Palmitic acid increased yields of milk and milk fat and nutrient digestibility across production level of lactating cows

Abstract

The effects of palmitic acid supplementation on feed intake, digestibility, and metabolic and production responses were evaluated in dairy cows with a wide range of milk production (34.5 to 66.2 kg/d) in a crossover design experiment with a covariate period. Thirty-two multiparous Holstein cows (151 ± 66 d in milk) were randomly assigned to treatment sequence within level of milk production. Treatments were diets supplemented (2% of diet DM) with palmitic acid (PA; 99% C16:0) or control (SH; soyhulls). Treatment periods were 21 d, with the final 4 d used for data and sample collection. Immediately before the first treatment period, cows were fed the control diet for 21 d and baseline values were obtained for all variables (covariate period). Milk production measured during the covariate period (preliminary milk yield) was used as covariate. In general, no interactions were detected between treatment and preliminary milk yield for the response variables measured. The PA treatment increased milk fat percentage (3.40 vs. 3.29%) and yields of milk (46.0 vs. 44.9 kg/d), milk fat (1.53 vs. 1.45 kg/d), and 3.5% fat-corrected milk (44.6 vs. 42.9 kg/d), compared with SH. Concentrations and yields of protein and lactose were not affected by treatment. The PA treatment did not affect dry matter (DM) intake or body weight, tended to decrease body condition score (2.93 vs. 2.99), and increased feed efficiency (3.5% fat-corrected milk/DM intake; 1.60 vs. 1.54), compared with SH. The PA treatment increased total-tract digestibility of neutral detergent fiber (39.0 vs.35.7%) and organic matter (67.9 vs. 66.2%), but decreased fatty acid (FA) digestibility (61.2 vs. 71.3%). As total FA intake increased, total FA digestibility decreased (R(2) = 0.51) and total FA absorbed increased (quadratic R(2) = 0.82). Fatty acid yield response, calculated as the additional FA yield secreted in milk per unit of additional FA intake, was 11.7% for total FA and 16.5% for C16:0 plus cis-9 C16:1 FA. The PA treatment increased plasma concentration of nonesterified FA (101 vs. 90.0 μEq/L) and cholecystokinin (19.7 vs. 17.6 pmol/L), and tended to increase plasma concentration of insulin (10.7 vs. 9.57 μ IU/mL). Results show that palmitic acid fed at 2% of diet DM has the potential to increase yields of milk and milk fat, independent of production level without increasing body condition score or body weight. However, a small percentage of the supplemented FA was partitioned to milk.

Comparison of enriched palmitic acid and calcium salts of palm fatty acids distillate fat supplements on milk production and metabolic profiles of high-producing dairy cows

“…In our previous experiment, PA decreased intake relative to a no-fat control, but was not different from Ca-FA . In addition, although not measured in the current experiment, plasma concentrations of gut peptides such as glucagon-like peptide 1 and cholecystokinin are often increased by unsaturated compared with saturated FA supplements (Relling and Reynolds, 2007;Bradford et al, 2008), and cholecystokinin was increased by a highly enriched palmitic acid supplement relative to no fat supplementation (Piantoni et al, 2013).…”

“…Piantoni et al (2013) reported approximately a 10% increase in plasma NEFA concentration and a tendency for increased plasma insulin concentration, but no change in plasma triglyceride concentration when feeding a highly enriched palmitic acid supplement compared with a no-supplemental-fat control. Previous investigations of saturated fat supplements lower in C16:0 and higher in C18:0 reported increased insulin and decreased NEFA concentrations compared with unsaturated FA (Harvatine and Allen, 2005;Relling and Reynolds, 2007).…”

“…An SFA supplement enriched in palmitic acid has recently garnered interest Piantoni et al, 2013;, as mammary extraction efficiency of palmitic acid is greater than that of stearic acid (Enjalbert et al, 2000). However, the response to enriched palmitic acid supplements also has been vari-able, with increased milk fat yield observed in some, but not all, experiments (see .…”

“…no fat supplement: decreased DMI , increased DMI (Mosley et al, 2007), or no effect on DMI (Piantoni et al, 2013;. Dry matter intake tends to be lower when feeding unsaturated compared with saturated fat supplements (Pantoja et al, 1994;Harvatine and Allen, 2006a;Relling and Reynolds, 2007).…”

“…In contrast, high-palmitic acid supplements increased milk fat yield in several studies spanning over 4 decades (Steele and Moore, 1968;Enjalbert et al, 2000). Specifically, increasing intake of C16:0 within a range of 1.8 to 5.2% of DMI linearly increased milk fat yield and C16:0 incorporation into milk fat (Mosley et al, 2007) and recent experiments also reported increased milk fat concentration and yield (80 to 100 g/d; Lock et al, 2013;Piantoni et al, 2013). In agreement, in the present experiment, PA increased milk fat yield when fed at 1.9% of ration DM.…”