Development of the lipid and fatty acid patterns of the liver of the pigeon after hatching

1. The fatty liver of newly‐hatched pigeons is caused by an accumulation of sterol esters (STE) amounting to 620 mg/g total lipids of which 80% was sterol oleate. Triglycerides (TG) accounted for only 20 mg/g of total lipids.

2. After hatching, the relative amount of STE in the liver tissue decreased considerably while that of TG increased. The proportion of phospholipids (PHL) remained essentially constant.

3. The fatty acid composition of the liver lipids changed significantly, but specifically for each individual class during postnatal growth. Striking differences were the higher values of long‐chain polyunsaturated acids (20 :4 ω6, 22 :4 ω6 and 22: 6 ω3) in PHL, TG and free fatty acids (FFA) and the higher proportion of oleic acid in the STE at hatching compared with those at older ages.

4. The predominant alterations in the relative composition of the liver lipids (lipid classes and fatty acids) occurred in the first week after hatching and may be accounted for by the decreasing yolk utilisation and adaptation to ingested food. The change within the diet itself from cropmilk to grain (starting around the 4th day) influenced the development of the lipid and fatty acid content only in a minor way.

5. The large weight decrease of the pigeon liver after the 19th day was accompanied by a decrease in absolute PHL content while TG stores were unaltered.     

Influence of age,sex and rearing systems on Toll-like receptor 7 (TLR7) expression pattern in gut,lung and lymphoid tissues of indigenous ducks

1. The objective of the experiment was to determine the influence of age, sex and rearing system on Toll-like receptor 7 (TLR7) gene expression in gut, lung and lymphoid tissues and physiological responses to stress in male and female indigenous ducks of Tamil Nadu, India.

2. A total of 36 ducks (12 males and 24 females) were obtained from local farmers and tissue samples of gut tissues (duodenum, jejunum, ileum and caecum), lymphoid organs (spleen and bursa) and lungs were collected in RNAlater solution followed by RNA extraction.

3. After normalisation to β-actin (endogenous control) qPCR analysis identified a significant effect of age, sex and rearing system on TLR7 expression in the ducks.

4. A significant up-regulation of TLR7 expression was observed in lungs, duodenum, jejunum, ileum and caecum of sexually mature (45 wk) compared with that of immature ducks (16 wk). Among sexes, male ducks had significantly higher TLR7 expression than female ducks.

5. Age and sex interactions were significant in lungs, duodenum, jejunum and caecum. Ducks reared in an extensive housing system showed significantly higher TLR7 expression in bursa, lungs, duodenum, ileum and caecum compared to intensively reared ducks. There were no effects of age, sex and rearing systems on TLR7 expression in the spleen.

6. The heterophil-to-lymphocyte ratio and serum corticosterone were higher in ducks reared on an intensive system compared with ducks from an extensive rearing system.     

Physiological responses to central and peripheral injection of polyinosinic-polycytidylic acid in chicks

1. The purpose of the present study was to determine if intracerebroventricular (ICV) and intraperitoneal (IP) injection of polyinosinic-polycytidylic acid (poly I:C), a viral mimetic that binds to toll-like receptor-3 (TLR3), affects food intake, voluntary activity, cloacal temperature, plasma corticosterone (CORT) and glucose concentrations, and crop emptying rate in chicks (Gallus gallus).

2. Both ICV and IP injection of poly I:C significantly decreased food intake.

3. IP but not ICV injection of poly I:C significantly suppressed voluntary activity, whereas ICV injection decreased time spent sitting. Both ICV and IP injection of poly I:C significantly increased plasma CORT and glucose concentration. Neither ICV nor IP injection of poly I:C significantly affected cloacal temperature.

4. In addition, ICV injection of poly I:C significantly reduced crop emptying rate, whereas IP injection had no effect.

5. These results suggested that central TLR3 is related to anorexia, stress response and retardation of crop emptying while peripheral TLR3 is related to anorexia, change in behaviour and stress responses during viral infection in chicks.     

Performance of lines selected for fast‐and slow‐hatching times and crosses among them 1

1. Males of a control line and two lines selected for fast‐ and slow‐hatching were mated to females of the same three pure lines and three crosses between them. Hatchability, egg weight and hatching time were measured.

2. No significant differences were found between genetic groups in hatchability.

3. Groups containing the fast‐hatching line genotypes were significantly smaller in egg weight than those not containing this line.

