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Pre-pubertal measurements of the somatotrophic axis as predictors of milk production in Holstein-Friesian dairy cows.
Domest Anim Endocrinol 2006; 31(1):1-18DA

Abstract

This study investigated possible relationships between measurements of the somatotrophic axis in pre-pubertal dairy calves and subsequent milk yields. Endogenous growth hormone (GH) release was measured through a fed and fasted period in fifty 6-month-old Holstein-Friesian heifers and they were then challenged with growth hormone-releasing factor (GRF) to assess their GH release pattern. Insulin-like growth factor-I (IGF-I), insulin and glucose concentrations were measured in relation to time of feeding. Cows were subsequently monitored through their first three lactations to record peak and 305-day milk yields. In the first lactation, milk energy output for the first 120 days of lactation was also calculated. The mean 305-day milk yield increased from 7417 +/- 191 kg in the first lactation (n=37) to 8749 +/- 252 kg in the third (n=25). There were no significant relationships between any measures of GH secretion and peak or 305-day yield in any lactation. A highly significant positive relationship was established between the GH peak measured 10 min post-GRF challenge and 120-day milk energy values in the first lactation. This relationship was, however, only present in the sub-population of 12 cows culled after one or two lactations and was absent in the 25 animals remaining for the third lactation. There were no significant relationships between pre-pubertal IGF-I and fed or fasted insulin or glucose concentrations and any subsequent measurement of yield. The usefulness of GH secretagogue challenges in calves as a predictive test for future milk production is thus limited but may have some bearing on nutrient partitioning and longevity.

Authors+Show Affiliations

Reproduction and Development Group, Royal Veterinary College, Hawkshead Lane, Hatfield, Hertfordshire AL9 7TA, UK. v.taylor@imperial.ac.ukNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

16219444

Citation

Taylor, V J., et al. "Pre-pubertal Measurements of the Somatotrophic Axis as Predictors of Milk Production in Holstein-Friesian Dairy Cows." Domestic Animal Endocrinology, vol. 31, no. 1, 2006, pp. 1-18.
Taylor VJ, Beever DE, Bryant MJ, et al. Pre-pubertal measurements of the somatotrophic axis as predictors of milk production in Holstein-Friesian dairy cows. Domest Anim Endocrinol. 2006;31(1):1-18.
Taylor, V. J., Beever, D. E., Bryant, M. J., & Wathes, D. C. (2006). Pre-pubertal measurements of the somatotrophic axis as predictors of milk production in Holstein-Friesian dairy cows. Domestic Animal Endocrinology, 31(1), pp. 1-18.
Taylor VJ, et al. Pre-pubertal Measurements of the Somatotrophic Axis as Predictors of Milk Production in Holstein-Friesian Dairy Cows. Domest Anim Endocrinol. 2006;31(1):1-18. PubMed PMID: 16219444.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Pre-pubertal measurements of the somatotrophic axis as predictors of milk production in Holstein-Friesian dairy cows. AU - Taylor,V J, AU - Beever,D E, AU - Bryant,M J, AU - Wathes,D C, Y1 - 2005/09/12/ PY - 2005/01/05/received PY - 2005/07/27/revised PY - 2005/08/15/accepted PY - 2005/10/13/pubmed PY - 2006/8/4/medline PY - 2005/10/13/entrez SP - 1 EP - 18 JF - Domestic animal endocrinology JO - Domest. Anim. Endocrinol. VL - 31 IS - 1 N2 - This study investigated possible relationships between measurements of the somatotrophic axis in pre-pubertal dairy calves and subsequent milk yields. Endogenous growth hormone (GH) release was measured through a fed and fasted period in fifty 6-month-old Holstein-Friesian heifers and they were then challenged with growth hormone-releasing factor (GRF) to assess their GH release pattern. Insulin-like growth factor-I (IGF-I), insulin and glucose concentrations were measured in relation to time of feeding. Cows were subsequently monitored through their first three lactations to record peak and 305-day milk yields. In the first lactation, milk energy output for the first 120 days of lactation was also calculated. The mean 305-day milk yield increased from 7417 +/- 191 kg in the first lactation (n=37) to 8749 +/- 252 kg in the third (n=25). There were no significant relationships between any measures of GH secretion and peak or 305-day yield in any lactation. A highly significant positive relationship was established between the GH peak measured 10 min post-GRF challenge and 120-day milk energy values in the first lactation. This relationship was, however, only present in the sub-population of 12 cows culled after one or two lactations and was absent in the 25 animals remaining for the third lactation. There were no significant relationships between pre-pubertal IGF-I and fed or fasted insulin or glucose concentrations and any subsequent measurement of yield. The usefulness of GH secretagogue challenges in calves as a predictive test for future milk production is thus limited but may have some bearing on nutrient partitioning and longevity. SN - 0739-7240 UR - https://www.unboundmedicine.com/medline/citation/16219444/Pre_pubertal_measurements_of_the_somatotrophic_axis_as_predictors_of_milk_production_in_Holstein_Friesian_dairy_cows_ L2 - https://linkinghub.elsevier.com/retrieve/pii/S0739-7240(05)00180-3 DB - PRIME DP - Unbound Medicine ER -