This study assessed daily milk yield (DMY), 100-day (MY100), and 305-day (MY305) milk yield, and lactation length (LL) in purebred Ankole cattle and Ankole crossbreds, and the influence of environmental factors on these traits. Milk yield data were obtained for 865 cows and 1234 lactations and analyzed using a mixed linear model. The overall least squares mean of DMY, MY100, and MY305 across breed groups was 2.7 L (N = 1234, SD = 1.7), 262 L (N = 959, SD = 176), and 759 L (N = 448, SD = 439), respectively, while the average lactation length was 256 days (N = 960, SD = 122). All factors included (breed group, season and year of calving, and parity) were significant for yield traits, except season of calving for MY305. First-parity cows had the lowest milk production, and fourth-parity cows the highest. For all traits, pure Ankole cows had the lowest milk yield. Among the crossbreds, there was no significant difference between Ankole × Friesian, Ankole-Jersey mother × Sahiwal sire, and Ankole-Sahiwal mother × Jersey sire, or between Ankole × Sahiwal and Ankole-Sahiwal mother × Sahiwal sire. It was concluded that Ankole crosses with Friesian or Jersey can be beneficial, even under a management system of limited nutrition as in Rwanda.

Breed improvement and conservation are optimally achieved when the available genetic resources are characterised and strategies developed to achieve the goals. This study aimed at investigating the management practices, performance and morphological features of the indigenous cattle ecotypes in Rwanda on 250 cattle farming households. A total of 20 measurements taken on 305 female and 45 male cattle were: body length (BL), height at withers (HW), leg height (LH), heart girth (HG), body weight (BW), tail length (TL), dewlap length (DL), dewlap width (DW), rump width (RW), ear length (EL), muzzle circumference (MC), horn length (HL), distance between horns (HS), hump length (HuL), hump width (HuW), navel depth (ND), udder length (UL), udder depth (UD), teat length (TL), and body condition score (BCS). Morphometric data was analysed by ecotype for each sex and age category since there were non-significant differences in geographical location. Results show that Rwanda has five types of indigenous cattle namely: Inyambo, Inkuku, Inkoromaijo, Inkungu and Bashi. The livestock system mostly used was extensive and household income was mainly from livestock. For Inyambo cattle, the popular ecotype, age at sexual maturity was 27.44±1.04 months for males and 28.76±1.02 months for female cows. Age at first calving was 33.8±0.83 months whereas calving interval was 13.60±0.45 months. Lactation length was found to be 6.84±0.29 months. The mean daily milk was 3.58±0.19 litres and the pre weaning calf survivability was 90±6.5%. Positive and high correlations were observed between BW, HG, HW, HuL, BL and HL. Indigenous cattle population of Rwanda are not homogenous by their morphological features and other productive traits, and therefore conservation will have to target the different ecotypes and this should be done with direct engagement of their keepers.

The objective of the study was to compare body weights and growth from birth to 18 months of age of various groups of crossbred cattle born from 1999 to 2007, being crossbreds of Ankole (A) with Brown Swiss (B), Holstein Friesian (F), Jersey (J), and Sahiwal (S). Average weights were 26.5 kg at birth, 161 kg at weaning, and 226 kg at 18 months. Both season and sex significantly affected birth weight (BW), weight at 8 and 18 months (W8 and W18), and average daily gain from weaning to 18 months (ADG18) and, unlike season, sex significantly affected average daily gain to 8 months and weaning age. The general trend was that average daily gain attained a maximum before weaning and thereafter decreased until 18 months. Least square means for AB and AF calves were comparable and significantly differed only for W18 and ADG18. AJ had the lowest BW but was comparable with AS, AJxS, and ASxJ for W8, age-adjusted weaning weight, and W18. Generally, AF was heavier than other breed groups, but the difference was smaller than expected probably because environmental conditions did not allow full expression of genetic potential for growth.