Comparisons of the skeletal systems of growing broiler and laying strain chickens

Skeletal systems of growing broiler and laying strain chickens were compared in an attempt to establish whether the rapid growth rates of broilers lead to qualitative or quantitative skeletal deficiencies. Qualitative comparisons included studies of bone histology and of bone ash, density and compression strength. Quantitative comparisons related bone weight to body weight. Bone “ matured “ very rapidly, as judged by its density, ash content and weight relative to bird weight in the first fortnight of life and thereafter more slowly in both broilers and laying strain birds. After the age of I week bones “ matured “ mainly by replacement of water by mineralised osteoid—the degree of mineralisation of osteoid being a less important factor in bone “ maturation “. There were no significant differences from the viewpoint of either quality or quantity between the skeletal systems of broilers and laying strain birds of the same age. At equal body weights, however, broilers had skeletal systems which were both qualitatively and quantitatively less “ mature “ than those of laying strain birds. These differences were most marked during early life when the rate of skeletal “ maturation “ was high.     

Higher lipid accumulation in broilers fed on saturated fats than in those fed on unsaturated fats

1. Two experiments were conducted to assess the effect of fat sources differing in degree of saturation on the performance of and fat deposition in broiler chickens fed on isocaloric and isonitrogenous diets. 2. There were no differences in initial body weight between sexes but female broilers had lower daily gains (P <0.0001), final weights (P <0.0001) and food intakes (P <0.0001) than males. Abdominal fat pad weight was lower in male broilers than in female (P <0.001). 3. There were no significant differences in intake, weight gain, final body weight or food-to-gain ratios between birds fed on diets differing solely in the degree of fat saturation. Broilers fed on diets containing an animal fat blend or tallow had higher abdominal fat pad weight (P <0.001) and intramuscular lipid content (P =0.0085) than those fed on diets containing sunflower oil. 4. It was concluded that dietary fat saturation affects fat accumulation in broiler chickens.     

The impact of nutrient density in terms of energy and/or protein on live performance,metabolism and carcass composition of female and male broiler chickens of two commercial broiler strains

The objective of this study was to investigate the effects of diet composition on performance, slaughter yield and plasma metabolites, as different modern broiler strains show different responses to feed intake. Broilers of two commercial strains and of both sexes received one of three diets being different in energy and/or protein level [control diet, low energy/low protein diet (LM/LP) and low protein diet (LP)]. Low energy/low protein diet chickens were characterized by significantly lower body weights and feed intake compared with their LP and control counterparts. Broilers of the Cobb strain or broilers that were fed the control diet were most efficient in converting energy to body weight. No significant differences in plasma metabolites were detected due to diet composition or genotype. The diet with the lower energy and crude protein levels reached the lowest slaughter yield but the highest drumstick and wing percentages. The lowest mortality percentages were observed for broilers fed the LM/LP diet, and Cobb birds appeared to be more sensitive for metabolic disorders resulting in death. It is obvious from this study that different genotypes respond differently to changes in diet composition and therefore have adjusted nutritional requirements.     

Ubiquitin gene expression and ubiquitin conjugation in chicken muscle do not reflect differences in growth rate between broiler and layer birds.

Previous work has shown that chicken strains selected for growth (broilers) degrade muscle proteins less rapidly than those selected for egg laying. They also have decreased calpain and increased calpastatin content in breast muscle. This study aimed to test the hypothesis that these differences correlate with changes in the ATP- and ubiquitin-dependent proteolytic system. Chickens of a broiler strain (Ross 1) and a layer strain (ISABrown) were reared to the age of 4 wk under identical conditions with ad libitum access to feed and water. Mean fractional growth rates were 10.4%/d for broilers and 7.4%/d for layers. Feed intake measured in the last week of the trial was slightly greater in layer birds (.11 and .12 g x g body weight(-1) x d(-1) for broilers and layers respectively; P < .006). Polyubiquitin (UbI) messenger RNA was abundant in the muscles of these well-fed birds, but it showed little difference between strains. Muscle did not significantly express the UbII polyubiquitin gene. The ATP-dependent system conjugating ubiquitin to endogenous proteins had greatest activity in the gastrocnemius muscle of broiler birds but was not significantly different between breeds. Proteins cross-reactive with antisera to recombinant human proteasome regulatory subunits MSS1 (multicopy suppressor of SUG 1; S7) and TBP1 (tat binding protein 1; S6') were present in muscle homogenates from both strains of bird. The chick equivalent of TBP1 was more abundant in breast muscle of broiler birds than in leg muscle, or in either muscle of layers. Antiserum to recombinant yeast subunit mts2 (mitosis temperature sensitive gene 2; S4) did not react with any protein of the expected size but detected a 30-kDa peptide that was not associated with the 26S proteasome; this was found only in muscle from the layer strain. Hence, during normal growth of chickens, rates of protein degradation are not controlled by the expression of ubiquitin mRNA or the conjugation of ubiquitin. However, the composition of the 26S proteasome may be a regulatory factor.     

