C Kamel’s research while affiliated with University of Leon and other places

Sow lactation performance is critical to piglet survival and pre-weaning growth. Effective lactogenesis combined with strong piglet vigour at birth will help prevent hypoglycaemia and mortality. In addition, immune protection of the sucking pig is dependant on the acquisition of immunoglobulins from the colostrum of the sow. High milk output in late lactation will ensure greater weaning weights, since piglet growth potential exceeds milk supply by day 10 of lactation (Harrell et al , 1993). Maximising sow feed intake ensures maximum milk production. A variety of plant extracts are recognised for their health and growth promoting properties which include stimulation of the digestive and immune systems (Platel and Srinvansan, 1996). The objective of this study was to evaluate the ability of various plant extracts to stimulate piglet and sow performance when used as supplements in the diets of lactating sows. Three extracts were selected for their potential benefits to health, appetite and digestion, these being Yucca Shidigera, Quillaja Saponaria and Combination (a blend of the spices capsicum 1.0%, cinnamaldehyde 1.25 % and oregano oil 0.85 %).

Some in-feed antibiotic growth promoters have been suspended from use within the EU. Alternatives to these antibiotics are actively being sought, especially ‘natural’ alternatives, such as essential oils, to try and maintain the performance advantage attributed to the use of these antibiotics. Some essential oils, e.g. thyme and origanum, have been shown to have anti-microbial activities (Hammer et al. , 1999). The active compounds responsible for this property have been identified, and include cinnamaldehyde, cineol and eugenol. A specific formulation of essential oils reinforced with their active compounds has been combined into a form suitable for use as a feed additive (Multi-Functional Feed Additive, MFA). An experiment was conducted to determine the effect of this MFA on the food conversion ratio (FCR) of calves.

The objective of this study was to evaluate the effects of increasing doses [0 (control: CON), 20, 60, 180 and 540 mg/L incubation medium] of garlic oil (GO) and cinnamaldehyde (CIN) on in vitro ruminal fermentation of two diets. Batch cultures of mixed ruminal microorganisms were inoculated with ruminal fluid from four sheep fed a medium-concentrate diet (MC; 50 : 50 alfalfa hay : concentrate) or four sheep fed a high-concentrate diet (HC; 15 : 85 barley straw : concentrate). Diets MC and HC were representative of those fed to dairy and fattening ruminants, respectively. Samples of each diet were used as incubation substrates for the corresponding inoculum, and the incubation was repeated on 4 different days (four replicates per experimental treatment). There were GO × diet-type and CIN × diet-type interactions (P < 0.001–0.05) for many of the parameters determined, indicating different effects of both oils depending on the diet type. In general, effects of GO were more pronounced for MC compared with HC diet. Supplementation of GO did not affect (P > 0.05) total volatile fatty acid (VFA) production at any dose. For MC diet, GO at 60, 180 and 540 mg/L decreased (P < 0.05) molar proportion of acetate (608, 569 and 547 mmol/mol total VFA, respectively), and increased (P < 0.05) propionate proportion (233, 256 and 268 mmol/mol total VFA, respectively), compared with CON values (629 and 215 mmol/mol total VFA for acetate and propionate, respectively). A minimum dose of 180 mg of GO/L was required to produce similar modifications in acetate and propionate proportions with HC diet, but no effects (P > 0.05) on butyrate proportion were detected. Methane/VFA ratio was reduced (P < 0.05) by GO at 60, 180 and 540 mg/L for MC diet (0.23, 0.16 and 0.10 mol/mol, respectively), and by GO at 20, 60, 180 and 540 mg/L for HC diet (0.19, 0.19, 0.16 and 0.08 mol/mol, respectively), compared with CON (0.26 and 0.21 mol/mol for MC and HC diets, respectively). No effects (P = 0.16–0.85) of GO on final pH and concentrations of NH3-N and lactate were detected. For both diet types, the highest CIN dose decreased (P < 0.05) production of total VFA, gas and methane, which would indicate an inhibition of fermentation. Compared with CON, CIN at 180 mg/L increased (P < 0.05) acetate proportion for the MC (629 and 644 mmol/mol total VFA for CON and CIN, respectively) and HC (525 and 540 mmol/mol total VFA, respectively) diets, without affecting the proportions of any other VFA or total VFA production. Whereas for MC diet CIN at 60 and 180 mg/L decreased (P < 0.05) NH3-N concentrations compared with CON, only a trend (P < 0.10) was observed for CIN at 180 mg/L with the HC diet. Supplementation of CIN up to 180 mg/L did not affect (P = 0.18–0.99) lactate concentrations and production of gas and methane for any diet. The results show that effectiveness of GO and CIN to modify ruminal fermentation may depend on diet type, which would have practical implications if they are confirmed in vivo.

