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    Influence of different levels of black soldier fly larvae meal on growth performance and carcass quality of broiler chickens
    (Elsevier B.V., 2024-11-02) Baderuddin SH; David LS; Wester TJ; Morel PCH
    A study was conducted to examine the impact of two inclusion levels of Black soldier fly larvae meal (BSFLM) replacing soybean meal on growth performance, nutrient utilization, carcass characteristics and meat quality of broilers. Three experimental diets based on corn-soybean meal were developed to contain 0 (control), 6 (BSF 6) and 12% (BSF 12) BSFLMfor both starter and grower phases. Each experimental diet was randomly allotted to six replicate pens (eight birds per pen). The birds were offered starter pellets from 0 to 14 day post-hatch and grower pellets from 15 to 28 day post-hatch. The experimental diets were tested for pellet durability index (PDI). There was an interaction between diet and growth phase (P < 0.001) for pellet durability index where starter diets had always a higher PDI than the grower diets, but the difference was greater for control diet than BSF 6 and BSF 12 diets. Apparent metabolizable energy (AME) of diets and coefficients of apparent ileal digestibility (CAID) of nutrients were measured on day 28 using titanium dioxide marker ratios in the diet and excreta/ileal digesta. On day 28, the weights of live body, carcass, fat pad, breast and gizzard were recorded, and then breast meat quality (meat pH, drip loss and cooking loss) was examined. Inclusion of BSFLM of up to 12 % did not reduce live weight gain or feed intake. Live weight and carcass weight were heavier in broilers fed 12 % BSFLM than controls (P < 0.02), but were not different than those fed 6 %, while controls were not different than those fed 6 %. Breast weight (percentage live weight) was lower in birds offered 12 % BSFL than in others (P < 0.04). No differences were observed between diets for the percentage weight as carcass, fat, pad and gizzard. The AME and AMEc of diets were the highest in broilers fed 6 % BSFLM diet (P < 0.005), but there were no differences between controls and those fed 12 % BSFLM. The CAID of DM, ash and N in birds fed 6 % BSFLM were greater than (P < 0.03) birds fed 12 %, but were not different than controls, which were also not different than those fed 12 %. Broiler breast meat quality was unaffected by dietary treatments. In conclusion, BSFLM at 12 % can be used effectively as a SBM replacement in starter and grower diets, without affecting the growth performance, nutrient utilization, carcass characteristics and meat quality of broiler chickens.
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    Feeding strategies to alleviate the effect of heat stress on growth performance in broilers: a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Animal Science at Massey University, Manawatū, New Zealand
    (Massey University, 2014) Jack, Heidi Anna
    Broiler production is seen as critical to socio-economic development within the tropics. With the higher and rising temperatures of the tropics, heat stress is a major challenge of the industry. Of the many approaches used to alleviate heat stress, nutritional strategies have been seen as more economically viable in comparison to non- nutritional strategies used to alleviate heat stress. The current study was done to assess both the combined and specific impact of diet density (high fat versus low fat diets) and diet form (mash versus pelleted diets), on alleviating heat stress in broilers. Biological responses were monitored through growth performance and digestibility data. The experimental design used in the study was a 2 x 2 x 2 factorial arrangement of treatments from day 10 to day 34 of the trial period. Birds were subject to one of eight treatments which included a combination of one of two different temperatures (normal or elevated), one of two different diet types (high fat or low fat) and one of two different diet forms (mash or pellet). These treatments included Low Fat Mash under Normal Temperature conditions (LMN), Low Fat Mash under Elevated Temperature conditions (LME), Low Fat Pellet under Normal Temperature conditions (LPN), Low Fat Pellet under Elevated Temperature conditions (LPE), High Fat Mash under Normal Temperature conditions (HMN), High Fat Mash under Elevated Temperature conditions (HME), High Fat Pellet under Normal Temperature conditions (HPN) and High Fat Pellet under Elevated Temperature conditions (HPE). Pellet fed birds had a higher growth performance under elevated temperature and in phase 2 (day 21 to 34), had the highest (P = 0.016) feed intake (166.9 g/b/d) compared to other treatments which were all statistically equivalent. With respect to ileal nutrient intakes, the intake of fat for the overall period and the intake of AME for phase 2 was highest (P = 0.045 and P = 0.018 for fat and AME respectively) on pellet fed birds housed under elevated temperature. Also, these birds had the highest (P = 0.048) growth efficiency (16.8 MJ/kg per kilogram gain) compared to mash fed birds (18.8 MJ/kg per kilogram gain).
