Performance of sheep grazing Panicum maximum cv. Massai and supplemented with protein sources during the dry season

The low quality of tropical grasses in the dry season justifies the use of dietary supplements to meet the nutritional needs of sheep. The objective of this study was to evaluate the effect of supplementation with high-protein feed on mutton sheep performance and yield in Massai grass pastures during the dry season. The treatments corresponded to four supplements, namely Leucaena leucocephala leaf hay, Gliricidia sepium leaf hay, soybean meal, and a treatment that received only multiple mixture (protein salt) ad libitum. The pasture was evaluated for canopy height, forage supply, and chemical composition of leaf blade, stem and dead material. Average daily gain, weight gain per area, and the stocking rate were also evaluated. There were four grazing cycles because the grazing method was rotational stocking with seven days of occupation and 35 days of rest. The interaction between supplements and grazing cycles was not significant, and no effects of the supplements were found for any of the variables. The highest forage and leaf blade offerings were observed in the first grazing cycle. The highest levels of crude protein and lower neutral detergent fibre and lignin of pasture components were observed in cycles 3 and 4. The highest average daily gains per animal and per area were observed in cycles 1 and 2. Protein supplementation of sheep in Massai grass pastures promotes satisfactory gains during the dry season, and Leucaena and Gliricidia hays can be used as protein sources instead of soybean meal. Keywords: Gliricidia sepium, leguminous, Leucaena leucocephala, pastur

Forage quality and performance of sheep in Massai grass pastures managed at pre-grazing canopy heights

The objective of this study was to evaluate the effects of pasture height at pre-grazing of Massai grass on the quality of available forage, forage intake and the performance of lambs raised for meat production. The treatments consisted of four pre-grazing canopy heights (35, 40, 45 and 50 cm). Pastures were managed by the intermittent stocking method and 32 sheep were used. Dry matter intake (DMI) was estimated by Lipe® indicator. Green forage allowance was not affected by pre-grazing heights. There was no effect of heights on the chemical composition of the stem or the leaf blades, except for crude protein content of leaf blades, which showed an inverse linear effect. Grazing time had a quadratic response in function of canopy height. The minimum point was at 42.6 cm, with 502.9 min/day. DMI increased linearly with increasing pasture height. Average daily weight gain (ADG) and stocking rate (SR) responded linearly to pre-grazing heights. Weight gain per hectare was not affected by height as a result of the compensation between SR and ADG. The increase from 35 to 50 cm in Massai grass canopy height reduces its nutritional value and individual performance and increases DMI of sheep intended for meat production.Keywords: Panicum maximum, tropical pasture, voluntary intak

Sward structure and livestock performance in guinea grass cv: Tanzania pastures managed by rotational stocking strategies

Grazing strategy is a key element in the determination of sward structure, herbage nutritive value and animal performance. We aimed to compare the herbage characteristics and performance of livestock in pastures of Panicum maximum cv. Tanzania managed, using two rotational stocking strategies, which provided either a fixed-length rest period (FRP) of 35 days in the spring and fall and 30 days in the summer, or a variable-length rest period (VRP), determined by the time required for the canopy to achieve 70 cm in height. The pastures were evaluated in the pregrazing condition for forage mass (FM); leaf (LP), stem (SP) and dead matter (DP) percentages; and nutritive value (NV). The animals were weighed every 28 days. Pastures managed with the FRPs exhibited greater FMs, SPs and DPs and lower LPs and NVs than those managed with the VRPs. The average daily livestock weight gain was greater during the spring and summer for the VRP than for the FRP pastures, resulting in an average animal weight gain per area of 990 and 860 kg ha−¹ wet period−¹ for the pastures managed with the VRPs and FRPs, respectively. Thus, pasture rest periods that were maintained after the sward reached 70 cm in height reduced the animal performance on Tanzania guinea grass