The effects of standard cow, goat and lactose-free cow milk powder on lactose intolerance symptoms and the nutritional status of dogs was studied. Forty adult Springer Spaniels with lactose intolerance were randomly allocated into four groups with ten dogs each and fed one of the milk powders or water for 21 d. The milk powders were reconstituted daily by diluting 10 g milk powder to 60 g water and 2 g milk powder/kg body weight was provided ad libitum and refusals were monitored daily. Lactose intolerance was assessed by faecal composition and pH, water and lactose contents. Biochemical markers for nutritional status were analysed. Feeding intolerance and lactose in faecal samples were observed in dogs fed the standard cow and goat milk powder, but not for the lactose-free milk powder or control groups. The high- and low-density lipoprotein cholesterol increased in all milk powder groups, while there were no other differences in nutritional status measurement. The results suggested that feeding lactose-free milk powder to dogs with lactose intolerance reduced the occurrence of symptoms, thereby enhancing the health and wellbeing of dogs.

Complete replacement of inorganic trace minerals (ITM) with proteinated organic trace minerals (PTM) at equal or lower inclusion rates was evaluated. One thousand and eight, one-d-old male chicks were divided into 24 pens containing 42 chicks, and randomly allocated to one of the following: T1: control group with ITM supplied at the standard commercial level in Ecuador; T2: PTM at 100% T1; T3: PTM at 66% TI; and T4: PTM at 33% T1. The 42-d experiment employed a three-phase feeding programme (1-14, 15-28 and 29-42 d). Restricted feeding was used to prevent the development of ascites associated with high altitude. At 21 and 42 d of age, Cu, Mn and Zn retention were measured in tibial bone, and Fe in whole blood. Lymphoid organ weights were at 21 and 42 d of age. Antibody titres were measured by ELISA at 42 d of age. Weight gain, feed consumption, feed conversion and mortality were similar among treatments, although were below breed expectations due to feed restriction practices. Blood Fe was not affected by treatment (P<0.05). At both 21 and 42 d of age, minerals in tibia differed (P<0.01), with Mn and Zn concentrations being significantly higher in all PTM groups, compared to ITM control at 42 d. However, at 21 d, Zn was higher for the ITM-fed birds. No differences in lymphoid organ (bursa, thymus, and spleen) weights were observed, or for Gumboro (infectious bursal disease), infections bronchitis virus and reovirus antibody titres. For Newcastle disease virus, T4 birds had significantly lower antibody titres compared to other treatment groups. In conclusion, replacement of inorganic minerals with a proteinated form organic minerals at lower inclusion rates had no negative impact on performance, lymphoid organ weight or antibody titres in broilers raised under commercial conditions of high altitude and restricted feeding.

A dose-response experiment was conducted to estimate optimal dietary apparent metabolisable energy requirement (AME) in Sansui ducks (Sansui Sheldrake duck) from hatch to 21 days of age. Three hundred thirty-six one-day-old male Sansui ducks were randomly assigned to six experimental treatments, each consisting of seven replicate pens with eight birds per pen. Birds were fed diets containing either 10.92, 11.38, 11.8, 12.26, 12.68 and 13.14 MJ AME/kg, respectively. At 21 d of age, the body weight, weight gain, feed intake, protein intake, energy intake and feed conversion ratio of ducklings from each pen were measured. Increasing AME content from 10.92 MJ/kg to 13.14 MJ/kg significantly improved body weight, weight gain, feed intake, feed conversion ratio and crude protein intake (P<0.05). No significant changes in energy intake were found among treatments (P>0.05). Based on broken-line regression analysis, the AME requirement of male Sansui ducks from hatch to 21 d of age was 11.49 and 11.59 MJ/kg for maximum body weight and best feed conversion ratio, respectively.