4. Significant differences in hatching time existed between male lines and between female lines within pure and cross‐line parent types while no differences were observed between the female parent types and no interactions of male by female lines occurred.

5. It was concluded that inbreeding in the pure lines (10%) did not affect any of the variables measured.

6. The results on hatching time support the conclusion that little genetic variance other than additive variance is involved for this trait.     

Methionine deficiency leads to hepatic fat accretion via impairment of fatty acid import by carnitine palmitoyltransferase I

1. To clarify the underlying mechanism of hepatic fat accretion due to methionine (Met) deficiency in broiler chickens, the present study investigated the effect of Met deficiency on the hepatic carnitine palmitoyltransferase (CPT) system, which imports fatty acids into mitochondria.

2. Fifteen-d-old male meat-type chickens were fed on either a control diet (containing 0.52 g/100 g Met) or a Met-deficient diet (containing 0.27 g Met/100 g). After a 10-d feeding period, the birds were killed by decapitation and their livers excised to determine hepatic CPT1 and CPT2 mRNA levels and for the related hepatic fatty acid-supported mitochondrial respiration to be measured.

3. Met deficiency decreased body weight gain and feed efficiency and increased hepatic lipid content compared to the control group. Whereas the hepatic CPT2 mRNA level in the Met-deficient group remained unchanged compared to that of the control group, the CPT1 mRNA level was decreased in the Met-deficient group and CPT1-dependent hepatic mitochondrial respiration was impaired.

4. Our results suggest that the hepatic lipid accretion that occurs in response to Met deficiency might be attributable to the impairment of CPT1-mediated fatty acid import into mitochondria.     

Fatty acid composition of broiler abdominal fat as influenced by temperature,diet, age and sex

1. Two environmentally controlled houses at 21°‐30°‐21°C (HT) and 21°C (LT) were used to study the effect of temperature on fatty acid composition of the abdominal fat of male and female broilers fed 13.8 and 13 MJ ME/kg diets and slaughtered at 34 and 54 d.

2. Extracts from the abdominal fat of 160 carcases and of the experimental foods were analysed for fatty acids by gas liquid chromatography.

3. Birds reared in HT had a significantly lower proportion of polyun‐saturated fatty acids (PUFA) in their abdominal fat between 34 and 54 d than birds in LT. The depot fat contents of oleic, linoleic and linolenic acids were all reduced by HT at 54 d.

4. For broilers slaughtered at 54 d, saturated fatty acid (SFA) content was much higher in females at high temperatures than in males while at low temperatures PUFA, especially linoleic, was much lower in males than in females.

5. Early finishing of broilers is advantageous from the viewpoint of fatty acid composition because the PUFA/SFA ratio declines significantly with age regardless of temperature.     

Effects of extruded flaxseed on layer performance,nutrient retention and yolk fatty acid composition

1. This study was conducted to determine the effects of feeding an extruded flaxseed (EF) on layer performance, apparent total tract nutrient retention (ATTR) and egg yolk fatty acid concentrations.

2. Seventy-two White Leghorn laying hens (58-week-old; three per cage) were randomly allotted to one of four dietary treatments: 0%, 7.5%, 15.0% and 22.5% of EF-supplemented diets for 8 weeks.

3. Supplementation with EF had no effect on feed intake, egg production, feed conversion ratio and egg weight. Egg components (yolk, albumen and shell percentages) were similar among treatments, except that shell percentage was greater for layers fed 22.5% EF than those fed 7.5% and 15% EF. The ATTR of dry matter and organic matter were highest for 0% and 7.5% EF, intermediate for 15% EF and lowest for 22.5% EF. Similar reductions on ATTR of crude protein and nitrogen-corrected apparent metabolisable energy were observed for layers fed 22.5% EF relative to those fed 0% or 7.5% EF.

4. Feeding EF at 7.5%, 15.0% and 22.5% of the diet markedly increased (by 92%, 198% and 271%, respectively) egg yolk concentrations of n-3 polyunsaturated fatty acid (PUFA) and reduced saturated fatty acid and n-6 PUFA concentrations.

5. It was concluded that omega-3 labelled eggs (300 mg/60 g of egg) may be produced with low (7.5% of diet) levels of dietary EF without compromising egg production parameters. However, feeding moderate to high levels of EF (i.e. 15% and 22.5% EF) may reduce total tract nutrient and energy utilisation.     