Comparison of three different diets for organic broilers: effects on performance and body condition

1. The aim of this study was to assess the feasibility of 100% organic feed for organic broilers by comparing it with 80% organic feed (situation at the time of the experiment; 2004) and 95% organic feed (alternative). 2. Diets were optimised for nutritional value, allowing a maximum 10% increase in feed price when using 100% organic feedstuffs. This could only be achieved at the expense of the methionine content. 3. The birds were reared from 0 to 3 weeks of age in a broiler house in three groups of 500 broilers each on either an 80, a 95 or a 100% organic starter diet. At 3 weeks of age, they were transferred to 15 pens with an outdoor run. Each treatment group of 500 birds was divided into 5 groups of 95 and given an 80, a 95 or a 100% organic finisher diet. 4. Broilers receiving 100% organic feed reached a lower body weight and grew more slowly than those receiving 95% organic feed, mainly because of a lower feed intake. 5. Broilers on 95 or 100% organic feed had a higher incidence of breast blisters than broilers receiving 80% organic feed. 6. The cost price for meat from broilers that received 80% organic feed was euro1.83 per kg live weight. The cost prices for broilers that received 95 and 100% organic feed were euro1.84 (+0.8%) and euro1.93 (+5.4%) per kg live weight, respectively. 7. In conclusion, 95% organic feed led to a better performance than 100% organic feed in this study. Probably, the lower methionine content in the 100% organic feed negatively affected performance. The results for 95% organic feed were similar to 80% organic feed, except for a higher incidence of breast blisters.     

早期限饲对肉鸡补偿性生长的影响

试验观察了几种早期限饲措施对肉鸡补偿性生长和消化器官发育的影响。结果显示,各种早期限饲处理均可明显降低肉鸡早期的生长速度和体重;恢复自由采食后肉鸡获得了补偿性生长,适当的早期限饲并不影响肉鸡的最终上市体重;早期限饲改善了饲料效率;限饲鸡胰脏相对重量和肌胃 腺胃相对重量显著高于非限饲鸡,提示早期限饲诱发肉鸡补偿性生长可能与限饲促进消化器官发育、提高消化能力有关。     

Chicken welfare as indicated by lesions on carcases in supermarkets

1. The extent of visible lesions in British broiler carcases was investigated in order to discover the extent of any poor welfare. It is well established that hock burn and some other injuries can occur during housing of broiler chickens, whilst other injuries can occur during handling. 2. Three hundred and eighty-four whole conventionally reared British Farm Standard Grade A chickens were scrutinised in supermarkets to assess the frequency of 15 kinds of lesions. Six lesions were analysed histopathologically and this showed that hock burn would have occurred several days pre-mortem, red alular and wrist bruise were very likely to have occurred pre-mortem, whilst red parson's nose and scratches were likely to have occurred pre-mortem. 3. Many broiler carcases in the supermarkets had dermal lesions: 0.82 had hock burns, 0.45 a red parson's nose, 0.32 a red alular, 0.21 wrist bruises and 0.21 had at least one scratch on a leg. The frequency of the larger hock burns increased with body weight. 'Organic' chickens had half as many hock burns as conventionally reared broilers, perhaps because of differences in litter quality or leg strength. 4. The sample studied indicates that painful lesions which would result in poor welfare are frequent in broilers slaughtered in the UK. The Grade A chickens observed exclude birds with obvious visible defects because these birds would have had the blemishes removed and the carcase would have been portioned. Hence the frequencies of lesions in farmed birds would be higher than those reported here.     

