Resumo em Inglês:

The objective was to evaluate the use of woody legumes (Albizia lebbeck, Cratylia argentea, Dipteryx Allata (Baru), a Leucaena hybrid (L. leucocephala + L. diversifolia), and Leucaena leucocephala cv. Cunningham) and herbaceous legumes (Arachis pintoi) intercropped with Panicum maximum cv. Massai, simultaneously implanted in a maize crop. The study made use of a randomized block experimental design with four replications. Assessments of biomass accumulation and forage nutritional value were made after the maize harvest, between June 2008 and October 2010. It was found that the residues of maize provided better growing conditions for Massai grass during the dry season. L. leucocephala cv. Cunningham and the Leucaena hybrid had the highest accumulation of all forage legumes evaluated, and provided the best nutritional value of all the arrangements tested. Of all woody legumes tested in this system, Leucaena was considered feasible for intercropping with Massai grass. The intercrop of perennial woody Baru with maize is not recommended. Albizia lebbeck and Cratylia argentea require further study, especially the yield assessment at different cutting intervals and cutting heights. Arachis pintoi had a low participation in the intercropping, showing greater performance over time, indicating slow thriving in this experimental condition.

Resumo em Inglês:

The objective was to evaluate elephant grass (Pennisetum purpureum Schum.) pastures, under the agroecological and conventional systems, as forage mass and stocking rate. In the agroecological system, the elephant grass was established in rows spaced by 3.0 m from each other. During the cool season ryegrass (Lolium multiflorum Lam.) was established between these rows, which allowed the development of spontaneous growth species during the warm season. In the conventional system the elephant grass was established singularly in rows spaced 1.4 m from each other. Organic and chemical fertilizers were applied at 150 kg of N/ha/year with in the pastures under agroecological and conventional systems, respectively. Lactating Holstein cows which received 5.0 kg/day supplementary concentrate feed were used for evaluation. The experimental design was completely randomized, with two treatments (agroecological and conventional systems) two replications (paddocks) and independent evaluations (grazing cycles). The pastures were used during the whole year for the agroecological system and for 195 days in the conventional year. The average values of forage mass were 3.5 and 4.2 t/ha and the stocking rates were 2.08 and 3.23 AU/ha for the respective systems. The results suggest that the use of the elephant grass under the agroecological system allows for best distribution of forage and stocking rate to be more uniform throughout the year than the use of elephant grass in conventional system.

Resumo em Inglês:

The objective of this study was to evaluate the effect of grazing intensity on herbage accumulation, animal performance, and total system yield on irrigated Tanzania grass pastures under rotational stocking. The experiment was conducted from October 1999 to January 2001, in a complete randomized block design with four replications. Treatments consisted of three grazing intensities, represented by the following quantities of green forage dry mass remaining after grazing: 1,000 (high intensity), 2,500 (intermediate intensity) and 4,000 (low intensity) kg ha−1. Grazing cycles were of 36 days (33 rest and 3 grazing). The values observed at the end of the experiment for post grazing forage mass were close to the proposed values. Forage yield was 25,278, 36,850, and 34,144 kg DM ha−1, whereas animal performance was 0.398, 0.541, and 0.564 kg BW day−1 for high, intermediate and low intensities, respectively. Grazing intensity was positive related to the stocking rate (6.5, 5.2 and 4.1 AU ha−1 at high, intermediate and low intensities, respectively). Total system yield was not affected by treatments, ranging between 1,518 and 1,287 kg BW ha−1 year−1.

Resumo em Inglês:

Two experiments were carried out to evaluate the reduction of crude protein (CP) in diets supplemented with synthetic amino acids for piglets of 15 to 30 kg. In the performance assay (Exp I), 60 piglets with initial weight of 15.34±0.87 kg and final weight of 30.08±1.59 kg were distributed in a randomized block design with six replicates, five treatments and two animals per experimental unit. The treatments consisted of five diets in which the CP was reduced by 1.5 percentage points, resulting in low-protein diets (19.24, 17.74, 16.24, 14.74 and 13.24%), meeting the requirements of amino acids with inclusion of L-lysine, DL-methionine, L-threonine, L-tryptophan, L-valine and L-isoleucine. The average daily gain and feed conversion according to the Linear Response Plateau model (LRP) were estimated at 14.23 and 14.79% of CP, respectively. As the CP levels were reduced, there was an increase in the essential:non-essential amino acids ratio. The plasma urea concentration decreased linearly, indicating that there was a better use for amino acids with the CP reduction. In the nitrogen balance (Exp II), 30 crossbred barrow piglets with average weight of 21.69±4.46 kg were housed in metabolic cages, distributed in a completely randomized design with five treatments and six replicates, and the experimental unit consisted of a piglet. The biological protein value in the diets remained above the ideal (70%), in which the level of 13.24% CP corresponded to the highest value. There was no difference in levels of urea in blood and urine. Reduction of protein levels is efficient in decreasing the pollution effect in the excreta, with lower nitrogen excretion in feces and urine.