Encapsulated benzoic acid supplementation in broiler diets influences gut bacterial composition and activity

1. The present study investigated the effects of encapsulated benzoic acid (BA) supplementation in broiler feed on performance and gastrointestinal microbiota.

2. Eighty broilers were randomly divided into two groups. Birds in the control group were fed on maize–soybean-based diets. Birds in the treatment group were provided the same diet supplemented with 2 g/kg BA encapsulated in a vegetable oil matrix.

3. At the end of the trial (d 35), pH, bacterial composition and metabolites were determined in the crop, jejunum, ileum and caecum.

4. Growth performance variables and pH were not significantly different.

5. BA concentration decreased rapidly in the proximal gut. However, the treatment diet showed higher BA in the crop, jejunum, ileum and caecum.

6. Total lactate in the crop and D-lactate in the jejunum was higher in the BA treated group. Caecal total and branched chain fatty acids were decreased due to the treatment.

7. Lactobacilli populations were significantly altered by BA supplementation. A trend for increased lactobacilli was observed in the crop, while it became significant in the jejunum and ileum. Lactobacillus species responded differently to the treatment. Four of 5 measured Lactobacillus species, particularly in the ileum, followed the course observed for total lactobacilli; only Lactobacillus salivarius was not modified.

8. Correlation analysis showed that BA modified the intestinal microbiota. Lactobacilli correlated negatively to all studied clostridial clusters and enterobacteria. Clostridial clusters IV and XIVa were significantly increased in the jejunum, whereas only clostridial cluster XIVa was increased in the caecum.

9. Encapsulated BA modified the intestinal microbiota which can lead to the conclusion, that the main beneficial mode of action of BA in the gut appears to be the enhancement of lactic acid bacteria, which in turn may act as a vanguard against pathogens.     

Studies on acid oils and fatty acids for chickens. II. Effect of free fatty acid content and degree of saturation of free fatty acids and neutral fat on fatty acid digestibility

1. Two experiments were designed to study the influence of free fatty acid content and degree of saturation of free fatty acids and neutral fat on digestibility of added fats and fatty acids. Sunflower oil and tallow were used as neutral fats, and palmitic, stearic, oleic and linoleic acids as free fatty acids. Fat inclusion was 80 g/kg and mixtures of each fat and each free fatty acid were prepared in the proportions 100:0, 70:30 and 40:60.

2. Experimental diets were evaluated for fat and fatty acid digestibilities with broiler chickens at 21 d of age. The metabolisable energy of fat was calculated from the product of digestibility and gross energy. Increasing concentrations of saturated free fatty acids decreased the ME of added fat, whereas unsaturated free fatty acids did not significantly affect the ME value of added fat.

3. Digestibilities of individual fatty acids were analysed by linear regression with rate of inclusion of free fatty acid in the fat blend: palmitic and stearic acids gave a negative slope, whereas oleic and linoleic acids gave a slope not statistically different from zero. Because slopes for saturated fatty acids did not differ between the sunflower oil and tallow treatments, synergism between unsaturated and saturated fatty acids was not detected.     

Effects of linseed oil and palm oil on growth performance,tibia fatty acid and biomarkers of bone metabolism in broilers

1. This study was conducted to determine the effects of different dietary fat sources on growth performance, tibia fatty acids and biomarkers of bone metabolism in broilers.

2. One-d-old commercial Arbor Acres broilers were fed with a maize–soya bean basal diet for 42 d, supplemented with oils according to the following 5 treatments: lard (lard group); linseed oil (linseed oil group); palm oil (palm oil group); linseed oil + palm oil (60:40 or 40:60 w/w, LP-1 group and LP-2 group, respectively).

3. No significant differences in weight gain, feed intake and gain/feed ratio were observed between the lard and linseed oil groups. Birds fed on palm oil had significantly greater weight gain and feed intake than those fed on lard or linseed oil. Growth performance in LP-1 and LP-2 was significantly greater than that of single-oil groups.

4. Tibia growth and bone characteristics were not influenced by supplementation with lard, linseed oil, or palm oil alone, but broilers fed on a mixture of fats had significantly greater tibia weight and length compared to broilers fed on linseed oil. Bone mineral density in tibia was significantly increased in LP-1 and LP-2 groups.

5. Supplementation of linseed oil alone or in combination with palm oil enhanced apparent digestibility of calcium, reduced serum calcium and increased tibia calcium concentrations. Moreover, supplementation with linseed oil alone or in combination with palm oil had a positive effect on biomarkers of bone growth.

