2013, Bhuiyan, Momenuzzaman, Islam, Afm Fakhrul, Cowieson, Aaron, Iji, Paul

In a 2x2x3 factorial study, the effect of milling technique (hammer vs. roller) with differing particle sizes (fine or coarse) of maize from three sources (Downs, Emerald or Moree) on growth performance, ileal digestibility and intestinal microbial profiles of broiler chickens (from 1-21 days post-hatch) was investigated. A total of 420 day-old male Cobb chicks were randomly allocated to 12 treatments of 5 replicates (seven birds per replicate) in brooder cages set up in an environmentally controlled room. The maize grain was finely ground using a hammer mill or roller mill with a 2 mm screen or coarsely ground through a 4 mm screen. Feed intake up to 7 days of age was higher (p<0.003) on the diet containing finely roller-milled grain than on the coarsely milled grain but no effect found on d21. Live weight was affected by the source of maize (p<0.04). The FCR to d21 was improved (p<0.042) on the Moree maize that was finely roller milled. The relative weight of proventriculus plus gizzard (p<0.01) and liver (p<0.01) were higher in diets containing coarsely milled grain than finely milled grain at 7 but not 21 days. Nutrient digestibility was affected due to maize source (p<0.01) and particle size reduction (p<0.01). These results suggest that fine grinding some sources of maize would be beneficial in terms of improvement in FI, LW and weight of proventriculus and gizzard in early ages as well as nutrient digestibility at a later age.

2014, Widodo, Aluisius Edi, Iji, Paul, Nolan, John

The general objective of this study was to investigate the potential for the use of high-yielding triticale in poultry feeding. Triticale cultivars were subjected to laboratory assessment and were used as the principal grain source for three feeding trials and the results are reported in this thesis. Male Cobb-500 broiler chicks were used in the first and second feeding trials, while Ross 308 chicks were used in the third feeding trial. All diets were provided as pellets, and the trials were conducted in environmentally controlled housing. The assessment of the chemical characteristics of triticale cultivars, and feeding trials with diets containing triticale are presented in individual chapters in the form of stand-alone research papers.

2012, Swick, Robert A, Wu, Shubiao, Mikkelsen, Lene, MacAlpine, Ron, Balding, Katherine, Torok, Valeria, Iji, Paul, Hughes, Robert J

A feeding study was conducted to compare the effects of litter material, dietary fibre and sex on growth performance, organ development, mucosal morphometry and gut microbial communities in broilers. Seven hundred twenty day old Cobb chicks were allocated to 24 floor pens in a 2 x 2 x 2 factorial design with 3 pens of 30 birds per replicate (3 pens of males and 3 pens of females). Factors were: litter material, paper or hardwood shavings; dietary fibre, low or high and sex. Diets consisted of wheat, soybean meal, meat meal, expeller canola meal, poultry fat, vitamin and minerals. Birds and feed were weighed on days 7, 21, and 35. Low fibre groups contained no oat hulls whereas high fibre groups contained 70 g/kg oat hulls. Birds grown on hardwood shavings had larger gizzards (P < 0.01) and a more favorable FCR (P < 0.03) than those grown on paper litter at 35 d. Dietary oat fibre was more beneficial in birds reared on paper litter than hardwood shavings as evidenced by significant fibre by litter interactions at 35 d for FCR (P < 0.02) and caecal 'C. perfringens' counts (P < 0.01). Dietary oat fibre improved body weight at 7 d (P < 0.04), and lowered gizzard pH (P < 0.02) at 35 d. The results suggest that the combination of clean paper litter with high oat fibre diet may be beneficial in enhancing gut health in broilers.

2007, Iji, Paul, Gao, F, Qu, MR, Chee, SH, Bao, Yumin

Early-age feeding strategies can enhance intestinal development and subsequent body growth of broiler chickens. Several supplements have been evaluated to identify the most suitable products and the best mode of delivery. The results of trials on the effects of these supplements differ and there is still a dearth of information on the mechanisms responsible for the effects of these products. In this review, we present an overview of the effects of early-age nutrition and discuss various methods of delivering supplements with emphasis on ongoing studies at the University of New England.

