The addition of lysolecithin to broiler diets improves growth performance across fat levels and sources: a meta-analysis of 33 trials.

1. This study aimed to quantify the effect of fat type (including unsaturated to saturated ratio (U:S)) and increasing doses of lysolecithin-based products on nutrient availability and growth performance in broiler chickens.2. A total of 33 separate experimental reports were collated according to predetermined selection criteria to provide 16 performance trials with 'on top' application, and 17 performance trials using reformulated diets, where the contribution of the lysolecithin was taken into account. Data on average daily gain (ADG) and body weight corrected FCR (FCRc) were analysed using the REML method with trial as a random effect.3. Across the constituent trials, average added dietary fat and oil inclusion was 4.42% (min 1.15%, max 7.00%), with varied U:S ratio (min 0.94, avg 2.50, max 7.65), reflecting diverse fat sources. Overall, neither bird growth performance nor response to lysolecithin supplementation were significantly affected by the U:S ratio of the diets.4. In performance trials where lysolecithin was added 'on top' of existing formulations, FCRc was significantly reduced by lysolecithin at 250 g/t inclusion compared to the control, with 125 g/t returning an intermediate value. In reformulated trials, FCRc was not significantly affected, suggesting lysolecithin supplementation at 125 and 250 g/t could recover average dietary energy reductions of 57.88 and 73.11 kcal/kg feed, respectively.5. In conclusion, this study showed that the addition of lysolecithin at levels of 125 g/t and above to broiler diets consistently improved feed efficiency across a range of basal dietary ingredients and fat sources.

Lysolecithin, but not lecithin, improves nutrient digestibility and growth rates in young broilers.

1. The potential of lecithin and lysolecithin to improve lipid digestion and growth performance was investigated in three experiments: 1. an in vitro model that mimics the intestinal conditions of the chick, 2. a digestibility trial with chicks (5-7 days of age), and 3. a performance trial until 21 days of age. 2. In experiment 1, palm oil (PO), palm oil with lecithin (PO+L), and palm oil with lysolecithin (PO+LY) were subjected to in vitro hydrolysis and applied to Caco-2 monolayers to assess lipid absorption. 3. The in vitro hydrolysis rate of triglycerides was higher in PO+LY (k = 11.76 × 103/min) than in either PO (k = 9.73 × 103/min) or PO+L (k = 8.41 × 103/min), and the absorption of monoglycerides and free fatty acids was highest (P < 0.01) for PO+LY. In experiment 2, 90 broilers were assigned to three dietary treatments: a basal diet with 4% palm oil, and the basal diet supplemented with either 250 ppm lecithin or lysolecithin. 4. ATTD of crude fat was higher in broilers supplemented with lysolecithin, but was lower in broilers supplemented with lecithin. DM digestibility and AMEn in birds supplemented with lysolecithin were significantly higher (3.03% and 0.47 MJ/kg, respectively). 5. In experiment 3, 480 broilers were randomly allocated to four dietary treatments: basal diet with soybean oil (2%), basal diet with lecithin (2%), soybean oil diet with 250 ppm lysolecithin, or lecithin oil diet with 250 ppm lysolecithin. 6. Lecithin diets significantly reduced weight at day 10 and 21 compared with soybean oil. However, the addition of lysolecithin to lecithin-containing diets significantly improved bird performance. 7. The results of these studies showed that, in contrast to lecithin, lysolecithin was able to significantly improve the digestibility and energy values of feed in young broilers.

Performance, gut morphology and microbiology effects of a Bacillus probiotic, avilamycin and their combination in mixed grain broiler diets.

1. This study aimed to determine the effect of avilamycin (AGP) and a multi-strain Bacillus probiotic (DFM) on the performance, gut histology and microbiology of broilers fed on a mixed grain diet. 2. A total of 800 chicks were allocated to four treatments: a control diet, control+AGP, control+DFM, or control+AGP+DFM. Bodyweight, feed intake and FCR were measured at d 0, 21 and 42. Samples were taken at d42 to determine villus height (VH), crypt depth (CD) and ratio (VH:CD). Mucosal E. coli and Lactobacilli counts were measured at d42. 3. At d42, DFM and AGP+DFM significantly increased weight over the control, with AGP returning an intermediate value. FCR followed a similar pattern. DFM and AGP+DFM significantly increased VH and CD in all gut sections compared to the control. 4. DFM and AGP+DFM reduced E. coli counts compared to control, with AGP reducing caecal counts only, while Lactobacilli counts were increased. 5. Divergent histology and microbiology between treatments highlight the different modes of action of AGP and DFM for improving broiler growth and feed efficiency.

Comparative effects of two multi-enzyme combinations and a Bacillus probiotic on growth performance, digestibility of energy and nutrients, disappearance of non-starch polysaccharides, and gut microflora in broiler chickens.

