Increasing Doses of DHA and EPA on Fetal Programming, Effect on Performance and Plasma Metabolites of Finishing Lambs

Feeding omega-3 (n-3) long chain fatty acids (LCFA) during late gestation may have fetal programming effects on the fetus, which will have lifelong impacts on development and production. The present study is the finishing trial of a fetal programming study. The objectives were to determine the effects of supplementing ewes with different doses of the n-3 LCFA eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) on lamb performance and metabolism. Ewes (n=72) were blocked by BW and allotted to pens (8 per treatment) with 3 ewes per pen. Ewes were supplemented with an EPA and DHA source (Strata G112) at concentrations of 0, 1 or 2% of DM during the last 50d of gestation. At lambing, all ewes were penned together and offered the same diet. After weaning at 60d of age, lambs were blocked by BW and sex and fed for 56d. All lambs were fed the same pellet diet (61% ground corn, 24% soyhulls, 11% soybean meal, 1.4% of Ca salt of palm oil and 2.6% of a mixed mineral vitamin), and were weighed and bled every 14 days until the end of the trial. Dry matter intake and refusals were weighed daily. Data were analyzed as a randomized complete block design with repeated measurements (SAS 9.4). Polynomial contrast (linear-L and quadratic-Q) was used for mean separation. There was no time by treatment interaction (P>0.17) for any variable. Feeding pregnant ewes an increased amount of EPA and DHA increased BW (L, P=0.01), ADG (L, P=0.04; Q, P=0.01), DMI (Q, P≤0.01) and plasma glucose concentration (L, P=0.04) but did not affect G: F nor plasma NEFA concentration (P≥0.53) (Table 1). Therefore, increasing supplementation of EPA and DHA in pregnant ewes has an impact on offspring performance increasing DMI, ADG and BW.

Table 1: Performance, plasma glucose, and NEFA concentration of lambs born from ewes supplemented with 0, 1 or 2% of an EPA and DHA enriched source during the last 50d of gestation.

	Treatments			SEM	P values
	0%	1%	2%		L	Q
Final BW, kg	49.2	49.6	52.6	1.03	<0.01	0.08
ADG, kg	0.42	0.41	0.46	0.02	0.04	0.01
DMI, kg	1.27	1.13	1.27	0.14	0.94	<0.01
G:F	0.328	0.343	0.344	0.07	0.56	0.53
Glucose	102.78	104.74	107.21	5.94	0.04	0.83
NEFA	210.63	212.22	218.87	59.51	0.70	0.80