C Kamel's research while affiliated with Universidad de León and other places

... Some researchers (El-Ashry et al. 2006;Khir and Ibrahim 2007;Aiad et al. 2008, Pankaj et al. 2008and Sirohi et al. 2012) stated that the beneficial effects of essential oils and saponins obtained from medicinal plants on rumen fermentation, nutrient utilization, and growth rate of calves. Greathead et al. (2000) added a mixture of cinnamaldehyde, cinol and eugenol essential oil components to the milk replacer feed at the level of 200 g/t and that the feed consumption increased with the addition of essential oil in the Holstein calves between 2-8 weeks, but it was reported that this increase was not statistically significant. Ünlü and Erkek (2011) determined that the daily addition of 250 mg of thyme and garlic essential oilsto the whole milk consumed by the calves did not have any effect on the daily live weight gain, feed and dry matter consumption, feed efficiency, body measurements, stool bacteria count and blood values. ...

... A limited number of studies have been conducted using cinnamaldehyde, garlic oil, or a mixture of the two as active ingredients in the diet of dairy cows (Yang et al., 2007;Benchaar et al., 2008b;Blanch et al., 2016). Previous work investigating the effects of an additive containing 129 mg of cinnamaldehyde and 15 mg of garlic oil in the diet of dairy cows showed that: (1) the mixture lowered milk urea nitrogen (MUN) and somatic cell counts (SCC) compared with their non-supplemented counterparts, but no differences were detected in milk yield and composition (Kamel et al., 2009), (2) the mixture reduced MUN and SCC while increased milk yield (Guozhong et al., 2010), and (3) the mixture did not affect MUN or SCC; however, supplemented cows increased serum insulin concentration and decreased serum total cholesterol concentrations compared with non-supplemented cows (Serbester et al., 2012). These changes suggest an improvement in nitrogen and energy metabolism in dairy cattle supplemented with a mixture of cinnamaldehyde and garlic oil. ...

... In particular, tannins are reported to be astringent and decrease palatability with negative effects on intake when administered at a high dietary level (Correddu et al. 2020). Also, negative effects of EOs on feed intake are generally related to palatability problems (Busquet et al. 2003). The lack of effect of the dietary treatment on the feed intake and nutrient digestibility observed in this study could be related to the moderate dose of EOs used. ...

... The inclusion of garlic at the rate of 135 mg/g of substrate resulted in more than 20% inhibition in CH 4 yield (mL/g DM), with no effect on gas production and a slight increase (2%) in in vitro DM degradability [98]; although such an inclusion rate is rather unrealistic for application at the commercial level. The effect of the inclusion of garlic oil on CH 4 and VFA production based on in vitro is also influenced by diet and dose-dependent factors [99]. ...

... The effects of EO on rumen microbiota seems also to be highly dependent on ruminal pH, as the pH level can influence the dissociated or undissociated status of EO molecules. Some authors suggested that the undissociated hydrophobic form of the active EO molecules is more effective in its antimicrobial activity because it dissolves better in the lipid bilayer of the bacterial membrane, and this is proven at low rumen pH [55,56]. However, increased pH in 24 h in vitro batch cultures of mixed rumen bacteria was found when 400 mg/L of thymol was added, which is the EO contained in Thymus and Origanum plants; in addition, no effects were reported at lower doses [41]. ...

... Previously, Dang and Kim (2020) and Barto s et al. (2016) also reported that pigs fed QS had improved the growth performance and ATTD of DM and N. Similarly, Vaclavkova and Beckova (2008) reported that QS at a level of 125 mg/kg had increased the ADG and ADFI of weaning pigs. On the other hand, Ilsley et al. (2003) stated that dietary supplemented with 250 mg/kg QS had improved DM and N of sows. However, Kang et al. (2010) and Turner et al. (2000) did not observe a significant difference in the growth performance and nutrient digestibility of dietary supplementation of a 450 and 500 mg/kg QS. ...

... These vegetable additives also contain fatsoluble vitamins (A, D, E, and K), which contribute to increased absorption and digestion of lipoproteins [7]. Aromatic plants and spices contain biologically active substances that stimulate the digestion process and the production of digestive enzymes because they contain many active compounds and chemicals such as anothiol, econol [8,9]. Since aromatic spices and medicinal plants consist of a large number of chemical compounds, therefore, it is likely that these compounds cannot be attributed to a single mechanism of action, but there are many different mechanisms by which these phenolic compounds work, which are mainly responsible for giving these extracts to these plants the characteristic The mission is as natural antibiotics that do not have any side effects on animals and humans consuming these animals [10][11][12][13]. ...

... Therefore, the objective of this study was to evaluate the in vitro ruminal fermentation of different silages of S. latissima. The diet of the donor is one of the main factors affecting in vitro fermentation parameters (Martínez et al. 2010b;Mateos et al. 2013), and therefore, the in vitro trials were conducted using as inoculum ruminal fluid from small ruminants fed either medium-forage or high-forage diets. Diets were formulated to be representative of different practical feeding conditions, such as those for dairy goats (medium-forage diet) and low-producing sheep (high-forage). ...

... The composition of the active compounds of essential oils in the plant of origin varies 15 . Essential oils from various plants at high doses largely reduced total VFA production and re ected a decrease in feed degradation, especially on microbial that ferment carbohydrate in the rumen to VFA production that used by animal host as the main energy source 17 In the current study, the concentration of microbial protein was decreased by using of nutmeg essential oil at 200 µL/mL by 10.91% of the control. The decrease of microbial protein concentration in this study correlated with reduced NH 3 and total VFA with using nutmeg essential oil at 200 µL/mL (Table 1). ...

... Moreover, ammonia-N concentrations were comparable (p > 0.05) in all AS supplementation groups (Table 3), except the highest dose (AS-10), where a reduction was evident (p < 0.01). Many researchers reported that essential oil supplementations resulted in a reduced population and diversity of hyper-ammonia-producing bacteria with a decrease in the rate of NH 3 production through compromising the deamination of dietary amino acids [44][45][46]. Cardozo, et al. [47], while investigating the effects of natural plant extracts in a concentrate-based diet on rumen fermentation, reported a reduction in ammonia-N concentration upon the supplementation of garlic oil at various dose levels (0.3, 3, 30, 300 mg/L). In contrast, an increased concentration of ammonia-N and unsaturated fatty acids without affecting the total VFA production was reported by Zhu, Mao and Zhu [34]. ...