The Effects of Differing Planes of Pre- and Post- Weaning Phase Nutrition on the Development of Holstein Heifer Calves

• Author / Creator

  Rosadiuk, Justin P.

• Pre- and post- weaning planes of nutrition offered to heifer calves raised on farm can significantly alter future profitability, both through reduced costs and increased animal performance. The objective of this research was to examine the effects of pre- and post- weaning diets, with differing levels of dietary energy, on intake, growth, select hormone and metabolite concentrations, and overall sexual development of Holstein heifer calves. In study 1, energy intake was greater for heifers offered the high plane of nutrition in both the pre- and post- weaning periods, while growth was greater in high plane heifers compared to low plane heifers in each phase, but not consistently. Concentrations of key hormones, including insulin, IGF-1 and leptin were affected by pre- and post- weaning diets, but no interactions between the two phases were detected. In study 2, LH pulse release parameters at 3 and 6 mo were not affected by pre- or post- weaning diets. The overall age and body weight at first ovulation, were also not affected by pre- or post- weaning diets, however, heifers offered the post-weaning high plane of nutrition were more likely to have attained puberty at 7 and 8 mo of age than low plane heifers. Also, heifers attaining puberty at ages less than 7 mo tended to have increased serum leptin concentrations in the first 6 mo of life. No interactions between pre- and post- weaning planes of nutrition were noted in study 2. Overall, these findings suggest that interactions between pre- and post- weaning planes of nutrition are limited before 6 mo of age and/or the attainment of puberty, given the parameters measured in this study. Additionally, this thesis provides information that can help enhance the understanding of relationships between levels of intake, growth, hormone and metabolite concentrations, and sexual development in heifer calves. These results are important in designing, implementing, and optimizing nutritional planes for heifer rearing.

• Subjects / Keywords

  • Plane of nutrition

• Graduation date

  Fall 2018

• Type of Item

  Thesis

• Degree

  Master of Science

• DOI

  https://doi.org/10.7939/R3FJ29V60

• License

  Permission is hereby granted to the University of Alberta Libraries to reproduce single copies of this thesis and to lend or sell such copies for private, scholarly or scientific research purposes only. Where the thesis is converted to, or otherwise made available in digital form, the University of Alberta will advise potential users of the thesis of these terms. The author reserves all other publication and other rights in association with the copyright in the thesis and, except as herein before provided, neither the thesis nor any substantial portion thereof may be printed or otherwise reproduced in any material form whatsoever without the author's prior written permission.