Introduction

FAMACHA, an acronym for “FAffa MAlan CHArt”, is a system evolved for the treatment and control of Haemonchus contortus (barber’s pole worm) in sheep and goats (Bath et al. 1996). The system estimates levels of anaemia and blood loss and makes it practically easy for farmers to identify and potentially treat clinically sick or more susceptible members of a flock without the need to treat the entire herd as was previously the case. The FAMACHA system involves comparing the ocular mucous membranes of sheep and goats with a colour chart bearing pictures of sheep conjunctivae classified into five categories ranging from the normal red through pink to practically white in severe anaemia (van Wyk and Bath 2002).

FAMACHA© has been extensively tested and validated in South Africa with very good results as there was a 90 % reduction in the total number of treatments given when the FAMACHA eye score was aided with packed cell volume (PCV) determination and 58 % when treatment was based only on FAMACHA (Van Wyk and Bath 2002). However, before, FAMACHA can be broadly recommended for use in any area or animal species; it is paramount to test and validate its applicability to the area or animal species. To this effect, several studies have been carried out in many parts of the world to evaluate and validate FAMACHA. Such studies have been done in sheep and goats in the USA (Kaplan et al. 2004), in goats in Switzerland (Scheuerle et al. 2010) and in sheep in South Africa (Reynecke et al. 2011). Presently, there is no documented evidence of FAMACHA© validation in Nigeria. Therefore, the present study was designed to test and evaluate the predictability of anaemia level in Nigerian goats which has not been tested previously, using the FAMACHA system. It is hoped that the results of this preliminary study will provide background information needed to carry out full validation and applicability of FAMACHA in Nigerian goats.

Materials and methods

Study area

The study was carried out in Nsukka located in the derived savanna zone of Eastern Nigeria lying approximately between longitude 6°52′–7°53′ E and latitude 6°38′–7°8′ N.

Animals

A total of 280 trade goats predominantly of Red Sokoto breed were used for the study. The goats comprised young (6–12 months; n = 66) and adult (>12 months; n = 214) animals (Holst and Denny 1980). The goats included male (n = 18) and female (262) animals randomly selected and examined between May and August 2011.

Experimental design

The colour of the ocular mucous membranes of each animal was examined and classified into one of five categories according to the FAMACHA© eye colour chart: 1 = red, non-anaemic; 2 = red-pink, non-anaemic; 3 = pink, mildly anaemic; 4 = pink-white, anaemic and 5 = white, severely anaemic (Bath et al. 1996). All animals were scored by a particular investigator to avoid bias and ensure uniformity. About 5 ml of blood was collected from the jugular vein of each animal for determination of haematological indices. PCV was estimated using the micro-hematocrit method, red blood cell (RBC) counts by the haemocytometer method and haemoglobin (Hb) concentration by the cyanomethaemoglobin method (Dacie and Lewis 1975; Schalm et al. 1995). Faecal samples were collected directly from the rectum into appropriately labelled sample bottle. Faecal examination was done by the simple test tube floatation method, while egg counts were done by the modified McMaster technique with saturated solution of sodium chloride as the floating medium (MAFF 1977). Faecal culture and larval recovery were done as described by MAFF (1977). In all cases, nematode stages were identified using standard parasitological criteria (MAFF 1977; Hansen and Perry 1994).

Data analysis

Statistical analysis was done using SPSS version 15, and data collected were analysed where appropriate by either descriptive statistic, Student’s t test or one-way ANOVA. Correlations between variables were analysed by Spearman’s rank order test for nonparametric data. The results are presented as prevalence (percentage of animals infected) or as means±standard errors of the mean (SEM). Probabilities (P) of 0.05 or less were considered significant.

Results

Results of the larval identification (Fig. 1) showed that all the animals sampled were positive for faecal egg, and H. contortus was the predominant gastrointestinal nematode parasite infecting the goats examined during the study. The mean percent of H. contortus L3 recovered from the faeces of the goat was 70.18 %. Other nematode larvae recovered were Trichostrongylus (12.37 %), Oesophagostomum (13.67 %), Strongyloides (2.67 %) and Bunostomum (1.11 %) species.

Fig. 1
figure 1

Percentage recovery of gastrointestinal nematode species recovered from faecal culture

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A significant negative correlation was obtained between eye colour chart values and the duo of PCV (R s = −0.490, P < 0.001) and Hb concentration (R s = −0.457, P < 0.001). Goats with eye score value of 5 had the least values of PCV, RBC counts and Hb concentration (15.86 ± 2.15, 10.05 × 105 ± 2.15 × 105 and 5.21 ± 0.75, respectively), whereas those with eye score value of 1 had the highest mean values of PCV, RBC counts and Hb concentration (39.32 ± 0.89, 16.34 × 105 ± 0.74 × 105 and 12.90 ± 0.26; Table 1).

