Enriched Conjugated Linoleic Acid (CLA) content in goat milk production by Lactobacillus plantarum dietary supplementation

Abstract

The objectives of this study were to determine the effect of Lactobacillus plantarum (L. plantarum) in rumen fermentation using in vitro gas production test parameters, pH, NH3 concentration, total VFA, individual VFA, degradability, and microbial mass yield (MBY) and to examine the effect of L. plantarum supplementation on goat milk production, milk composition, fatty acid profile and CLA content in goat milk. The in vitro gas production kinetics and rumen fermentation products were conducted using total mixed ration (TMR) supplemented with different concentrations of L. plantarum supplementation using rumen liquor from Thai native cattle. The experiment design was Completely Randomized Design (CRD). The in vitro procedure was completed using 200 mg DM of TMR from four different concentrations of L. plantarum; CON (without supplementation of L. plantarum), T1 (107 CFU.mL-1 of L. plantarum supplementation), T2 (108 CFU.mL-1) of L. plantarum supplementation), and T3 (109 CFU.mL-1 of L. plantarum supplementation). The samples were prepared in three replications and incubated for 96 hours for gas production. The in vitro rumen degradation experiment was done in four replications and incubated for 24 hours. In vitro gas production for 96 hours and gas production from insoluble fraction were improved in the T1 and T2 groups (P < 0.05). The in vitro dry matter and organic matter degradability, and true degradability were particularly enhanced in the T1 group compared to other treatments (P <0.05). The pH and NH3 in this study were significantly affected (P <0.05) with the T3 group producing the highest ammonia concentration and pH among other treatments. While individual VFA is not affected by the treatments, the total VFA concentration is affected by L. plantarum with T3 generating higher total VFA than other treatments. Additionally, the supplementation of L. plantarum lowered the A:P ratio in the higher-level supplementation group than the group without supplementation. Subsequently, the in vivo experiment was conducted using a randomized block design (RCBD) with the number of days in milk and milk yield serving as the blocking factors. Fifteen multiparous lactating Saanen goats (BW 41.77 ± 0.44 kg) were collected from the herds. There were three groups of five animals each containing the animals. The groups consist of control with no supplementation of L. plantarum; LP6 = supplementation of 106 CFU head-1 L. plantarum; and LP7 = supplementation of 107 CFU head-1 L. plantarum. The data of milk yield, milk composition, milk fatty acid profile, and CLA were analyzed using repeated measures. Milk yield (g/d), FCE (kg MY/kg DMI), milk fat (%), milk composition yield (g/d), total PUFA (%), and CLA (%) were higher in the LP7 group compared to other groups. The CLA (%) in LP7 groups increased from 0.024% to 0.618% during the study period. The DMI (kg/d), milk lactose (%), protein (%), total solid (%), and solid non-fat (%) were not adversely affected by the supplementation of L. plantarum. The supplementation at 107 CFU.head-1 L. plantarum could improve in vitro substrate digestibility and rumen fermentation products as well as lactation performance, and increase milk fat yield, total PUFA, and CLA, without any negative effects on dry matter intake. This result displayed L. plantarum as a safe strain of direct-fed microbial and beneficial both for animal and human health. The investigation of gut microbiota diversity from the rumen to the large intestine could be considered in further research.