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    Investigation of energy partitioning in modern broiler chickens : a thesis presented in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Poultry Nutrition at Massey University, Palmerston North, New Zealand
    (Massey University, 2014) Shatnawi, Khaldoun
    Studies were conducted to estimate the energetic efficiencies for fat deposition from different energy sources (carbohydrate, protein, soybean oil and tallow) and to determine the maximum protein deposition (Pdmax) and minimum body lipid to protein ratio (minL/P) of the modern broiler chickens. Energetic efficiencies for fat deposition were assessed by feeding birds extra energy from different energy sources when protein was limiting in the diet. Comparison of birds slaughtered before and after the dietary treatments were applied allowed the determination of the energy retained as fat or protein. In the first experiment (Chapter 3), the energetic efficiencies of fat deposition from vegetable oil and starch were estimated to be 0.82 and 0.69, respectively. In the second experiment (Chapter 4), the energetic efficiencies of fat deposition were estimated to be 0.93 from soybean oil and 0.90 from tallow, but there was no significant difference between soybean oil and tallow. In the third experiment (Chapter 5), the efficiency of energy deposition as fat from non-essential amino acid intake was calculated to be 0.63. In the fourth experiment (Chapter 6), the Pdmax and minL/P were determined by feeding diets not limited for protein with varying energy levels. The maximum daily protein deposition was predicted at 22 g/day. According to broken-line model, the rate of protein deposition increased when the apparent metabolisable energy intake above maintenance requirement (AMEIp) increased up to the break point of 1.2 MJ/day. Further increases of AMEIp did not lead to an increase in protein deposition rate whereas the fat deposition rate sharply increased. The body weight and energy intake affect the L/P ratio. Across all treatment groups, the minimum value of L/P ratio was observed at 0.31 for birds fed 1 MJ/day of AMEIp at 4 kg live body weight. From the knowledge of net energy requirements and considering the efficiency of metabolisable energy for fat and protein deposition from all experiments, a simple mechanistic growth model was developed for modern broilers (Chapter 7). The model simulates the daily growth of broilers and it was able to predicting the broiler performance and carcass composition under a variety of nutritional conditions. Moreover, the model was evaluated with a range of experimental data (Chapter 8) and prediction values were in close agreement with observed values. The relative prediction errors were 3.8% and 7.3%, for prediction of slaughter live body weight for dependent and independent dataset, respectively. In conclusion, the efficiencies of energy utilisation for fat deposition varied depending on energy sources with the highest values for soybean oil and tallow followed by starch and the lowest for protein. Modern broilers have an upper limit for protein deposition (22 g/day). The body weight and energy intake affect the L/P ratio and the minimal L/P ratio was observed at 0.31. The mechanistic growth model based on energy partitioning concepts can be a tool to predict the carcass composition and broiler performance and can deal adequately with the complexity of nutritional factors. The finding of this thesis is that the broiler performance can be improved by formulating the diet to maximise the protein deposition with minimum fat deposition. The maximum protein deposition can be achieved when the birds consumed 1.2 MJ/day of AMEIp or 2.5 MJ/day of AME intake, further energy intake will deposited as lipid
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    A survey of commercial small-scale poultry production systems and nutrient characterisation of local feed ingredients in Laos : a thesis presented in partial fulfilment of the requirements for the degree of Master of AgriScience at Massey University
    (Massey University, 2014) Phommasack, Outhen
    This thesis comprises of two separate studies. A survey of small-scale chicken production (layer and broiler) in Laos is presented in Part 1 and the characterisation of local feed ingredients is presented in Part 2. Part 1 examined aspects of demographic details, breeds and sources, management systems, labour, diseases, production parameters, marketing and farmer attitude in small-scale chicken farms. For the survey of layer farms, a total of 35 farmers from Xaythany and Naxaithong districts were interviewed. All producers were over 30 years of age. Almost 75% of interviewees were males, showing that males play a significant role in the leadership in the families. The average hen day production was found to be 0.65 and an average of 1.81 kg feed was required to produce a dozen eggs. It was observed that