The effect of plane of nutrition during rearing on growth, production, reproduction and health of dairy cattle. I. Growth to 24 months

Abstract

1. Eighteen pairs of one-egg and 6 pairs of two-egg twin calves were used in a balanced incomplete block design to examine four systems of rearing: (1) a continuous high plane of nutrition from birth to first calving (HH); (2) a high plane for the first 44 weeks followed by a low plane until 2 months before calving (HL); (3) a continuous low plane until 2 months before calving (LL); and (4) a low plane to 44 weeks followed by a high plane to first calving (LH). All animals were fed on a high plane during the two months before calving. 2. Mean daily consumptions of DM, TDN, S.E. and DCP are given and the net energy intakes compared with a recently recommended standard. 3. At 44, 80 and 104 weeks of age there were highly significant differences between the groups in all weights and measurements due to treatment. Low-plane feeding retarded the growth of the skeleton to only a limited extent as compared with live-weight. After the changeover, animals on the HL system lost much of the advantage in body measurements they had gained over those fed on a continuous low plane. 4. All groups reached sexual maturity at the same stage of physical development but at different ages. The HL animals were the slowest to attain maturity indicating that as with growth the changeover from a high plane to a low plane of nutrition had had an adverse effect. 5. Low-plane animals on poor hill pasture made better growth than their mates on good arable pasture. Evidence is presented, however, to show that part of this greater growth in live-weight was due to increased ‘fill’.