Lv S-J, Yang Y, Dwyer C M, Li F-K
1College of Life Sciences,Linyi University,Shuangling Road,Linyi City,276005,Shandong,China.
2Linyi Agriculture Science Institute,North Street of Su River,Linyi City,276009,Shandong,China.
Animal. 2015 Jul;9(7):1195-202. doi: 10.1017/S175173111500052X. Epub 2015 Apr 10.
The aim of this experiment was to study the effects of pen size and parity on maternal behaviour of twin-bearing Small-Tail Han ewes. A total of 24 ewes were allocated to a 2×2 design (six per pen), with parity (primiparous or multiparous) and pen size (large: 6.0×3.0 m; small: 6.0×1.5 m) as main effects at Linyi University, Shandong Province, China. Behaviour was observed from after parturition until weaning. All ewes were observed for 6 h every 5 days from 0700 to1000 h and from 1400 to 1700 h. Continuous focal animal sampling was used to quantify the duration of maternal behaviours: sucking, grooming and following as well as the frequency of udder accepting, udder refusing and low-pitched bleating. Oestradiol and cortisol concentrations in the faeces (collected in the morning every 5 days) were detected using EIA kits. All lambs were weighed 24 h after parturition and again at weaning at 35 days of age. The small pen size significantly reduced following (P<0.005), grooming (P<0.001) and suckling durations (P<0.05), as well as the frequency of udder refusals (P<0.001). However, there was a significant interaction with ewe parity, with decreased grooming and suckling in the small pen largely seen in the multiparous ewes (P<0.001). Independent of pen size, multiparous ewes accepted more sucking attempts by their lambs (P<0.05) and made more low-pitched bleats than primiparous ewes (P<0.001). Multiparous ewes had higher faecal oestradiol concentrations than primiparous ewes (P<0.001), and ewes in small pens had higher faecal cortisol levels compared with ewes in larger pens (P<0.001). As lambs increased in age, the duration of maternal grooming, following and suckling as well as frequency of udder acceptance and low-pitched bleating all declined, and the frequency of udder refusing increased (P<0.001 for all). Ewe parity, but not pen size, affected lamb weight gain during the period of observation (P<0.001). This is the first study to show that pen size, interacting with parity, can affect the expression of maternal behaviour in sheep during lactation. The study is also the first to report on the maternal behaviour of Chinese native sheep breeds (Small-Tail Han sheep), with implications for the production of sheep in China.
本实验旨在研究围栏大小和胎次对产双羔的小尾寒羊母性行为的影响。在中国山东省临沂大学，将24只母羊分配到一个2×2设计中（每个围栏6只），以胎次（初产或经产）和围栏大小（大：6.0×3.0米；小：6.0×1.5米）作为主要因素。从分娩后到断奶期间观察母羊行为。每隔5天，在07:00至10:00以及14:00至17:00对所有母羊进行6小时的观察。采用连续焦点动物取样法来量化母性行为的持续时间：吮乳、舔舐和跟随，以及乳房接受、乳房拒绝和低声咩叫的频率。使用酶免疫分析试剂盒检测粪便中（每5天早晨收集）的雌二醇和皮质醇浓度。所有羔羊在出生后24小时称重，并在35日龄断奶时再次称重。小围栏大小显著减少了跟随行为（P<0.005）、舔舐行为（P<0.001）和吮乳持续时间（P<0.05），以及乳房拒绝的频率（P<0.001）。然而，围栏大小与母羊胎次存在显著交互作用，小围栏中舔舐和吮乳行为的减少在经产母羊中更为明显（P<0.001）。与围栏大小无关，经产母羊比初产母羊接受羔羊更多的吮乳尝试（P<0.05），并且发出更多的低声咩叫（P<0.001）。经产母羊粪便中的雌二醇浓度高于初产母羊（P<0.001），小围栏中的母羊粪便皮质醇水平高于大围栏中的母羊（P<0.001）。随着羔羊年龄的增长，母羊舔舐、跟随和吮乳的持续时间以及乳房接受和低声咩叫的频率均下降，而乳房拒绝的频率增加（所有P<0.001）。在观察期间，母羊胎次而非围栏大小影响羔羊体重增加（P<0.001）。这是第一项表明围栏大小与胎次相互作用会影响绵羊泌乳期母性行为表达的研究。该研究也是首次报道中国本土绵羊品种（小尾寒羊）的母性行为，对中国绵羊生产具有重要意义。
