Sidnei Antônio Lopes

Replacement of soybean meal by treated castor meal in supplements for grazing heifer during the dry-rainy season period

The objective of this work was to evaluate the effect of multiple supplement with different levels of castor meal (Ricinus communis L.) treated with calcium oxide on intake, on the total apparent digestibility of dietary components, on the efficiency of microbial synthesis and on the performance of beef heifers grazing Brachiaria decumbens during the dry-rainy transition period. The experimental area was composed of five 2.5-ha paddocks with availability of potentially digestible dry matter of 2,858.4 kg/ha. It was used 25 Nellore heifers and 10 crossbred with predominance of Zebu breed heifers at 13 months of age and body weight of 210 ± 0.8 kg in a completely randomized experimental design. Supplements contained approximately 25% of crude protein (CP) and they were formulated with 0; 33; 67 and 100% of castor meal replacing soybean meal. Daily weight gain was 366.1 g for animals in the control group and 439.7; 478.9; 556.3; and 493.9, respectively for those fed supplements with 100% of soybean meal and 33, 67 and 100% castor meal. There was no effect of treated castor meal levels on daily weight gain of the animals, which was higher in those animals fed supplements. Levels of castor meal had decreasing linear effect on intakes of dry matter (DM), organic matter (OM), ether extract (EE), digested dry matter and digestible neutral detergent fiver and on the intake of total digestible nutrients. Coefficients of apparent digestibility of DM, OM, CP, EE and non-fibrous carbohydrates were greater for animals under supplementation. Microbial efficiency, expressed in g of crude protein per kg of consumed TDN, did not differ among groups. Replacement of soybean meal by castor meal treated with calcium oxide does not harm animal performance.

Levels of multiple supplements or nitrogen salt for beef heifers in pasture during the dry season

The study assessed performance, microbial protein synthesis, intake and digestibility of nutrients by beef heifers receiving levels of multiple supplements or nitrogen salt, in a self-controlled intake, on pasture, during the dry season. Thirty-five beef heifers, from 6 to 9 months of age and average initial body weight of 203.4 + 4.5 kg, were used. Study factors were: control - mineral mixture; nitrogen salt - 50% of urea + mineral mixture, at proportion of 1:1, and 50% of corn (75% of crude protein); levels of multiple supplementation - multiple supplements with different percentages of intake controller mixture (urea + mineral mixture, at the proportion of 1:1), corn and soybean meal (45% of crude protein). Supplement consumptions observed were: 115, 173, 572 and 1214 g/animal/day for animals fed on nitrogen salt, low, medium and high levels of multiple supplement, respectively. Supplemented animals had greater average daily gain, evidencing the positive linear effect of the levels of multiple supplementation on average daily gain. Overall, there were no significant differences between average daily gain of animals fed on multiple supplements or nitrogen salt. Supplementation increased the intake and digestibility of nutrients, except for digestibility of neutral detergent fiber, although the intake of digested neutral detergent fiber increased. Supplementation increased the production of microbial nitrogen as well as nitrogen losses in urine, although the quantity of nitrogen assimilated by bacteria, proportionally to intake, was higher. Supplementation improves nutritional parameters and weight gain.

Cottonseed meal is a suitable replacement for soybean meal in supplements fed to Nellore heifers grazing Brachiaria decumbens

The objective was to evaluate the effect of substituting soybean meal with cottonseed meal in supplements containing 15% and 30% of crude protein (CP), as well as evaluate the effect of supplementation use, on the performance and nutritional status of Nellore heifers. Forty heifers that were 13 months old and 250 ± 4 kg were kept in five 2.5-ha paddocks covered with Brachiaria decumbens. They were compared as they received different supplements (1 kg/head.day) in a 2 × 2 + 1 factorial – two protein sources (soybean and cottonseed meal) by two protein concentrations (15% and 30%) plus a Control treatment, which was a mineral mix only. The supplemented heifers showed greater weight gains, final bodyweight (P < 0.10) and higher intake of all evaluated nutrients (P < 0.10), as well as greater digestibility of these nutrients compared with those from the Control treatment. The animals fed supplements containing 15% CP had lower digestibility of dry matter, organic matter, CP and neutral detergent insoluble fibre corrected for ash and protein. These animals also had lower total digestible nutrients as compared with those which received a supplement containing 30% CP (P < 0.10). The treatments containing cottonseed meal provided greater dry matter digestibility (P < 0.10). Cottonseed meal can fully substitute soybean meal to grazing heifers during the rainy season. Supplements containing 30% of CP provided greater digestibility than 15% CP supplements. Supplemented animals had better performance.

Performance and nutritional evaluation of beef cattle raised on pasture, castrated at different ages, with and without supplementation

The objective of this study was to evaluate performance and nutritional traits of beef cattle raised on pastures, castrated at different ages, with and without supplementation. Forty-four crossbred young bulls with predominance of Zebu breed at initial average age of 120±30 days were used in the experiment. Animals were distributed in a completely randomized design in a factorial arrangement with four ages of castration and two supplementation systems. The animals were distributed into four groups and placed on Brachiaria decumbens Stapf pastures, where they were fed concentrate supplementation or mineral salt ad libtum (control). Animals were castrated at 120, 240 and 360 days of age with average body weight of 115, 175 and 276 kg, castrated or not, in each supplementation group. Concentrate supplement composition and the amount supplied to the animals varied according to the time of the year and development phase of the animals. Trials were carried out to evaluate nutritional variables in each of the following phases: suckling, growth in the dry season and growth in the dry/rainy transition season. Concentrate supplementation improved the use of pasture, although it may have caused substitutive effect in all seasons evaluated. Castration of the animals before the dry season impaired animal development until the following dry/rainy transition season, especially when carried out during weaning. Concentrate supply may reduce some effects of this stress.