ASSESSMENT OF THE USESFULNESS OF HETEROPHIL-LYMPHOCYTE RATIOS (HL RATIOS) AND TEMPERAMENT SCORES AS BIOMARKERS OF DOCILITY OF THE LOCAL GUINEA FOWL (Numida meleagris) VARIETIES IN GHANA

Abstract

The aim of this research was to study the usefulness of the Heterophil-Lymphocyte ratios (H/L ratios) and temperament scores as biomarkers for docility in Guinea fowls. The study was carried out at the Poultry Section of the Department of Animal Science Education, University of Education, Winneba, Mampong-Ashanti campus, Ghana from May 2016 to June 2016. Docility was defined as ability of the bird to accept human presence, novel object, human contact and handling. The ability of acceptance was measured on a 4-point scale and these included: docile (1), flighty (2), restless (3) and aggressive (4). The birds were consecutively tested for temperament 2 times in a week and 8 times in all. The docility test was carried out on seventy (79) Guinea fowls comprising Pearl (37 males and 20 females), Lavender (6 males and 5 females) and White (5 males and 6 females) local varieties all of average age 10 months. The birds were tested for behavioural docility and hematological parameters which includes heterophil, lymphocytes counts and H/L ratios in a Completely Randomised Design experiment. Data were analysed using SAS and SPSS separation of means was done using LSD. Average docility score of the population was 2.15 representing 64.6% suggesting that the birds studied were generally flighty. The research revealed that the birds were consistent on this docility category. According to behavioural docility testing, sex and varieity had no significant effect (P>0.05) on docility. Males had a docility score of 2.2 and female 2.1 meaning both male and female Guinea fowls were flighty. From this experiment the Pearl and White had similar ability to withstand stress as indicated by their H/L ratios of 0.11 which was significantly different from that of the Lavender (0.09). The behavioural docility score and the H/L ratio of the Lavender both indicated that it was a more promising type in terms of acceptable docility score and ability to withstand stress. The cumulative effect of sex, variety and test criteria (method) had significant effect (P<0.05) on docility. Only 14.2% of the birds were docile. The research revealed that the birds were not generally aggressive in nature as only 1.3% of them were seen as being aggressive. There was no significant (P>0.05) effect of docility on feed intake and weight gain of the Guinea fowls. There was no significant (P>0.05) influence of docility on heterophil-lymphocyte ratio of the Guinea fowls. The variety factor had significant (P<0.05) effect on H/L ratios and H/L counts. The Lavendar recorded the lowest H/L ratio among the three varieties which was statistically significant (P<0.05). With the use of H/L ratios, the pearl would easily be stressed followed by the white and then Lavendar. The H/L ratio positively correlated with the docility but rather very weakly (P=0.023). The research revealed that the test criterion has significant (P>0.05) effect on docility. Based on this observation, the individual criteria were unique in their own right and can be used independently for the assessment of docility status of the birds. The Human Presence Test (HPT), Novel Object Test (NOT), Contact (CT), and Handling Test (HT) produced consistent docility scores across the weeks. The HPT, NOT and CT are similar in effect. The method which produces the greatest impact on the birds is HT. If the test methods are to be used individually, then HPT, NOT and Contact test will be ideal. The most suitable pair of method that assesses the underlying docility trait very effectively was the human presence test (HPT) with the novel object test (NOT) and is therefore recommended as the best suitable pair for behavioural docility scoring. The docility trait should be included in the breeding objectives of the Guinea fowls in order to achieve more acceptable docility scores.