# Nanoemulsified Corn Oil in Lactating Barki Nutrition: Effect on Intake, Nutrient Digestibility, Rumen Fermentation Characteristics, and Microbial Population

## TL;DR

Nanoemulsified corn oil helps retain unsaturated fatty acids in sheep without harming digestion or rumen bacteria.

## Contribution

Nanoemulsified corn oil reduces biohydrogenation without affecting intake or rumen health in lactating sheep.

## Key findings

- Nanoemulsified corn oil (NCO) reduced biohydrogenation of fatty acids compared to raw corn oil.
- NCO increased rumen unsaturated fatty acid accumulation without altering microbial populations.
- NCO did not negatively impact dry matter intake or rumen fermentation patterns.

## Abstract

Incorporating poly-unsaturated fatty acids into diets is essential for enhancing the functional attributes of ruminant products (meat or milk). Oils have been a preferred option for that aim. However, innovative methods are needed to provide unsaturated fatty acid-rich oils to the rumen in a manner that is less harmful to rumen bacteria compared to the traditional raw supplementation. The following experiment intended to compare raw corn oil (CO) with nanoemulsified corn oil (NCO) administered at 3% of the dry matter fed to dairy sheep. Compared to Control and NCO, the CO reduced dry matter intake, ammonia, and total volatile fatty acid concentrations in the rumen. Nonetheless, NCO exerted a lesser influence on the biohydrogenation of fatty acid intermediates compared to CO. Increased accumulation of unsaturated fatty acids (UFA) occurred in the rumen when NCO was administered. The population of rumen microorganisms in the rumen remained mostly unaltered by NCO, particularly the biohydrogenation bacteria. In conclusion, feeding NCO circumvented the biohydrogenation process that typically converts unsaturated fatty acids into their saturated form. This enhancement was not accompanied by alterations in dry matter intake, nutrient digestion, or ruminal fermentation pattern.

Nanoemulsified corn oil was tested on twenty-one multiparous lactating Barki ewes (mean ± SD: 3 ± 0.4 parity, 44.3 ± 1.9 kg body weight, 30 ± 2.7 months of age, and 402 ± 23 g/d of prior milk production) randomly allocated to the following treatments (n = 7 ewes/group): Control—a basal diet consisting of 50% concentrate mixtures and 50% berseem clover; CO—the Control diet + 3% of corn oil; NCO—the Control diet + 3% of nanoemulsified corn oil. A completely randomized design of 25 days of adaptation and 5 days of sampling was employed with seven ewes per treatment. Despite feeding oil according to the recommended values, CO decreased the dry matter intake by 8.3% and 6.7% compared to the Control and NCO, respectively. The negative impact of CO extended to reducing the concentrations of ammonia and total volatile fatty acids in the rumen. On the other hand, NCO had less effect on the biohydrogenation intermediates profile compared to CO; noticeably, higher proportions of unsaturated fatty acid (UFA) were associated with NCO; these results were also supported by an increase in the rumen microbial population with NCO compared to CO, especially the biohydrogenation bacteria, which showed higher abundance with NCO despite the low presence of biohydrogenation intermediates. In conclusion, the NCO demonstrated the ability to decrease the transformation of unsaturated fatty acids into saturated fatty acids in the biohydrogenation environment. This effect was not associated with decreased dry matter intake, changes in nutrient digestibility, or alterations in fermentation patterns.