this feed conversion efficiency level was similar to those reported in some tropical countries, but poorer than the recommendation by breeding companies for modern layers (1.58 kg feed/dozen eggs). Hens were culled after 18 months of production (around 2 years of age). During this period, a hen produced an average of 242 eggs, which was lower than the 300 or more eggs expected for modern layers under optimum conditions. Number factors are responsible for the poor layer performance under small farm conditions in Laos, with poor management being the main cause. This problem can be solved by the involvement of government and better veterinary and extension services. The average mortality was 11%; diarrhoea and bird flu were the main causes associated with the deaths. Vaccines and drugs were regularly used by all farms. For the broiler survey, 7 broiler farms in Naxaithong district were surveyed. All farms operated under contract with a large company (Charoen Pokphand Laos Company). The annual broiler output per farm ranged from 15,000 to 24,000 birds. The number of production cycles per year and the type of breed provided are decided by the company. Three breeds are raised, namely Ross 308, Brown Nick and 3-line crossbreeds. The average market age was 8.6 weeks at an average body weight at 1.5 kg. The FCR (feed conversion ratio) was 2.1 kg feed/kg gain. Although all farms received good quality feed and regular monitoring from the CP Company, the feed efficiency was higher compared to breeding company standards (1.6 kg feed/kg gain). The average mortality was 1.4%. Ross 308 was found to be more susceptible to the hot environment than the other two breeds. Deaths in Ross 308 were related largely to the faster growth rate. The study reported in Part 2 aimed at characterising the nutrient contents of locally available poultry feedstuffs so that dependence on imported commercial feeds can be reduced. Fifteen local feedstuffs (rice bran, broken rice, cassava leaf meal, cassava root meal, coconut meal, fish meal, green banana meal, groundnut, leucaena leaf meal, maize, sesame seed, snail meal, soybean, sweet potato tuber meal and taro meal) were collected. Each sample was analysed for proximate composition, minerals and amino acids. Of the tested ingredients, fishmeal had the highest crude protein content (54.4 g/100 g), while sweet potato tuber meal had the lowest crude protein content (3.5 g/100 g). The highest crude fat value (65.0 g/100 g) determined for full-fat copra, followed by sesame and groundnut seeds (54.8 and 54.4 g/100 g, respectively). Roce bran had the highest fibre content (14.7 g/100 g) and snail meal the highest ash content (71.3 g/100 g). Snail meal had the highest calcium content (30.0 g/100 g) followed by fish meal (4.50 g/100 g). Snail meal was also rich in t iron, copper, manganese and zinc. Fish meal had high contents of amino acids. Whereas cassavas root meal had the lowest.
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    Whole grain inclusion in poultry diets : effects on performance, nutrient utilisation, gut development, caecal microflora profile and coccidiosis challenge : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Animal Science at Institute of Veterinary, Animal and Biomedical Sciences (IVABS), Massey University, Palmerston North, New Zealand
    (Massey University, 2013) Singh, Yashpal
    Whole grain feeding has recently received renewed interest in the commercial poultry industry as a mean of lowering feed manufacturing cost. Wheat is the cereal grain of choice for whole grain feeding, despite the fact that globally maize is the most commonly cereal grain. Published data on the use of whole maize in poultry diets are scant. The size of maize grain may be the major reason for the lack of interest in feeding whole maize. The first three experiments of the thesis investigated alternative feeding strategies such as pre-pelleting inclusion or minor modifications such as cracking or coarser grinding to overcome the issue of maize kernel size. Experiment four evaluated whole wheat (WW) feding and examined the interaction between pellet diameter (3.0 vs 4.76 mm) and method of wheat inclusion (ground wheat (GW) or WW pre-and post-pelleting). The intention of using a larger pellet die was to retain the larger wheat particle size in pellets. Experiment five investigated the effect of whole wheat feeding in broilers experimentally challenged with a mixed infection of Eimeria. Pre-pelleting inclusion of 0 to 600 g/kg whole maize replacing (w/w) ground maize in broiler starter diets showed that the weight gain of broilers was poorer despite improvements in gizzard development, nutrient utilisation and pellet quality (Chapter 4). Poor weight gain was due largely to reduced feed intake. Inclusion of 0 to 600 g/kg coarse maize, replacing (w/w) finely-ground maize, in broiler diets in mash form from day 11 to 35 post-hatch resulted in improvements in weight gain and