Effect of hatch location and diet density on footpad dermatitis and growth performance in broiler chickens

The effect of hatch location and diet density on the prevalence of footpad dermatitis and growth performance in broiler chickens was studied. Broilers (Ross 308), incubated at 2 different hatch locations but originating from the same parent stock, were subjected to 2 feeding programs differing in energy content (2,750 vs. 2,950, 2,850 vs. 3,050, 2,900 vs. 3,100, and 2,900 vs. 3,100 kcal/kg for starter, grower I, grower II, and finisher diets, respectively) in a 2 × 2 factorial design (6 replicates per treatment combination). Broilers were housed under conditions and managed according to Dutch practice. Hatch location did not affect hatching results nor the prevalence and severity of footpad dermatitis, but did affect BW gain, feed, and water intake. A significant interaction was found between hatch location and feeding program; broilers fed the low-energy (LE) program had a better performance when hatched at Location 2 than at Location 1, whereas performance was similar for the high-energy (HE) broilers hatched at both locations. Broilers fed the LE program had similar BW gain but a higher feed conversion due to a higher feed intake as compared to broilers fed the HE program. In addition, moisture content of the litter in the pens with LE birds was higher than in pens with HE birds. As a result, broilers fed the LE program had more footpad dermatitis and hock burns at d 36 as compared to broilers fed the HE program. It is concluded that the HE feeding program is preferred to prevent footpad dermatitis and hock burn, and with respect to growth performance. The differences in growth performance between the 2 hatch locations merit further study but indicate the importance of the incubation and hatching environment and posthatch handling in relation to the growth performance of broilers on-farm.     

The individual and combined effects of citrinin and ochratoxin A in broiler chicks

Citrinin (CTN) and ochratoxin A (OA) were fed alone and in combination to broilers from day of hatch until 3 weeks of age. Dietary concentrations of 300 micrograms CTN/g and 3.0 micrograms OA/g were used. Birds fed CTN had significantly (P less than or equal to 0.05) lower body weights than controls on days 14 and 21 and increased water consumption on days 7, 14, and 21. Birds fed OA had significantly lower body weights than controls on days 7, 14, and 21 and increased water consumption on day 14. Birds fed CTN and OA in combination had lower body weights than controls and increased water consumption during the experiment, but the alterations were intermediate in severity when compared with those in birds fed CTN or OA alone. Birds fed OA alone or combined with CTN had higher liver and kidney weights than controls, but birds fed CTN alone had only higher kidney weights. Birds fed both CTN and OA had concentrations of serum constituents similar to those in birds fed OA alone, except the levels of cholesterol and triglycerides were not significantly different from those in the controls. Histological evaluation of the kidney indicated no lesions in birds fed CTN alone, but birds fed OA, alone or in combination with CTN, had increased tubular casts and tubular hyperplasia compared with controls. These data suggest that there were no additive or synergistic toxic interactions when 300 micrograms CTN/g and 3.0 micrograms OA/g were fed simultaneously to broiler chicks for 3 weeks. However, the severe growth depression resulting from OA and the increased water consumption associated with CTN toxicosis were ameliorated when CTN and OA were fed in combination. These data may be useful in diagnosing field cases of mycotoxicosis where both CTN and OA are involved.     

Using locally produced millet as a feed ingredient for poultry production in Sub-Saharan Africa

Using locally produced feedstuffs for poultry production in developing countries can greatly lower production costs. Pearl millet is a drought-resistant plant that produces a nutritious grain. Its cultivation in Mali spans thousands of years, but the suitability of the millet grain currently produced in Mali for poultry production is unknown. Therefore, the nutrient composition of 7 different, widely available varieties of pearl millet grown in Mali was assessed before completing experiments in which laying hens or broilers were fed diets containing 0, 14, 28, or 43% whole pearl millet. The 7 varieties of pearl millet grown in different regions of Mali all had protein concentrations that were better than corn and had apparent digestible amino acid coefficients similar to corn. The nitrogen-corrected true metabolizable energy values ranged from 3,395 to 3,738 Kcal/kg on an as-is basis. Egg production and egg weight did not differ between the hens fed the different levels of millet through out a 16-wk experiment. Broilers fed the highest level of pearl millet from 1 to 42 d of age gained less (3.088 versus 2.949 kg) body weight than those fed the control diet. However, body weight gains did not differ between the broilers fed the control diet and the diets containing 14 or 28% whole millet. The results indicate that Malian-grown pearl millet would be an effective feed ingredient for poultry production and that this small seed could be added in whole form into laying hen and broiler diets.     

