Animals, materials and methods

2. Animals, materials and methods

2.1. Experimental site and system of management The study was carried out at the National Goat Breeding station of the Animal Ž . Production Department of the Ministry of Agriculture Ghana . The station is located at Ž X X . Kintampo in the Brong Ahafo region of Ghana Longitude 1 805 W and Latitude 7840 N and is in the derived Savannah zone. The station has 10 paddocks ranging in size from 1.2 to 2.5 ha. The different flocks on the station are rotated on these paddocks containing grass forage such as Panicum maximum and Cyanodon nlemfuensis mixed with Stylosanthes hamata and Centrosena pubescens. Two weeks prior to mating, the does were flushed. Does observed to exhibit signs of parturition were sent to a holding pen and kept under 24-h observation. After kidding, does and their kids were allowed to stay together for 4 h before the kids were weighed, sexed and ear-tagged. This period of non-interference was necessary to allow sufficient time for does and their kids to establish a bond. 2.2. Animals Ž Before the experiments, a preliminary study was conducted using 28 kids 14 singles . and 7 sets of twins and their dams. The purpose of this preliminary study was to determine the appropriate modalities to be adopted for the tests. In this preliminary study, the kids were allowed access to their dam’s teats. Based on the results obtained, the teats of the does were covered with plaster 2 h before they were tested in the subsequent experiments. Fifty-six does and their single-born kids were used for the main study. Seven of the does and their kids were tested at 18 h, 10 at 24 h, 14 at 36 h and 25 at 48 h. Out of the 25 does tested at 48 h, nine were primiparous and 16 were multiparous. Based on the mean birth weight of West African Dwarf goats, which is Ž . about 1.2 kg, the kids were classified as either low weight F 1.2 kg or high weight Ž . 1.2 kg . Sixteen of the kids tested at 48 h fell into the low-weight class and nine in the high weight class. Sixteen were males while nine were females. Each doe and her kid were tested once to prevent familiarization with the test procedure due to previous experience. 2.3. Testing pen Ž . The testing pen used for the preliminary study and all three experiments Fig. 1 was Ž . a modification of the one used by Oppong-Anane 1991 . It was a funnel-shaped enclosure of wire mesh about 1.0 m high. At the smaller end were two pens for kids each measuring 0.5 m = 0.5 m and separated by a space of the same dimensions. Seven metres away, at the opposite end of the enclosure, were two pens each measuring 1.0 = 0.8 m. These pens were separated by a space of the same dimensions and were allocated to the test and alien does. The partitions between adjacent pens and the outside Fig. 1. Diagram of pen used for testing the response of does and their kids to separation and their mutual recognition. of all pens were covered with black plastic sheets to prevent animals from seeing one another. The enclosure was weeded completely to eliminate any grazing material that might serve as a point of distraction. 2.4. Experiment 1: The behaÕioural response of does and their single-born kids to separation when the kids had not been suckled for 2 h This experiment was carried out at 18, 24, 36 and 48 h. Prior to the test, each test doe and her kid were confined to one of the doe pens for about 10 min to allow the animals settle down and also to ensure that they were the correct doe–kid combination. Another Ž . doe and its kid which was born about the same time i.e., within 6 h as the test kid and which had also been prevented from sucking for 2 h were confined to the other doe pen to serve as alien animals in the recognition test. At the beginning of the experiment, the test and alien kids were removed and placed in separate kid pens with the test kid facing Table 1 Key to score used for the behavioural response of does and their single-born kids to separation Score Kid behaviour Doe behaviour 5 Very active, continuous high-pitched bleats Restless, continuous high-pitched bleats and a search 4 Not very active but high-pitched bleats Continuous high-pitched bleats and a search 3 Active, but few bleats Some bleats with a little search 2 Inactive, few bleats Few bleats, no search 1 Down, inactive No response the alien doe and the alien kid facing the test doe. The plaster covering the teats of both the test and alien does were then removed. The behavioural response of the test doe and her kid to separation was observed over a 5-min period and ranked with the score used Ž . by Oppong-Anane 1991 and shown in Table 1. 2.5. Experiment 2: The ability of single-born kids to discriminate between their own and alien does in a two choice situation at a distance of 6 m when they had not been suckled for 2 h After the behavioural response of the doe and her kid to separation had been scored, the test kid was removed and placed at a point 6 m from the does. It was placed in a central position directly in line with the space between the two doe pens. The kid was then gently released and observed for 5 min. Its dam recognition ability was ranked Ž . according to the score used by Oppong-Anane 1991 and shown in Table 2. 2.6. Experiment 3: The ability of does to distinguish between their own single-born and an alien kid in a two choice situation at a distance of 7 m when the kid had not been suckled for 2 h After experiment 2, the test kid was returned to its pen and the test doe released. The doe was observed for 5 min for her kid recognition ability and ranked according to the Ž . score used by Oppong-Anane 1991 and shown in Table 3. 2.7. Statistical analysis Ž . The chi-square procedure of the Statistical Analysis Institute 1989 statistical package was used to determine whether age or hours post-partum had an effect on the Table 2 Key to score used for dam recognition ability of single-born kids Score Kid behaviour 5 Goes directly to mother and stays 4 Goes to mother after hesitating between both does 3 Goes to alien doe first but switches to mother and stays 2 Goes to alien doe and stays 1 Does not reach either doe Table 3 Key to score used for kid recognition ability of single bearing does Score Doe behaviour 5 Goes directly to own kid and stays 4 Goes to own kid after hesitating between the 2 kids and stays 3 Goes to alien kid first but switches to own kid and stays 2 Goes to alien kid and stays 1 Does not make contact with either kid behavioural response to separation exhibited by does and their kids and on their mutual recognition. The procedure was also used to determine whether the sex and birth weight of kids and parity of their dams had an effect on these behavioural parameters at 48 h post-partum. All comparisons were at 5 level.

3. Results