**2.2.1 Analysis models**

ANOVA using General Linear Model (GLM) (SAS, 2000) for calf body weight was tested. This was done to determine the fixed effects of various factors on body weight at 30-day intervals from the first month of birth to 12 months of age (360 days). The data was classified according to the experimental variables covering the twelve months periods 1-30, 31-60, 61-90, 91-120, 121-150, 151-180, 181-210, 211-241, 241-270, 271-300, 301-330 and 331-360 days (Table 1).

Various analyses were run for different combinations of the fixed effects. Those effects with non-significance levels at P>0.05 were dropped from the next test model until the final model was developed. After final adjustments for the various differences and exclusions of non-significant effects such as year of birth, farmer herd and interaction of cattle breed with season of birth, the final model (i) below was arrived at; that included the fixed effects of breed, sex of calf, season of birth and district of birth (model ii) below.

$$\mathbf{Y}\_{ijklm} = \mu + \mathbf{B}\_i + \mathbf{X}\_j + \mathbf{S}\_k + \mathbf{D}\_l + \mathbf{e}\_{ijklm} \tag{ii}$$

Where:

324 A Bird's-Eye View of Veterinary Medicine

Cattle handling varied from farmer to farmer depending on availability of handling structures. In some cases the animals were put in a crush, restrained and weight measurement taken using the heart girth tape. In other cases, individual animals were restrained manually by field assistants using ropes. The heart girth and weight estimates were taken using the tape when the animal was calmed down and standing in an upright and straight position. The measurements were immediately recorded in field data sheets.

On-farm data involved 4 genetic breeds of cattle including pure Ankole and Boran crossbred Friesian and Boran. It was, however difficult to determine the exact level of the crossbred animals. At the start of the field study, the calves that were 3 months old were recruited for measurements. However, with time, calves were born among the herds of the participating farmers. The measurements of such calves were recorded within the first month of birth. The heart girth and weights were again taken at the time of the next visit. This was done on monthly intervals though, in some cases, delays could occur due to late release of operational funds. The sample sizes were however larger than on-station with Kiruhura district offering 141 animal records, 182 in Ibanda district and 189 in Sembabule . Continuous recording of heart girth and body weight estimates was done for only 9 months due to the heavy expense and limited funding. All data was entered in Excel at 30 days intervals i.e. period 1 for 1-30 days, period 2 for 31-60 days, etc. All calves were managed under similar conditions allowing suckling up to 8-12 months or at the time when the farmers observe that the cow is nearing to calve down again. All experimental animals from the selected participating farmers were on free range management system under herding. The comparison was based on fixed effects under a free range management focussing on four cattle breed differences, that is Ankole, Boran, Boran x Ankole , and Friesian x Ankole. Prior to the ANOVA was employed to examine the distribution of live body weight data structured at 30-day intervals. Those values whose means showed gross errors and outlying were excluded from the data set to avoid adversely affecting the means, standard deviations, variances and standard errors. This was achieved again by applying the VIEWTABLE, GPLOT and MEANS procedures of SAS (2002). The GPLOT showed the

Thereafter, the data was transferred into Excel for back up, collation and analysis.

distribution of observations against the different time intervals of 30 day means.

ANOVA using General Linear Model (GLM) (SAS, 2000) for calf body weight was tested. This was done to determine the fixed effects of various factors on body weight at 30-day intervals from the first month of birth to 12 months of age (360 days). The data was classified according to the experimental variables covering the twelve months periods 1-30, 31-60, 61-90, 91-120, 121-150, 151-180, 181-210, 211-241, 241-270, 271-300, 301-330 and 331-360

**X***j* = the fixed effect of sex of calf (j = 1, 2) **S***k* = the fixed effect of season of birth (k =1, 2)

**2.2 Description of on farm cattle data** 

**e***ijkl* = the random residual effect

**2.2.1 Analysis models** 

days (Table 1).

Y*ijklm* = the live weight of the mth calf born under ith calf cattle breed, jth sex of calf, kth season of birth and lth district of birth

*µ* = the common parameter (konstant) **B***i* = the fixed effect of breed of cattle (i = 1, 2) **X***j* = the fixed effect of sex of calf (j = 1, 2) **S***k* = the fixed effect of season of birth (k =1, 2) **D***l* = the fixed effect of district of birth (l =1, 2, 3) **e***ijklm* = the random residual effect
