Plasma alpha 1‐acid glycoprotein concentration in broilers: Influence of age,sex and injection of escherichia coli lipopolysaccharide

1. The influence of age, sex and injection of Escherichia coli lipopolysaccharide (LPS) on the plasma concentration of alpha‐1 acid glycoprotein (AGP) was determined in broilers using the single radial immunodiffusion method.

2. Plasma AGP concentration increased in the 3 d after hatching, and then stabilised at 240 ± 33 μg/ml up to 14 d of age.

3. No sex‐related differences in plasma AGP concentration were observed up to 6 weeks of age.

4. A single injection of 900 μg LPS per chick resulted in a 5‐fold increase in AGP concentration compared with that in saline‐injected chicks. Multiple injections of LPS (200 μg/chick every 2d for 14d) caused only a 50% increase in AGP concentration.     

Effects of short intermittent lighting on food consumption and performance of dwarf broiler breeders and progeny

1. Two hundred and sixty four dwarf broiler breeder hens were subjected to ad libitum or restricted feeding and to four lighting patterns: 15L (bright light):9D (dark), 15L:9d (dim light), 2L:10d: 1L:11d, (0.5L:3.5d) × 6.

2. Breeder hens fed ad libitum and subjected to either conventional or intermittent lighting ingested respectively, 25 g and 14 to 17 g more than hens restricted to 115 g/d.

3. Body weight was greater in hens fed ad libitum irrespective of the lighting pattern and of the amount of food intake.

4. Persistency of egg production was impaired by intermittent lighting.

5. Ad libitum feeding reduced egg fertility. The decrease was larger in breeder hens on intermittent lighting.

6. Hatchability was increased in hens submitted to the symmetrical lighting pattern (0.5L:3.5d).

7. Egg and chick weights were higher in hens fed ad libitum.

8. Shell index and shell breaking strength increased in restricted hens on the intermittent lighting pattern (0.5L:3.5d) × 6.

9. The best performance was obtained in restricted hens on the conventional lighting pattern.     

The influence of tungsten on the molybdenum status of poultry

1. Large doses of tungsten, administered to the chick either by injection or by feeding, increased tissue concentrations of tungsten and decreased tissue concentrations of molybdenum and tissue activities of xanthine dehydrogenase.

2. The rate of loss of large doses of tungsten from the liver occurred in an exponential manner with a half‐life of 27 h.

3. When tungsten was administered to chicks fed on a semi‐synthetic diet containing abnormally low concentrations of molybdenum, the activity of hepatic xanthine dehydrogenase was reduced to negligible levels.

4. The alterations in molybdenum metabolism resulting from the administration of large doses of tungsten to the chick appears to be the result of tungsten toxicity and not of molybdenum deficiency.

5. Deaths from tungsten toxicity occurred when tissue concentrations of tungsten were increased to approximately 25 μzg/g liver. At this tissue tungstencon centration the activity of xanthine dehydrogenase was zero.     

Antimicrobial substances and chick growth promotion: Comparative studies on selected compounds in vitro and in vivo

1. Antibacterial activity of selected compounds in vitro and their ability to promote growth when added to the diet of chicks were not correlated.

2. The difference in growth‐promoting activity between streptomycin, which was active, and kanamycin which was not, was not related to their effects on the flora adhering to the wall of the crop, jejunum or ileum, to their relative toxicity to the chick nor to differences in their stability in the diet.

3. When low concentrations ofkanamycin or streptomycin were given, the antibiotic was concentrated in the caecal contents. In contrast, penicillin was undetectable in the caeca of birds given high concentrations of benzyl penicillin.

4. In chicks given benzyl penicillin, the numbers of Streptococcus faecium increased at the expense of Strep, faecalis. This probably resulted from changes in the crop flora.

5. Birds given high dietary concentrations of benzyl penicillin showed improved weight gains, in spite of increased numbers of Escherichia coli in the small intestine.     