2018-04-14, Abdallh, Medani, Iji, Paul, Bhuiyan, Md Momenuzzaman

The commercial poultry industry is considered the most rapidly growing of all the agricultural sectors. Feed costs constitute around 70% of the total cost of poultry production. The most important feed ingredients for poultry production are energy and protein sources. The poultry industry mainly relies on a limited number of animal and vegetable protein ingredients, such as oilseed meals, legumes and animal by-products (Broomhead, 2013; FAO, 2013). The commonly used animal protein sources such as blood, meat, meat and bone and fish meals are recognized as high- quality protein, with excellent nutritive value and balanced amino acids. Furthermore, chickens tend to prefer animal by-products to vegetable proteins (Hossain et al., 2013). On the other hand, there are some constraints to the use of animal by-products as feed ingredients for animals; high prices, restricted hygienic conditions and the risk that birds may suffer from zoonotic diseases if the animal by-products are processed under sub-optimal conditions. Therefore, for ethical and/or health reasons, animal proteins are excluded from production systems in some parts of the world such as the European Union (Hamilton, 2002).
There are numerous vegetable protein sources of local importance around the world, such as soybean, canola, cottonseed, sunflower seed, peanut, and sesame meals, but these have less nutritive value than animal protein sources (Hamilton, 2002; Aftab, 2009). Most of the vegetable protein sources contain one or more anti-nutritive factors, which can limit the digestion of their nutrients and eventually affect overall animal health, for instance trypsin inhibitors, glucosinolates, and gossypol in soybean meal, canola and cottonseed meals, respectively (Akande et al., 2010). The average crude protein content of different vegetable protein sources ranges between 235 g/kg in peas and 480 g/kg in soybean meal (SBM). Soybean meal is the primary plant protein source used by the poultry industry around the world. However, canola meal (CM) is increasing in importance (Hamilton, 2002; Nagalakshmi et al., 2007). The price of both soybean and canola meals do fluctuate but are generally high, particularly in importing countries. Besides CM, there are other vegetable protein sources close to SBM in nutritive value, low in prices and locally produced such as cottonseed meal (CSM) and sunflower seed meal (SFM).
Cotton (Gossypium), a genus of the Malvaceae family, covers approximately 2.5 % of the agricultural land around the world. Cotton production worldwide is estimated as 23013 thousand tonnes. The highest cotton producing countries in 2015/2016 were India, China, United States, Pakistan, Brazil, Uzbekistan, Turkey and Australia with 5748, 4790, 2806, 1524, 1285, 827, 577 and 566 thousand tonnes, respectively (USDA, 2017).
Cotton yields a number of by-products which are of great value to humans and domesticated livestock. Cottonseed is one of the most valuable by-products produced after the fine cotton fibres are harvested. Jones (1985) reported that for each kg of fibre produced there is 1.5‐1.7 kg of cottonseed separated out in the ginning process. Cottonseed meal or cake is a by-product of oil extraction from cottonseed. It has been reported that crushing one tonne of cottonseed produces around 200 kg of oil, almost 500 kg of cottonseed cake and 300 kg of cottonseed hulls or exteriors (Campbell et al., 2009). Several factors affect the quality of cottonseed obtained, including genetic differences, environmental conditions and harvesting techniques, which indirectly affect the composition of the resulting cottonseed meal. In addition to the genetic differences and environmental effect, the differences in the produced cottonseed meal arise from the residual oil content due to the method of extraction. For this reason there are different types of cottonseed meals, in terms of their protein, fibre and oil contents. The three main methods used by the oil industry to extract oil from oilseeds are: mechanical, solvent and pre-press solvent extraction. Mechanical extraction is the traditional method; it uses a circular motor and hydraulic press or expeller. In this method the seed may need to be decorticated, dried and/or heated before extraction. Besides the cakes produced by this method being tough and large, another important disadvantage is that around 20% of oil remains inside the meal. This high amount of oil, although it considered as valuable energy source, but it may increase the cost and reduce the palatability and storage period of diets. The difference between the mechanical method and the direct solvent extraction method is that in the latter method the oil is extracted by solvents (hexane or ethanol) alone without mechanical pressing and the meal produced has lower oil content. The third method, the pre-press solvent extraction, was developed from a combination of the preceding two methods. This method is considered an integrated method because screw-pressing is followed by solvent extraction, resulting in the extraction of almost 97 % of the oil content of oilseeds (Morgan, 1989; Ash, 1992; O'Brien et al., 2005).
Cottonseed meal is a palatable and excellent source of protein for ruminants. Although it's nutritive value is less than SBM, but its low cost in some regions makes it the main source of protein for cattle especially in parts of India, Australia and United States. Furthermore, CSM can replace all other oilseed meals in dairy cow feeds without affecting milk production (McGregor, 2000). Using whole cottonseed as a major source of protein has been tested to some extent in large animals, but its use in poultry diets as such results in decreased feed consumption and conversion, reduced nutrient digestibility, and poor growth (Devanaboyina et al., 2007). Furthermore, incidence of lameness and a high mortality rate are also associated with feeding entirely CSM as a source of protein to birds (Kakani et al., 2010). The presence of anti-nutritional factors such as gossypol and cyclopropenoid fatty acid, high fibre content and a deficiency in lysine are the well-known factors that limit the use of CSM in poultry diets (Swiatkiewicz et al., 2016). Cottonseed meal has a high crude protein content that ranges between 220 g kg-1 in the in the non-decorticated and 560.2 g kg^-1 in the completely decorticated seed, with metabolizable energy in the range of 7.4 to 11.99 MJ kg^-1. Furthermore, the fibre content of CSM exceeds that of SBM by 25% in the non- decorticated to 5% in the fully decorticated seed (Nagalakshmi et al., 2007). This promising nutrient profile of CSM, along with the fluctuation in the price of SBM around the world encourages poultry nutritionists and producers to trial CSM as a cost-effective and best nutritional alternative to SBM (Aftab, 2009).
Numerous ways have been reported that help in alleviating the limitations associated with the inclusion of CSM in poultry diets and raise its nutritive value. These include genetic manipulation of Gossypium through conventional breeding approaches and/or modern biotechnology, ingredient processing, using effective feed processing techniques, to decrease and inhibit anti-nutrients, and supplementation with nutrients such as synthetic amino acids, fat and vegetable oils. However, microbial enzymes appear to be the most effective solution to overcoming the limitations of the high-fibre and the non-starch polysaccharide (NSP) contents of alternative vegetable proteins that limit their inclusion at high levels in poultry diets (Scott et al., 1998: Leeson and Summers, 2001). All the above-mentioned techniques have helped to increase the CSM inclusion rate from 5% to around 30% of complete formulated diets for broiler chickens without compromising birds' performance (Watkins et al., 1995). Poultry lack specific enzyme systems to target NSP. For this reason, researchers are concentrating on developing single and composite microbial enzyme products that target NSP and enhance the nutritive value and nutrient digestibility of diets containing fibrous vegetable protein meals (Scott et al., 1998).
The poultry industry has employed microbial enzymes to improve the quality of temperate cereals and oilseed cakes. Therefore, inclusion of appropriate exogenous microbial enzymes in poultry feeds has clearly been demonstrated to increase the bio-availability of poorly digested diets, promote utilization of fibrous diets and improve the feed conversion ratio. These positive effects of the usage of exogenous enzymes have been frequently reported in recent studies as a result of the use of newly developed products for specific ingredients (Creswell, 1994; Slominski et al., 2006; Raza et al., 2009).
Much research and many industry field studies have been conducted to investigate the possibilities of replacing more expensive plant protein sources, like SBM, with alternatives with a similar nutritive value but lower prices such as CM, CSM and SFM. The present study is one of these investigations, and, hence, the main objectives of this study are to:

