1. For the purposes of Regulation (EEC) No 1078/77 and this Regulation: (a) "dairy cow" means a female domestic bovine animal suitable for the production of milk for marketing purposes and having calved at least once ; this definition shall include in-calf heifers;
(b) "dairy herd" means all female domestic bovine animals at least six months old suitable for the production of milk for marketing;
(c) "cow of a beef breed" means a female domestic bovine animal having calved at least once and belonging to one of the breeds recognized as fit for meat production by the competent authority of the Member State concerned ; the definition shall include in-calf heifers of a beef breed;
(d) "area under forage" means the total agricultural area farmed by a producer within the meaning of Article 5 (a) of Regulation (EEC) No 1078/77.
2. Only a heifer in respect of which the recipient has presented proof to the competent authorities that it calved or aborted within nine months after it was counted in for the purposes of the rights and obligations arising under this Regulation shall be recognized as a dairy cow or cow of a beef breed.
3. In determining the quantity of milk on which the premium will be calculated: (a) the following equivalences shall be applied to the dairy products disposed of by the producer in the 12 calendar months preceding the date when the application is lodged: - one kilogram of milk equals one litre of milk,
- one kilogram of butter equals 23 litres of milk,
- one kilogram of cheese equals 10 litres of milk,
- one kilogram of milk fat equals 27 litres of milk;
(b) the quantity of milk arrived at by applying point (a) shall, where appropriate, be reduced proportionally: - as provided for in Articles 2 (1) and 3 (1) of Regulation (EEC) No 1078/77, where the number of dairy cows kept on the holding as recorded on the date of approval of the application is less than the appropriate number for the quantity of milk in question;
- by a further amount, where it is found that during the period between the day when the application is lodged and the day when it is approved the applicant has not, in respect of all his dairy cows other than those which are the subject of a reduction made under the foregoing indent, observed the undertakings referred to in the second and third indents of Article 2 (2) (b) of Regulation (EEC) No 1078/77 ; this adjustment shall be calculated on the basis of the number involved of the livestock units referred to in Article 2 (1) (b).