De. Morin et al., COMPARATIVE-STUDY OF PROTEINS, PEROXIDASE-ACTIVITY AND N-ACETYL-BETA-D-GLUCOSAMINIDASE ACTIVITY IN LLAMA MILK, Small ruminant research, 17(3), 1995, pp. 255-261
Increased rearing of llamas in the USA has been associated with a need
to supplement milk to orphaned or undernourished llama neonates. Rumi
nant milks and milk replacers are used, but there are few data compari
ng the nutrient composition and protective factors of llama milk to th
ose of ruminant milks. We compared proteins in llama milk with those i
n cow, sheep, and human milks. Proteins were separated by sodium dodec
yl sulfate-polyacrylamide gel electrophoresis and visualized by Coomas
sie blue. Caseins were the predominant proteins in llama milk, as in c
ow and sheep milks. A considerably lower proportion of casein was iden
tified in human milk. alpha-lactalbumin was present in similar amounts
in llama, sheep, and cow milks, with proportionately more alpha-lacta
lbumin in human milk. beta-Lactoglobulin, the major whey protein of co
ws and sheep, was not detectable by this method in either llama or hum
an milk. Gel profiles of llama milk contained a relatively higher prop
ortion of a protein band co-migrating with lactoferrin compared with c
ow or sheep milk, but not as much as in human milk. We also compared t
he activities of peroxidase and N-acetyl-beta-D-glucosaminidase in mil
ks of the four species. Peroxidase activity in llama milk was more tha
n ten times less than in cow or sheep milk. Activity of N-acetyl-beta-
D-glucosaminidase was more than 20-fold higher in llama milk than in m
ilks of the ruminants. Activities of both enzymes in llama milk more c
losely resembled activities in human milk. Results of this study sugge
st that llama milk differs from cow and sheep milk in protein composit
ion, and that the relative importance of protective factors, such as l
actoferrin, peroxidase, and N-acetyl-beta-D-glucosaminidase, in milk m
ay be different for llamas compared with ruminants.