Dietary carbohydrates and amino acids influence oocyte quality in dairy heifers

Abstract

The objective of the present experiment was to determine whether increasing plasma insulin by different nutritional regimes affects oocyte quality. Holstein dairy heifers (eight per treatment) were assigned, using a two times two factorial design, to diets containing either low or high dietary leucine and either low or high dietary starch. Each heifer underwent six sessions of ovum pick-up beginning 25 days after introduction of the diets. Oocyte quality was assessed by development to the blastocyst stage in synthetic oviducal fluid following in vitro fertilisation. Feeding diets containing high leucine resulted in significantly higher plasma free leucine and tyrosine concentrations. The high-starch diet significantly increased plasma insulin but not glucagon concentration, whereas high dietary leucine increased plasma glucagon but not insulin. Oocyte cleavage was not influenced by diet. The high-starch diet, which was associated with a high plasma insulin : glucagon ratio, had adverse effects on oocyte quality that were avoided when leucine intake was increased. There was an association between total plasma free amino acid concentration and oocyte cleavage. Therefore, in dairy heifers dietary amino acids and carbohydrates during antral follicle development appear to mediate effects on oocyte quality by different mechanisms. These findings have implications for both diet formulation and feeding regimes.

Metabolic control of oocyte development: linking maternal nutrition and reproductive outcomes

“…In dairy heifers, it was shown that a high-starch diet had negative effects on oocyte developmental competence, and these were avoided when leucine intake was increased [193]. Crude protein overfeeding also compromises the subsequent capacity of bovine oocytes to develop to blastocysts, probably via direct toxic effects of elevated ammonia and urea concentration in the follicular environment [194, 195].…”

Heifer fertility and carry over consequences for life time production in dairy and beef cattle

“…A significant proportion of the moderately fat and overfed animals were hyperinsulinaemic. Rooke et al (2009) subsequently used a factorial design to alter insulin levels in dairy heifers. They found that a high-starch diet had adverse effects on oocyte quality which were associated with a high plasma insulin : glucagon ratio but that these were avoided when leucine intake was also increased.…”

Maternal control of oocyte quality in cattle “a review”

“…High-energy diets have also adverse effects on early embryonic development and these effects may be programmed even before fertilization, during the acquisition of oocyte developmental competence in the follicle (Rooke et al, 2009). In the high-yielding dairy cow, supplementary dietary carbohydrates can reduce the quality of oocytes and the development of embryos, resulting in fewer blastocyst cells and a lower rate of blastocyst production (Fouladi-Nashta et al, 2005).…”