| dc.description.abstract | A two part longitudinal study was carried out to investigate the causes of high dairy calf
morbidity and mortality in Kilifi Plantations of Kilifi District, Kenya, with the aim of
quantifying both morbidity and mortality, identifying the factors that influenced these
events at the farm and proposing an intervention to reduce or curb them altogether.
The first part was a retrospective longitudinal study in which infor
mation was gathered from the records available at the Livestock office in the farm.
Calves born within seven months to the commencement of the study were selected
randomly from the calf inventory at the farm and data on the potential risk factors of
morbidity and mortality were obtained from these records.
The second part was a prospective longitudinal study, subdivided further into two
sections as follows:
1) Calf follow-up study:
In this section, calves that were less than four months old were selected randomly and
recruited as study subjects. A systematic random sampling procedure was used to
incorporate every second neonate female calf born during this time.
2) Peripartum calf management study:
All the calves born during the study period were included in this section of the study and
followed-up for one month. Data were collected actively on the potential risk factors of
morbidity and mortality to one month of age.
In the retrospective part of the study, crude morbidity and mortality rates of 1.685 and
0.77 per calf-year at risk, respectively were estimated. As per the information obtained
from the records, the cause specific morbidity rates of pneumonia, scours, septicaemia,
bloat, and poisoning were 0.11, 0.441, 0.32, 0.11 and 0.089 occurrences/calf-year at risk,
respectively. Conditions of indeterminate aetiology accounted for 34.21 % (0.584
cases/calf-year at risk) of the morbidity. Similarly, cause-specific mortality rates were
highest for scours (0.342 per calf-year at risk), septicaemia (0.091 per calf-year at risk),
pneumonia (0.053 per calf-year at risk), bloat (0.036 per calf-year at risk) and poisoning
(0.017 per calf-year at risk), in a descending order. Indeterminate causes accounted for
the largest proportion (0.219 per calf-year at risk) of mortality.
Treatment rates were quite low as only 66.18% (45/68) of the calves that fell sick during
this period received therapy and treated sick calves were 2.15 times more likely to die (P
< O. 05). Of all the mortalities to seven months of age, 73.68% (28/38) occurred in calves
below one month of age and 86.84% (33/38) were in those aged below two months.
There was a dramatic reduction in calf survival in the first four weeks, from 0.97 ( 95%
CI = 0.93 to 0.987) in the first week to 0.82 (95% CI = 0.749 to 0.872) to the fourth week
of life. This reduction compared to a survival rate of 0.729 (95% CI = 0.643 to 0.798) to
the zs" week of life.
Sex of the calf was significantly associated with morbidity (P<0.05) in that female calves
were 2.1 [95% CI; 1.5, 2.7] more likely to fall sick. Treatment of sick calves appeared to
be significantly associated with mortality (P<0.05) as treated sick calves were 2.2 [95%
CI; 1.4,2.9] times more likely to die relative to those not treated.
In the follow-up phase of the study, morbidity and mortality rates were 5.724 and 0.452
per calf-year at risk, respectively. The incidence density rates for mortality, scours and
pneumonia were 0.102, 1.635 and 0.1939 occurrences/3 calf-months at risk, respectively.
Disease events were significantly associated with mortality and calves with scours were
48 times more likely to die relative to those with pneumonia (P < 0.001).
In the peripartum calf management study, the crude morbidity and mortality rates were
2.872 and 0.372 per calf-month at risk, respectively. Only two disease conditions, scours
and septicaemia, were observed to affect this age group. Umbilical cord disinfection
beyond ten minutes of birth was significantly associated with morbidity (P< 0.05) as well
as mortality (P<O.OO 1). Ability of the calf to suckle within one hour of birth was
significantly associated with morbidity (P<0.05) but not mortality. Septicaemia,
occasioned by delayed umbilical cord disinfection and unhygienic calving environment
was significantly associated with mortality (P<O.OOI). Indeed, all the calves (11111) that
came down with septicaemia died within one month of life.
The association between the sex of the calf and morbidity was significant (P<O.05).
Female calves were 4 times more likely to fall sick relative to male calves [OR = 3.839;
2.8, 4.9, 95% Cl]. Delayed umbilical cord disinfection was an important factor of
morbidity (P<O.05) as calves disinfected after 10 minutes of birth were 14 times more
likely to fall sick [12.3, 15.9, 95% Cl] relative to those disinfected promptly. These
calves were also at a significantly higher risk of mortality (P<O.05) and were 14 times
more likely to die [OR = 13.75; 13.1, 14.5,95% Cl].
The observed high morbidity and mortality rates were attributed largely to poor calf
management practices especially during the peripartum period and inadequate disease
prevention and control practices owing to a deficiency of animal health skills at the farm.
Appropriate immediate and long-term remedial measures are proposed. | en |
