Product system

The product system comprises a farm in the Middle Southwest region of Bahia state (Fig. 1), chosen because of its production volume and technology level.

Middle Southwest region of Bahia, Northeast Brazil

The milk production system is semi-intensive. The herd comprises 128 animals, Girolando and mixed-race with a blood degree within 1/2 and 3/4 Holstein, featuring 52 lactating cows, 38 dry cows, 18 heifers, and 20 calves. Cattle feed includes pasture, corn silage, concentrate, and mineral salt supplementation.

Pasture area consists of 67.8 hectares, of which 16% is irrigated. Rotational grazing occurs in an area divided into 100 paddocks fertilized annually with phosphate and nitrogen products. Previous soil analysis showed that potassium fertilization was not necessary.

Milk productivity averaged 970 L per day (6,808.65 L per cow per year), and lactating cows are fed according to their average daily milk production:

High productivity cows (21 cows yielding 19 L) feed on pasture and concentrate as a supplement

Intermediate productivity cows (15 cows yielding 15 L) exclusively feed on pasture

Low productivity cows (16 cows yielding 8 L) feed post-grazing residues, comprising a 25–30 cm height pasture, in which intermediate productivity cows have previously been fed

The feeding strategy for heifers comprises pasture, concentrate, and mineral salt supplementation. Calves are fed twice a day with a commercial milk replacer, which is succeeded by pasture and concentrate feed around the 45^th to 60^th day of life. Moreover, the diet of dry cows is composed of pasture and mineral supplementation.

Mechanical milking occurs initially in the morning for all lactating cows, and a second milking is performed in the evening only for high productivity lactating cows. The milk is cooled at 4 °C in a 2050 L-capacity tank and stored to be sent on alternate days for processing in dairy industries located in the region.