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”.本数据集包含21头经12周挤奶的西非矮山羊母羊的泌乳曲线参数（a、b、c），以及影响这些参数的相关因素。所有参数值均通过1967年伍德方程（Wood equation）计算得到。 21头泌乳母山羊被均分为3组，每组7头，试验组间母山羊的活体重保持一致。对照组（T0）不注射催产素（0国际单位，IU），第二组（T1）注射2 IU催产素，第三组（T2）每周注射4 IU催产素，持续12周。产羔后第5天启动产奶量数据收集工作。羔羊与母羊于每日晚7:00起开始分离，每次分离间隔5分钟，以避免挤奶时间冲突。分离完成后，通过在后肢肌肉注射1 IU合成催产素以排空残乳。次日早7:00（间隔12小时），按照分组为母山羊注射催产素后进行手工挤奶。 将收集到的数据拟合至伍德模型以生成泌乳曲线参数。采用SAS 9.1软件对所得数据进行方差分析。参数a、b、c的平均值分别为361.69±2.43、0.414±0.03和2.972±2.80，决定系数（R²）为99.3%。产奶量相关指标PY、PW与PSS的平均值分别为340.45±11.35、2.288±0.14和2.304±0.22。催产素对参数a、b，指标PW、PY及R²均存在显著影响（P<0.05）；产羔数对参数a、b，指标PW、PY无显著影响（P>0.05）；胎次对参数a、b及指标PW无显著影响（P>0.05）。参数a的数值在4 IU组最高，其次为2 IU组，0 IU组最低。参数b与c的数值在0 IU组最高，其次为4 IU组，2 IU组最低。本研究结果显示催产素可降低参数b与c的数值，进而延长泌乳持续时间。产羔数为2的母山羊参数a更高，但参数b更低；初产母山羊的参数a更高，但参数b更低。