6. The combination of linseed and palm oils was beneficial for growth performance, tibia growth and biomarkers of bone metabolism.     

A comparison of the osmotic pressures along the digestive tract of the domestic fowl and the rabbit

1. The osmotic pressures of the contents of the alimentary tract from the adult hen and cockerel and rabbit were measured.

2. In the rabbit osmolality of the fluids from the different segments of the digestive tract was similar (331 ± 12 mOsm) and slightly hypertonic to blood plasma (297 ± 0.12 mOsm).

3. In the hen osmotic pressures were: crop 537, gizzard 312, duodenum 571, proximal jejunum 650, distal jejunum 573, proximal ileum 514 and distal ileum 451 mOsm. Only osmolality of the crop contents was influenced by egg formation.

4. In the cockerel osmotic pressure in the alimentary tract followed the same pattern as the hen and was modified by the time of day.

5. Plasma osmolality in the fowl was about 320 mOsm. Absorption of water across the proximal jejunum is achieved therefore against a gradient of about 330 mOsm in the female and 420 mOsm in the male fowl.     

Effect of different dietary supplemental fats and oils on the tissue fatty acid composition and growth of female broilers

1. A study was undertaken to examine the effect of supplementation of diets with fats of different chain length and degree of unsaturation on the performance, carcase characteristics and tissue fatty acid composition of broilers.

2. Three hundred and sixty 19‐day‐old female broilers were fed on diets containing supplemental fat/oil (50 g/kg) in the form of beef tallow (BT) (diet T‐T), soyabean oil (SBO) (diet S‐S), rapeseed oil (RSO) (diet R‐R), marine oil (MO) (diet M‐M) or binary mixtures (0.5:0.5 w/w) of these lipids (diets T‐S, T‐R, T‐M, S‐R, S‐M, and R‐M) to 54 d of age. Food intake, live weight, plucked weight and the lipid concentration and fatty acid composition of abdominal fat pad, liver and breast muscle were measured.

3. Food intake, plucked weight and live weight were greatest for diet T‐T and lowest for diet R‐R. Food conversion ratio was poorest for birds fed on diets containing BT. Lipid concentration in abdominal fat pad was significantly higher in birds fed on diets containing SBO. liver lipid concentration was significantly reduced by diets containing RSO.

4. Abdominal fat pad fatty acid profile was most readily altered by dietary fatty acids. There was a strong correlation between dietary fatty acid composition and tissue fatty acid composition for all fatty acids except C14:0, C20:0, C20: 2n‐6 and C20: 4n‐6. The tissue P/S ratio ranged from 0.40 for diet T‐T to 1.40 for diet S‐S. The n‐6/n‐3 ratio was significantly increased by the inclusion of SBO and decreased by the inclusion of MO.

5. Liver fatty acid profile was least modified by dietary fatty acids. There was an inverse relationship between liver and dietary C20:4n‐6 concentration. Tissue C18:2n‐6 and C20:4n‐6 were highly correlated, suggesting significant interconversion by ?‐6 desaturase in this tissue. The n‐6/n‐3 ratio was significantly increased by inclusion of SBO and significantly decreased by the inclusion of MO.

6. In breast muscle MO‐based diets increased the proportion of n‐3 PUFA at the expense of n‐6 PUFA. The tissue concentrations of C18:ln‐9, C18:2n‐6, C20:ln‐9, C20:5n‐3, C22:5n‐3 and C22:6n‐3 were strongly correlated with dietary fatty acid composition. Muscle and diet P/S and n‐6/n‐3 ratios were highly correlated.     

Identification of antibodies against hydropericardium syndrome in wild birds

1. Domestic fowl and free-living birds were examined for the presence or absence of antibodies against hydropericardium syndrome (HPS) using an indirect haemagglutination assay.

2. Two-hundred and eighty serum samples of commercial (45 broilers, 20 adult layers and 15 Fayoumi fowl) and wild birds, including 65 peafowl, 45 pigeons, 10 crows, 30 house sparrows, 10 doves, 15 ducks, 10 parrots and 15 guinea fowl, were collected and examined.

3. The percentage of HPS-positive serum samples was 80% in house crows, 78% in pigeons, 7% in house sparrows and 6% in peafowl.