gizzard weight without any negative effect on nutrient utilisation and carcass yield (Chapter 5). Increased caecal counts of beneficial bacteria Lactobacilli spp. and Bifidobacteria spp. and decreased counts of Clostridium spp., Campylobacterium spp. and Bacteroides spp. were also reported. Similarly, feeding diets containing 0 to 600 g/kg coarse maize to laying hens, from 39 to 62weeks of age, had no adverse effects on any production parameters and egg quality (Chapter 6). These results indicated that ground maize in broiler and layer diets could be completely replaced by coarsely ground maize with no adverse effects of bird performance. . Data reported in Chapter 7 showed that the effect of pellet diameter on broiler performance varied depending on the form of wheat and method of WW inclusion. Larger pellet diameter increased the weight gain and lowered feed per gain of birds fed diets with GW and post-pellet inclusion of WW. However, in birds fed diets with pre-pelleting inclusion of WW, the larger pellet diameter lowered weight gain and increased feed per gain, due largely to reduced feed intake which may be attributed partly to poorer pellet quality. Relative gizzard weight was increased by larger pellet diameter with pre-pelleting inclusion of WW, but was unaffected by diets containing GW or post pelleting inclusion of WW. Larger pellet diameter increased the apparent metabolisable energy and ileal starch digestibility, irrespective of method of WW inclusion. These results suggested that, irrespective of whether the wheat grain was milled or added whole post-pelleting, a larger diameter pellet was beneficial. On the other hand, when WW was added pre-pelleting, a smaller diameter pellet resulted in improved weight and feed per gain in broiler performance. In the final experiment (Chapter 8), broilers fed WW either pre-or post-pelleting and experimentally challenged with a mixed Eimeria infection at 21 day of age showed that mortality in challenged birds was highest in those fed diets with WW post-pelleting, followed by pre-pelleted WW and GW (58, 35, and 17%, respectively). The pattern of mortality paralleled the changes in gizzard size, which suggested that WW feeding exacerbated the severity of coccidiosis infection, possibly via a mechanism involving enhanced gizzard development.
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    Factors influencing fat digestion in poultry : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Poultry Nutrition at Massey University, Palmerston North, New Zealand
    (Massey University, 2012) Tancharoenrat, Piyamas
    The first experiment in this thesis was conducted to understand the digestion of fat along the gastrointestinal tract and ileal endogenous fat losses. The second, third and fourth experiments investigated the factors influencing fat digestion in broilers, including age of birds, cereal type, fat source and dietary calcium concentrations. In the fifth experiment, influence of unsaturated to saturated fatty acid ratio (U:S ratio) on fat digestion was examined. The first experiment reported in Chapter 4 showed that jejunum is the major intestinal site where majority of fat and fatty acids is digested and absorbed. Long chain fatty acids showed lower digestibility than short chain fatty acids, and unsaturated fatty acids were better digested than saturated fatty acids. The fatty acid profile of ileal endogenous fat was remarkably similar to that of the bile, suggesting that the reabsorption of fat and fatty acids in bile was incomplete. Data reported in Chapter 5 showed that the apparent metabolisable energy (AME) and total tract digestibility of fats was influenced by the age of broilers. The AME of fat was markedly lower during the first week, increased rapidly during second week and then remained constant thereafter. Total tract fat digestibility was poor during the first week and then increased until the third week of age. No further improvement was observed after the third week. The AME and fat digestibility of soybean oil, poultry fat and palm oil were determined to be higher than those of tallow. Blending of tallow and soybean oil resulted in AME and fat digestibility estimates higher than the arithmetic averages of tallow and soybean oil. The study reported in Chapter 6 showed that the supplementation of tallow in wheat- and maize-based diets resulted in lower weight gain than that of soybean oil, but fat source had no effect on the weight gain of broilers fed sorghum-based diets. Broilers fed soybean oil supplemented diets had lower feed per gain, higher total tract retention and ileal digestibility of fat compared to those fed tallow supplemented diets. In addition, supplementation of xylanase in wheat-based diets resulted in improved weight gain and feed efficiency of broiler starters irrespective of the fat source. Xylanase supplementation increased the AME of tallow supplemented diets, but had no effect on soybean oil