Effect of concentrates level on digestibility, ruminal fermentation, and bacterial community in growing camels.

Understanding the rumen microbiota of camels under different feeding conditions is necessary to optimize rumen fermentation and productivity. This study aims to investigate the effects of different concentrate supplement levels on digestion, rumen fermentation and bacteria in growing camels. Fifteen growing camels were divided into three groups and were fed alfalfa hay in addition to one of the three concentrate supplement levels based on body weight (BW): low (0.7%), medium (1%), and high (1.3%). Increasing the concentrate supplement level in the diet increased total dry matter intake but had no effect on nutrients digestibility, except for crude protein digestibility, which was enhanced with the high concentrate level. Growing camels at low-level had considerably higher rumen pH than those fed medium or high levels. Increasing the supplement level also increased rumen propionic acid but decreased acetic acid concentration. Principal coordinate analysis showed that concentrate levels clearly separated the ruminal bacterial communities where Bacteroidetes and Firmicutes were the dominant phyla and Prevotella, Ruminococcus, Butyrivibrio, RC9_gut_group, and Fibrobacteres were the dominant bacterial genera. This study expands our knowledge regarding the rumen microbiota of growing camels under different concentrate levels and reveals that medium concentrate levels could be appropriate for growing camels.

Modulation of rumen bacterial community and feed utilization in camel and sheep using combined supplementation of live yeast and microalgae.

The combination of live yeast and microalgae as feed supplementation could improve rumen fermentation and animal productivity. This study aimed to investigate the impact of a mixture of (YA) yeast (Saccharomyces cerevisiae) and microalgae (Spirulina platensis and Chlorella vulgaris) as feed supplementation on feed intake, rumen disappearance of barley straw, bacteria, and fermentation, blood parameters of camels and sheep. Three fistulated camels and three fistulated rams were fed a concentrates mixture and ad libitum barley straw as a basal diet alone or supplemented with YA mixture. The dietary supplementation improved the feed intake, rumen disappearance of barley straw nutrients, and the blood immunity parameters. The YA supplementation affected rumen fermentation as well as the composition and diversity of rumen bacteria; however, the response to the supplementation varied according to animal species. Principle Coordinate Analysis (PCoA) separated bacterial communities based on animal species and feeding treatment. Phylum Bacteroidetes and Firmicutes dominated the bacterial community; and the dominant genera were Prevotella, RC9_gut_group, Butyrivibrio, Ruminococcus, Saccharofermentans, Christensenellaceae_R-7_group, and Succiniclasticum. Our results suggest positive impacts of YA supplementation in rumen fermentation and animal performance.

Effect of olive and date palm by-products on rumen methanogenic community in Barki sheep.

Rumen methanogens prevent the accumulation of fermentation gases in the rumen and generate methane that increases global warming and represents a loss in animals' gross energy. Non-traditional feed resources such as the by-products of date palm (Phoenix dactylifera) and olive (Olea europaea) trees have received attention to be used in animal feeding. This study evaluated the impact of non-traditional feed resources including olive cake (OC), discarded dates (DD), and date palm frond (DPF) in sheep diet on rumen fermentation, diversity and relative abundance of rumen methanogens. Nine adult rams were assigned to three equal groups and fed three diets: traditional concentrates mixture (S1); non-traditional concentrate mixture (S2) based on DD and OC; and (S3) composed of the same S2 concentrate supplemented with DPF as a roughage part. The results showed that rumen pH was higher with S3 diet than the other two diets. However, the S1 diet showed the highest values of total volatile fatty acids (TVFA) and rumen ammonia. In addition, the proportions of acetic and butyric acids were increased, whereas propionic acid declined in S2 and S3 compared to the S1 diet. Rumen methanogens were dominated by Methanobrevibacter that showed a numeric decline by including DD, OC, and DPF in the animal diets. Principal component analysis (PCA) based on rumen fermentation parameters and relative abundances of methanogens genera showed three distinct clusters. Also, positive and negative correlations were revealed between methanogens genera and rumen metabolites. This study expands the knowledge regarding the effect of agricultural byproducts on rumen fermentation and the methanogenic community.

Rumen bacterial community profile and fermentation in Barki sheep fed olive cake and date palm byproducts.

Rumen bacteria make the greatest contribution to rumen fermentation that enables the host animal to utilize the ingested feeds. Agro-industrial byproducts (AIP) such as olive cake (OC) and date palm byproducts (discarded dates (DD), and date palm fronds (DPF)) represent a practical solution to the deficiency in common feed resources. In this study, thirty-six growing Barki lambs were divided into three groups to evaluate the effect of untraditional diets including the AIP on the growth performance. Subsequently, nine adult Barki rams were used to evaluate the effect of experimental diets on rumen fermentation and rumen bacteria. Three rations were used: common concentrate mixture (S1), common untraditional concentrate mixture including OC and DD (S2), and the same concentrate mixture in S2 supplemented with roughage as DPF enriched with 15% molasses (S3). The animals in S2 group showed higher dry matter intake (DMI) and lower relative growth rate (RGR) as compared to the animals in S1 group. However, the animals in S3 group were the lowest in DMI but achieved RGR by about 87.6% of that in the S1 group. Rumen pH, acetic and butyric acids were more prevalent in animals of S3 group and rumen ammonia (NH3-N), total volatile fatty acids (TVFA), propionic acid were higher in S1. Rumen enzymes activities were higher in S1 group followed by S3 and S2. The bacterial population was more prevalent in S1 and microbial diversity was higher in the S3 group. Principal coordinate analysis revealed clusters associated with diet type and the relative abundance of bacteria varied between sheep groups. The bacterial community was dominated by phylum Bacteroidetes and Firmicutes; whereas, Prevotella, Ruminococcus, and Butyrivibrio were the dominant genera. Results indicate that diet S3 supplemented by OC, DD, and DPF could replace the conventional feed mixture.