The plant extract mixture (XT) used in the present experiment, containing carvacrol, cinnamaldehyde, and capsicum oleoresin, has previously been shown to decrease diarrhea mortality and to modify the intestinal environment of pigs after weaning. However, results obtained among experiments have not been consistent. We hypothesized that dietary protein could be a main factor determining the effect of plant extracts on intestinal environment. Thus, in the present study we assessed the effects of XT in piglet diets with different protein sources and amounts. Pigs weaned at 20 +/- 1 d of age (n = 240) were allocated to 1 of 6 treatments, which followed a factorial arrangement, with 2 amounts (as-fed basis) of the XT (0 and 200 mg/kg) and 3 diets with various amounts of CP and protein sources. Diet FM18 contained 10% of low-temperature fish meal (LT-FM) and a CP level of 18%; diet SBM18 contained 5% of LT-FM plus 9% of full fat extruded soy and a CP level of 18%; and SBM20 diet contained 10% of LT-FM plus 6.3% of full fat extruded soy and a CP level of 20%. Growth performance of the animals was recorded for 14 d, but no differences were detected among treatments. Eight pigs per treatment were killed to examine variables describing aspects of gastrointestinal ecology. For diets containing 18% CP, FM18 and SBM18, XT tended to decrease ileal digestibility of OM (P = 0.064 and 0.071, respectively) and decreased starch digestibility (P = 0.032 and 0.014, respectively). It also reduced villi length (P = 0.003 and 0.013, respectively) and tended to decrease intraepithelial lymphocyte number (P = 0.051 and 0.100, respectively) in the proximal jejunum. The XT inclusion also increased ileal lactobacilli:enterobacteria (P = 0.017) ratio and decreased VFA production in the cecum (P = 0.045) for all diets. A decreased CP level appeared to favor the effects of the studied plant extracts in a positive or negative way depending on the variable measured. The microbial differences produced by XT could be the reason for improved digestive health observed by the authors in stronger challenging conditions (e.g., dirtier environments or long fasting periods after weaning).

The objective of this study was to determine effects of four doses (i.e. 0, 0.5, 5 and 10mg/l incubation medium) of allicin and diallyl disulfide on in vitro fermentation of a 1:1 alfalfa hay:concentrate diet in batch cultures of mixed rumen micro-organisms from the rumens of sheep fed either a high forage (HF inoculum; 700:300 alfalfa hay:concentrate; 4 sheep) or a high concentrate (HC inoculum, 300:700 alfalfa hay:concentrate; 4 sheep) diet. It was hypothesised that additive effects would depend on the rumen microbial populations, and thus on the type of diet fed to the host sheep. Initial pH in the incubation medium was 6.98 and 6.39 for HF and HC inoculum, respectively. Since antimicrobial effects of both compounds seemed to be time-dependent, 6, 12 and 24h incubations, representing 5 replicates on non-consecutive days, were chosen. Allicin at the lowest concentration (i.e. 0.5mg/l) increased (P

Two representative strains of Gram-negative rumen bacteria from the genus Prevotella were used as model organisms in order to evaluate the effect of cinnamaldehyde (the secondary metabolite found in extracts of the Cinnamomum family) vs. sodium monensin on growth, cell size and cell protein production. Prevotella bryantii B(1)4 was found to be remarkably more resistant to the action of both compounds than Prevotella ruminicola 23. The approximate IC(50) concentrations of sodium monensin influenced the increase in cell size of both strains during growth, which was much more pronounced in the case of the B(1)4 strain. A similar effect was observed in strain B(1)4 when 1.438 mmol/L cinnamaldehyde was added to the growth medium, indicating a possible interference with cell division. The action of cinnamaldehyde on P. bryantii B(1)4 was concentration-dependent, in contrast to the effect observed on P. ruminicola 23.

Four Holstein heifers (360 +/- 22 and 450 +/- 28 kg of BW in Exp. 1 and 2, respectively) fitted with ruminal trocars were used in 4 x 4 Latin square designs to evaluate the effects on ruminal microbial fermentation of the following: Exp. 1, no additive, alfalfa extract (30 g/d, AEX), a mixture of cinnamaldehyde (0.18 g/d) and eugenol (0.09 g/d; CIE1), and AEX and CIE1 in combination; and Exp. 2, no additive, anise oil (2 g/d), capsicum oil (1 g/d), and a mixture of cinnamaldehyde (0.6 g/d) and eugenol (0.3 g/d). Heifers were fed a 90:10 concentrate:barley straw diet (16% CP; 25% NDF) for ad libitum intake. Each period consisted of 15 d for adaptation and 6 d for sampling. On d 16 to 18, DM and water intakes were measured. On d 19 to 21 ruminal contents were sampled at 0, 3, 6, 9, and 12 h after feeding to determine ruminal pH and the concentrations of VFA, L-lactate, large peptides, small peptides plus AA (SPep+AA), and ammonia N. On d 20 and 21, samples of ruminal fluid were collected at 0 and 3 h after feeding to determine protozoal counts. In Exp. 1, CIE1 and AEX decreased (P < 0.05) total DMI, concentrate DMI, and water intake. The increase (P < 0.05) in SPep+AA and the decrease (P < 0.05) in ammonia N when supplementing CIE1 suggest that deamination was inhibited. Treatment AEX increased (P < 0.05) the acetate to propionate ratio, which is less efficient for beef production. Treatment CIE1 increased (P < 0.05) counts of holotrichs. Effects of AEX and CIE1 were not additive for many of the measured metabolites. In Exp. 2, treatments had no effect on ruminal pH, total VFA concentration, and butyrate proportion. The capsicum oil treatment increased (P < 0.05) DMI, water intake, and SPep+AA N concentration and decreased (P < 0.05) acetate proportion, branched-chain VFA concentration, and large peptide N concentration. The cinnamaldehyde (0.6 g/d) and eugenol (0.3 g/d) treatment decreased (P < 0.05) water intake, acetate proportion, branched-chain VFA, L-lactate, and ammonia N concentrations and increased (P < 0.05) propionate proportion and SPep+AA N concentration. The anise oil treatment decreased (P < 0.05) acetate to propionate ratio, branched-chain VFA and ammonia N concentrations, and protozoal counts. The results indicate that at the doses used a mixture of cinnamaldehyde and eugenol, anise oil, and capsicum oil may be useful as modifiers of rumen fermentation in beef production systems.