Evaluation of the Feeding Value of Common Reed (Phragmites australis) and Its Potential as a Substitute for Straw in Diets of Fattening Male Baluchi Lambs

Introduction: Common reed (Phragmites australis) is a widely distributed perennial plant that produces considerable amounts of biomass in wetland and marginal areas. Although its relatively high cell-wall content may limit its nutritional value, the availability of this plant and the possibility of harvesting its biomass have raised interest in its potential use as a roughage source for ruminants. In particular, utilization of common reed as a partial substitute for straw could provide an alternative use for locally available biomass while reducing pressure on conventional forage resources. However, its nutritional value depends on its chemical composition, ruminal degradation characteristics, and its effects on animal feed intake and growth performance. Therefore, the present study was conducted to determine the chemical composition and in situ ruminal dry matter degradability of common reed and to evaluate the effects of replacing different levels of straw with common reed on feed intake and growth performance of fattening male Baluchi lambs.




Method: The study consisted of two complementary experiments. Common reed samples were evaluated for chemical composition and in situ ruminal dry matter degradability. The plant material was collected from the study area, dried, ground, and analyzed for dry matter (DM), ash, neutral detergent fiber (NDF), acid detergent fiber (ADF), crude protein (CP), ether extract (EE), and gross energy (GE). Ruminal degradability was determined using the nylon-bag technique. Approximately 3 g of the ground common reed sample was placed in nylon bags and incubated in the rumen of a fistulated bovine for 2, 4, 8, 16, 24, 48, and 72 h. Following incubation, the bags were removed and processed to determine DM disappearance. The degradation characteristics were described using the parameters a, b, and c, representing the rapidly degradable fraction, potentially degradable fraction, and degradation rate constant, respectively.




In the second experiment, 18 male Baluchi lambs were assigned to three dietary treatments with six animals per treatment in a completely randomized design. The experimental period lasted 75 days following a 7-day adaptation period. The diets were formulated to contain 70% fattening concentrate and 30% forage. In the control treatment (T1), the forage portion consisted of 20% alfalfa and 10% straw. In T2, 20% alfalfa, 5% straw, and 5% common reed were included, whereas in T3, 20% alfalfa and 10% common reed were used, with straw completely replaced by common reed. The experimental diets were offered as a total mixed ration twice daily. Daily feed intake, total feed intake, final body weight, average daily gain, total weight gain, and feed conversion ratio were determined. The data were analyzed using SAS software, and treatment means were compared using the Tukey–Kramer test. Initial body weight was considered as a covariate in the statistical analysis.




Results: Chemical analysis showed that common reed contained 67.90% DM, 9.00% ash, 70.94% NDF, 57.89% ADF, 6.59% CP, 1.31% EE, and 3909.44 cal/g gross energy. In situ ruminal DM disappearance increased progressively with incubation time, from 1.57% at 2 h to 4.41%, 5.83%, 10.73%, 12.83%, 14.83%, and 29.91% at 4, 8, 16, 24, 48, and 72 h, respectively. The estimated degradation parameters were 10.00% for fraction a, 72.11% for fraction b, and 0.0087 h for degradation rate constant c. The relatively small rapidly degradable fraction and low degradation rate indicate that a considerable proportion of the potentially degradable material in common reed is degraded slowly in the rumen.




The inclusion of common reed as a replacement for straw did not significantly affect daily feed intake, total feed intake, final body weight, average daily gain, total weight gain, or feed conversion ratio. Although these differences were not statistically significant, lambs receiving 5% common reed and 5% straw showed numerically greater final body weight and weight gain and a numerically better feed conversion ratio than the other treatments. These findings indicate that partial replacement of straw with common reed at the levels evaluated did not adversely affect growth performance or feed intake of the lambs.




Conclusions: The results of this study demonstrated that common reed (Phragmites australis) has a relatively high cell-wall content and a slow ruminal degradation pattern but can nevertheless be incorporated into diets of fattening male Baluchi lambs at the levels evaluated without significant adverse effects on feed intake or growth performance. Replacement of straw with 5 or 10% common reed did not significantly alter daily feed intake, total feed intake, final body weight, average daily gain, total weight gain, or feed conversion ratio. Among the experimental diets, the combination of 5% common reed and 5% straw showed a numerical advantage in growth performance and feed conversion, although this difference was not statistically significant. Therefore, common reed can be considered a potential locally available roughage resource for partial replacement of straw in diets of fattening Baluchi lambs.