4. The sera obtained from parrots, doves, ducks and guinea fowl were all negative.

5. This study suggests that crows and pigeons could be carriers of the HPS agent.     

The presence of salmonellae during the rearing of Turkeys

1. The incidence of salmonellae was investigated in two batches of turkeys in the environmentally‐controlled houses and naturally ventilated pole‐barns of a commercial turkey enterprise.

2. The poults were free from contamination on arrival at the rearing house but were contaminated via the water supply from troughs which had been ineffectively fumigated.

3. Foodstuffs did not appear to be a source of contamination.

4. The spread of salmonellae in this turkey rearing enterprise was very similar to that in chicken rearing houses.     

Effects of dietary medium-chain fatty acids on performance,carcass characteristics,and some serum parameters of broiler chickens

1. This study aimed to evaluate the effects of dietary medium-chain fatty acids (MCFAs) on the performance, carcass characteristics, and some serum parameters of broiler chickens.

2. A total of 176 one-day-old male broiler chicks (Ross 308) were assigned to four treatments including control treatment (basal diet), 0.1% MCFA, 0.2% MCFA, and 0.3% MCFA treatments according to a completely randomised design. Each treatment consisted of 4 replicates with 11 chicks for each replicate. In MCFA treatments, the amounts of MCFAs were added to basal diet as a substitution of soybean oil.

3. There were not any significant differences in body weight, feed intake, and feed conversion ratio among the treatments in different stages of the experiment. However, MCFA treatments had a lower abdominal fat and a higher breast yield compared to control treatment.

4. Blood glucose, cholesterol, and low-density lipoprotein (LDL)-cholesterol concentrations were significantly decreased, but blood high-density lipoprotein (HDL)-cholesterol concentration was significantly increased in the MCFA treatments compared to the control treatment.

5. These results indicate that dietary MCFA has a positive effect on the health and productivity of broiler chickens.     

Effect of dietary fatty acids on humoral immune response of Turkeys

1. This study examined the effect of increasing amounts of dietary polyunsaturated fatty acids on the fatty acid composition in serum and antibody production following a standard vaccination programme in growing turkeys. Turkey poults were fed on 5 diets containing 75g/kg added fat made up of different proportions of palm and soyabean oils, and were vaccinated against Newcastle disease, infectious bronchitis and necrotic enteritis according to a standard vaccination programme. Blood samples were taken before and one week after each vaccination.

2. Fatty acid composition in serum reflected the composition of the diets although arachidonic acid concentration was not changed by dietary fatty acid content. Growth, erythrocyte and leukocyte parameters were not affected by the respective diets.

3. Specific antibody production was related quadratically to serum linoleic and total n‐6 polyunsaturated fatty acid concentrations. No correlation was found with linolenic or arachidonic acids.

4. It is concluded that dietary fatty acid composition can augment the specific anti‐vaccine immune response in turkey poults.     

Effects of diet,age and gender on the polyunsaturated fatty acid composition of broiler anatomical compartments

1.?The objective of this study was to investigate the effect of dietary fatty acid (FA) composition, age, and gender on the FA composition of different broiler anatomical compartments. Four dietary fat sources (palm fat, P; soybean oil, S; linseed oil, L; fish oil, F) were added to a wheat–soybean meal based diet at 30 g/kg in addition to 50 g/kg palm fat. Diets were fed separately to female and male birds from d 1 to either d 21 or d 42 of age.

2.?The total FA content (mg/100 g tissue) and the FA composition (g/100 g FAME) was determined in 7 anatomical compartments (skinless thigh muscle, skinless breast muscle, liver, heart, brain, abdominal fat pad, and remainders plus carcase trimmings named Rest compartment). The FA profiles differed greatly among compartments and were strongly affected by diet.

3.?The S diet resulted in a 2–3-fold increase of the proportion of C18:2n-6 and C20:4n-6 in all compartments compared to the other diets, except for brain.

4.?The response in the proportion of C18:3n-3 following feeding the L diet was much greater, with 4–20-fold increases compared to the other diets, except again for brain.

5.?In all compartments except brain, the L diet resulted in approximately a 2-fold increase in the proportion of C22:6n-3 compared to the P and S diets and smaller, but also significant, increases for C20:5n-3 and C22:5n-3.

6.?The proportions of C20:5n-3, C22:5n-3 and C22:6n-3 were much higher on the F diet in all compartments, except for brain, compared to the P and S diets. The F diet resulted in higher proportions of C22:6n-3 than the proportions of C20:5n-3 and C22:5n-3 in breast and thigh meat, and liver, in contrast to the other diets.

