Suchergebnisse

The goal of this work was to evaluate the growth dynamics and chemical characteristics of the upper and lower strata of summer perennial grasses under a four cuts system. The experiment was conducted in a randomized block design, composed of 28 treatments in a factorial arrangement of 7x4, with four repetitions. The cultivars evaluated were Star Grass, Coast-cross, Tifton 68, Tifton 85, Jiggs, Roxinha and Quicuio. Each cultivar was cut when it reached 95% light interception. The cultivars Jiggs and Tifton 68 had the highest (P < 0.05) accumulation of dry biomass ha-1 during the four cuts, with productions of 21,348 and 21,016 kg ha-1, respectively. The ash content varied (P < 0.05) among species and times of cutting for both strata. Cellulose contents were significantly different in the upper stratum, with the highest concentrations found in cvs. Quicuio and Tifton 68 (39.12% and 38.07%, respectively). We found the highest levels of lignin (P < 0.05), for both strata, in cv. Quicuio. Cultivars Jiggs and Tifton 68 were the most appropriate for a management system of four cuts, displaying good chemical composition and high productivity.

The objective of the experiment was to evaluate the productivity, nutritional value and degradability of forage and silage of wheat (Triticum aestivum cv. BRS Umbu) and black oats (Avena strigosa cv. Embrapa 139), preceded by successive cuts, harvested at the hard dough stage, subjected or not to treatment with pyraclostrobin fungicide. Plants were harvested manually with a height of 0.08 m from the ground surface, at the hard dough stage, after two cuts at the vegetative stage; two applications of pyraclostrobin, 0.6 L ha-1 were made, before the first and the second cut. Pyraclostobin decreased the dry matter losses from 21.1% of the control system to 7.7% for the system with pyraclostrobin, reduced the neutral detergent fiber from 70.05% to 66.73%, decreased detergent fiber acid from 43.37% to 39.96%, decreased lignin from 14.37% to 10.13% and increased the relative value of the food from 75.27% to 82.72%, all in the forage, which resulted in changes in silage, with a decrease in neutral detergent fiber from 64.00% to 58.46%, acid detergent fiber from 38.76% to 35.87%, lignin from 10.11% to 6.78% and an increase in the relative value of the food from 85.87 to 97.26. In the evaluation of the forages, wheat presented the best productivity, with 10,068 kg ha-1 vs. 8,238 kg ha-1 black oats, lower neutral detergent fiber (60.32% vs. 76.46%), lower acid detergent fiber (34.49% vs. 48.84%) and higher relative value of the food (96.04 vs. 61.95), these data were from the forage, which were reflected in the resulting silage. It is recommended to use pyraclostrobin as it reduces losses during fermentation, changes fiber composition and improves the degradability of the food. Among the forages, the wheat was more promising, than black oats, due to its productivity, combined with its better chemical composition and degradability.

The objective was to evaluate the associative effect of monensin sodium to virginiamycin on the performance, dry matter intake, apparent digestibility and ingestive behavior of steers in the initial feedlot phase. The experiment lasted for 30 days, divided into two experimental periods. Thirty-six Angus Nellore steers, non-castrated, with a mean age of 10 months and an average weight of 300 kg, were divided into 18 pens. Animals were assigned to three treatments with six replications each, with the inclusion of the following additives: T1-monensin sodium, dose of 200 mg day-1; T2-monensin sodium, dose of 125 mg day-1 + virginiamycin, dose of 125 mg day-1; and T3-monensin sodium, dose of 200 mg day-1 + virginiamycin, dose of 125 mg day-1. All experimental procedures were previously submitted to the UNICENTRO Committee for Ethics in Animal Experimentation (CEUA), and were approved for execution (Official Letter 021/2019). The combination of monensin sodium with virginiamycin at a dose of 200 mg + 125 mg animal day-1 showed greater (P < 0.05) average daily weight gain (1.919 kg day-1) and better feed conversion (4.27 kg DM kg of weight gain-1) compared to diets with monensin alone (200 mg animal day-1) or monensin combined with virginiamycin (125 mg + 125 mg animal day-1), even with no significant (P> 0.05) difference in DM intake, with a mean value of 7.88 kg animal day-1. Regardless of the isolated or combined supplementation of the additives, no significant differences were detected in the analysis of the feeder and feces scores, ingestive behavior, and rectal temperature or infrared thermography during the evaluation period. The combination of monensin sodium with virginiamycin at 200 mg + 125 mg animal day-1 proved to be efficient in the initial feedlot period, determined by the greater weight gain and better feed conversion observed in this study.

he objective of this study was to evaluate the production and physical composition of three maize hybrids (Zea mays, L.) for silage production at six maturity stages. The hybrids evaluated were Maximus VIP3, Defender VIP and Feroz VIP. The experiment was conducted in a completely randomized block design with four replicates. The mean plant heights observed at harvest time (2.33 m, 2.45 m and 2.40 m) demonstrated that all materials were medium-sized hybrids. A positive correlation was observed between plant height and height of the ear insertion, varying from 0.86 for the Feroz VIP hybrid to 0.88 for the Maximus VIP3 hybrid, but these two variants had no correlation with the productivity data. There was a significant difference for the production of fresh biomass at the R1, R2 and R5 stages, with Maximus VIP3 obtaining the highest yields. The proportion of grains in the physical composition of plant varied between hybrids, where Maximus VIP3 and Defender VIP (482.2 and 461.7 g kg-1, respectively) were superior to Feroz VIP (429.7 g kg-1). With the advancement of maturity, there was a decreasing linear behavior for stem and leaf participation, with reductions of 3.8 g kg-1 and 4.5 g kg-1, respectively, per day (R2 = 0.79 and 0.80, respectively), quadratic behavior for bracts and corncob and a linear increase in grain participation in the plant structure, with an increase of 7.7 g kg-1 per day (R2 = 0.88). In general, the three hybrids present good characteristics for silage production and permit harvesting in the hard grain stage, allowing the addition of starch in relation to the farinaceous grain stage.

