Abstract:
This study was conducted with the objectives of assessing the perception of Fogera cattle farmers
on climate change and variability, the impact of climatic variability on the growth performance of
Fogera cattle, the effect of heat stress (HS) on physiological, hematological, biochemical, and
growth parameters of Fogera cattle calves during different seasons and analyzed the impact of
climate change and land use/cover (LULC) on Fogera cattle population dynamics. The Awi zone
was clustered into three agroecology based on the altitudinal variation, and primary data was
collected from 150 households having at least 3 Fogera cattle through systematic random
sampling while secondary data were sourced from unpublished documents of zonal and district
agricultural offices. Over 36 years (from 1983 to 2019) of meteorological data were taken from
the National Meteorological Agency (NMA). For trend analysis all animals born and calves that
were weaned from 2005 to 2019 were used in this study. Furthermore, a total of 72 calves (24 for
each season) of 6 months of age with an equal number of males and females were used for
physiological, hematological, biochemical, and growth parameters study. Daily ambient
temperature (AT) and relative humidity (RH) recorded two times per day throughout the study
periods were used to calculate the daily temperature-humidity index (THI) that can serve to assess
the HS condition of the ranch location. Landsat images of 1986, 2000, and 2019 were used to
generate LULC of the study area. For LULC classification supervised image classification using
the maximum likelihood classifier in ERDAS imagine software was used. A total of 303 samples
were collected using a global positioning system (GPS) and used for accuracy assessment.
Moreover, data for Fogera cattle numbers from 1986 to 2019 were taken from the record book of
the ranch. Likewise, pasture land data that was used for grazing purpose was obtained from the
classified images of these years. Based on the nature of the data, data were analyzed by least squares means analysis of variance using R software version 3.5.2 program and PROC GLM using
SAS software version 9.4. Moreover, a multiple linear regression model was also used to regress the
contribution of climatic variables on growth parameters. Furthermore, to check the variability of
annual rainfall standardized anomaly index was calculated. The survey result revealed that
97.13% of the farmers were experiencing climate change in all agro-ecologies. The annual
temperature trend was increasing while rainfall was declining from time to time. About 80.91%
of Fogera cattle farmers reported experiencing negative impacts of climate change and variability
on cattle during severe water shortages. The frequency of drought, duration of the dry spell, wind,
and floods were increasing (p<0.001) in all the agro-ecologies. Moreover, about 84.48, 65.3, and
60.47% of Fogera cattle farmers in the lowland, midland, and highland, respectively perceived
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that increasing cattle mortality in the areas (p<0.001). The meteorological data result also
confirms that climate was changing across the agro-ecologies. Both the mean annual maximum
and minimum temperature were considerably increasing for all agro-ecologies whereas the mean
annual rainfall was decreasing which, was consistent with the farmers' perception. The
meteorological result also showed that the rainfall during short rainy season and dry season shows
high interannual variability. The trends in birth weight (BW) and weaning weight (WW) of calves
were significantly decreasing along the study period. The result also indicated that the RH and AT
regression coefficient was negative for BW and WW. The Pearson correlation coefficient also
indicated that there was a negative relationship between growth parameters and climatic
variables. When THI increases from 67 to 72, the BW and WW of the calves were decreased by
3.5 and 25 kg, respectively. However, higher BW and WW were recorded for the optimum THI less
than or equal to 67. Physiological parameters, except rectal temperature, were affected by the
seasons. Hematological parameters were also affected by season except for packed cell volume.
Biochemical and growth parameters were also significantly affected by the seasons. The result
also revealed that between 1986 and 2019 expansion of farmland and forest was exhibited in the
ranch, which has increased by about 34.8 and 0.4 ha, respectively. However, the area covered by
grazing land and shrub has shown a decreasing trend over the entire study period with a rate of -
13.7 and -21.5 ha, respectively. The overall trend analysis result showed that the Fogera cattle
population was significantly increasing whereas, the pasture land was decreasing during the study
period. The increase in Fogera cattle population from 1986 to 2000 was due to an increase in
pasture land. However, the cattle numbers declined from 2000 to 2019 due to a reduction in
pasture land in these years. Moreover, the overall stocking rate for grazing land was also
increasing from 1986 to 2019, with an annual change rate of 0.8%. The lower BW and WW of
calves observed in this study might be due to the cumulative effect of the climate conditions of the
study area and herd management practices. Climate change and variability in the past 30 years
attested by farmers and meteorological data harms herd size, feed availability, water availability,
and growth performance of Fogera cattle in the study areas. However, the positive performance
in terms of growth parameters in the thermo-conformable zone in the different seasons suggests
the need to consider ameliorative strategies such as appropriate feeding, housing, and health care
in the breed improvement and conservation program in the future. Generally, the THI value of 66
can be considered optimum for high weight gain and normal physiological responses to HS in
Fogera cattle calves under their current production system