574
Grazing Alfalfa as an alternative to reduce production costs in intensive milk production systems
Intensively managed grassbased milk production systems in Brazil are highly dependent on concentrate supplementation of the milking cows to achieve high productivity levels, and depending on feed prices the production costs can be very leading to low profitability. This study aimed to evaluate the use of grazing alfalfa (Medicago sativa, sp.) as an alternative reduce concentrate inputs and reduce production costs. The trial was conducted at EMBRAPA's (Brazilian Agricultural Research Corporation) research station, located in Sao Carlos, SP, in the southeast region of Brazil. 36 lactating dairy cows were used on a complete blocks design to evaluate the effect of allowing the cows to graze alfalfa for different periods on milk production, dry matter intake and feed efficiency. Cows were alocated to 4 experimental treatments (A = control, no alfalfa grazing; B = access to alfalfa paddocks for 1 hour; C = access to alfalfa paddocks for 2 hours; D = access to alfalfa paddocks for 4 hours) according to stage of lactation and milk production; All cows rotationaly grazed tropical grass paddocks and were suplemented with different concentrate quantities (9.82, 9.32, 9.03 and 8.73 kg of DM daily for treatments A, B, C, and D, respectively) Cows on treatment A had no access to alfalfa and cows on the other treatments had access to alfalfa paddocks for 1, 2 or 4 hours immediately after the morning milking. Results are shown on table 1.
| Treatment A | Treatment B | Treatment C | Treatment D | |
| DMI, kg/d | 15,68 | 15,84 | 15,81 | 15,09 |
| Milk, kg/d | 23,86 | 23,28 | 23,41 | 24,21 |
| FE, kg/kg | 1,605 | 1,566 | 1,549 | 1,656 |
Data were analyzed using MIXED procedure of SAS and averages were compared with Tukey test. Treatment differences were considered significant at P<0.05. No effects were observed among treatments for any parameter analyzed. Based on the results, alfalfa grazing may be a good strategy to reduce production costs dependin on the prices of the concentrate supplements.
Keywords: milk production, grazing, alfalfa