title: Longitudinal observation on reproductive and lactation performances of smallholder crossbred dairy cattle in Fitche, Oromia region, central Ethiopia.
abstract: A two-year longitudinal study was conducted to assess the reproductive and lactation performances of smallholder crossbred dairy cattle in Fitche, central Ethiopia. Twenty-four smallholder dairy farms were monitored and data on reproductive, breeding, lactation and management aspects of crossbred dairy cows (n=69) were collected and analysed. Moreover, milk samples were collected and analysed for progesterone. The overall Least-squares means for calving interval (CI), calving to conception interval (CCI) and first observed oestrus after calving were 516, 253 and 141 days, respectively. Suckling significantly prolonged these intervals. The mean first onset of luteal activity (OLA) after calving was 52 days, while 67.4% n=43) had a delayed (>55 days) return to cyclicity after calving. Suckling and parity number significantly (p < 0.05) influenced the OLA. The mean lactation length was 54.4 weeks. The overall daily mean milk yield for the first 43 weeks of lactation after calving was 11.7 L/day. The estimated daily milk yield increased slowly and reached peak (13.8 L/day) around the 11th week post partum and declined gradually and steadily. Suckling status, season of calving and parity number significantly influenced the estimated daily milk yield. In conclusion, the present study indicated that the smallholder crossbred dairy cows in the study area had prolonged intervals to first oestrus after calving, to conception and to the next calving, and thus their reproductive performance is unsatisfactory. Delayed first onset of luteal activity (postpartum anoestrus) contributed to these extended intervals. Further detailed investigation is suggested to examine the effects of other relevant factors on the reproductive and lactation performances of smallholder crossbred dairy cows for appropriate intervention.
authors.affiliation: Department of Clinical Sciences, Swedish University of Agricultural Sciences, Box 7054, SE-750 07 Uppsala, Sweden. fikre_lobago@yahoo.com
authors.forename: Fikre
authors.initials: F
authors.lastname: Lobago
authors.forename: Merga
authors.initials: M
authors.lastname: Bekana
authors.forename: Hans
authors.initials: H
authors.lastname: Gustafsson
authors.forename: Hans
authors.initials: H
authors.lastname: Kindahl
mesh_terms: D000818:Animals; D000833:Animals, Suckling; D002417:Cattle / Q000502:physiology*; D003433:Crosses, Genetic; D003612:Dairying / Q000379:methods*; D004971:Estrus / Q000502:physiology; D005002:Ethiopia; D005260:Female; D007774:Lactation / Q000502:physiology*; D008892:Milk / Q000737:chemistry / Q000378:metabolism*; D010298:Parity; D011247:Pregnancy; D018873:Pregnancy Rate; D011270:Pregnancy, Animal / Q000502:physiology*; D011374:Progesterone / Q000032:analysis; D012098:Reproduction / Q000502:physiology*; D012621:Seasons; D013997:Time Factors
chemical_list: D011374:Progesterone