Effects of Addition of Exogenous Fibrolytic Enzymes on Digestibility and Milk and Meat Production – A Systematic Review

Abstract

Exogenous fibrolytic enzymes (EFE) added to the ruminant diet can increase fiber digestibility and production efficiency. A systematic review was conducted to understand the interactions between EFE and diet on digestibility and animal performance. The database included variables from 384 experiments with EFE and 264 controls from 85 papers published since 2000 (classification criteria: 1) type of study (in vitro, in situ, in vivo), 2) type of ruminants (sheep, Buffaloes, goats, beef and dairy cattle), 3) primary EFE activity (Cellulases (Cel) or Xylanases (Xyl)), 4) forage proportion (FP), 5) type of plant (TP: legumes or grasses), 6) number of ingredients in diets, and 7) application time (AT)). In over of 52.85% of cases, EFE improved the degradability of dry matter (DMD), neutral and acid detergent fiber (NDFD and ADFD), in vitro gas production (GP), volatile fatty acids (VFA), the acetate: propionate ratio (A:P ratio), protein and fat milk, milk yield and average daily gain (ADG) (by 7.78–21.85%). Cel improved organic matter degradability (OMD), GP, VFA, milk yield, and milk protein and fat content. EFE in FP≥40% diets enhanced the ADG, and in grass-based diets increased the dry matter intake (DMI). The AT of EFE affected the DMD, NDFD, and ADFD. Significant correlations were found between the improvements of NDFD or ADFD with DMD (r>0.59), milk yield (r=0.64), and ADG (r=0.59). In conclusion, many factors interact with EFE supplementation effects, but EFE consistently enhanced the DMD, NDFD, and ADFD of ruminant diets, which are related to improvements in productive performance.

Improvement of Ruminal Neutral Detergent Fiber Degradability by Obtaining and Using Exogenous Fibrolytic Enzymes from White-Rot Fungi

“…However, sometimes, adding EFEs does not have positive effects on DMD, NDFD [ 74 ] or DM intake [ 70 ]; milk production [ 13 ]; or ADG. Consistent results have been documented in meta-analyses, such as the improvement of milk production and composition; FC; and ADG [ 15 , 16 , 17 ].…”

“…The use of cellulases [ 63 ], xylanases [ 64 ], ferulic acid esterases [ 65 ], and combinations of cellulase and xylanase [ 63 ] may improve the in vitro digestibility of DM (IVDMD) and IVNDFD. However, the effects of EFEs are primarily related to factors such as the cellulase-to-xylanase ratio; the type and doses of EFE; the types of ruminants, plants (legumes or grasses), or studies (in vivo, in situ, or in vitro); the ingredients of the diets; and the forage-to-concentrate ratios [ 16 , 17 , 30 , 63 ].…”

“…The removal of lignin and/or hemicellulose is the first step to exposing the cellulose to an attack by cellulolytic enzymes in order to release glucose, due to the hydrolysis of the polysaccharide fraction of NDF to fermentable sugars. Although, the effects of including cellulases and xylanases on ruminant performance are highly variable, due to many external factors [ 13 , 14 , 15 , 16 , 17 ], some enzyme mixtures and doses, under particular ruminal conditions, can promote optimal hydrolysis of cell walls’ components to release sugars; moreover, they can improve milk yield and quality, as well as average daily gain (ADG) [ 14 , 15 , 16 , 17 , 18 ].…”

Expression of Genes Encoding Selected Orexigenic and Anorexigenic Peptides and Their Receptors in the Organs of the Gastrointestinal Tract of Calves and Adult Domestic Cattle (Bos taurus taurus)

“…In livestock animals, such as domestic cattle, optimal nutrition and consistent weight gain are important factors. These not only impact production efficiency, but further influence the health, longevity, and quality of products such as meat and dairy [ 15 , 16 ]. With such implications, studies on feed intake regulation and related genes are highly valuable [ 17 , 18 ].…”

Effects of yeast and exogenous fibrolytic enzyme inclusion in the diet of hair lambs on performance, carcass traits, physicochemical parameters and meat fatty acid profile

“…Furthermore, the addition of EFEs can increase meat tenderness, as well as protein and essential amino acid contents (Zhou et al, 2023). Tirado-González et al (2021) applied EFE dietary supplementation and observed alterations in the fat composition of meat, notably, reduced saturated fatty acids (SFA) and increased polyunsaturated fatty acids (PUFA) contents. Nevertheless, the administra-tion of yeast and EFE as feed additives for ruminant animals is contingent on factors such as the dosage, diet composition, and method of incorporation, necessitating consideration of these aspects to achieve the goal of producing higher-quality meat (Amin and Mao, 2021).…”