II. MEMORIA
2.2 Sostenibilidad Urbana
2.2.2 Libro Blanco de la Sostenibilidad en el Planeamiento Urbanístico
Reduction in milk yield
Agropastoral households quantified milk yield from cattle only (n=47 households), rural smallholders reported milk yield from cattle (n=20) and goats (n=3), and pastoralists reported about cattle (n=47), goats (n=17) and sheep (n=4). Cow milk yield in absence of FMD reported by households in the study is shown in Figure 3.11 and Table 3.13.
Agropastoral and pastoral cows yielded significantly less milk compared to rural smallholder cows (Figure 3.11, Tables 3.13 and 3.14).
Decreased cow milk during FMD outbreaks was reported by 90% (CI: 83.5-94.6%) of households. Decreased goat milk was reported by 66% (CI: 51.2-78.8%). Cow milk yield during FMD outbreaks was significantly lower than normal (Paired t-test: t = 6.8, p = 7.3 x 10-9, degrees of freedom =54). Goat milk yield data with and without FMD were only available for five pastoral herds, but a decrease in goat milk during outbreaks was suggested (Table 3.13).
Figure 3.11: Density plots showing reported cow milk production in the three different management systems with (red) and without (green) FMD.
Agropastoral
Pastoral
Rural smallholder
0.0 0.5 1.0
0.0 0.5 1.0
0.0 0.5 1.0
0.0 2.5 5.0 7.5 10.0
Litres per cow per day
Density
FMD No FMD
Effect of FMD outbreaks on cow milk production
Table 3.13: A summary of cattle, goat and sheep milk yields with and without foot-and-mouth disease.
Where the same herd reported milk yields with and without FMD, FMD milk yield was expressed as a proportion of normal milk yield at herd level and then summarised for all herds with these data available. No data were available for sheep
milk yield with FMD.
Summary of milk production (Median and interquartile ranges of litres per animal per day)
Cattle Goats Sheep
Normal During FMD
Herd level
FMD/Normal Normal During FMD
Matched
Table 3.14: The results from a general linear model explaining milk per cow with livestock practice.
(Null deviance: 157.9 on 54 degrees of freedom, Residual deviance: 93.3 on 52 degrees of freedom)
Variable Difference in
Livestock practice -24.93 28.9 5.2 x 10 ^-7
Agropastoral compared to rural smallholder
-2.9 (-3.9--1.9) 0.1 (0-0.2)
Pastoral compared to rural smallholder -3 (-4--1.9) 0.1 (0-0.1)
Drivers of milk loss
For the 55 herds with data available about milk per cow (at herd level) with and without FMD (Table 3.13), the following explanatory variables were examined: livestock practice, estimated milk yield and herd size. In addition to these variables, data about outbreak season and morbidity were available for 35 and 14 data points respectively.
Herd size, livestock practice, estimated litres of milk produced per animal and season of
morbidity during the FMD outbreak helped explain a small amount of the variation in milk losses (Pseudo R-squared: 0.11) (Table 3.15).
Table 3.15: Results of GLMs explaining variation in milk loss due to FMD.
N = number of, AIC = Akaike information criterion, LRT = likelihood ratio test, CI = confidence interval.
Difference in
AIC LRT Χ2 p Estimate (95%
CI) Odds Ratio
(95% CI) Negative = more
milk loss
Morbidity -2.05 4.0457 0.04428
Per extra unit (1/100) morbidity
-1.397 (-2.679--0.114)
0.247 (0.069-0.892)
Impact on milk sales and consumption
The majority (63.9%, CI: 53.5-73.5%) of households stopped selling milk during FMD outbreaks. Fewer households (24.7%, CI: 16.5 -34.5%) reported that they stopped consuming milk (Figure 3.12). There were similar patterns of cessation of milk sales and consumption during FMD outbreaks in all three management systems (Figure 3.12).
Figure 3.12: Proportions of households in the three management systems that stopped selling and consuming milk during FMD outbreaks.
Bars represent 95% confidence intervals.
Oxen’s ability to pull carts and ploughs
Of the households that used cattle for draught purposes, 70.5% (CI: 61.2-78.8%) reported that their animals’ ability to pull carts and ploughs was affected by FMD, whereas 65.7%
reported that their crop production was affected (Figure 3.13). These trends were similar across the production systems (Figure 3.13).
0.00 0.25 0.50 0.75 1.00
Stopped selling Stopped consuming
Impact
Proportion households reporting
Agropastoral Pastoral Rural smallholder Impact of FMD on milk sales and consumption
Figure 3.13: Proportions of households in the three management systems reporting impacts on the draught ability of their animals and on crop production due to FMD.
Bars represent 95% confidence intervals.
Impact on livestock management and sales
Time spent tending to livestock was altered due to FMD in 83.8% (CI: 75.6-90.1%) of households, and the main reason for this was increased time spent looking after and treating sick animals (Figure 3.14).
Only 17.1% (CI: 10.8-25.2%) of households reported that they changed grazing and watering areas due to an FMD outbreak. Households changed their grazing and watering practices to avoid perceived disease risk and due to affected livestock’s inability to walk longer distances. Households that did not change their practices indicated that this was due to a lack of access to alternative grazing or watering points.
In the case of alterations in livestock sales, 12% (CI: 6.9-19%) of households reported FMD to have an impact. The most frequently described reason for changing plans for selling livestock was because animals that were thin or sick due to FMD would be more difficult to sell and would fetch a lower price.
0.00 0.25 0.50 0.75 1.00
Traction affected Crops affected
Impact
Proportion households reporting
Agropastoral Pastoral Rural smallholder Impact of FMD on traction and crop production
Figure 3.14: The proportion of households in the three management systems reporting impacts on animal sales, time tending to livestock and grazing and watering
practices due to FMD.
Bars represent 95% confidence intervals.
Duration of FMD impacts
Information about the duration of FMD impacts was available from four agropastoral households in the outbreak follow-up study that had suffered serial FMD outbreaks.
Duration of lameness due to FMD lesions was reported to be 1-2 weeks. However, draught animals were unable to pull carts or ploughs for 1-2 months after each FMD outbreak.
Milk yield remained lower for 1-2 months after the outbreaks and it took the livestock 3 -4 months to regain weight lost during an FMD outbreak.