Hostname: page-component-586b7cd67f-r5fsc Total loading time: 0 Render date: 2024-11-26T20:22:23.304Z Has data issue: false hasContentIssue false

Pre-pubertal mammogenesis in the sheep 1. The effects of level of nutrition on growth and mammary development in female lambs

Published online by Cambridge University Press:  02 September 2010

I. D. Johnsson
Affiliation:
National Institute for Research in Dairying, Shinfield, Reading, Berkshire RG2 9AT
I. C. Hart
Affiliation:
National Institute for Research in Dairying, Shinfield, Reading, Berkshire RG2 9AT
Get access

Abstract

Female lambs were given a high energy and high protein diet in varying amounts to achieve either high (H; 220 g/day) or low (L; 110 g/day) rates of gain during two consecutive periods between 4 and 20 and 20 and 36 weeks of age. The effects on body growth and mammary gland development were compared by slaughtering an initial group of four lambs at 4 weeks of age (mean live weight 11 kg), eight L lambs (24 kg) and eight H lambs (33 kg) at 20 weeks of age, and eight LL lambs (36 kg), eight LH lambs (49 kg) and eight HL lambs (48 kg) at about 36 weeks of age.

At slaughter, a single mammary fat pad from each lamb was trimmed and weighed, and the deoxyribonucleic acid (DNA) content of the portion containing parenchyma determined. The mean weight (g) and DNA content (mg) were: 4-week-old lambs, 8·6 g, 1·5 mg; L, 14·7 g, 32·3 mg; H, 30·0 g, 25·9 mg; LL, 46·0 g, 61·2 mg; LH, 86·7 g, 91·0 mg; HL, 70·3 g, 73·0 mg respectively. Relative growth coefficients for mammary parenchyma, estimated from the increase in DNA relative to that for live weight, were 3·7 and 2·4 for L and H lambs respectively, between 4 and 20 weeks, and 1·6, 1·4 and 2·6 for LL, LH and HL lambs respectively, between 20 and 36 weeks of age.

These results are consistent with the hypothesis that a high plane of nutrition can decrease the rate of allometric growth of mammary parenchyma before puberty. However, the cessation of this growth phase was not related to the attainment of puberty, or of a specific live weight or age, but may be related to the availability of mammary fat pad tissue limiting further parenchymal development after 20 weeks of age.

Type
Research Article
Copyright
Copyright © British Society of Animal Science 1985

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Anderson, R. R. 1975. Mammary gland growth in sheep. J. Anim. Sci. 41: 118123.CrossRefGoogle ScholarPubMed
Black, J. L. 1974. Manipulation of body composition through nutrition. Proc. Aust. Soc. Anim. Prod. 10: 211218.Google Scholar
Burton, J. H. and Reid, J. T. 1969. Interrelationships among energy input, body size, age and body composition of sheep. J. Nutr. 97: 517524.CrossRefGoogle ScholarPubMed
Butler-Hogg, B. W. and Johnsson, I. D. 1986. Fat partitioning and tissue distribution in crossbred ewes following different growth paths. Anim. Prod. 42:6572.Google Scholar
Cowie, A. T. 1949. The relative growth of the mammary gland in normal, gonadectomized and adrenalectomized rats. J. Endocr. 6: 145157.CrossRefGoogle ScholarPubMed
Foldager, J. and Sejrsen, K. 1983. Milk production in dairy cows in relation to nutrition during rearing. 34th A. Meet. Study Commissions Eur. Ass. Anim. Prod., Madrid Paper C.5a.l.Google Scholar
Glencross, R. G. and Pope, G. S. 1981. Concentrations of oestradiol-17β and progesterone in the plasma of dairy heifers before and after clopostenol-induced and natural luteolysis and during early pregnancy. Anim. Reprod. Sci. 4: 93106.CrossRefGoogle Scholar
Gould, M. B. and Whiteman, J. V. 1975. Relationship between pre-weaning growth rate of female lambs and the growth of their offspring. J. Anim. Sci. 40: 585589.CrossRefGoogle Scholar
Harrison, R. D., Reynolds, I. P. and Little, W. 1983. A quantitative analysis of mammary glands of dairy heifers reared at different rates of live-weight gain. J. Dairy Res. 50: 405412.CrossRefGoogle ScholarPubMed
Johnsson, I. D. and Obst, J. M. 1984. The effects of level of nutrition before and after 8 months of age on subsequent milk and calf production of beef heifers over three lactations. Anim. Prod. 38: 5768.Google Scholar
Little, W. and Harrison, R. D. 1981. Effects of different rates of live-weight gain during rearing on the performance of Friesian heifers in their first lactation. Anim. Prod. 32: 362 (Abstr.).Google Scholar
Little, W. and Kay, R. M. 1979. The effects of rapid rearing and early calving on the subsequent performance of dairy heifers. Anim. Prod. 29: 131142.Google Scholar
Martin, R. F., Donohue, Diana C. and Finch, L. R. 1972. New analytical procedure for the estimation of DNA with p-nitrophenylhydrazine. Analyt. Biochem. 47: 562574.CrossRefGoogle ScholarPubMed
Martin, R. F. and Hodgson, G. S. 1973. Estimation of DNA, RNA and 125I- and 3H-labelled DNA in the same sample. Analyt. Biochem. 52: 462469.CrossRefGoogle Scholar
Murray, D. M. and Slezacek, Olga. 1976. Growth rate and its effect on empty body weight, carcass weight and dissected carcass composition of sheep. J. agric. Sci., Camb. 87: 171179.CrossRefGoogle Scholar
Reynolds, I. P. 1982. The impairment of lactation associated with rapid growth in Friesian heifers. Ph.D. Thesis, Univ. Reading.Google Scholar
Searle, T. W., Graham, N. McC. and Donnelly, J. B. 1982. The effect of plane of nutrition on the body composition of two breeds of weaner sheep fed a high protein diet. J. agric. Sci., Camb. 98: 241245.CrossRefGoogle Scholar
Sejrsen, K. 1978. Mammary development and milk yield in relation to growth rate in dairy and dual-purpose heifers. Ada Agric. scand. 28: 4146.CrossRefGoogle Scholar
Sejrsen, K., Huber, J. T. and Tucker, H. A. 1983. Influence of amount fed on hormone concentrations and their relationship to mammary growth in heifers. J. Dairy Sci. 66: 845855.CrossRefGoogle ScholarPubMed
Sejrsen, K., Huber, J. T., Tucker, H. A. and Akers, R. M. 1982. Influence of nutrition on mammary development in pre- and post-pubertal heifers. J. Dairy Sci. 65: 793800.CrossRefGoogle Scholar
Sinha, Y. N. and Tucker, H. A. 1969. Mammary development and pituitary prolactin level of heifers from birth through puberty and during the oestrus cycle. J. Dairy Sci. 52: 507512.CrossRefGoogle Scholar
Umberger, S. H. 1980. The effect of accelerated growth and fattening from early weaning to parturition on ewe reproduction and lactation. Ph.D. Thesis, North Carolina State Univ., Raleigh.Google Scholar
Wallace, C. 1953. Observations on mammary development in calves and lambs. J. agric. Sci., Camb. 43: 413421.CrossRefGoogle Scholar