Effects of Feeding Dry Glycerin to Early Postpartum Holstein Dairy Cows on Lactational Performance and Metabolic Profiles

Abstract

Effects of feeding a dry glycerin product (minimal 65% of food grade glycerol, dry powder) to 39 multiparous Holstein dairy cows (19 control and 20 glycerin-supplemented; lactation number = 2.2 +/- 1.3 SD) on feed intake, milk yield and composition, and blood metabolic profiles were investigated. Dry glycerin was fed at 250 g/d as a top dressing (corresponding to 162.5 g of glycerol/d) to the common lactating total mixed ration from parturition to 21 d postpartum. Individual milk was sampled from 2 consecutive milkings weekly and analyzed for components. Blood was sampled from the coccygeal vein at 4, 7, 14, and 21 (+/-0.92, pooled SD) d in milk and analyzed for urea nitrogen, glucose, insulin, nonesterified fatty acids, and beta-hydroxybutyrate. Urine was tested for the acetoacetate level weekly by using Ketostix. Average feed intake, milk yield and components, blood metabolites, and serum insulin concentrations were not affected by dry glycerin supplementation. Glycerin-supplemented cows experienced a more positive energy status (higher concentrations of plasma glucose, lower concentrations of plasma beta-hydroxybutyrate, and lower concentrations of urine ketones), which was observed during the second week of lactation, suggesting that energy availability may have been improved. This glucogenic effect of dry glycerin did not result in an increase in feed intake or milk yield during the first 3 wk of lactation, likely because of the relatively less negative energy status of cows transitioning into lactation. The tendency toward higher milk yield for glycerin-supplemented cows during wk 6 of lactation (52 vs. 46 kg/d) after the supplementation period (dry glycerin was terminated at wk 3 of lactation) suggested a potential benefit of dry glycerin on subsequent milk production, perhaps through changes in metabolism, which requires further investigation.

Crude glycerin in supplement to primiparous lactating cows grazing on tropical pasture: nutritional and productive characteristics

“…The lack of effects of adding glycerol to the total dry matter intake (TDMI) is consistent with other findings of research conducted in feedlot (DeFrain et al, 2004;Chung et al, 2007;Donkin et al, 2009;Wang et al, 2009). However, our findings were in contrast with the studies of Fisher et al (1971), who reported that glycerol stimulated consumption when the animals were fed 472 g/day in the concentrate, and Ogborn (2006), who stated that this trialcool has a depressive effect on consumption.…”

“…found that milk composition was not affected by the addition of glycerol at 150 g/kg of diet DM. Therefore, the lower milk fat content in the diet with the addition of glycerol is consistent with DeFrain et al (2004) and Chung et al (2007), who reported a lower production of milk fat when animals were fed glycerol.…”

“…The decreasing effect of the DeFrain et al (2004), is probably due to the effect of gliconeogenic glycerol that increases energy intake thereby reducing the excretion of nitrogen as urea in milk. However, other studies have found no effect of glycerol on MUN (Ogborn, 2006;Chung et al, 2007). Milk urea nitrogen was found at an average of 15.67 mg/dL for production of 13.9 kg milk/day, which is above the value found by Lucci et al (2006) of 14.15 mg/dL for the treatment that completely met the requirements of crude protein, but the production was 12.4 kg milk/day.…”

“…Donkin et al (2009) suggest that changes in energy efficiency may be due to direct effects on rumen fermentation of glycerol metabolism. Studies with postpartum cows receiving glycerol in the diet (Chung et al, 2007) or water (Osborne et al, 2009) reported reductions in plasma betahidroxibutirate levels. These results suggest a metabolic change to reduce the oxidation of fatty acids to ketones or increase the use of ketones by extrahepatic tissues when the animals are fed glycerol.…”

“…There were no differences between treatments (P>0.05) for milk production (MP) and feed conversion (FC) ( Table 7). Several studies in the literature found no significant differences for MP (Chung et al, 2007;Donkin et al, 2009;Wang et al, 2009;Rico et al, 2012;Shin et al, 2012). However, Boyd et al (2009) evaluated the response of adding glycerol (none, 200 and 400 g) in the diets of lactating cows and found a drop in milk production.…”