Impact of Dietary Fatty Acids on Oocyte Quality and Development in Lactating Dairy Cows1

Abstract

The purpose of this study was to examine the effects of level of rumen inert fatty acids on developmental competence of oocytes in lactating dairy cows. Estrous cycles were synchronized in 22 cows on a silage-based diet supplemented with either low (200 g/day) or high (800 g/day) fat. A total of 1051 oocytes were collected by ultrasound-guided ovum pickup (OPU) in seven sessions/cow at 3-4 day intervals. Oocytes were matured, fertilized, and cultured to the blastocyst stage in vitro. Embryo quality was assessed by differential staining of Day 8 blastocysts. The high-fat diet reduced numbers of small and medium follicles. There was no effect on the quality of oocytes (grades 1-4) or cleavage rate. However, high fat significantly improved blastocyst production from matured (P < 0.005) and cleaved (P < 0.05) oocytes. Blastocysts from the high-fat group had significantly more total, inner cell mass and trophectoderm cells than the low-fat group (P < 0.05). Regression analysis showed negative effects of milk yield (P < 0.001), dry matter intake (P < 0.001), metabolizable energy intake (P < 0.005), and starch intake (P < 0.001) on blastocyst production in the low-fat group but not in the high-fat group. Within the low-fat group, blastocyst production was negatively related to growth hormone (P < 0.05) and positively related to leptin (P < 0.05). The low-fat group had higher nonesterified fatty acids than the high-fat group (P < 0.05). In conclusion, higher milk yields were associated with reduced developmental potential of oocytes in cows given a low-fat diet. Provision of a high-fat diet buffered oocytes against these effects, resulting in significantly improved developmental potential.

Follicular dynamics and production of oocytes in young Nellore heifers with energetic supplementation

“…Regarding the effects of feed supplementation on oocyte quality, the literature data are controversial. Many of the studies indicate that increasing the amount of energy in diets for beef and dairy cows and heifers produces deleterious effects on oocyte competence and embryo quality (Armstrong et al, 2001;McCaffery et al, 2000;Nolan et al, 1998;Freret et al, 2006); other studies have shown beneficial effects of supplementation and fat (Fouladi-Nashta et al, 2007). However, most studies disregard the effects of the initial body condition of the animals or their overconditioning as for the response of the yield and quality of oocytes and embryos.…”

Nutritional sub-fertility in the dairy cow: towards improved reproductive management through a better biological understanding

“…Gong et al (2002) found, at equal levels of milk production and energy balance, that the increased insulin from a glucogenic diet significantly increased the proportion of cows ovulating at 50 days postpartum. However, there is also evidence that high concentration of blood insulin has negative effects on oocyte quality (Fouladi-Nashta et al, 2005). These observations led to the proposal of a strategy of glucogenic feeding to give a high insulin level and thereby reduce the length of the postpartum anoestrus, followed by more lipogenic feeding to lower insulin levels and improve oocyte developmental quality (Garnsworthy et al, 2008c).…”

“…In this context, dietary fat supplementation increases the size and estradiol secreting capacity of pre-ovulatory follicles and provides the substrates for enhanced progesterone secretion (Leroy et al, 2008b). Lipogenic diets may reduce insulin (Garnsworthy et al, 2008b) as well as improving blastocyst development rate (Fouladi-Nashta et al, 2007). Using synchronised multiparous Holstein cows (n 5 30), Garnsworthy et al (2008a) showed that glucogenic diets tended to be detrimental for oocyte quality.…”

The effect of nutrition and metabolic status on the development of follicles, oocytes and embryos in ruminants

“…Moreover, in these animals, there was an increase in the proportion of long-chain fatty acids in the plasma and cumulus cells (Zeron et al, 2002). In dairy cows, another study has shown that a diet enriched in a mixture of saturated and unsaturated fats affected oocyte development and maturation (Fouladi-Nashta et al, 2007). The two fatty acids linoleic acid (LA) and linolenic acid (ALA) are both found in the plasma and follicular fluid of cows (Childs et al, 2008), and it has been reported that supplementation of bovine oocytes with ALA during IVM resulted in an increased maturation rate, a higher yield of blastocysts and the production of better-quality blastocysts (Marei et al, 2009).…”