zh %E6%94%BE%E7%89%A7

牧食又稱囓食，是植食动物在自然环境中通过啃食各种植被的根茎、枝叶和花果摄入碳水化合物和植物蛋白等营养成分的行为。放牧則指人类将驯化的草食性家畜（比如牛、羊、马等等）放到户外环境去自由進食野生植物（例如草和灌木）或其他多細胞自營生物（例如藻類和地衣）的行為，是畜牧业的重要一環。透過放牧，植物中人类无法消化的纤维素会被间接變成可以食用的肉和奶、以及有商业价值的毛皮等动物产品。許多小型食草動物也會跟隨在大型食草動物之後，以這些大型食草動物啃食植物後暴露出的嫩苗為生。地球上近25%的陆地面积被用于放牧^[1]。

牧食動物和食嫩植動物最大的差異在於牧食動物多以草及闊葉雜草（英语：forb）為食，而食嫩植動物則多以樹及灌木的葉和嫩枝為食^[2]。

合理的放牧有助于维持以草本植物为主的生态群落，同时促进更多样化的传粉者生存，并提供更多潜在的筑巢资源^[3]。然而过度放牧行为对生态系统和畜牧业都带来不利影响^[4]。牲畜的过度采食会导致植被高度和生物量降低，植物多样性锐减，植被组成发生变化，同时也会引起土壤条件的改变，如践踏和粪便沉积等一系列环境和生态问题^[4]。

動物行為

食草動物

食草動物指的是以草（尤其是禾本科）為主食的動物^[5]，包括馬、家牛、水豚、河馬、蚱蜢、鵝、貓熊等。貓熊的食物中有 99% 為亞高山帶竹子物種^[6]。

食糞動物

兔子以草為食，其中含有大量難以消化的纖維素，牠們透過後腸醱酵（英语：hindgut fermentation）來解決這項問題。兔子會排出兩種糞便：黑色顆粒狀的硬便以及較為柔軟的盲腸便（英语：Cecotrope）。兔子會重新攝入盲腸便，進行消化並取得更多營養^[7]。

偽反芻動物

河馬為大型半水生的哺乳動物，棲息於河流、湖沼及紅樹林沼澤中。白天時，牠們多半會待在水中或泥中，交配與生產也都在水中，黃昏後才會來到陸地上進行牧食。河馬雖然群居於水中，但在牧食時多半為獨自行動。牠們的門齒長度可以超過 40厘米（16英寸），犬齒長度則能超過 50厘米（20英寸）^[8]。然而河馬的門齒與犬齒僅能用於打鬥，並無法協助進食；牠們透過厚實的嘴唇將植物拔出地面，再透過臼齒磨碎^[9]。河馬被認為是一種偽反芻動物（英语：pseudoruminant），牠們的胃具有三個腔室，但是並不會進行反芻^[10]。