supplemented diets. Data reported in Chapter 7 indicated that high dietary calcium concentrations had negative impact on broiler performance, irrespective of tallow inclusion levels. High calcium concentrations resulted in higher excreta soap and, lowered the total tract retention of fat, calcium and phosphorus. Lower calcium concentrations resulted in higher ileal digestibility of fat, nitrogen and phosphorus. Data from the final experiment (Chapter 8) showed that the U:S ratio influenced the performance of broilers during the starter period (1 to 21 day), but had no effect on the performance over the whole trial period (1 to 35 day). Increasing the U:S ratio decreased the AME of diet and increased the total tract retention of fat. A positive linear correlation between U:S ratio and the AME of fat blends was observed, with increasing U:S ratios improving the AME of fat blends. In conclusion, the research reported in this thesis identified several factors that influence the digestion of fat in poultry. Age of broilers influenced the digestion and absorption of fat, particularly during the first week of age. The findings consistently demonstrated that tallow was more poorly digested than soybean oil. The utilisation of these two fat sources was influenced by the cereal base used in the diets, with the effect of fat source on weight gain differing between cereal types. High dietary calcium concentrations were detrimental to the digestibility of nutrients, especially of fat. A finding of practical interest was that digestion and absorption of animal fats, containing high concentrations of saturated fatty acids, can be improved by blending with soybean oil to increase the U:S ratio.
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    Pharmacology of analgesic drugs in birds : thesis in fulfilment of the degree of Doctor of Philosophy in Animal Science
    (Massey University, 2011) Singh, Preet Mohinder
    Analgesics drugs are widely used to alleviate pain in mammals and birds. However, in the case of birds, there is a scarcity of information on their usage and dosing regimen. A lack of pharmacokinetic knowledge can result in under or over-dosing of drugs with subsequent loss of efficacy or side-effects. Complete understanding of a drug requires knowledge of its pharmacokinetics as well as pharmacodynamics. Considering the various voids in pharmacological research in birds and in an effort to know more about pain and welfare in birds, this study was designed to study the pharmacokinetics of morphine, butorphanol, aspirin and salicylic acid in broiler chickens. Broiler chickens were used as a model for wild and rare birds. Morphine and butorphanol were injected intravenously at 2 mg/kg, while aspirin and salicylic acid were injected intravenously at 50 mg/kg. All the analgesic drugs were well distributed in chickens. The plasma clearance for these drugs was much higher than in mammals, resulting in shorter half-lives. All the drugs remained within the theoretical therapeutic range for 2 hours. For analgesic efficacy testing, all the drugs except aspirin were injected in lame broiler chickens at similar dose rates as in the pharmacokinetics experiment. The results from the efficacy tests suggest that butorphanol and salicylic acid provided adequate analgesia which lasted for less than 2 hours. Morphine at 2 mg/kg intravenously induced sedation and drowsiness in chickens, which might be due to the high dose. It may have analgesic effects at lower dose rates, however this needs to be further evaluated. The approximate therapeutic range in broiler chickens for butorphanol is 50 to 80 ng/mL and for salicylic acid is 50 to 110 ng/mL. The therapeutic range for butorphanol is much higher in birds as compared to mammals while for salicylic acid it is in the mammalian range. The duration of analgesia in birds could be increased by using sustained released formulation or drug delivery systems, which warrants further research. Plasma concentrations after butorphanol given at 4 mg/kg in an injured Northern Royal Albatross under surgical conditions were also evaluated. This is the only pharmacokinetic study of an analgesic drug in a sea bird. The pharmacokinetics of butorphanol in this albatross differed significantly from chickens, with slower clearance and lower tissue distribution, although these were much higher than in mammals. The difference in pharmacokinetic parameters could either be due to species variation or due to the continuous fluid therapy along with butorphanol administration. This albatross was suffering from a major femur fracture, which potentially altered its normal physiology and metabolism. Chickens may be used as a model of drug research for wild and rare avian species, especially for preclinical trials. The dosing regimens can be extrapolated from chicken pharmacokinetics data, but this should be done with extreme caution as pharmacokinetics are highly variable between the species.
