Rumen-Protected Fat and Rumen-Protected Choline Co-Supplementation: Impacts on Performance and Meat Quality of Growing Lambs

TL;DR

Adding protected fat and choline to lamb feed boosts feed intake and improves meat fat content, enhancing both productivity and meat quality.

Contribution

This study shows that co-supplementing rumen-protected fat and choline improves lamb feed intake and meat fatty acid profiles.

Findings

RPFC co-supplementation increased dry matter intake by 5.3% compared to RPF alone.

RPFC increased C16:1 fatty acid levels in lamb meat while reducing harmful C18:2n-6t levels.

RPFC improved meat color and lipid metabolism markers like HDL and total cholesterol.

Abstract

Choline enhances energy utilization and redirects fatty acids toward beneficial pathways. This study investigated the effects of supplementing growing lambs with rumen-protected fat and rumen-protected choline on performance and meat quality. Co-supplementation increased feed intake and elevated levels of the C16:1 fatty acid in lamb meat. These changes were linked to the role of choline in regulating lipid metabolism, which highlights that RPF and RPC co-supplementation improve both productivity and nutritional value in lamb production.

This study aimed to assess the effect of co-supplementing rumen-protected fat and rumen-protected choline on growth performance, carcass traits, and meat quality in lambs. Using a randomized experimental design, 45 weaned female Tian×Hu crossbred lambs (3 months old; average body weight: 27.34 ± 0.57 kg, mean ± SD) were randomly allocated to one of three dietary treatment groups. The three dietary treatments were as follows: a basal diet group (CON), a group receiving 2% rumen-protected fat in place of 2% barley (RPF), and a group supplemented with 2% rumen-protected fat and 0.4% rumen-protected choline, replacing 2% barley and 0.4% corn germ in the basal diet (RPFC). Compared to the CON group, neither the RPF nor RPFC treatments resulted in significant differences in growth performance (p > 0.05). However, the RPFC group showed a 5.3% increase in dry matter intake (DMI) compared to the RPF group (p < 0.05). Compared with the CON, the RPF treatment increased 69.23% the relative abundance of C18:2n-6t (p < 0.05), but the content of C17:0, C17:1, C18:1n-9c, and iso-C18:0 in Longissimus lumborum was decreased by 16.49%, 15.78%, 6.45% and 27.78%, respectively (p < 0.05). The RPFC treatment increased the relative abundance of C16:1 in Longissimus lumborum (p < 0.05). The RPF and RPFC treatments significantly increased serum levels of high-density lipoprotein (HDL) and total cholesterol compared to the CON group (p < 0.05). The RPF treatment raised HDL by 50.00% and total cholesterol by 38.03%, while the RPFC treatment increased HDL by 39.47% and total cholesterol by 26.03%. Furthermore, compared to the RPF group, the RPFC treatment led to a 13.47% increase in the 45 min b* color value of the Longissimus lumborum (p < 0.01) and a significant 45.45% reduction in the relative abundance of C18:2n-6t fatty acid in the same muscle (p < 0.05). In summary, rumen-protected choline reduces the negative effects of rumen-protected fat on feed intake in lambs and changes fatty acid profile in meat.