非草食牧食

廣泛的牧食定義包括：一個生物體以另一個生物體為食，但並不會使該生物體死亡^[11]。

這樣的範例包括以海草為食的海膽，以及以藻類、矽藻、附著於水中基質上生物薄膜為食的水生螺類。

參考文獻

^ Zhao, Qiujie; Guo, Huijun; Meng, Guangtao; Zhong, Mingchuan; Yin, Jun; Liu, Zhuocheng; Li, Pinrong; Chen, Li; Tao, Yi; Qiu, Sheng; Wang, Hong; Zhao, Yanhui. Effects of grazing on bees and suggestions for its ecological restoration. Biodiversity Science. 2023-05-20, 31 (5): 23037. doi:10.17520/biods.2023037.
^ Browsing is a specialized form of grazing. "Graze, verb: 2. Eat growing grass." "Browse, verb: 1. Feed on, crop, (leaves, twigs, scanty vegetation).". Concise Oxford Dictionary 6. 1976. ISBN 0-19-861122-6.
^ Black, Scott Hoffman; Shepherd, Matthew; Vaughan, Mace. Rangeland Management for Pollinators. Rangelands. 2011-06, 33 (3): 9–13. doi:10.2111/1551-501X-33.3.9.
^ ^4.0 ^4.1 Ravetto Enri, Simone; Probo, Massimiliano; Farruggia, Anne; Lanore, Laurent; Blanchetete, André; Dumont, Bertrand. A biodiversity-friendly rotational grazing system enhancing flower-visiting insect assemblages while maintaining animal and grassland productivity. Agriculture, Ecosystems & Environment. 2017-04, 241: 1–10. doi:10.1016/j.agee.2017.02.030.
^ Definition of GRAMINIVOROUS. www.merriam-webster.com. [2019-03-22]. （原始内容存档于2019-03-22）.
^ ZHOU, Shiqiang; et al. Effects of wildness training giant pandas? Grazing and artificial harvesting on clone population biomass of umbrella bamboo (Fargesia robusta). Chinese Journal of Applied & Environmental Biology. 2012, 18 (1): 1–8 [2019-03-22]. doi:10.3724/sp.j.1145.2012.00001. （原始内容存档于2019-02-12）.
^ Information for Rabbit Owners — Oak Tree Veterinary Centre. Oaktreevet.co.uk. [2010-08-30]. （原始内容存档于2012-06-23）.
^ Estes, R. The Behavior Guide to African Mammals: Including Hoofed Mammals, Carnivores, Primates. University of California Press. 1992: 222–26. ISBN 0-520-08085-8.
^ Kingdon, J. East African Mammals: An Atlas of Evolution in Africa, Volume 3, Part B: Large Mammals. University Of Chicago Press. 1988: 256–77. ISBN 0-226-43722-1.
^ Eltringham, S.K. The Hippos. Poyser Natural History Series. Academic Press. 1999. ISBN 0-85661-131-X.
^ Begon, M., Townsend, C. and Harper, J. Ecology 3. Blackwell Science, London. 1996. ^{[页码请求]}

"Benefits of Grazing Animals". East Bay Regional Parks District. Retrieved 1 Dec 2008

外部連結

[1] Zhao, Qiujie; Guo, Huijun; Meng, Guangtao; Zhong, Mingchuan; Yin, Jun; Liu, Zhuocheng; Li, Pinrong; Chen, Li; Tao, Yi; Qiu, Sheng; Wang, Hong; Zhao, Yanhui. Effects of grazing on bees and suggestions for its ecological restoration. Biodiversity Science. 2023-05-20, 31 (5): 23037. doi:10.17520/biods.2023037.

[2] Browsing is a specialized form of grazing. "Graze, verb: 2. Eat growing grass." "Browse, verb: 1. Feed on, crop, (leaves, twigs, scanty vegetation).". Concise Oxford Dictionary 6. 1976. ISBN 0-19-861122-6.

[3] Black, Scott Hoffman; Shepherd, Matthew; Vaughan, Mace. Rangeland Management for Pollinators. Rangelands. 2011-06, 33 (3): 9–13. doi:10.2111/1551-501X-33.3.9.

[j.agee.2017-4] 4.0 ^4.1 Ravetto Enri, Simone; Probo, Massimiliano; Farruggia, Anne; Lanore, Laurent; Blanchetete, André; Dumont, Bertrand. A biodiversity-friendly rotational grazing system enhancing flower-visiting insect assemblages while maintaining animal and grassland productivity. Agriculture, Ecosystems & Environment. 2017-04, 241: 1–10. doi:10.1016/j.agee.2017.02.030.

[5] Definition of GRAMINIVOROUS. www.merriam-webster.com. [2019-03-22]. （原始内容存档于2019-03-22）.

[6] ZHOU, Shiqiang; et al. Effects of wildness training giant pandas? Grazing and artificial harvesting on clone population biomass of umbrella bamboo (Fargesia robusta). Chinese Journal of Applied & Environmental Biology. 2012, 18 (1): 1–8 [2019-03-22]. doi:10.3724/sp.j.1145.2012.00001. （原始内容存档于2019-02-12）.

[7] Information for Rabbit Owners — Oak Tree Veterinary Centre. Oaktreevet.co.uk. [2010-08-30]. （原始内容存档于2012-06-23）.

[estes-8] Estes, R. The Behavior Guide to African Mammals: Including Hoofed Mammals, Carnivores, Primates. University of California Press. 1992: 222–26. ISBN 0-520-08085-8.

[kingdon-9] Kingdon, J. East African Mammals: An Atlas of Evolution in Africa, Volume 3, Part B: Large Mammals. University Of Chicago Press. 1988: 256–77. ISBN 0-226-43722-1.

[The_Hippos-10] Eltringham, S.K. The Hippos. Poyser Natural History Series. Academic Press. 1999. ISBN 0-85661-131-X.

[Ecology-11] Begon, M., Townsend, C. and Harper, J. Ecology 3. Blackwell Science, London. 1996. ^{[页码请求]}

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放牧