Body weight,meat quality and blood metabolite responses to carbohydrate administration in the drinking water during pre‐slaughter feed withdrawal in broilers

This study was conducted to determine weights of body (BW), carcass (CW), gastrointestinal tract (GTW), meat quality and some blood metabolite responses to corn starch, saccharose or glucose administration in the drinking water during pre‐slaughter feed withdrawal (FW) in broilers. On day 42 of age, 200 broilers (Ross 308) were allocated randomly to five treatments with four replicates. During a 10‐h FW, control broilers (C) were provided with non‐treated water and the standard finisher diet ad libitum, whereas fasted broilers provided with non‐treated (NFW) or treated water, 3 g glucose (G), saccharose (S) or corn starch (CS)/L. Eight birds (four males and four females) per treatment were slaughtered. Birds receiving non‐treated or treated water had lower BW and higher carcass yield than the full‐fed broilers. The full‐fed broilers had higher absolute and relative GTW than the fasted birds. Broilers consumed more readily treated water compared with non‐treated water. While the a* value of breast meat from CS birds was higher than that from NFW, the b* value of that was higher than S and C birds. The c* values of breast meat from S birds were lower compared with that from the CS treatment. The thigh meat from NFW broilers had higher h* value than that from C and G broilers. The thigh meats of C and CS broilers had higher c* value than that of G birds. The full‐fed broilers had higher plasma triglyceride concentration than NFW, S and G birds. The full‐fed broilers had higher plasma uric acid and uric acid nitrogen concentrations than S birds. These results show that carbohydrate administration in the drinking water cannot be a good alternative for the FW period before slaughter due to the fact that the carbohydrates do not reduce BW losses and do not lead to increases in meat quality.     

共轭亚油酸对肉仔鸡体组成和肉品品质的影响

本试验旨在探讨日粮添加共轭亚油酸(CLA)对肉仔鸡体组成和肉品品质的影响。240只1日龄肉仔鸡随机分配到4个日粮处理组(0%、0.25%、0.5%和1%CLA),每个处理6个重复,每个重复10只鸡。试验结果表明:42d时,0.5%和1%CLA组肉仔鸡胸肌率显著高于对照组(P<0.05),1%CLA组肉仔鸡42d腿肌率显著高于对照组,肉仔鸡的腹脂率在各处理之间没有显著差异(P>0.05),1%CLA组肉仔鸡胸肌粗蛋白质粗脂肪比显著高于对照组(P<0.05)。0.5%、1%CLA组肉仔鸡胸肌滴水损失和丙二醛(MDA)含量显著降低(P<0.05)。试验结果表明,CLA可改善肉仔鸡屠体性状,增加鸡肉系水力和延长货架存放时间。     

鸡混合感染J亚群禽白血病病毒与禽网状内皮增殖症病毒的初步研究

对1日龄肉鸡混合感染J亚群禽白血病病毒和禽网状内皮增殖症病毒进行了初步研究,结果表明:感染鸡生长发育不良,体重显著下降(P<0.05),新城疫疫苗免疫后血清中新城疫抗体效价明显低于对照组(P<0.05),同时使早期鸡对大肠杆菌等细菌性疾病的易感性增加,死亡率升高。这种作用在两种病毒的混合感染后尤为显著。     

A study on feeding hazelnut kernel oil meal as a protein source for broiler chickens

An experiment was conducted to evaluate the effect of substituting different levels of hazelnut kernel oil meal (HKM) for soybean meal (SBM) in diets for broiler. A total of 450 one-day-old female Ross 308 broiler chicks were allocated randomly to three treatment groups of 150 birds each in a randomized design. Each treatment group consisted of five replicates each of 30 chicks. All diets (in mash form) were formulated to meet nutrient concentrations recommended for broilers. The experiment lasted for six weeks. In the experiment, an SBM control (SBM) diet was compared to two HKM diets, replacing 50 (50HKM) and 100% (HKM) of SBM protein, respectively. Body weight gain, feed intake and feed conversion ratio of broilers were adversely affected ( P  < 0.05) by the HKM diets at 42 days of age. Broilers fed 50HKM and HKM had growth performances similar ( P  > 0.05). The carcass yield and abdominal fat pads of birds fed diets with SBM were higher ( P  < 0.05) than those of chicks fed the 50HKM and HKM diets. The edible inner organ weight of chicks fed diets with HKM was the heaviest ( P  < 0.05). It is concluded that SBM cannot be replaced even up to 50% with HKM in commercial broiler diet.     