This study compared supplementation with a single dose of xylanase to a double dose of xylanase or a non-starch polysaccharide (NSP) degrading enzyme cocktail (NSP-ase cocktail) on productive performance, nutrient utilisation and the gastrointestinal environment in broilers fed commercial diets. Cobb 500 broilers (n=1,080) were fed 12 dietary treatments; four Australian commercial diets (based on wheat-barley, wheat-maize, wheat-sorghum or wheat only) with three different enzyme treatments (single dose of xylanase (16,000 BXU/kg), double dose of xylanase (32,000 BXU/kg) or NSP-ase cocktail (xylanase, β-glucanase, cellulase, pectinase, mannanase, galactanase, arabinofuranosidase). There were 108 pens, nine replicates per dietary treatment, with 10 birds per pen. Performance (total pen body weight, feed intake and feed conversion ratio corrected for mortality) was determined at d 0-35. On d 35, one male and one female were weighed individually and used to determine breast meat, thigh and drumstick weight, dry matter (DM) contents from the gizzard, jejunum and ileum, ileal protein, energy, starch and dry matter digestibility, ileal viscosity and xylo-oligosaccharide (XOS) concentration, caecal microbiota and short chain fatty acid (SCFA) composition. The double dose of xylanase and NSP-ase cocktail had no effect on bird performance, meat yield, ileal viscosity, ileal starch, energy or DM digestibility or digesta DM content. The double xylanase dose and NSP-ase cocktail increased protein digestibility in birds fed the wheat-sorghum based diet (P=0.041) and increased caecal concentration of butyric acid in birds fed the wheat-maize based diet (P=0.040), and propionic, valeric and lactic acid and Bifidobacteria and Enterobacteria spp. in birds fed the wheat-based diet (P<0.05). The double xylanase dose increased XOS production, particularly in birds fed the wheat-barley based diets (P<0.05). The lack of performance effects observed when feeding the double xylanase dose or NSP-ase cocktail suggested that the current recommended xylanase dose (16,000 BXU/kg) is sufficient.

This study assessed the influence of green tea powder diet supplementation on performance, nutrient utilisation, caecal microbiota profile and meat quality in broiler chickens. A total of 144, one-day-old broiler (Ross 308) chicks were allocated to 18 cages (eight broilers/cage) which were randomly assigned to one of three dietary treatments: a wheat-based basal diet or supplemented with one of two types of green tea; normal (N-GT) or selenium-rich (Se-GT) tea, at an inclusion rate of 1%. Bird performance, nitrogen-corrected apparent metabolisable energy (AMEn), and total tract digestibility of fat and starch were measured on d 7, 21 and 35. Effects on microbiota profile on d 7, 21 and 35 were determined in a cohort study. Green tea supplementation reduced (P<0.05) the weight gain and feed intake but improved (P<0.05) feed efficiency. Supplementation with N-GT increased the AMEn on d 7 and 21, and with Se-GT on d 7 (P<0.05). AMEn increased with age for all treatments. Fat digestibility increased (P<0.05) in birds fed N-GT on d 21 and Se-GT on d 7 and 21. Starch digestibility increased (P<0.05) on d 21 with N-GT supplementation and on d 7 with Se-GT supplementation. Carcass and breast meat yields were unaffected (P<0.05) by the dietary treatments. The abdominal fat pad decreased (P<0.05) in the N-GT diet and numerically in the Se- GT diet. Drip loss was less in meat from birds (P<0.05) fed both green tea treatments. Cooking loss was reduced in the Se-GT treatment (P<0.05). Dietary inclusion of green tea powder positively influenced microbiota profile, with increased (P<0.05) numbers of beneficial bacteria (Lactobacillus spp. and Bifidobacterium spp.) and reduced (P<0.05) numbers of pathogenic bacteria (Clostridium spp. and Bacteroides spp.). Differences were observed between the two green tea types, with Se-GT being more beneficial than N-GT in the positive modulation of intestinal microbiota.

