Roberts M C, Kidder D E, Hill F W
Gut. 1973 Jul;14(7):535-40. doi: 10.1136/gut.14.7.535.
Two enzymes having lactase activity are present in the equine small intestine. The first, the digestive enzyme, neutral beta-galactosidase, declines in activity from birth to three years, disappearing completely between 3 and 4 years of age. The other, the soluble lysosomal enzyme, acid beta-galactosidase, having affinity for lactose and a synthetic beta-galactoside, shows a decrease in activity in the first three months of life and thereafter varies little in activity and represents the lactase enzyme in the adult horse. This pattern may parallel the development of lactase activity in many other mammals and in the majority of the world's human population.
马的小肠中存在两种具有乳糖酶活性的酶。第一种是消化酶，即中性β-半乳糖苷酶，其活性从出生到三岁逐渐下降，在3至4岁时完全消失。另一种是可溶性溶酶体酶，即酸性β-半乳糖苷酶，它对乳糖和合成β-半乳糖苷具有亲和力，在出生后的前三个月活性下降，此后活性变化不大，是成年马体内的乳糖酶。这种模式可能与许多其他哺乳动物以及世界上大多数人口中乳糖酶活性的发展情况相似。