Effect of a Chinese herb medicine formulation, as an alternative for antibiotics, on performance of broilers

1. A total of 720 female broiler chicks was used to test the effects of 4 dietary concentrations of a Chinese herbal medicine (CHM) formulation (0.25, 0.5, 1 and 2g/kg), as an alternative for virginiamycin (VRG), on growth performance in broilers. 2. A total of 72 birds from non-supplemented, VRG and 0.5 g/kg CHM groups was selected and killed and the relative weights of the intestinal segments were assessed. 3. The CHM dietary treatments produced increased body weight gain at 7 to 21 d of age but not at 21 to 28 d of age compared with the non-supplemented and VRG groups. The CHM groups had a higher feed intake and a higher feed conversion ratio (FCR) than the VRG group between 21 and 28 d. 4. The dissection results showed that the liver colour of the birds in the CHM group varied less between animals than that of the VRG and the non-supplemented groups. Neither CHM nor VRG had any significant effects on either liver or intestinal tract weights. 5. It was concluded that the birds of the CHM group had better growth performance from d 7 to 21 but not thereafter. Further experiments are needed to elucidate the mechanisms underlying enhanced growth performance by CHM in broilers.     

Retrospective and prospective studies of transmissible viral proventriculitis in broiler chickens in Brazil

We investigated the occurrence and pathologic findings of transmissible viral proventriculitis (TVP) associated with the chicken proventricular necrosis virus (CPNV) in commercial broiler chickens in southeastern Brazil. Seventy-three broilers, 25–36 d old, with a history of reduced growth, were referred to our veterinary pathology services from 2013 to 2017. Broilers were clinically examined, weighed, and euthanized for postmortem examination. Broilers of different ages with proventricular histologic lesions were positive for CPNV by RT-PCR; however, the intensity of histologic lesions was higher among 33-d-old animals, and viral RNA detection was more frequent among those that were 28 d old. In the proventriculi of 35 of 73 (48%) broilers, lesions were characterized by glandular epithelial necrosis, lymphoplasmacytic and histiocytic infiltrates, and metaplasia of glandular epithelium to ductal epithelium. In 24 of 73 (36%) broilers with histologic TVP-compatible lesions, CPNV was detected by RT-PCR for the viral protein 1 (VP1) gene. Broilers with histologic lesions were lighter than expected compared to the Cobb 500 standard weight. TVP has not been reported previously in broiler chickens in Brazil, to our knowledge.     

Pituitary weight and gonadotrophin concentration, body weight and ovarian weight in growing and mature female turkeys exposed to different light regiments

Anterior pituitary weights and gonado‐trophin concentration, body weight changes and ovarian weights were followed every two weeks in three lighting treatment periods in spring hatched turkeys. In the growing period (12 to 20 weeks of age), all of the characters changed with the increasing age of the birds while no changes were associated with the lighting treatments (either 14 hr of light daily or natural daylight). During the conditioning period (20 to 28 weeks) anterior pituitary weight, body weight change and ovarian weight all increased with increasing age. No changes were found in anterior pituitary gonadotrophin concentration. Body weight change and ovarian weight were also greater in birds maintained on range as compared with birds treated with 6 or 14 hr of light daily. In the production period (28 to 40 weeks), the birds were divided into laying and non‐laying groups. In the laying group, no differences were found in the three characters studied (ovarian weight not included) within the ages studied. In the non‐laying group, the birds on range had greater body weight increases within the 34th to 38th week than the birds on the other lighting treatments. More of the birds given 6 hr of light during the conditioning period were classified as layers in the production period than birds treated with either 14 hr or natural light (14.3 decreasing to 11.5 hr) during the conditioning period. Once a bird had started laying, a decided drop in anterior pituitary gonadotrophin occurred.     

Effects of Early Feed Restriction on Performance and Ascites Development in Broiler Chickens Subsequently Raised at Low Ambient Temperature

