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nutrition throughout), high-low (good nutrition to first calv ing and poor nutrition thereafter), and low-high (poor nutrition to first calving and goo-d nutrition thereafter). The results are reported in three stages, calf, yearling, and cow. Calf Stage : Seasonal body weights of the well-reared (rotationally-grazed) and poorly-reared (set-stocked) calves for the last five years were as follows :

Body Weights as at 31st March

Yearling Stage: Body-weight differences of the two groups of heifers were as follows :

Body Weights as at 31st March

Cumulative data on reproduction behaviour are summarized below :

Reproduction Behaviour

The poorly-reared heifers still continue to show fewer animals coming into oestrus before mating, substantially fewer total oestrus periods before mating, fewer mating heats, and a better conception rate than their well-reared mates. Culling rate for empty heifers was only 2-4 per cent, in the poorly-reared group and 11-2 per cent, in the well-reiared group.

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Seasons. Well Reared. Poorly Reared. • Difference. Number. Weight. Number. Weight. lb. lb. lb. 1944-49 94 385 104 288 97 1948-49 10 414 12 288 126 Twins (split) 12 408 10 325 83

Seasons. Well Grown. Poorly Grown. Difference. Number. Weight. Number. Weight. lb. lb. lb. 1944^49 72 709 75 557 152 1948-49 10 753 12 543 210 Twins (split) 10 693 10 552 141

Well Grown. Poorly Grown. Total number of heifers .. .. 80 83 Number showing heats before mating .. 78 60 Number of recorded heats before milking 336 141 Number of mating heats— Total 134 117 Fertile cows 107 113 Number in calf 71 81 Services per conception— Total 1-89 1-44 Fertile cows .. .. 1-51 1-40