7.?Brain was less responsive than other tissues to changes in the dietary FA composition. The proportion of C22:6n-3 in brain was similar on the L and F diets.

8.?The effect of gender on the FA composition of different anatomical compartments was marginal. The long-chain n-3 and n-6 PUFA in breast, liver, and brain decreased with age.     

Effect of gender on breast and thigh turkey meat quality

1. The influence of gender on chemical composition, physicochemical parameters, fatty acid profile, amino acid and mineral composition of turkey breast and thigh meat was studied in order to assess nutrient requirements.

2. Chemical composition showed that only intramuscular fat in breast meat was significantly affected by gender (p < 0.05). The results showed a higher percentage of intramuscular fat in male samples, almost double the amount found in females (0.73% vs. 0.38%).

3.For meat colour parameters, only a* showed different results between sexes, with male samples (breast: p < 0.01; thigh: p < 0.001) having the highest values.

4. Fatty acid profiles showed that medium chain unsaturated fatty acids were the most abundant. The significant differences (p < 0.05) found in both breast and thigh muscle could be linked to a difference in metabolism between males and females.

5.There were higher levels of C16:1n-7 in females (breast: p < 0.001; thigh: p < 0.01) compared with male muscle sample (5.05 vs. 2.67 g/100 g in breast and 4.95 vs. 3.27 g/100 g in thigh). Nutritional indices (n-6/n-3 and thrombogenic index) were more favourable in female samples demonstrating that female turkeys had better fatty acid profile than the others.

6. Turkey meat is an important source of dietary amino acids, and female samples had the highest contents both of essential and non-essential amino acids. Furthermore, gender had a numeric effect (p > 0.05) on amino acid composition.

7. Mineral composition showed that Na, Zn and Fe were the minerals most affected by turkey gender.     

The necessity of supplementing laying hen diets with linoleic acid

Results from four experiments with laying hens have been re‐examined using the means of individual 28‐d periods during egg production to investigate the influence of the developing ovary and linoleate storage during growth on the linoleic acid requirement of the laying hen.

Apart from a possible beneficial effect during the first few weeks of production, little increase in egg weight occurs when birds are fed on conventional rearing diets and then fed on laying diets containing linoleic acid in excess of requirement.

After depletion of linoleate reserves, dietary supplementation with linoleic acid significantly increases egg weight at any age.

The necessity of supplementing diets for laying hens with linoleic acid is discussed.     

Effect of broiler breeder feeding programme and feeder space change at photostimulation using maize- or wheat-based diets on broiler progeny growth performance and leg health

1. The aim of this study was to evaluate the effects of diet type, maternal feeding programme at 29 weeks of age and breeder feeder space change at photostimulation on broiler progeny performance and leg health at 6 weeks of age.

2. Fast-feathering Cobb 500 broiler breeders were fed on either maize- or wheat-based diets that had been formulated to have similar nutrient composition during growing and layer phases. Two feeding programmes, fast or flow, were used from 14 to 29 weeks of age. At 22 weeks, 69 females from each pen were placed in a layer house where feeder space was either similar to that in rearing (6.3 to 6.5 cm/female) or was increased from 6.3 to 8.4 cm/female. Eggs produced at 32 and 44 weeks of age were collected and incubated for two broiler experiments. A total of 16 male and 16 female one-d-old chicks were placed in floor pens in two experiments, respectively, with 6 and 4 replicate pens. Broiler gait scores and leg problem prevalence were evaluated at 6 weeks of age.

3. Data were analysed as a 2 × 2 × 2 factorial design with diet type, feeding programme and feeder space change as main factors.

4. The wheat diet increased the probability of observing crooked toes in broiler progeny compared to the use of maize, but only when breeders were fed according to the fast feeding programme and given similar feeder space as during rearing.

5. Breeders given more feeder space in the laying period produced progeny with more locomotion problems compared with those provided similar feeder space, but only when maize was used and the slow feeding programme was applied to the breeders.

6. The maternal feeding programme interacted with other factors to influence progeny leg health, but it did not solely influence walking ability or leg problems of progeny.

7. In conclusion, an increased probability of observing walking impairment of broiler progeny was detected when breeders were given greater feeder space at photostimulation rather than no change and fed according to the slow feeding programme using maize diets in breeders and progeny.