Lahrmann H P, Oxholm L C, Steinmetz H, Nielsen M B F, D'Eath R B
1Danish Agriculture and Food Council,Pig Research Centre,Axelborg,Axeltorv 3,DK-1609 Kbh. V.Denmark.
2Animal and Veterinary Sciences,SRUC,West Mains Road,Edinburgh,EH9 3JG,UK.
Animal. 2015 May;9(5):862-70. doi: 10.1017/S1751731114003024. Epub 2014 Dec 15.
In the EU, pigs must have permanent access to manipulable materials such as straw, rope, wood, etc. Long straw can fulfil this function, but can increase labour requirements for cleaning pens, and result in problems with blocked slatted floors and slurry systems. Chopped straw might be more practical, but what is the effect on pigs' behaviour of using chopped straw instead of long straw? Commercial pigs in 1/3 slatted, 2/3 solid pens of 15 pigs were provided with either 100 g/pig per day of long straw (20 pens) or of chopped straw (19 pens). Behavioural observations were made of three focal pigs per pen (one from each of small, medium and large weight tertiles) for one full day between 0600 and 2300 h at each of ~40 and ~80 kg. The time spent rooting/investigating overall (709 s/pig per hour at 40 kg to 533 s/pig per hour at 80 kg), or directed to the straw/solid floor (497 s/pig per hour at 40 kg to 343 s/pig per hour at 80 kg), was not affected by straw length but reduced with age. Time spent investigating other pigs (83 s/pig per hour at 40 kg), the slatted floor (57 s/pig per hour) or pen fixtures (21 s/pig per hour) was not affected by age or straw length. Aggressive behaviour was infrequent, but lasted about twice as long in pens with chopped straw (2.3 s/pig per hour at 40 kg) compared with pens with long straw (1.0 s/pig per hour at 40 kg, P=0.060). There were no significant effects of straw length on tail or ear lesions, but shoulders were significantly more likely to have minor scratches with chopped straw (P=0.031), which may reflect the higher levels of aggression. Smaller pigs showed more rooting/investigatory behaviour, and in particular directed towards the straw/solid floor and the slatted floor than their larger pen-mates. Females exhibited more straw and pen fixture-directed behaviour than males. There were no effects of pig size or sex on behaviour directed towards other pigs. In summary, pigs spent similar amounts of time interacting with straw/solid floor when long and chopped straw were provided, and most aspects of pig-directed behaviour and injuries were not affected by straw length. There was an increase in pigs with minor shoulder lesions with chopped straw, perhaps because of increased aggression. The use of chopped straw as an enrichment material for pigs warrants further investigation in larger and more detailed studies.
在欧盟，猪必须能够随时接触到可操控的材料，如稻草、绳索、木材等。长稻草可以满足这一功能，但会增加猪圈清洁的劳动量，并导致板条地板和粪便处理系统堵塞的问题。切碎的稻草可能更实用，但用切碎的稻草代替长稻草对猪的行为有什么影响呢？将15头商品猪饲养在1/3为板条地板、2/3为实心地板的猪圈中，每头猪每天分别提供100克长稻草（20个猪圈）或切碎的稻草（19个猪圈）。在猪体重约40公斤和80公斤时，于每天06:00至23:00对每个猪圈中的三头焦点猪（分别来自小、中、大体重三分位数）进行一整天的行为观察。猪整体用于拱掘/探究的时间（从40公斤时每头猪每小时709秒降至80公斤时每头猪每小时533秒），或用于稻草/实心地板的时间（从40公斤时每头猪每小时497秒降至80公斤时每头猪每小时343秒），不受稻草长度影响，但随年龄增长而减少。用于探究其他猪（40公斤时每头猪每小时83秒）、板条地板（每头猪每小时57秒）或猪圈固定装置（每头猪每小时21秒）的时间，不受年龄或稻草长度影响。攻击行为很少见，但与使用长稻草的猪圈（40公斤时每头猪每小时1.0秒）相比，使用切碎稻草的猪圈中攻击行为持续时间约为两倍（40公斤时每头猪每小时2.3秒，P = 0.060）。稻草长度对猪尾巴或耳朵损伤没有显著影响，但使用切碎稻草时，猪肩部出现轻微擦伤的可能性显著更高（P = 0.031），这可能反映了攻击水平较高。较小的猪比较大的同圈猪表现出更多的拱掘/探究行为，特别是针对稻草/实心地板和板条地板。雌性猪表现出比对稻草和猪圈固定装置更多的行为。猪的大小和性别对针对其他猪的行为没有影响。总之，提供长稻草和切碎稻草时，猪与稻草/实心地板互动的时间相似，并且猪的行为和受伤的大多数方面不受稻草长度影响。使用切碎稻草时，肩部有轻微损伤的猪有所增加，可能是因为攻击行为增加。将切碎稻草用作猪的富集材料值得在更大规模和更详细的研究中进一步调查。
