The aim of this study was to determine the effects of different amounts of crude glycerol (CGL) on dry matter intake, milk yield, milk protein yield, and milk fatty acid profile of dairy cows grazing on a Kikuyu-based pasture. Six Holstein cows were used in the first third of lactation (mean ± SD 559 ± 22.5 kg body weight, 43 ± 10 days in milk, and 26.8 ± 1.2 kg milk/day) and were randomized within a replicated 3 × 3 Latin square arrangement. Animals grazed the Kikuyu grass and were supplemented with a commercial energy-protein concentrate at 1.0 kg/4.0 kg of milk. The experimental period was 69 days. The following treatments were administered: CGL0 (control, without glycerol), CGL1 (750 g/cow/day), and CGL2 (1,500 g/cow/day). The addition of 750 and 1,500 g of CGL did not affect grass and concentrate intake (P > 0.05). However, milk yield (FCM 3.5%) increased by 14.2% in the CGL2 group compared to that obtained in the control group (CGL0) (P = 0.02). The addition of 1,500 g of CGL to the diet resulted in a 2.1% greater yield of milk protein compared to that obtained with CGL0 treatment (P = 0.01). Further, the addition of 1,500 g of CGL did not impact grass intake, milk fat concentration, or fatty acid composition (P < 0.05). Thus, the inclusion of CGL as a co-product may be a nutritional strategy to increase the productivity of dairy production systems in tropical perennials, such as Kikuyu grass.

This study aimed to evaluate the influence of botanical composition calibration on the accuracy of undisturbed sward height and comparative yield method (CYM) techniques for herbage mass estimation...

This study evaluated the effects of increasing levels of crude glycerol (CG) on the effective degradability of neutral detergent fiber (EDNDF) in Pennisetum clandestinum Hochst. Ex Chiov (kikuyu forage) and ruminal fermentation parameters in grazing dairy cows. Four non-lactating cannulated Holstein cows were used in a 4 × 4 Latin square design. Treatments consisted of CG infusion in the rumen at the following levels: 0 (G0), 500 (G500), 1000 (G1000), and 1500 (G1500) g/animal/day. Two kikuyu forages harvested (D) at 35 (DR35) and 45 (DR45) days of regrowth were incubated in the rumen for 72 h. The infusion of CG into the rumen increased (p < 0.05) EDNDF in both incubated forages. Total volatile fatty acids (VFAs) and pH values in the ruminal fluid were unaffected (p > 0.05) by the infusion of CG. However, propionate and butyrate molar proportions increased (p < 0.05) at the expense of acetate at all CG levels. In addition, the NH₃-N levels decreased (p < 0.05) by approximately 20% with the infusion of 1000 and 1500 g of CG. In conclusion, supplementation with CG increases ruminal EDNDF, improving rumen fermentation dynamics in cows grazing kikuyu forage under tropical conditions. This greater EDNDF was achieved for both harvesting times.