Lactobacillus plantarum as feed additive to improvement in vitro ruminal biofermentation and digestibility of some tropical tree leaves.

AIM: This study was performed to investigate the effects of Lactobacillus plantarum (LP) on the in vitro gas production (GP) kinetics and ruminal fermentation parameter of three species of tropical forage Ziziphus mauritiana, Acacia victoriae and Moringa oleifera. METHODS AND RESULTS: Treatments were (i) Z. mauritiana (Z) without LP (-ZLP), (ii) Z. mauritiana (Z) with LP (+ZLP), (iii) A. victoriae (A) without LP (-ALP), (4) A. victoriae (A) with LP (+ALP), (5) M. oleifera (M) without LP (-MLP) and (6) M. oleifera (M) with LP (+MLP). The LP was used at 0·5 Mcfarland (1·5 × 108 colony-forming unit per millilitre (CFU per ml)). Kinetic of GP (GP from the fermentable fraction [b], GP rate [c] and lag phase [L]) and GP were affected (P < 0·05) by plant species and LP. The highest value of b, c and GP were observed in +MLP treatment compared with other treatments. The lowest value of L was observed for the +ZLP treatment compared with other treatments. The GP and fermentation parameter included organic matter digestibility (OMD), metabolizable energy (ME) content, microbial CP (MCP) and truly degraded substrate (TDS) were affected by plant species and LP supplementation. The highest OMD, ME, TDS and MCP values were observed in +MLP treatment. At different incubation times, the highest amount of ammonia-N was observed in treatment +MLP compared with other treatments. Under the influence of experimental treatments (effect of plant species and LP), the highest concentrations of total volatile fatty acids, acetate and acetate to propionate ratio were observed in treatments +MLP, +ALP and +ALP, respectively. Concentrations of propionate, iso-butyrate, n-valerate and iso-valerate were affected by plant species, and the highest levels were observed in -ZLP, +MLP, -MLP and +MLP tretments, respectively. CONCLUSIONS: The use of LP as a microbial additive had a positive effect on the in vitro digestibility and ruminal fermentation of tannins-rich tropical plants. Results suggest that dietary LP inclusion could be an option to improve ruminant energy utilization efficiency of tannins-rich tropical plants. SIGNIFICANCE AND IMPACT OF THE STUDY: Regardless the effect of the forage species, the use of LP as a microbial additive improved GP and kinetics and also increased OMD, TDS, MCP and enhanced the total in vitro ruminal VFAs production.

Investigating the population structure and genetic diversity of Arabian horses in Oman using SNP markers.

Arabian horses were selected for metabolic efficiency, beauty, efficiency and endurance. Therefore, Bedouins have for centuries traced their prized horses' ancestries. With the establishment of the World Arabian Horse Organization (WAHO), registration of Arabian horses became centralized and countries worldwide registered them in its database. Most existing Arabian horses in Oman today were imported after the 1970s and are predominantly flat-racing Arabians. This work aimed at revealing the genetic background and diversity of Omani Arabian horses by comparing them with Arabian horses from a diverse genetic background. To that end, we genotyped 63 randomly sampled Arabian horses from Oman using the Illumina Equine SNP70. For comparison, SNP genotypes of 12 Saudi Arabian horses, 27 French, 77 Egyptian, 11 Polish and 36 US Arabians were included in the study. We additionally included 17 Thoroughbred horses and 21 horses representing large and small breeds as an outgroup. Our MDS analysis and phylogenetic analysis showed that the Arabian horses in Oman cluster primarily with French Arabian horses, with a few horses clustering within the Polish/US Arabians. The French Arabian horse cluster was the closest to the Thoroughbred horses. Amongst the Arabian horses, plink average genomic inbreeding levels were highest in the Egyptian Arabian (0.169) followed by the Saudi Arabian horses (0.137) and lowest in the Omani and French Arabian horses, -0.041 and -0.079 respectively. To our knowledge, this is the first report on the genetic background and diversity of Arabian horses in Oman. Our results demonstrated a definite subpopulation structure among Arabian horses and this information should advise future decision-making on Arabian horse breeding.