Protein synthesis measured in the whole body of chick embryos cultured in vitro

1. Whole body protein synthesis was measured in chick embryos cultured in vitro. On day 7 of incubation chick embryos were cultured for 60 min in synthetic serum‐free medium containing 4‐[³H]phenylalanine. Specific radioactivities in free and protein‐bound phenylaline in the whole embryo were measured, starting 2 min after commencement of the culture process.

2. The values for fractional synthesis rate (FSR) estimated in vitro at 20, 30, 45 and 60 min during the embryo culture agreed well, ranging from 35 to 40%/d, suggesting that the method would serve as a useful model for studying the effect of growth promoters in chick embryos.

3. Bovine insulin in the synthetic medium did not affect FSR of protein in chick embryos cultured in vitro.     

The relationship between hatching egg weight and subsequent performance of broiler chickens

Small eggs constitute a high proportion of the eggs laid by pullets. The literature shows that chick hatching weight is strongly correlated with egg weight, but evidence on the influence of egg weight on hatchability and subsequent performance of chicks is less certain.

The aim of this experiment was to determine the profit returned at 12 weeks by broiler chickens hatched from eggs ranging in weight from 44 g. to 58 g. at one gram intervals and to determine how competitive and separate rearing might modify the relationship.

A total of 6000 eggs were collected during 10 days from a 28‐week‐old, broiler breeding flock and graded into the above mentioned egg weight classes. From these, a total of 3480 day‐old broilers were housed. Each egg weight class was equally represented and balanced for sex.

Hatchability and fertility showed no consistent trend with egg weight for eggs above 46 g., but below the 47 g. level there was a trend of declining fertility and hatchability.

A strong positive relationship was found between the weight of the chick at 1 day of age and egg weight for both males and females with no significant difference overall in body weight between the two sexes.

Body weight to 12 weeks was found to be strongly related to egg weight, in a linear fashion, though this influence declined with age.

There was a greater influence of egg weight on body weight at all ages in the separate rearing treatment compared with competitive rearing but this was not significant after 10 weeks.

Egg weight had an important bearing on body weight and profit at 12 weeks, but no effect on food conversion or mortality.

The increased profit over food costs per 100 day‐old chicks was found to be 52.75 cents for the separately reared birds respectively for each 3 g. increase in egg weight.     

The nutritional value of low lathyrogenic Lathyrus (Lathyrus sativus) for growing chicks

1. The feeding value of new low β‐N‐oxalyl‐amino‐L‐alanine (BOAA) lines of Lathyrus sativus (lathyrus) and the benefits of dehulling the seed or of pre‐adapting chicks to lathyrus‐based diets were examined in several experiments.

2. Chicks fed on diets containing 400 g/kg of the low (1.3 g BOAA/kg seed) and medium (2.2 g BOAA/kg seed) BOAA lines did not differ (P>0.05) in weight gain (WG) or in apparent fat and protein digestibilities compared to birds fed on a wheat‐based diet.

3. Consumption of 600 g low BOAA lathyrus/kg diet caused a slight, but significant (P< 0.05), decrease in WG. Food efficiency decreased as the amount of dietary lathyrus was increased, suggesting that lathyrus may contain an antinutritive factor(s) other than BOAA.

4. Removal of the hull (70 g hull/kg seed) from the seed did not affect chick performance (P> 0.05).

5. Pre‐adapting chicks for 7 d to diets containing up to 600 g medium line lathyrus/kg diet did not reduce the detrimental effects of the lathyrus.

6. Although dehulling and pre‐adaptation of chicks to lathyrus were not beneficial, the low and medium lines of lathyrus tested show potential for use in chick diets up to at least 400 g lathyrus/kg diet.     

Growth performance and meat quality of broiler chickens supplemented with Rhodopseudomonas palustris in drinking water

1. The effect of the bacterium, Rhodopseudomonas palustris, on the growth performance and meat quality of broiler chickens was investigated.

