Milk production traits among indigenous and crossbred dairy cattle in Senegal
Milk production and milk composition of various cattle breeds and their crosses in the North Central Peanut Basin of Senegal have been analysed. In total, 6082 records were collected from 1447 cows. But finally, only 1923 test-day records of milk volume were evaluated from 319 cows with 370 lactations during a longitudinal survey. A subset of 227 cows was used to determine the milk composition of the main breed-groups that were present and which were clustered into four groups: Indigenous zebus (Zebu Gobra; Zebu Maure), Indigenous zebu by Guzerat (Indigenous zebu cross with 25% to 50% Guzerat), Indigenous zebu by Bos taurus taurus (Indigenous zebu cross with 25% to 50% Bos taurus taurus where the Bos taurus taurus includes breeds such as Montbeliarde and Holstein-Friesian) and High Bos taurus taurus (cows with a high component of Bos taurus taurus, typically 75% to 100% of previous Bos taurus taurus). The daily milk yield, cumulative milk yield of 305 days, milk fat and protein percentages were determined for each cluster. The daily milk yield varied from 1.43 L/day in indigenous zebus to 7.04 L/day in High Bos taurus taurus. In general, the daily milk yield increased with the number of parturitions. Indigenous zebus showed the lowest 305-day milk yield (466 L and 496 L for first and later lactations, respectively) whilst High Bos taurus taurus cows showed the highest milk production (1408 L and 2108 L for first and later lactations, respectively). Fat percentage increased from the primiparous to the multiparous cows. Primiparous Indigenous zebus by Bos taurus taurus cows showed the highest fat content (5.10%), followed by Indigenous zebus (4.44%). The average calving interval ranged from 519 days for Indigenous zebus by Bos taurus taurus to 580 days for Indigenous zebus. The average lactation length for all cows was 370 days.
Key words: Dairy cows, lactation, milk yield, milk quality, breed differences, Senegal