Effects of Palm Kernel Cake on Nutrient Utilization and Performance in Confined Cattle, Sheep and Goats: A Comparative Meta-Analytical Approach.

This meta-analysis explored the relationship of palm kernel cake inclusion level (PKC) with nutrient utilization and performance in cattle, goats and sheep under confinement. For this purpose, a dataset with 51 studies was constructed by using the PRISMA (Preferred Reporting Items for Systematic Review and Meta-Analysis) Protocol. Relationships of PKC with dry matter (DM), crude protein (CP), EE (ether extract), NDF (neutral detergent fiber) and TDN (total digestible nutrients) intake and digestibility, as well as with ADG (average daily gain) and FE (feed efficiency), were explored under a mixed model approach, considering the species and study as fixed and random effects, respectively. Data revealed independent ( < 0.075) relationships of EE and TDN intake and digestibility with PKC for cattle, goats and sheep. However, the relationship of CP intake and digestibility with PKC did not differ ( > 0.114) between ruminant species. Goats and sheep demonstrated similar quantitative patterns for DM and NDF intake but different quantitative patterns ( < 0.037) from those observed for cattle with the increase in PKC in the diet. Regarding performance, FE responses were similar between cattle and sheep but differed ( < 0.001) from those observed for goats; however, ADG demonstrated similar ( = 0.243) decreasing rates among ruminant species in function of dietary PKC. In conclusion, PKC has differential effects on the intake and digestibility of DM and most of the nutritional components in confined cattle, goats and sheep, except for CP. The data reported herein could be used in future nutritional models to allow for the better use of alternative feedstuffs, such as PKC in productive ruminants under confinement.