EMMA WOOD LACTATION CURVE

The data shows the Parameters (a, b, c) of lactation curve of 21 lactation West African Dwarf Does milked for twelve weeks, it also shows factors that affect this parameters. The values of the parameters were generated using Wood equation 1967. The twenty-one lactating does were divided into three groups of seven does each. Liveweight of the does were equalized among the treatment groups. The control group (T0) did not receive injection of oxytocin (0 IU), second group (T1) received 2 IU and third groups (T2) were given 4 IU oxytocin once a week for twelve weeks. Data collection on milk yield started five days after kidding. Separation of the kids from their dam starting 7:00pm and an interval of 5 minutes was given between separations to avoid clash of milking time. Residual milk was removed by injection of 1 IU synthetic oxytocin intramuscularly at the hind limb after separation. At 7:00am the next day (12 hours) does were injected with oxytocin according to their group and hand milked.
Data collected were fitted into Wood model to generate lactation curve parameters. SAS 9.1 version was used for analysis of variance for the values obtained. The mean “a”, “b” and “c” parameters were 361.69 ± 2.43, 0.414 ± 0.03 and 2.972 ± 2.80, respectively with R2 value of 99.3 %. Mean for (PY), (PW) and (PSS) were 340.45 ± 11.35, 2.288 ± 0.14 and 2.304 ± 0.22. Oxytocin (P<0.05) influenced “a”, “b”, “PW”, “PY” and “R2”. Litter size (P>0.05) influenced “a”, “b”, “PW” and “PY”. Parity (P>0.05) influenced “a”, “b” and “PW”. Parameter “a” was higher with 4 IU, 2 IU and then 0 IU respectively. Parameter “b” and “c” were higher with 0 IU, 4 IU and then 2 IU respectively. The results indicated lower b and c parameters and thus, oxytocin could extend lactation duration. Does with litter size 2 had higher “a” but lower “b”. Does in first parity had higher “a” with lower “b”.