The efficacy of two exogenous enzyme combinations and a multi-strain Bacillus probiotic (DFM) on the growth performance, nutrient digestibility, disappearance of non-starch polysaccharides (NSP) and gut microbial composition was investigated in broilers. One-day old Ross 308 chicks were assigned to 36 pens with 22 birds/pen and 6 pens/treatment (Experiment 1) or 36 cages with 8 birds/cage and 6 cages/treatment (Experiment 2). Treatment additives were added to nutritionally complete corn/soy based starter (d 1 to 21) and finisher (d 22 to 42) diets. Treatments included 1) a control diet containing 500 FTU/kg phytase (CTL), 2) CTL + xylanase (2,000 U/kg) and amylase (200 U/kg; XA), 3) CTL+XA + protease (4000 U/g; XAP), 4) CTL+DFM (150,000 cfu/g of 3 strains of Bacillus spp), 5) CTL+DFM+XA, and 6) CTL+DFM+XAP. Supplementation with DFM increased BW, BWG, and FI compared with the CTL (P < 0.05); XAP, but not XA, resulted in increased final BW, BWG and FI compared to the control (P < 0.05). XA and XAP improved apparent ileal digestibility (AID) of starch and fat on d 22 to 42 with XAP improving AMEn (by ∼82 kcal) compared with CTL birds (P < 0.01). DFM+XAP improved apparent ileal digestible energy (AIDE), AID of fat and starch on d 22 to 42, and additionally had a greater than additive effect on AIDE and AMEn. Supplementation with DFM+XAP reduced the ileal and total tract flow of insoluble arabinose and additionally total tract flow of soluble and insoluble xylose and total galactose (P < 0.05); similar effects of XA+DFM were not seen or were lower in magnitude, suggesting that the protease component plays an important role in increasing the availability of NSP for hydrolysis. Supplementation with DFM alone did not affect gut bacterial populations, but XA and XAP reduced numbers of Campylobacter species (by > 2.5 log cfu/g; P < 0.001) and Bacteroides (P < 0.02) in the cecum compared with CTL birds.

Hydrolysable tannin-based diet rich in gallotannins has a minimal impact on pig performance but significantly reduces salivary and bulbourethral gland size.

Tannins have long been considered 'anti-nutritional' factors in monogastric nutrition, shown to reduce feed intake and palatability. However, recent studies revealed that compared with condensed tannins, hydrolysable tannins (HT) appear to have far less impact on growth performance, but may be inhibitory to the total activity of caecal bacteria. This in turn could reduce microbial synthesis of skatole and indole in the hindgut of entire male pigs (EM). Thus, the objective of this study was to determine the impact of a group of dietary HT on growth performance, carcass traits and boar taint compounds of group housed EM. For the study, 36 Swiss Large White boars were assigned within litter to three treatment groups. Boars were offered ad libitum one of three finisher diets supplemented with 0 (C), 15 (T15) or 30 g/kg (T30) of HT from day 105 to 165 of age. Growth performance, carcass characteristics, boar taint compounds in the adipose tissue and cytochrome P450 (CYP) isoenzymes CYP2E1, CYP1A2 and CYP2A19 gene expression in the liver was assessed. Compared with C, feed efficiency but not daily gain and daily feed intake was lower (P<0.05) in T15 and T30 boars. Except for the percentage carcass weight loss during cooling, which tended (P<0.10) to be greater in T30 than C and T15, carcass characteristics were not affected by the diets. In line with the numerically lower androstenone level, bulbourethral and salivary glands of T30 boars were lighter (P<0.05) than of T15 with intermediate values for C. Indole level was lower (P<0.05) in the adipose tissue of T30 than C pigs with intermediate levels in T15. Skatole levels tended (P<0.10) to be lower in T30 and C than T15 pigs. Hepatic gene expression of CYP isoenzymes did not differ between-treatment groups, but was negatively correlated (P<0.05) with androstenone (CYP2E1 and CYP1A2), skatole (CYP2E1, CYP2A) and indole (CYP2A) level. In line with the numerically highest androstenone and skatole concentrations, boar taint odour but not flavour was detected by the panellists in loins from T15 compared with loins from C and T30 boars. These results provide evidence that HT affected metabolism of indolic compounds and androstenone and that they affected the development of accessory sex glands. However, the effects were too small to be detected by sensory evaluation.

The addition of a Buttiauxella sp. phytase to lactating sow diets deficient in phosphorus and calcium reduces weight loss and improves nutrient digestibility.

Improving the efficiency of P use by pigs is especially important for lactating sows, whose metabolic requirements for P and Ca are high. The effect of a sp. phytase on lactating sow performance and nutrient digestibility was investigated using the combined data set for 6 studies. Treatments included a nutritionally adequate positive control diet (PC), a negative control diet (NC; with an average reduction of 0.16% available phosphorous and 0.15% Ca vs. PC), and NC supplemented with a sp. phytase at 250, 500, 1,000 or 2,000 phytase unit (FTU)/kg, respectively. Phosphorus and Ca deficiency in the NC resulted in significantly higher BW loss compared with the PC. All phytase treatments maintained BW loss at the same level as the PC. Increasing doses of phytase significantly ( < 0.05) reduced sow BW loss and increased energy intake, with improvements most apparent in sows older than parity 5. The positive effects on BW and energy intake were not observed in first-parity sows. This may be a consequence of fewer first parity sows in the data set. The apparent total tract digestibility of DM, OM, and CP were not affected by phytase supplementation. Digestible P and Ca were significantly improved (linear, < 0.0001; quadratic, < 0.0001) by increasing the dose of phytase supplementation. Significantly lower apparent total tract digestibility of energy, Ca, and P was found in the NC treatment vs. the PC treatment, whereas no significant differences were found between phytase treatment and the PC treatment. In conclusion, phytase supplementation at a level of 250 FTU/kg can replace 0.16% available phosphorous and 0.15% Ca; however, increasing the phytase dose can further reduce BW loss in sows fed P- and Ca- deficient diets.