A. A. Hassan

Performance of crossbred dairy Friesian calves fed two levels of Saccharomyces cerevisiae : intake, digestion, ruminal fermentation, blood parameters and faecal pathogenic bacteria

The effect of feeding two levels of Saccharomyces cerevisiae on the performance of crossbred Friesian calves was investigated. Twenty-four neonatal male Friesian × Baladi calves (35·5 ± 0·25 kg of initial body weight) were randomly assigned in a completely randomized design into three experimental groups for 90 days (eight calves per group). Calves fed their diets without yeast ( S. cerevisiae ) were considered as Control, while the diets of other calves were supplemented daily either with 2·5 g (YL diet) or with 5 g (YH diet) of yeast per calf. Calves fed the YH diet showed increased feed intake, while dry matter and fibre digestibilities were increased in calves fed YH and YL diets. Calves fed YL and YH diets showed lower ruminal ammonia-N and higher total volatile fatty acids, acetate and propionate concentrations than Control calves. Both YH and YL calves showed increased plasma concentrations of total protein, globulin and glucose and decreased cholesterol and triglycerides concentrations. Calves’ final weight and daily gain were increased with S. cerevisiae yeast supplemented diets. After 42 days of experiment, Clostridium spp., Escherichia coli and Enterobacteria spp. counts were down to undetectable levels in the faeces of calves fed S. cerevisiae additive. It could be concluded that adding S. cerevisiae to milk-fed calves increased feed utilization and improved pre-weaned calf performance and health status, reducing faecal pathogenic bacteria.

Effects of Some Herbal Plant Supplements on Growth Performance and the Immune Response in Nile Tilapia (Oreochromis Niloticus)

Abstract Using of natural plants as immunostimulant in fish is more useful than antibacterial drugs that cause adversely side effects for fish, environment and consumers. Therefore, the present study was to investigate the effects of dietary turmeric (Curcuma longa), rosemary (Rosmarinus officinalis) and thyme (Thymus vulgaris) as feed additives on growth performance, proximate composition and some immuno-hematological parameters on Nile tilapia. Four nitrogenous (31.43-31.56 % crude protein) and isocaloric (17.90-18.04 kJ/g) diets were formulated to contain 0% (control), 1% of turmeric, rosemary or thyme, respectively. The results reveled that, supplementation with medicinal herbs significantly increased (P<0.05) weight gain, specific growth rates and protein efficiency ratio (PER) compared to those in the control group. Moreover, the medicinal herb additives had insignificant effect on carcass composition and some biochemical composition. Hematocrit and leukocrit levels in the fish fed with turmeric, rosemary and thyme added diet were found to be significantly (P <0.05) higher than the control group. However, leukocyte level among the experimental groups was not significantly differed (P >0.05). In neutrophils of experimental fish groups, there were higher numbers of NBT (+) cells fixed on lamellas than those of the control group. So, based on the current findings together with the low cost and the immunostimulative effect of turmeric, rosemary and thyme it can be recommended to be used in fish feed to minimize the mortalities caused by some pathogens.