Birth 



9 WEEKS 



4 1 WEEKS 



- 46rf - 35y 



Hifirf+i'^? 



19 s: 



HIGH-PLANE 



45tf 

 LOW 



!So - 

 PLANE 



lOe 



Figure 11. The effect of the plane of nutrition on the growth of bones in 

 lambs at various ages. A low level of nutrition affects the late-developing 

 thickness growth of the bone much more than it does the early-developing 

 length growth, and it affects the wether more than the smaller ewe. (Palsson 

 and Verges, 1952.) 



.^5^ 



^ 0^ U^^e IN THE ^ 



5^^-Lactation / 

 / 



/f 



'^ 



<4y 



1^^- Lactation 



g"*"^- Lactation 



Figure 12. A diagrammatic scheme of the life cur\'es of the mammary gland 

 of the cow during the lifespan of the animal. Note the change in the shape of 

 the lactation curve with the age of the animal. (Hammond, 1947.) 



