ABSTRACT
Socio-economic and cow husbandry factors associated with the prevalence of reproductive
disorders, sub-clinical mastitis and calf mortalities were investigated in the smallholder dairy
cow farming system of the urban and peri-urban Kampala and Gulu. The effect of 20 years
difference of post war conflict in Gulu and Kampala on management practices by smallholders
was evaluated by comparing the reproductive performance of the dairy cows in the two
locations. Herd-level managerial factors influencing the calving, abortion and neonatal calf
mortality rates for crossbred dairy cows were compared by least square means. In Kampala,
managerial practices affecting resumption of post-partum luteal activity in the open and zerograzed cows were further investigated in a longitudinal study. Additionally, the prevalence for
subclinical mastitis and the species of coagulase negative staphylococci (CNS) in clinical and
sub-clinical mastitis cases among cows of smallholders, were identified and characterized.
In Kampala and Gulu, household socio-economic and cow husbandry factors and reproductive
management practices differed (p˂0.05) and influenced calving more than abortion and neonatal
calf mortality rates. Reproductive performance of dairy cows was higher (p ˂ 0.05) in Kampala
than in Gulu. Although the majority (81.4%) of cows in Kampala ably resumed postpartum luteal
activity by 60 days, inappropriate husbandry practices were associated with 57.7% of them. Only
23.7% of those in which luteal activity resumed could maintain the tempo of cyclicity for
optimal breeding to achieve a calf per cow per year. Husbandry practices, particularly provision
of appropriate feed supplements and better reproductive health management, were critical for
sustainability of postpartum ovarian cyclic activity. Milk production (16.1 litres) under zero
grazing (ZG) was higher (p˂0.05) compared to 11.7 litres in open grazing (OPG). Average milk
production on brew waste dairy supplementation (19.3 litres) was comparatively higher
(p˂0.001) than on banana peels and crop residues (10.4 litres) or brew waste/wheat
bran/molasses (9.7 litres).
In Kampala, sub-clinical mastitis prevalence of 86.2% among cows was high and mainly due to
CNS pathogen (31.7-54.7%), Streptococci (16.2-22.2%) and mixed flora (41.6%). Zero grazing
system, strip-milking, non-use of dry cow therapies, mis-use of antibiotics, poor hygiene at
milking and non-observance of milking order were associated with the prevalent sub-clinical
mastitis. CNS isolates prevalent in up to 80% of sub-clinical mastitis cases and resistant to
penicillin were of concern and deserved further studies regarding measures to mitigate their
prevalence. Milk quality and its productivity was compromised by prevalence of sub-clinical
mastitis. The number of sub-clinically affected quarters/cow (2.59 Vs 1.86) varied by stage of
lactation and parity, level of hygiene in the predominant (Friesian) cow breed and production
system. Sub-clinical mastitis quarters/cow with CMT ≥ 3 (2.59 Vs 1.86) were respectively,
higher in mid (120 days) than early (60 days) lactation (p˂0.06); multiparous than primi-parous
(p˂0.02); poor than good body hygiene score among the Friesian breed (p˂0.003) and with
tendency (p˂0.13) to be higher in ZG than OPG. The presence of penicillin-resistant CNS were
common among 31.7% samples followed by streptococcus agalactiae (22.2%). Penicillin-
resistant CNS species isolates, S epidermidis (85%) and S haemolyticus (15%) were found in
80% of CNS isolates and were associated with hand milking in all clinical and sub-clinical
(CMT ≥ 4) mastitis cows in the Kampala area. The prevalence of both the udder adapted S
epidermidis and the environment-adapted S haemolyticus was associated with malpractices
during milking, but could also be due to imprudent use of antibiotics in the Kampala smallholder
dairy production system.
In conclusion, the studies established that reproductive performance and milk production, of
crossbred dairy cows in Kampala were better (p ˂ 0.05) than in Gulu, and attributed to the socioeconomic dissimilarities in husbandry practices linked to the difference in post-civil war social
stability of the two urban settings. The resumption of postpartum ovarian function in crossbred
dairy cows of Kampala as indicated by luteal activity, was normally occurring (56 days) and
comparable to other cows elsewhere although its sustenance in the majority was hampered by
sub-optimal husbandry factors and practices on farms. Zero-grazing, poor environmental hygiene
and on-farm malpractices at milking such as poor hygiene and strip hand milking techniques or
imprudent use of antibiotics were associated with high prevalence of sub-clinical mastitis and
presence of CNS species resistant to penicillin among clinical and severe sub-clinical mastitis
cases.