steaks (0 and 14 days) were more tender and brilliant and their colors enhanced. Results suggest aging has great benefits on tenderness in young intact males with carcasses of 230 kg and 4 mm of fat thickness.

Avaliação do microclima de instalações para gado de leite com diferentes recursos de climatização

Este trabalho foi realizado no verao de 2002 e teve como objetivo avaliar a influencia de alguns recursos de climatizacao no microclima interno das instalacoes. Foram utilizadas tres instalacoes: i) controle; ii) com aspersao associada a ventilacao, e iii) com tela de sombreamento. Os dados climaticos de cada instalacao foram registrados e, posteriormente, calculados os indices de temperatura e umidade, do globo negro e umidade e a entalpia. Foram selecionados e analisados 26 dias com entalpia elevada. Os indices de temperatura e umidade (ITU) e de temperatura do globo e umidade (ITGU), nos horarios mais quentes do dia, diferenciaram-se para a instalacao climatizada (ii), que apresentou melhor desempenho em relacao as demais. A entalpia menor foi observada no tratamento com tela (iii).