Effects of Glycerol-Producing Yeast Supplementation on Production Performance, Biochemical Indexes, Subclinical Ketosis Incidence and Rumen Fermentation Performance of Dairy Cows

Research Article

Int J Nutr Sci. 2021; 6(1): 1049.

Effects of Glycerol-Producing Yeast Supplementation on Production Performance, Biochemical Indexes, Subclinical Ketosis Incidence and Rumen Fermentation Performance of Dairy Cows

Mao X1,2, Fu C1,2, Liu K1,2, Li H1,2, Malyar RM1,2, Li B1,2, Pan C1,2, Gan F1,2, Huang K1,2 and Chen X1,2*

¹College of Veterinary Medicine, Nanjing Agricultural University, China

²Institute of Nutritional and Metabolic Disorders in Domestic Animals and Fowls, Nanjing Agricultural University, China

*Corresponding author: Xingxiang Chen, College of Veterinary Medicine, Nanjing Agricultural University; Institute of Nutritional and Metabolic Disorders in Domestic Animals and Fowls, Nanjing Agricultural University, Nanjing 210095, China

Received: March 13, 2021; Accepted: April 10, 2021; Published: April 17, 2021


Glycerol could be used to alleviate negative energy balance in highproducing dairy cows as an important precursor participating of glucose synthesis. However, some industrial glycerol may do harm to cow health because of some mixed toxic chemicals. The purpose of this study was to investigate the effects of glycerol-producing yeast prepared in our laboratory on improving the production performance and reducing the subclinical ketosis incidence of transition dairy cows. The results showed that the concentrations of the β-Hydroxybutyric Acid (BHBA) and Non-Esterified Fatty Acid (NEFA) in the groups with glycerol-producing yeast were significantly decreased (P<0.05), while the concentrations of glucose, TP and the production of propionic acid were significantly increased (P<0.05) compared with the control groups on the 21st day. Moreover, the glycerol-producing yeast improved the milk quality by significantly increasing the rate of milk protein and milk fat (P<0.05). Rumen fermentation performance was improved by supplementation of glycerol-producing yeast with significant increase in propionic acid and Microbial Crude Protein (MCP) concentrations (P<0.05). Meanwhile, supplementation of glycerol-producing yeast reduced the incidence of subclinical ketosis by improving the blood glucose and NEFA concentration and decreasing the concentration of BHBA. In conclusion, glycerol-producing yeast supplementation benefits dairy cows on their production performance, some biochemical indexes, subclinical ketosis incidence and rumen fermentation performance. This study provided some supportive data for the application of glycerol-production yeast supplementation in dairy production.

Keywords: Glycerol-producing yeast; Dairy cows; Production performance; Biochemical indexes; Subclinical ketosis incidence


Dairy cows increase energy intake during lactation after delivery. However, Due to slow recovery of postpartum appetite, dry matter intake may be reduced [1]. Therefore, cows tend to have negative energy balance during perinatal period, where energy intake cannot meet energy demand. When cows are in negative energy balance, the body moves body fat to make up for the lack of energy [2]. Whereas excessive fat mobilization can lead to metabolic disorders in animals, leading to a range of energy metabolism disorders, especially clinical and subclinical ketosis. Compared with clinical ketones, subclinical ketones have no significant symptoms, but may reduce milk production, increase the incidence of other perinatal disease, causing serious economic losses [3-5].

Glycerol plays an important role in glucose metabolism and it is an important precursor to glucose synthesis, which can effectively alleviate the energy metabolism problem and prevent the occurrence of ketosis [6,7]. Adding glycerol to diet can improve the performance of dairy cows [8-10]. On the other hand, It is reported that glycerol can be absorbed by the gastrointestinal tract, into the glucose generation pathway to synthesize glucose, which better regulates the blood glucose and insulin levels of the ruminants [11-13]. In recent years, industrial glycerol has been widely used as feed additive [14]. However, industrial glycerol is mixed with a large number of harmful substances that can have a negative impact on animal health and food safety issuers. Fermented glycerol is produced by microorganisms made from sugar, starch, or agricultural by-products. Compared with industrial glycerol, fermented glycerol can reduce production cost and has a broad prospect in the breeding of ruminant animals [15].

In our laboratory, we used yeast to produce glycerol and obtained glycerol-producing yeast supplementation. In this study, we assessed the effects of glycerol-producing yeast on the production performance, blood biochemical indexes, incidence of subclinical ketosis and rumen fermentation performance of dairy Holstein cows.

Materials and Methods

Animals and management

All animal experiments complied with the ARRIVE guidelines and were carried out in accordance with the U.K. Animals (Scientific Procedures) Act, 1986 and associated guidelines, EU Directive 2010/63/EU for animal experiments. Twenty female Holstein cows were fed in double row with tail tether and free access to water. TMR basic diet (Table 1) was used in the experiment, which was fed three times a day and fixed column and fixed position. Cows averaged calves 2.1 ± 0.13, body condition score 3.27 ± 0.63, total amount of lactation in the last cycle (305 days) 9961 ± 103.12 kg at the beginning of the study. In order to evaluate the overall effect of glycerol producing yeast preparation, twenty cows were randomly divided into two groups. The experimental period was 21 days. The control group was fed with basic diet, and each cow in the test group was fed with 1 L of glycerol-producing yeast supplementation (containing 108.2 g/L of glycerol, and 2.8×109 CFU/mL of viable yeast) every day.