2. A total of 900-d-old Arbor Acres broilers were allocated to three experimental treatments for 6 weeks. Chicks were administered with R. palustris in drinking water as follows: (i) control group without R. palustris; (ii) treatment 1 (R1) with R. palustris of 8 × 10⁹ cells per chick per day in drinking water; (iii) treatment 2 (R2) with R. palustris of 1.6 × 10¹⁰ cells per chick per day in drinking water.

3. The results showed that, compared with that of control, both groups of R. palustris treatment increased daily weight gain and improved feed conversion ratio of broiler chickens significantly during the whole growing period of 6 weeks.

4. Both total and glutamic acid contents of chicken breast fillet in R. palustris treatment R2 were higher, while the fat content was lower, than those of the control group. Furthermore, R. palustris treatments also improved sensory attributes of chicken breast fillet.

5. As a probiotic providing rich nutrients and biological active substances, R. palustris administration in drinking water displayed a growth promoting effect and improved meat quality of broiler chickens.     

Efficiency of the cloacal sexing technique in greater rhea chicks (Rhea americana)

1. The feasibility and accuracy of the cloacal sexing technique in greater rhea chicks was assessed using chicks of two captive populations of greater rhea in Córdoba, Argentina.

2. A total of 46 greater rhea chicks of 2 to 3 months of age were randomly arranged into three groups and the members of each group were sexed by a different operator.

3. A feather of each chick was plucked for sexing through a molecular method and results were used as controls.

4. Sex was correctly assigned by cloacal inspection in 98% of the cases. Chick manipulation was easily performed and no infections or traumatic lesions were observed a posteriori.

5. Cloacal sexing of rhea chicks up to 3 months of age does not affect animal welfare and should be considered an efficient alternative to molecular methods.     

Gene expression profile of IGF1 and MSTN mRNA and their correlation with carcass traits in different breeds of geese at 70 d of age

1. The expression of insulin-like growth factor-1 (IGF1) and myostatin (MSTN) mRNA in breast and leg muscle was quantified in 70-d-old Taihu and Wanxi geese by using a Multiplex Competitive Fluorescent–PCR method and the correlations between mRNA levels and carcass traits were analysed.

2. IGF1 mRNA expression in breast muscle in Taihu geese was significantly higher than that in Wanxi geese and the MSTN mRNA level in leg muscle in Taihu geese was significantly higher than that in Wanxi geese.

3. There was no significant difference in breast muscle MSTN or leg muscle IGF1 mRNA expression between the two breeds.

4. Within the same breed, the IGF1 mRNA expression in leg muscle of male geese was significantly higher than that in female geese, and MSTN mRNA expression in leg muscle was significantly higher than that in breast muscle.

5. There was no difference in the IGF1 mRNA expression between tissues.

6. There was a positive correlation between IGF1 mRNA and MSTN mRNA and a negative correlation between IGF1 mRNA expression of breast muscle and leg muscle ratio.

7. In Wanxi geese, MSTN mRNA expression in leg muscle was negatively associated with body weight and leg muscle weight.     

Use of khesari (lathyrus sativus) in chick diets

1. Broiler chicks, reared for 14 d in battery brooders, were given diets containing 100, 222 or 367 g/kg of khesari meal (Lathyrus sativus) in three different experiments.

2. Birds receiving raw khesari consumed less food and grew more slowly than birds receiving a maize‐soya diet. Supplementation with DL‐methionine did not improve the nutritive value of khesari diets, but the inclusion of L‐tryptophan produced a positive response.

3. When khesari was either autoclaved or heated in a commercial “ micronisation “ process and then incorporated at 367 g/kg in a balanced chick diet, growth and efficiency of food utilisation were at least equal to those obtained with a maize‐soya diet.

4. Khesari depresses chick growth when fed raw, but is an excellent protein source for growing chicks if fed after a suitable heat treatment. Since the component in raw khesari which is toxic to chickens is heat‐labile, it is probably not the same factor that is responsible for human lathyrism.     

