M.. Toorchi, S. Aharizad, M. Moghaddam, F. Etedali, S. H. Tabatabavakil,
Volume 11, Issue 40 (7-2007)
Abstract
Sainfoin in believed as an important forage crop regarding its suitable agronomical characteristics and feeding livestock. Evaluation of general combining ability is a critical preliminary stage before selection of suitable parent and production of synthetic varieties. Thirty six sainfoin landraces which have been collected from different parts of Iran were grown in 2000 in a randomized complete block design (RCBD) with 24 replications as a polycross nursery. The resulting polycrosses were sown in 2001 in a triple lattice design. Characters such as fresh forage yield per plot based on unit length, fresh forage yield per plant, and dry forage yield for each cutting stage and for the whole season were measured. Also a yield index for the two first cuttings and forage palatability for the second cutting were determined. Results showed that there was no significant difference between partial blocks within each replication and therefore data was analyzed based on RCBD. High heritability was observed for forage palatability, yield index, and fresh forage yield per plant. So selection can be made to improve forage yield and palatibility in sainfoin. In terms of general combining ability, six landraces for fresh forage yield, six landraces for dry forage yield, nine landraces for yield index, and ten landraces for palatibility showed high estimates. The lanraces having highest amounts of general combining ability for each variable can be used as suitable parents to produce synthetic varieties of sainfoin.
N. Hedaiat, Y. Rouzbehan, S. A. M. Modares Sanavi,
Volume 11, Issue 41 (10-2007)
Abstract
The nutritive value of the annual alfalfa (Medicago rigidulla, Medicago polymorpha and Medicago scutellata) species harvested at flowering stage was assessed by chemical composition, in vitro dry matter and nitrogen digestibility, in sacco dry matter and nitrogen degradation (0, 8, 12, 24, 48 and 72 h) and palatability (short-term intake rate, STIR) methods. Mean values of the chemical analysis results (%) for M. rigidulla, M. polymorpha and M. scutellata respectively were as follows: OM 85.1, 86.1 and 86.9 CP 25.1, 23.8 and 15.6 NDF 23.2, 24.8 and 30.0 ADF 18.3, 19.9 and 24.0 ADIN 0.36, 0.11 and 0.22 calcium 1.4, 1.3 and 1.2 phosphorus 0.23, 0.28 and 0.24 potassium 1.5, 1.5 and 1.4. The digestibilities of the DM and OM for M. rigidulla were 0.82 and 0.79 M. polymorpha 0.83.5 and 0.80 M. scutellata 0.75 and 0.69, respectively. The degradabilities of DM and CP at outflow rate of 0.05 for M. rigidulla were 0.72 and 0.55 M. polymorpha 0.71 and 0.57 M. scutellata 0.63 and 0.58, respectively. Finally, the palatabilities (using short-term intake rate method) for M. rigidulla, M. polymorpha and M. scutellata species were 13.6, 12.8 and 11.3 (g DM/min) respectively. According to the methods used, the descending ranking order (high to low) of these species on the basis of their nutritional value was M.rigidulla, M.polymorpha and M.scutellata.