‘Woody breast’ (WB) and ‘white striping’ in broiler meat is a global problem. With unknown etiology, WB negatively impacts bird health, welfare and is a significant economic burden to the poultry industry. New evidence has shown that WB is associated with dysregulation in systemic and breast muscle-oxygen homeostasis, resulting in hypoxia and anaemia. However, it has been observed that phytase (Quantum Blue (QB) a modified, E. coli-derived 6-phytase) super dosing can reverse dysregulation of muscle-oxygen homeostasis and reduces WB severity by ~5%. The objective of this study was to assess whether levels of Ins(1,3,4,5,6)P 5, the main allosteric regulator of haemoglobin, are influenced by changes in plasma myo-inositol arising from super dosing with phytase. To enable this, methods suitable for measurement of myo-inositol in tissues and inositol phosphates in blood were developed. Data were collected from independent trials, including male Ross 308 broilers fed low and adequate calcium/available phosphate (Ca/AvP) diets supplemented with QB at 1,500 phytase units (FTU)/kg, which simultaneously decreased gizzard InsP 6 (P<0.001) and increased gizzard myo-inositol (P<0.001). Similarly, male Cobb 500 broiler chicks fed a negative control (NC) diet deficient in AvP, Ca and sodium or diet supplemented with the QB phytase at 500, 1000 or 2,000 FTU/kg increased plasma (P<0.001) and liver (P=0.007) myo-inositol of 18d-old birds at 2,000 FTU/kg. Finally, QB supplementation of Cobb 500 breeder flock diet at 1,250 FTU/kg increased blood myo-inositol (P<0.001) and erythrocyte Ins(1,3,4,5,6)P 5 (P=0.011) of their 1d-old hatchlings. These data confirmed the ability of phytase to modulate inositol phosphate pathways by provision of metabolic precursors of important signalling molecules. The ameliorations of WB afforded by super doses of phytase may include modulation of hypoxia pathways that also involve inositol signalling molecules. Elevations of erythrocyte Ins(1,3,4,5,6)P 5 by phytase supplementation may enhance systemic oxygen carrying capacity, an important factor in the amelioration of WB and WS myopathy.

The present study evaluated the in vitro efficacy of different feed enzymes on degrading non-starch polysaccharide (NSP) residues present in digesta collected from broilers’ gastrointestinal tract. Two dietary treatments, wheat-soy or maize-soy based diets, were assigned to broilers (12 replicates per treatment; 10 birds per replicate pen) from d 0 to 35. At 35 d of age, digesta was collected from the gizzard, jejunum and ileum from three birds per replicate and pooled. The digesta samples were digested in vitro with one of nine enzymes; GH10, GH11 and GH8 xylanase, arabinofuranosidase, a combination of GH10 xylanase and β-glucanase (XYN+BG), β-mannanase, protease, cellulase cocktail and pectate lyase. When using the gizzard digesta as substrate, GH8 xylanase reduced (P<0.005) both insoluble and soluble NSP levels compared to the control, regardless of diet type. Analysis of NSP degradation in jejunal digesta from birds fed the wheat-soy diet revealed that the three xylanases and arabinofuranosidase reduced (P<0.001) insoluble NSP level compared to the control, but the soluble NSP level was not affected by the enzyme treatments. All enzymes, except the cellulase cocktail and pectate lyase, reduced (P=0.005) the insoluble NSP level in the jejunal digesta collected from birds fed the maize-soy diet. Similarly, all enzyme preparations reduced (P<0.001) the insoluble NSP level in ileal digesta obtained from birds fed the maize-soy diet. The GH10 and GH11 xylanase, XYN+BG, cellulase cocktail and pectate lyase reduced (P<0.001) the insoluble NSP level in the ileal digesta from birds fed the wheat-soy diet compared to the control, with XYN+BG exhibiting the greatest reduction. Collectively, the present in vitro study indicated that the in vitro efficacy of enzyme preparations was dictated by the amount and type of NSP remaining undigested in various parts of the gut, which perhaps affect the in vivo efficacy.