• Test the response of broiler chickens to CSM-containing diets supplemented with new microbial enzyme products (Avizyme 1502 and Axtra XB).
• Assess the potential of microbial enzymes in improving the nutritive value of CSM in diets for broiler chickens, especialy NSP-targeting enzymes.
• Evaluate CSM as a cost-effective alternative protein ingredient to SBM without compromising broiler performances.
• The study is intended to, among other things, determine the optimum levels of CSM and the test microbial enzymes in diets for broiler chickens and establish CSM as a competitive alternative to SBM.

2010, Widodo, Aluisius Edi, Iji, Paul, Nolan, John V

Triticale is a cereal grain that holds great promise as an alternative to wheat and other conventional grains used in poultry diets. Triticale generally has a higher yield than wheat and adapts to more difficult agronomic conditions than wheat (Korver et al., 2004). A crop breeding group at the University of New England (UNE) has developed varieties that are even more high-yielding and more disease-resistant than the current commercial strains. These varieties will need further evaluation to establish their potential for animal, and particularly poultry feeding.

2005, Vidanarachchi, Janak Kamil, Mikkelsen, Lene, Sims, I, Iji, Paul, Choct, Mingan

Phytobiotics represent a wide range of bioactive compounds that can be extracted from various plant sources. In recent years, some interesting and novel applications of phytobiotics in the production and wellbeing of monogastric animals have emerged, and these aspects are reviewed in the present paper. Recent studies at the University of New England indicate that water—soluble carbohydrate extracts from some Australian and New Zealand native plants can be used as potential phytobiotic compounds to modify the gut microflora in broiler chickens. Compared with other in—feed antibiotic alternatives, the evaluation of phytobiotics is still in its infancy and their potential use needs to be investigated with broader emphasis.

