Genetic trends for milk, fat and protein in the Zimbabwean Holstein-Friesian population from 1973 to 1994

Abstract

SummaryGenetic trends based on 30 395 records with parities 1 to 8 were estimated using average information restricted maximum likelihood algorithm (AIREML), which had overall mean, herd, month of calving, year of birth, parity and linear and quadratic effects of days in milk. Due to changes in the Zimbabwean milk recording system data set was split into records of cows born from 1973 to 1989 and the other from 1987 to 1994. The first data set was further split into even numbered herds (EVNH73) and odd numbered herds (ODNH73), due to computational limitations. The highest milk production was from May to August. Peak milk production was observed in parity 4. The heritabilities for FCM (0.22 to 0.26), fat percent (0.24 to 0.28) and protein percent (0.21) were comparable to literature values. The annual genetic trends of FCM ranged from 8.36 kg to 13.2 kg, fat per cent ranged from 0.0 % to -0.008 % and protein per cent was -0.003 % in the three data sets. Genetic trends for milk yield, fat and protein yield were also positive but overally lower than in most other countries. The positive genetic trends obtained for milk, fat and protein yields imply that some progress has been made in increasing the milk production despite the relatively small population and significant restrictions. There is need to develop a selection index to improve milk yield and milk composition.

Comparative evaluation of non-genetic factors affecting milk yield and composition of Red Dane and Jersey cattle in Zimbabwe

“…Calving interval, parity and month of calving had a significant (P < 0.0001) effect on milk, fat and protein yields of Red Dane and Jersey cattle in Zimbabwe. The results found in this study are consistent with literature (Makuza 1995 ; Mandizha 1998 ; Imbayarwo-Chikosi 1999 ; Kunaka 1999 ; Amimo et al 2007 ; Missanjo 2010 ; Nyamushamba et al 2013 ). It is expected that the different herds have different levels of production because of variations in the level of management.…”

“…It is expected that different herds have different levels of production because of variations in the level of management. Different month of calving and seasons in different agro-ecological zones can also contribute to the differences between herds (Kunaka, 1999 ). Differences in breeds also contribute differences in milk, protein and butterfat yields in Zimbabwe.…”

Milk yield and reproductive performance of Friesian cows under Sudan tropical conditions

“…The analysis of variance of milk yield per lactation and daily milk yield revealed a highly significant (p<0.001) effect of sire, year-season, parity number, and linear and quadratic regressions on lactation length in both characters. These findings agree with the results of MBAP and NGERE (1989) who analyzed Friesian data from Nigeria, ATIL (2000) for Holstein Friesian in Egypt, KUNAKA et at. (2001) for a Friesian population in Zimbabwe, and HERNANDEZ et al (2002) for Holsteins in Mexico.…”

Effects of Environment on Productive Performance of Holstein-Friesian Dairy Cows in Three Agro-Ecological Regions of Zimbabwe

“…However, the observation of peak milk yield in the hotdry season was not expected, since it is the period of forage scarcity and heat stress. Earlier studies (Muchenje et al, 1997;Makuza and McDaniel, 1997;Kunaka and Makuza, 2005) reported peaks for milk yield and compositional traits in the cooler months between May and August. Theoretically, milk production in cows decreases with increasing heat load (Rodriguez et al, 1985).…”

“…These temporal variations may be related to socio-economic and environmental factors experienced each year (Fontaneli et al, 2005). Kunaka and Makuza (2005) reported that the amount and distribution of rainfall has a positive effect on forage and feed resource availability and disease challenges experienced each year. Serious drought conditions were experienced in the years 2007-2009.…”