The capacity of a novel bacterial 6-phytase variant (PhyG) to totally replace dietary supplemental inorganic phosphate (Pi) in broilers aged one day old was evaluated using a phased dosing strategy and reduction in dietary phytate. A total of 1,248 one-day-old Ross 308 broilers were assigned to 24 pens (52 birds/pen, 12 pens/diet, six each males and females) in a complete randomised block design with a 2×2 factorial arrangement (two diets, two genders). Diets comprised: (1) a positive control (PC) based on maize, wheat and soybean meal, containing Pi from monocalcium phosphate and 2,000 XU/kg xylanase, and; (2) an inorganic phosphate-free (IPF) diet equivalent to PC but with reduced Ca (-2.0 g/kg) and supplemented with PhyG at 3,000, 2,000 and 1000 FTU/kg from d 0 to 11 (3.4 g/kg phytate-P (PP)), d 11 to 22 (3.3 g/kg PP) and d 22 to 42 (2.8 to 2.9 g/kg PP), respectively. A negative control was not included for animal welfare reasons. Tibias were collected on d 11, 22 and 42 from two birds/pen. Treatment IPF maintained or improved average daily gain (ADG), average daily feed intake and feed conversion ratio (FCR) vs PC during all phases; Body weight was higher in the IPF treatment than the PC at d 42 (+3.97%, P<0.01) and ADG during d 0 to 42 (+4.10%, P<0.01). Overall (d 0 to 42), treatment IPF improved FCR in males (-5 points vs PC, P<0.05) but not females. Tibia ash was equivalent in IPF and PC throughout, with no gender differences. In conclusion, when applied as a phased dosing strategy to diets with graded reduction in PP content, PhyG totally replaced supplemental Pi during all growth phases in males and females.

Medium chain organic acids (MCOA) offer the potential to replace zinc oxide, without dependence on antibiotic use, and can replace or reduce the use of benzoic acid in pig production. A study was conducted to evaluate the effects of caproic acid (C6) and C12 monolaurin (C12M) on the growth performance of weaned pigs, in comparison with zinc oxide (ZnO) and benzoic acid (BA). Specifically, the trial examined whether MCOA, at a reduced inclusion level of BA, could maintain performance levels of pigs similar to those receiving a higher inclusion level of BA. In total, 240 pigs from weaning until 27 d post-weaning were used in a completely randomised block trial with six treatments and eight replicate pens per treatment. Treatments were: (1) control (CON), basal diet (BD); (2) BD+ZnO (ZnO); (3) BD+5,000 mg/kg BA (BA); (4) BD+2,500 mg/kg BA+2,000 mg/kg C12M+700 mg/kg C6 (BAlow/MCOA); (5) BD+2,000 mg/kg C12M+700 mg/kg C6 (MCOA); (6) BD+1000 mg/kg C12M+700 mg/kg C6 (MCOAlow). Feed and water were provided ad libitum. Pigs receiving BA or BA low/MCOA had improved feed conversion ration (FCR) during the period 0-14 days, compared with control pigs (1.02 vs 1.17, P<0.05; 1.06 vs 1.17; P=0.084, respectively). The FCR of pigs receiving BAlow/MCOA was similar to those receiving BA at the higher inclusion-level. Pigs showed good health throughout the study, as indicated by clinical and faecal scores. Replacement of ZnO was inconclusive and further studies with more challenging health conditions are required to conclude benefits.

Limestone is used in poultry diets as a calcium (Ca) source. Feed formulation is often based on an estimate of limestone Ca content or, less frequently, wet chemistry analysis. However, limestone composition may vary, which has not previously been studied on a large scale. In this study, 641 limestone samples supplied to poultry feed mills in 40 countries across eight global regions were collected and analysed for macro- and micromineral content, particle size (geometric mean diameter, GMD), and in vitro solubility. Mean Ca content of fine limestone (GMD<1000 μm, n=566) was 37.8% (range 33.3-39.7%) and for coarse limestone (GMD>1000 μm, n=75) was 38.0% (range 34.7-40.0%). There was marked variation among and within regions in the concentration of other macro minerals and microminerals. Particle size (GMD) of fine limestone was 288 μm (range 37.7-991.9 μm) and 1,689 mm for coarse limestone (range 301.6-3,067.9 μm). In vitro solubility of fine limestone (5 min incubation, pH=3.0) was 68.4% (range 18.8 to 99.4%). Particle size only explained 52% of the variation in 5 min incubation solubility (R2=0.52). For coarse limestone, mean solubility (30 min incubation) was 65.5% (range 23.2-96%) which was not correlated (R2=0.09) with particle size. Particle size and solubility rate of limestone have been shown to alter Ca and phosphorus utilisation in broilers and laying hens. Hence, better understanding of variation in mineral analysis, particle size and solubility rate would enable more accurate feed inclusion and subsequently digestibility to support health and performance.