Suchergebnisse

The aim of this study was to evaluate performance and economic viability of producing sheep fed different levels of roughage, concentrate, and water. Forty Santa Inês crossbred sheep with an average initial weight of 18.85 ± 2.80 kg and an average age of 5.0 ± 2.0 months were distributed in a completely randomized design with a 2 × 2 factorial arrangement composed of two proportions of roughage and concentrate (30:70 and 70:30) and two levels of water supply (ad libitum, and 50% restriction), with 10 replicates. Water restriction had a negative effect (P0.05) feed conversion or feed conversion. Total weight gain, average daily gain, feed conversion, and feed efficiency were influenced by the proportions of roughage and concentrate. In conclusion, the diet with 70% roughage, associated with a water restriction of 50%, reduced the uptake of energy and protein, compromising the animal performance. The combination of the diet plus concentrate and water restricted to 50% of the free consumption provides a better cost-benefit ratio.

This study aimed to evaluate the fecal recovery of the internal markers indigestible dry matter (iDM), indigestible neutral detergent fiber (iNDF), and indigestible acid detergent fiber (iADF) and to compare them as estimators of the fecal dry matter output (FDMO) and digestibility of the dry matter (DM) with values observed in total feces collection in trials with feedlot sheep. For this, 82 sampling units from two experiments were evaluated. Internal markers were quantified in the feed supplied, orts, and feces. The recovery of the markers was determined by the comparison of the amount of marker consumed and excreted. Fecal dry matter output and digestibility were determined based on the amount of marker consumed and on its concentration in the feces through individual collections directly from the rectum of the animals, with values compared with those observed in the total feces collection from orthogonal contrasts. The mean bias, the concordance correlation coefficient, and the mean squared prediction error were also evaluated. For all statistical procedures, the critical level of probability for type-I error was fixed at 0.05. The marker iDM showed complete fecal recovery (100.03%) and was efficient in estimating FDMO (482.9 g day-1) and DM digestibility (542 g kg-1) as compared with the values observed in the total feces collection (454.7 g day-1 and 561 g kg-1 for FDMO and DM digestibility, respectively). The iNDF and iADF markers did not show complete recovery in the feces and were not effective in the estimate of FDMO and DM digestibility.

This study aimed to evaluate the adequacy of seven non-linear models (France, Orskov and McDonald, Gompertz, exponential, logistic, two-pool exponential and two-pool logistic) in the adjustment of the curve and in the generation of parameters of cumulative gas production from five tropical feedstuffs (rice hulls, sugarcane, cassava chips, turnip by-product, and peach-palm by-product) used in ruminant nutrition. To this end, the feedstuffs were incubated in vitro in graduated glass syringes together with a buffer inoculum solution, in triplicate. Gas production was read at 0, 2, 4, 6, 8, 10, 12, 24, 26, 28, 30, 32, 36, 48, 52, 54, 56, 60 and 72 h of incubation. The data were used to generate the parameters of each model using the SAS statistical package. After the parameters were generated, the gas volume values were obtained at the aforementioned times, for each model, and these were compared with the values observed at incubation by using Model Evaluation System (MES) software. For the comparison, regression parameters were tested using Mayer's test, in addition to the evaluation of the mean bias (MS), concordance correlation coefficient (CCC), and mean squared prediction error (MSPE). The France, Logistic, and Gompertz models, for rice hulls, and the Orskov and McDonald model, for cassava chips, were significant (P < 0.1) according to Mayer's test, indicating lack of fit of the model. Besides presenting the lowest MSPE, the models that showed fit according to Mayer's test were the two-pool logistic for rice hulls and cassava chips, and the two-pool exponential for sugarcane, turnip, and peach palm. Thus, the non-linear two-pool models are the most efficient in adjusting to the curve and in the generation of parameters of cumulative production of gases from the tested feedstuffs.

The objective was to evaluate the parameters of kinetics of ruminal fermentation of cocoa husks (CH) treated with alkali and thermal agents, using the semi-automated in vitro gas production technique. Cocoa husks samples were subjected to alkali and thermal methods (effect of time of exposure) treatment, as follows: control; alkaline treatment with calcium hydroxide ((Ca(OH)2) and calcium oxide (CaO), both doses of 15.0; 30.0 and 45.0 g kg-1 of CH; heat treatment in an autoclave at a pressure of 1.23 kg cm-2 (15 psi) and a temperature of 123°C for 30, 60 and 90 minutes. For statistical analysis, orthogonal contrasts and regression. The degradation rate and the final volume of gases of non-fiber carbohydrates decreased with the addition of Ca(OH)2 and CaO, however, for fibrous carbohydrates effects were positive. For each percentage of Ca(OH)2 and CaO included, it is estimated an increase of 5.74 and 2.9% in the final volume of the fiber, respectively. When the heat treatment, a decrease in all parameters was estimated. For each minute of exposure to heat, there was a decrease of 0.4% in total final volume of gases. The alkali treatment can be an efficient alternative for improving the digestibility of fibrous fractions of CH.

The aim of this study was to evaluate the feeding behavior of lambs fed diets containing peach palm meal replacing maize (0, 10, 40, 60, and 85% DM). Thirty Santa Inês sheep with an average initial body weight of 21.6 ± 0.87 kg were distributed in a completely randomized design with five diets and six replicates. Feeding time in min kg–1 DM and min kg–1 NDFap increased by 34 min and 99.6 min, respectively, with each level of substitution of maize for the peach palm meal. Rumination and chewing times, in min kg–1 DM and min kg–1 NDF, also increased in response to the substitution of maize for peach palm meal. When expressed in min day–1, rumination and chewing activities decreased by 12.4 and 14.6 min, respectively, as the amount of peach palm meal in the concentrate was increased. The time spent idle increased linearly (P &lt; 0.05), by 14.6 min day–1, with the replacement levels, compared with the control diet. Peach palm meal in the composition of sheep diets reduces the intakes of dry matter and fiber and decreases the feed and rumination efficiencies. Replacing maize by peach palm meal increases the feeding time and rumination and chewing activities of feedlot lambs.