Haslin Emmanuelle, Corner-Thomas Rene A, Kenyon Paul R, Peterson Sam W, Morris Stephen T, Blair Hugh T
School of Agriculture and Environment, Massey University, Palmerston North 4474, New Zealand.
Animals (Basel). 2021 Jul 9;11(7):2052. doi: 10.3390/ani11072052.
Mammary cistern size was positively correlated with milk yield of mature dairy ewes, but the association in ewe lambs is unknown. This experiment aimed to examine the associations between mammary ultrasound measurements and the milk yield of ewe lambs at one year of age and to determine the accuracy of using maternal mammary ultrasound to predict single lamb growth rates. Single-bearing ewe lambs (n = 45) were randomly selected and 30 were milked once at weeks three (W3), five (W5), and seven (W7) of lactation. Mammary ultrasound scans were performed at day 110 of pregnancy, W3, W5, W7, and weaning (L69). Single lambs (n = 30) were weighed at birth and at each mammary scanning event. Udder measurements explained 26.8%, 21.4%, and 38.4% of the variation in milk yield at W3, W5 and W7, respectively, and 63.5% and 36.4% of the variation in single lamb growth to W3 and to L69. This ultrasound technique was more accurate in predicting single lamb growth to W3 than milk yield and may enable the identification of pregnant ewe lambs whose progeny would have greater growth rates. More research is needed to identify accurate indicators of superior milk yield and determine whether ultrasound could be used to select ewe lambs.
乳腺贮乳池大小与成年泌乳母羊的产奶量呈正相关，但在母羊羔羊中的关联尚不清楚。本实验旨在研究乳腺超声测量值与一岁母羊羔羊产奶量之间的关联，并确定使用母羊乳腺超声预测单羔生长率的准确性。随机选择单胎母羊羔羊（n = 45），其中30只在泌乳第3周（W3）、第5周（W5）和第7周（W7）各挤奶一次。在妊娠第110天、W3、W5、W7和断奶时（L69）进行乳腺超声扫描。单羔（n = 30）在出生时和每次乳腺扫描时称重。乳房测量分别解释了W3、W5和W7产奶量变化的26.8%、21.4%和38.4%，以及到W3和到L69时单羔生长变化的63.5%和36.4%。这种超声技术在预测单羔到W3时的生长方面比预测产奶量更准确，并且可能有助于识别其后代生长率更高的怀孕母羊羔羊。需要更多的研究来确定高产奶量的准确指标，并确定超声是否可用于选择母羊羔羊。