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    Influence of feed processing on the performance, nutrient utilisation and gut development of poultry and feed quality : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Poultry Nutrition at Massey University, Palmerston North, New Zealand
    (Massey University, 2011) Abdollahi, Mohammad Reza; Abdollahi, Mohammad Reza
    The first two experiments of this thesis investigated the effects of conditioning temperature in relation to grain type (maize, wheat and sorghum) on the performance, nutrient utilisation and digestive tract development of broiler starters. The third experiment examined the influence of feed form (mash vs. pellet) and conditioning temperature in broiler starters fed wheat-based diets. The effects of improved pellet quality from the addition of a pellet binder or/and moisture to a wheat-based diet, and the effects of pellet diameter and pellet length on the quality of pellets and, performance, nutrient utilisation and digestive tract development of broilers were studied in fourth and fifth experiments, respectively. In the first experiment discussed in Chapter 4, increasing conditioning temperatures decreased the weight gain and feed intake of broilers fed wheat-based diets, whereas birds fed maize-based diets conditioned at 60 and 90 ºC had higher weight gain and feed intake than those fed the diet conditioned at 75 ºC. Increasing conditioning temperatures increased the feed per gain in both grain-type diets. Pellet durability index (PDI) improved with increasing conditioning temperatures in wheat-based diets, but was unaffected in maize-based diets. In wheat-based diets, increasing conditioning temperatures decreased the ileal digestibility of nitrogen (N) and starch. Ileal N digestibility of maize-based diets conditioned at 60 and 90 ºC was higher than at 75 ºC. Starch digestibility was unaffected by conditioning temperature in maize-based diets. No effect of conditioning temperature was found for the apparent metabolisable energy (AME). Data reported in Chapter 5 showed that birds fed maize- and sorghum-based diets conditioned at 60 ºC had a similar weight gain to those fed diets conditioned at 90 ºC and higher than those fed diets conditioned at 75 ºC. In both grain-type diets, birds fed diets conditioned at 60 and 90 ºC tended to have higher feed intake than those fed diets conditioned at 75 ºC. Conditioning temperature had no effect on the feed per gain. Increasing conditioning temperatures caused gradual improvements in the PDI of maize-based diets, while the improvement was marked in the sorghum-based diet conditioned at 90 ºC. In both grain-type diets, pellet hardness increased with increasing conditioning temperatures, particularly at 90 ºC. In maize-based diets, ileal N digestibility was poorer at 75 ºC compared with 60 and 90 ºC whereas ileal starch digestibility was unaffected by conditioning temperature and AME was higher at 75 ºC compared with 60 and 90 ºC. For sorghum-based diets, increasing conditioning temperatures resulted in linear reductions in the ileal N and starch digestibility and AME. Data reported in Chapter 6 showed that in mash diets, increasing conditioning temperatures above 60 ºC had negative effects on weight gain, feed per gain and nutrient utilisation of broiler starters. But the deterioration in performance parameters caused by conditioning at higher temperatures was restored when steam-conditioned mash diets were pelleted. Pellet durability and hardness increased with increasing conditioning temperatures. Data reported in Chapter 7 showed that the negative effect of higher conditioning temperature on weight gain, and to some extent feed intake, of broilers is not limited to the starter period (d 1 to 21), but can also be carried over the whole growth period (d 1 to 35). This study also illustrated possibilities for high quality pellets to be manufactured by the addition of pellet binder or/and moisture to a mash diet without the need for high conditioning temperatures. The final experiment (Chapter 8) demonstrated that increasing the pellet length from 3- to 6-mm during the grower period (d 10 to 21) positively influenced the weight gain and feed per gain of broilers. While the weight gain response disappeared as the birds grew older, improvements in feed per gain was maintained over the finisher (d 22 to 42) and whole grow-out (d 10 to 42) periods in 4.76-mm diameter pellets. This study also showed that using a small diameter die hole and longer pellet length may have an additive effect on pellet quality, and provide opportunities to produce high quality pellets under low conditioning temperatures. The major finding of this thesis research was that the balance between the negative effect of high conditioning temperatures on nutrient availability and the positive effect on pellet quality is relevant in determining the broiler performance. The probability and magnitude of these two counteracting effects determine the performance of broilers. Another important finding was that the pre-conditioning addition of moisture and the use of small diameter die hole and longer pellet length can effectively address pellet quality concerns at low conditioning temperatures.