2007, Olnood, Chen Guang, Mikkelsen, Lene, Choct, Mingan, Iji, Paul

A total of 294 one-day old Cobb broiler chickens were used to investigate the effects of four lactobacillus strains on production performance. The chicks were assigned randomly to six groups with 7 replicates of 7 chicks per treatment. The six dietary treatments were: (i) basal diet (negative control, Tl); (ii) basal diet with added Zinc-bacitracin (ZnB, 50 ppm, T2), iii) one of four strains of Lactobacillus (tentatively identified as L. johnsonii, L. crispatus, L. salivarius and unidentified Lactobacillus sp., T3, 4, 5 and 6). The probiotic strains were selected from 235 lactobacilli isolates based on their in vitro antagonistic effect against Clostridium perfringens and Escherichia coli. Results showed that the addition of probiotic Lactobacillus spp. to the feed did not significantly improve body weight gain, feed intake and feed conversion ratio of broiler chickens raised in cages during the 6-wk experimental period.

2016, Akter, Marjina, Graham, H, Iji, Paul

Five hundred and seventy six-d old Ross 308 broiler chicks (6 cages per diet, 8 birds per cage in 3 x 2 x 2 factorial arrangement) were fed on maize–soybean meal-based diets containing three concentrations of Ca (6, 8 or 10 g/kg), two concentrations of non-phytate phosphorus (NPP) (3 or 4 g/kg) and two levels of exogenous microbial phytase (0 or 500 FTU/kg) from d 0 to 35. Body weight(BW), feed intake(FI) and mortality records were collected. Two birds per replicate were killed at 24 d of age to obtain tibia samples.Increasing Ca level significantly reduced the FI and body weight gain (BWG) between hatch and 10 and 24 d, especially with the phytase-supplemented diets. However, phytase supplementation of the diet containing 4 g NPP/kg improved the FI and BWG at d 10 and 24. At d 24, phytase supplementation improved feed conversion ratio (FCR) of birds that consumed diets containing high NPP. The overall FCR was better in birds offered the phytase-supplemented, medium-Ca diet.There was a significant reduction in length, width and breaking strength of the tibia bone in birds fed on a diet with high Ca and low NPP. Phytase supplementation improved the tibia ash content and bone breaking strength of chicks fed on the diet containing 8 and 4 g/kg Ca and NPP, respectively. The Ca content of the tibia bone was low in birds fed on diets with 6 and 4 g/kg Ca and NPP, respectively, but this was counteracted by phytase supplementation.Birds fed on diets with 4 g/kg NPP had the best carcass percentage and parts yield. Phytase supplementation to high-Ca diets significantly reduced the carcass yield of birds.These results confirmed the detrimental effect of high dietary Ca on phytase activity and subsequent growth and bone development of birds, especially when NPP is in short supply.

2018, Widodo, A E, Nolan, John V, Akter, Mohammed, O'Neill, H M, Iji, Paul

A total of 384 day-old male Ross 308 broiler chicks were allocated to 8 dietary treatments to examine the influence of supplementation with xylanase and phytase, individually or in combination, in diets based on two new cultivars of triticale (Bogong and Canobolas). The inclusion of phytase alone in either Bogong or Canobolas diets increased (P < 0.01) feed intake and body weight; however, the effect of grain was not significant. The ileal digestibility of crude protein, gross energy, starch, calcium, and phosphorus was increased by inclusion of phytase and xylanase (P < 0.05). The interaction between xylanase and phytase positively influenced (P < 0.01) the digestibility of crude protein, gross energy, calcium, and phosphorus. Ileal viscosity was decreased (P < 0.05) by the inclusion of xylanase and phytase individually or in combination. The inclusion of phytase and xylanase increased (P < 0.001) the phytate- P degradation. Birds on Bogong-based diet had a higher (P < 0.05) degradation of phytate than those on the Canobolas-based diet. The weight of various visceral organs on day 7 was not affected by the inclusion of enzymes, nevertheless the weight of proventriculus plus gizzard was higher (P < 0.01) for chickens offered Canobolas-based than chicks on the Bogong-based diets. On day 21, the liver weight was reduced (P < 0.001) by the inclusion of phytase. An interaction (P < 0.01) between grain and phytase inclusion led to an increased weight of proventriculus plus gizzard on the Bogong diets with phytase. The inclusion of xylanase increased (P < 0.01) maltase activity at the jejunum on day 7, while it decreased the pancreatic protein content on day 21. The activity of chymotrypsin amidase was reduced (P < 0.01) by the inclusion of phytase. These results show that supplementation of phytase and xylanase to triticale-based diets can improve broiler performance by increasing the activities of some digestive enzymes and nutrient utilization.