Milk production in East African zebu cattle

Abstract

An analysis has been made of milk production data from indigenous East African zebu cattle at the Baraton, Maseno and Sangalo Livestock Improvement Centres in Kenya, covering a period of twenty-five to thirty years.The relationships between milk production and length of lactation, dry period, calving interval, month of calving and age were examined. Lactation length accounted for from 53% to 66% of the total variance in milk yield. Variations in length of dry period caused significant differences in milk yield between, but not within cows. Increasing length of previous calving interval improved current lactation milk yield but month of calving had no significant effect. Yield increased from first to second lactation by 8% after which it remained relatively constant up to the fifth lactation. Age at first calving was positively correlated with first lactation milk yield.Intra-herd repeatabilities were 0·55 for milk yield, 0·38 for lactation length, 0·17 for calving interval and 0·12 for dry period. The highest estimates of heritability were those obtained for lactation yield and length (0·5); the lowest, for calving interval, was close to zero. All heritability estimates had high standard errors. The probable genetic improvement in milk production achieved by the selection practised in the herds was estimated as ranging from zero to 0·15% of the average yield per year.

Estimation of reliable genetic parameters for production traits in a tropical breed of dairy cattle

“…The variability in the production traits and lactation length was very high as evident from the coefficients of variation for their traits, which was more than 50% for first two production traits and more than 40% for the last two traits. The higher variability observed in this study for 305-day and total lactation yields was in agreement with the reports of ALIM (1960, '62), GALUKANDE et al (1962), ACHARYA and LUSH (1968), BALAINE et al (1970), MOULICK et al (1972 and JOHAR and TAYLOR (1973) in different breeds of tropical dairy cattle. The coefficient of variation in their reports ranged from 40 to 75% for first lactation milk yield.…”

“…This results in a large variability in the production traits besides the disconnectedness of sires with years and herds. The coefficient of variation for first lactation milk yield in tropical dairy cows is quite high (more than 35 percent) as compared to less than 20 percent in temperate dairy cattle (ALIM, 1960; GALUKANDE et al, 1962;MAHADEVAN 1966 RAO and SUNDARESAN 1979). The genetic parameters for different traits are generally estimated after adjusting the records for environmental factors using the constants obtained in the first run with a model including only environmental effects and then using a model with only sires in the second run.…”

6.2 Some aspects and experiences, past and present, of intensive milk production in Kenya

“…This compares with the figures given by Galukande et al (1962) for indigenous Zebu stock -823 kg in 239 days (with 123 days dry period). As it turned out its efforts proved highly successful and KCC still exists although it appears that there is now a move to have it broken down into localized fragments.…”

On-farm characterization of the indigenous small East African Shorthorn Zebu cattle (SEAZ) in the Southeast rangelands of Kenya

“…Semenye (1987) observed that the lactation curve of the Maasai Zebu responds to forage availability regardless of the month of lactation. In spite of the low milk production levels in Zebu cattle, high within-breed variation in milk production has been observed with certain strains or individuals within the SEAZ type of cattle having very high milk production levels (Galukande et al, 1962). Farmers interviewed also observed this.…”