Resumo em Inglês:

Twenty weaned male hair lambs with average body live weight of 19.20 kg±2.18 kg (SD) were used to evaluate the effect of zeranol on growth, composition and carcass yield. The animals were distributed into a completely randomized design with two treatments: no anabolics (control); and treatment with zeranol, using a subcutaneous dose of 10 mg/50 kg body live weight. Lambs received a diet with 15 g/100 g of crude protein and 2.8 Mcal of metabolizable energy/kg dry matter for 84 days. At the end of experiment all animals were harvested and entire carcass and its parts (neck, shoulder, loin-rib, loin-skirt and leg) were weighed to determine the composition of muscle and bone. Control animals had higher dry matter intake (1.01 vs 0.88 kg/d), average daily gain (198 vs 172 g/animal) and total weight gain (12.9 vs 10.9 kg) compared with those treated with zeranol. Zeranol group had higher muscle weight (1.76 vs 1.98 kg) and less bone (0.86 vs 0.61 kg) in leg section. The leg area represented about 16 kg/100 kg of the carcass weight for both treatments. No differences for other carcass traits were observed. Lambs treated with zeranol have better leg conformation because they develop more muscle mass, though their average feed intake and daily gain decrease.

Resumo em Inglês:

The changes in the concentration of trans-vaccenic (C18:1t-11) and rumenic (C18:2c-9,t-11) acids in the milk from cows grazing on Pennisetum clandestinum, fed a supplement containing palm oil, rice bran or whole cottonseed were evaluated. Three supplements were assessed: one control supplement containing palm oil (C), with a low concentration of linoleic acid mainly from palm oil, and two supplements containing rice bran (RB) or whole cottonseed (CS) as the main source of linoleic acid. Six Holstein cows (4.2±1.7 years of age, 532.5±50.7 kg BW, 125±29 days in milk and a milk yield of 21.7 5.8 kg d−1; Mean±SD) were assigned to each treatment using a double 3 × 3 × 3 Latin Square Design. Compared with treatment C, the milk fat concentrations of trans-vaccenic acid (31.1 and 23.8 g kg−1 of fatty acids for RB and C, respectively), rumenic acid (14.1 and 11.3 g kg-1 of fatty acid for RB and C, respectively) and unsaturated fatty acids (348.7 and 325.4 g kg−1 of fatty acid for RB and C, respectively) were higher for RB. Compared with C and CS treatments, the Δ9-desaturase index was higher for RB (0.37, 0.35 and 0.34 for RB, C and CS, respectively) and the thrombogenicity index was lower (3.09, 3.43 and 3.50 for RB, C and CS, respectively). The atherogenicity index was lower for RB treatment compared with C, but not compared with CS (1.85, 2.03, 1.97 for RB, C and CS, respectively). Supplementing rice bran to grazing dairy cows is a good alternative for producing a kind of milk beneficial to human health, due to its higher concentrations of trans-vaccenic and rumenic acids, unsaturated fatty acids and lower thrombogenicity and atherogenicity indexes.

Resumo em Inglês:

The objective of this study was to analyze the behavior of three genetic groups of confined goats by image monitoring using nine unneutered goats of the Azul, Graúna and Moxotó genotypes. The experimental design was completely randomized, in a 3 × 3 factorial arrangement (genetic groups × periods - morning, afternoon and night), with three replications. Animals were monitored by video cameras placed at the ceiling of each stall for 10 days. There were interaction factors in the frequency of behavioral categories: interaction with the trough, self-cleaning, standing bipedally, social interaction, and other activities. Azul, Graúna and Moxotó native goats kept in the same environment under the same system of containment and feeding show different frequencies and durations in their behaviors, which are influenced by the period of the day.

Resumo em Inglês:

The objective of this study was to characterize the sorghum farming and ensiling systems in the Cariri region of Paraíba State (Brazil), and to identify different groups of producers based on productive characteristics using frequency distributions, and principal component and cluster analyses. A total of 100 milk producers in the Caturité and Boqueirão municipalities in the dairy region of Cariri, Paraíba, were selected to fill out a questionnaire comprised of 32 questions to collect data on both qualitative and quantitative variables. Of the 100 properties studied, 88% cultivated sorghum as silage forage for feeding dairy cows, demonstrating the importance of this cultural practice in the region of Cariri. Statistical analyses based on the variables studied identified four groups, composed of 35, 8, 6, and 39 farmers. The sorghum cultivation and ensiling production system in Cariri can be improved through the evaluation and improvement of soil fertility to obtain higher forage production, application of weed control using herbicides, and implementation of mechanized planting and harvesting to improve efficiency and reduce costs associated with manpower.