Eriton Egidio Lisboa Valente

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.

Grazing Behavior and Locomotion of Young Bulls Receiving Different Nutritional Plans in a Tropical Pasture

The objectives of this study were to compare visual observation and an electronic grazing time method and to evaluate the effects of nutritional plans on intake, grazing behavior and horizontal and vertical locomotion of young bulls in a tropical pasture. Thirty-nine Nellore young bulls with an average body weight of 345±9.3 kg kept in pasture were used. The experimental treatments consisted of: restricted: animals kept in a plot with a low mass of forage receiving mineral mixture only; control: animals receiving mineral mixture only; HPHC: a high protein and high carbohydrate supplement; HPLC: a high protein and low carbohydrate supplement; LPHC: a low protein and high carbohydrate supplement; LPLC: a low protein and low carbohydrate supplement. GPS collars equipped with activity sensors were used. Information about head position, latitude, longitude and altitude were recorded. Daytime grazing behavioral patterns monitored by a continuous focal animal recording method was compared to behavior estimated by the activity sensor. Feed intake was estimated by a marker method. The Restricted group presented lower (p<0.05) intake of dry matter and TDN. However, difference in dry matter intake was not found (p>0.05) between non-supplemented and supplemented animals. Difference was not found (p>0.05) in daytime grazing time obtained by visual observation or the activity sensor method. The restricted group showed longer (p<0.05) grazing time (9.58 h/d) than other groups, but difference was not found (p>0.05) in the grazing time between Control (8.35 h/d) and supplemented animals (8.03 h/d). The Restricted group presented lower (p<0.05) horizontal locomotion distance (2,168 m/d) in comparison to other groups (2,580.6 m/d). It can be concluded that the use of activity sensor methods can be recommended due to their being similar to visual observation and able to record 24-h/d. While supplements with high carbohydrates reduce pasture intake, they do not change grazing behavior. Moderate supplementation (until 50% of protein requirement and 30% of energy requirement) of beef cattle on tropical pasture has no effect on daily locomotion.