Table 1 Mean±SEM of packed cell volume (PCV), red blood cell (RBC) counts and haemoglobin (Hb) concentrations based on FAMACHA© eye score categories of the goats
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Table 2 shows the effect of age on the mean PCV, RBC counts, Hb concentrations and eggs per gram (epg) of the goats belonging to the different anaemia categories. No significant difference was observed between the mean PCV, RBC, Hb concentrations and epg values of the young and adult goats for all the FAMACHA categories.

Table 2 Mean±SEM of the packed cell volume (PCV), red blood cell (RBC) counts, haemoglobin (Hb) concentrations and FAMACHA readings of young and adult goats examined at Nsukka, Nigeria
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Discussion

H. contortus is the predominant gastrointestinal nematode parasite infecting the goats slaughtered at the Nsukka abattoir with average larval recovery of 70.18 %. A similar prevalence has been reported by other researchers in this and other geographical zones of the country (Fabiyi 1970; Okon and Enyenihi 1975; Fakae 1990; Nwosu et al. 1996; Mbaya et al. 2009). The main pathogenic effect of H. contortus is anaemia due to active blood sucking and bleeding from the haemorrhagic bite wounds caused by the worms (Soulsby 1982). Other blood sucking gastrointestinal nematodes capable of causing anaemia which were also observed during this study was Bunostomum spp. (1.11 %).

In the present study, three indices of anaemia namely, PCV, RBC counts and Hb concentrations were evaluated using the colour of the ocular membrane of the goats. The results of the mean PCV and Hb concentrations of the goats based on their FAMACHA© categories indicate the ability of FAMACHA© eye score to predict anaemic goats and consequently those that may require treatment in the case of haemonchosis. The strong significant negative correlation between the eye scores and the anaemia indices (PCV and Hb concentration) further underscores its value as an indicator of anaemia in Nigerian goats. It can be further deduced from the results that with respect to normal values for PCV and Hb concentrations, goats with FAMACHA© score of 5 (mean PCV = 15.86 ± 2.15; Hb = 5.21 ± 0.75) were severely anaemic and those with scores of 4 (mean PCV = 25.00 ± 1.31; Hb = 9.41 ± 0.48) are marginally anaemic. Goats with FAMACHA© scores 1 and 2 had mean PCV (39.32 ± 0.89 and 36.05 ± 0.64 respectively) and Hb concentration (12.09 ± 0.26 and 11.91 ± 0.22, respectively) values that are within the upper limit of the normal range for goats (normal range—PCV = 22–40 %; Hb = 7–15 g/dl; Tambuwal et al. 2002). The results of the present study suggest that eye score values of 3 could be used as FAMACHA cut-off for indicating anaemic animals.

Scheuerle et al. (2010) reported a sensitivity of 93 % when FAMACHA treatment cut-off of ≥3 was used in evaluating the accuracy of FAMACHA in diagnosing anaemia and haemonchosis in Switzerland, using the anaemia criteria of PCV ≤30, and epg >600 epg as cut-off values for treatment. In the work of Kaplan et al. (2004), a similar FAMACHA treatment cut-off of ≤3 had sensitivity of 93.9 and 100 %, respectively, for PCV cut-off of < 19 and < 15 in goats. Kaplan et al. (2004) observed that the cut-off for PCV used for declaring anaemia will have a great impact on the results in evaluating the ability of FAMACHA© to correctly identify anaemic animals in need of treatment. In the present study, a PCV cut-off ≤28 % and FAMACHA cut-off ≤3 are likely the most appropriate treatment cut-off criteria to be used in detecting goats that have succumbed to haemonchosis and thus require treatment in Nigeria.

The results further suggest that age might not have effect on the predictability of anaemia using the FAMACHA© technique as there was no significant difference (P > 0.05) in the mean values of the PCV, RBC counts and Hb concentration between the young and adult goats. This suggests that FAMACHA© might be used in Nigerian goats regardless of their age post-weaning. Nevertheless, this cannot be said to be true for goats less than 6 months of age.

It can be concluded that the FAMACHA method can be used by farmers in Nigeria to identify anaemic goats. The preliminary findings in this study shall form a basis for further work on the full-scale validation of FAMACHA in Nigerian goats.