The objective of this study was to examine the effectiveness of early-age growth limitation, achieved through feed restriction (FR), as a means of reducing ascites mortality in broiler chickens exposed to low ambient temperatures. Feed restriction was applied to broilers from 5 to 11 d of age so as to reduce their weight gain to about 40% of that of control broilers that were fed ad libitum (AL). At the age of 21 d the chickens were exposed to a temperature of 15°C, which induced ascites. By 46 d of age, ascites incidence and mortality in the feed-restricted birds were reduced to 15.79 vs. 36.84% and 7.89 vs. 26.32%, respectively, compared with those in the controls (P < 0.05). After feed restriction was stopped, the FR chickens had accelerated weight gain and improved feed conversion ratio from 11 to 18 d of age (P < 0.05), and by 46 d they had achieved the same body weight as the AL birds. Ascitic broilers had smaller relative breast muscle and spleen weights than those of the healthy broilers at 46 d (P < 0.05). However, the relative weights of lung, heart, and liver and the right ventricle weight per total ventricle weight (RV:TV) ratios were greater in ascitic broilers (P < 0.05). At age 37 d, when ascites had developed but not yet caused mortality, the ascitic broilers had lower plasma concentrations of the thyroid hormones thyroxine and triiodothyronine, and higher hematocrit values (P < 0.05) in comparison with the healthy ones. Ascitic birds also had lower oxygen consumption at 6 wk (P < 0.05), which agrees with information that the terminal stage of the ascites syndrome can be characterized by low oxygen consumption. We concluded that the early-age feed restriction reduced ascites incidence and mortality and prevented reduction of the thyroid hormone concentrations in male broilers reared at low ambient temperature from the age of 3 wk onward.     

饲粮精氨酸水平对黄羽肉种鸡产蛋高峰期繁殖性能的影响

本试验旨在研究不同饲粮精氨酸水平对黄羽肉种鸡繁殖性能的影响。试验选用780只36周龄的黄羽肉种鸡作为试验鸡,采用单因素随机分组试验设计分成5个组(饲粮精氨酸水平分别为0.65%、0.80%、0.95%、1.10%和1.25%),每组6个重复,每个重复26只鸡。试验预试验2周,饲喂精氨酸水平为0.65%的饲粮;正试期10周。结果表明:饲粮中添加不同水平精氨酸对试验全期种鸡产蛋率、平均蛋重和料蛋比均没有显著影响(P0.05)。1.10%精氨酸组的产蛋率最高,与0.65%和1.25%精氨酸组相比有提高的趋势(P0.10)。1.25%精氨酸组平均蛋重最低,与其他4组相比均有降低的趋势(P0.10)。饲粮中添加不同水平精氨酸对种蛋蛋壳强度、蛋壳厚度、蛋黄比例、蛋白质含量以及种鸡血浆中丙二醛含量和还原型谷胱甘肽/氧化型谷胱甘肽值均有显著影响(P0.05)。饲粮精氨酸水平对种蛋受精率、孵化率、健雏率和健雏平均出壳重均没有显著影响(P0.05)。由此可见,适度添加精氨酸一定程度上能提高黄羽肉种鸡产蛋率,增强种蛋蛋壳强度和种鸡抗氧化能力。综合分析本试验多项指标,推荐快大型黄羽肉种鸡产蛋高峰期饲粮中精氨酸水平为1.10%。     

Growth response, blood characteristics and copper accumulation in organs of broilers fed on diets supplemented with organic and inorganic dietary copper sources

1. A 56-d experiment was conducted to study the comparative influence of organic and inorganic dietary copper (Cu) sources on growth, blood characteristics and copper accumulation in organs of broilers. 2. A total of 480 Arbor-Acre unsexed broilers were fed on diets containing copper sulphate (CuSO(4)) or copper proteinate (Cu Pro) at concentrations of 50, 100 or 150 mg/kg of Cu supplementation. The birds were given a broiler starter diet from 1-28 d and a broiler finisher diet from 29-56 d which contained 30·8 mg/kg and 41·1 mg/kg basal copper concentration respectively. Growth performance, blood characteristics and Cu accumulation in organs of the broilers were measured. 3. At 28 d, Cu Pro-fed birds had improved feed conversion ratio compared with CuSO(4). At 56 d, birds fed on Cu Pro diets had significantly greater body weight than CuSO(4)-fed birds. Birds fed on CuSO(4) supplemented diets had significantly better feed conversion efficiency. Feed consumptions for the two Cu sources were not significantly different. At no stage did the concentration of added Cu affect the productive traits measured. 4. Cu Pro supplementation increased haemoglobin concentration but reduced plasma triglyceride and plasma cholesterol. Plasma cholesterol decreased as Cu concentration increased. 5. There was a greater accumulation of Cu in the blood, heart, lung, liver and bone of broilers fed on Cu Pro than in those receiving CuSO(4). The liver Cu concentration increased as dietary Cu concentration increased. 6. Cu Pro was more effective in promoting growth and reducing blood cholesterol, and was more bio-available in the organs of broilers.