The Brazilian livestock activity is undergoing constant evolution, and aiming at its maximum efficiency, it is necessary to have available to the animals food in quantity and quality all the year. To this end, the cultivation of winter forage is carried out. The present study aimed to evaluate the productive and qualitative agronomic traits of ryegrass forage. The experiment was a randomized block design in a 3 x 2 factorial arrangement consisting of six treatments, three plant stands (525, 1050 and 2095 plants m-2) associated with two successive cutting times (vegetative and full vegetative), and four repetitions. There was no interaction between population stand and cutting times for the variables studied. The stand of 525 plants m-2 had a higher participation of green leaves (50.52 %), higher digestibility of the whole plant dry matter (84.81 %) compared to the stands of 1.050 and 2.095 plants m-2, and dry biomass production per unit area equivalent to the others (6087, 7243 and 6989 kg ha-1, respectively). The first harvest season presented higher participation of green leaves and better leaf/stem ratio, 58.62 % and 3.41 % respectively, as well as higher digestibility of green leaves (77.26 %) and stem (80.82 %).

The objective of this study was to evaluate the associative effect of monensin sodium to virginiamycin and/or essential oils on performance, consumption of nutrients and dry matter, apparent digestibility, feeding behavior and carcass characteristics of feedlot finished steers. The experiment lasted 106 days with 10 days of adaptation and 96-day trial, and had 32 crosses angus steers, average age 12 months and average weight of 376 kg, divided into 16 stalls, the weighing took place every 21 days and at the end of the experiment. The treatments consisted of the combination of the following additives to the diet included: Monensin sodium, 200 mg day-1 (MO); Monensin sodium, a dose of 200 mg day-1 + essential oil dose of 1.5g day-1 (MO+EO); Monensin sodium, a dose of 200 mg day-1 + virginiamycin, 200 mg day-1 (MO+VI); Monensin sodium, 200 mg day-1 + essential oil dose of 1.5g day-1 + virginiamycin day, 200 mg day-1 (MO+EO+VI), each treatment had four repetitions, where each repetitions consisted of a bay with two animals. The MO+VI association in relation to MO only increase in average daily gain (ADG) of 24.44%, 22.35%, 21.10% and 17.31% in weighing 42, 63, 84 and 96 days, similar the combination of MO+EO+VI which provided an improvement of 21.94%, 13.59%, 15.45% and 14.75% respectively in the same weightings. The daily carcass gain and carcass overall gain were higher in associations MO+VI and MO+EO+VI and provided an average gain of 16.67 kg more compared to MO and MO+EO. In the parameters feed efficiency, dry matter intake and nutrient expressed in kg day-1 and percentage of live weight were not observed differences (P > 0.05) between treatments. Data on apparent digestibility, feeding behavior and carcass characteristics did not show statistical difference between treatment, except for fat thickness which was higher when associated with any of the additives to the MO, and farm weight was higher in associations containing VI. Associating MO+VI or MO+EO+VI proved to be best in this work compared to MO+EO or only MO in the diets of steers in termination.

The objective of this experiment was to evaluate the in situ dry matter degradability and in situ crude protein degradability of soybean meal subjected to different treatments (thermal, chemical, tannins or saponins). The treatments were: conventional soybean (CON); soybean expeller (EXP); lignosulfonate-treated soybean meal (LIGS); condensed tannin-treated soybean meal (CTAN); hydrolysable tannin-treated soybean meal (HTAN) and Yucca schidigera extract-treated soybean meal (YUC). Samples of 5 g soybean meal were packed in nylon bags and incubated in the rumen of 2 fistulated cattle for seven incubation times (0, 3, 6, 9, 12, 18 and 24 hours), in sequence were washed, dried and weighed. The ruminal kinetics parameters were calculated, and the experiment was completely randomized, with six treatments, four replicates each, with duplicates. The EXP and LIGS treatments showed lower crude protein disappearance (CPD) within 12 hours, the CON, HTAN and YUC treatments had the highest CPD, and the CTAN presented an intermediate value (41.84%) (P < 0.05). EXP had the lowest fraction "a" (soluble) of crude protein (CP) (10.1%) followed by LIGS and CTAN (average of 14.82%). EXP and LIGS had the highest rumen undegradable fraction of CP (57.35 and 51.62%), respectively. In addition, ruminal disappearance rates of dry matter and CP of the treatments ranged from 2.17 to 1.36% h-1 and from 2.63 to 1.2% h-1, respectively. The most efficient treatments to reduce ruminal protein degradation were EXP, LIGS and CTAN.