Egg production of light and medium hybrids given diets varying in energy level during the chick,rearing and laying stages

A total of 1000 birds, one‐half of which were light and the other half medium hybrids, were given diets containing either high or low levels of metabolisable energy ad libitum during the chick (0.6 weeks), rearing (6–16 weeks), early laying (first 8 months) and late laying (last 4 months) stages.

The medium hybrids ate more and were heavier than the lighter hybrids at all stages. More eggs were laid by the light than by the medium hybrids but the latter laid larger eggs so that the total weight of eggs laid did not differ significantly between the two groups.

Medium hybrids given a low‐energy chick diet laid more eggs subsequently than those given a high‐energy chick diet, while the opposite result was obtained for the light hybrids.

Birds given a low‐energy rearing diet were lighter at 16 weeks and subsequently laid more eggs than birds reared on a high‐energy diet.

During the first part of the laying period consumption of the low‐energy diet was greater than that of the high‐energy diet, but the level and efficiency of egg production were the same for both dietary treatments. Mortality during lay was not significantly affected by dietary treatment or breed.     

An in vitro culture method for chick embryos obtained from the anterior portion of the magnum of oviduct

1. Chick embryos, obtained from the anterior portion of the magnum of the oviduct 60 to 80 min after the preceding egg had been laid, were cultured in vitro in small and large recipient eggshells until hatching.

2. Of 82 embryos cultured, 46.3% had survived to day 4 of incubation, and 19.5% survived to hatching.

3. The method for culturing embryos used in this experiment could facilitate research on the in vitro manipulation of early chick embryos.     

Changes in the tubular compartment of the testis of Gallus domesticus during development

1.?The aim of the present study was to analyze histological and stereological changes in the tubular compartment in Gallus domesticus testes, as well as the variations in the number and size of their cells, from the start of morphological differentiation of the gonads (8-d chick-embryo) until the adult reproductive stage (28 weeks old).

2.?In embryonic chick testes, the total volume occupied by the interstitial tissue is greater than that occupied by the tubular compartment, but in the post-hatched chick the total volume of tubular compartment exceeds that of the interstitial tissue.

3.?From day 1 until 28 weeks of age, the seminiferous tubules increased in total volume, diameter, and epithelial height, which was directly related to the increase in the number of Sertoli and germ cells and the size of Sertoli cells.

4.?In the testes of one-day- and 6-week-old chicks, Sertoli cells were the most abundant cell type in the seminiferous tubules due to hyperplasia, but in 28-week-old birds the germ cells were the most abundant cell type. Hypertrophy rather than hyperplasia of Sertoli cells appears to be responsible for the increase in the total volume of seminiferous tubules.

5.?There are marked age-dependent changes in the tubular compartment of chick testes that help to understand the histological and stereological events occurring during normal development.     

Use of Lathyrus Sativus L. (var. seminis albi) as a foodstuff for poultry

1. The gross composition of Lathyrus sativus was examined, and its use as a foodstuff for growing chicks over time as well as the influence of supplementation with certain amino acid combinations were studied.

2. Chemical analyses indicated lathyrus to be high in crude protein with adequate concentrations of most inorganic elements and amino acids except methionine and cystine.

3. The performance of growing chicks fed 800 g/kg lathyrus over a four week period was significantly poorer than those given a wheat/ soyabean meal‐based diet (P<0.05), but there appeared to be some adaptation to the antinutritive factors in the lathyrus.

4. Chick performance was markedly improved by dietary methionine supplementation alone (P<0.05); it was slightly better when trypto‐phan was added in combination with methionine but was still inferior to that on a wheat/soyabean meal‐based diet.

5. Supplementation of lathyrus‐based diets with methionine and tryto‐phan may improve chick performance, but it is not sufficient to overcome the effects of antinutritive factors in the legume.     

Factors affecting the weight and water status of the chick at hatch

1. Variation in chick weight at the moment of escape from the shell is accounted for by the fresh weight of the egg, the weight lost from the egg during the incubation period and the weight of the shell and residues at hatch.

2. Over 97% of the variation in chick weight at hatch can be explained by two factors, fresh egg weight and weight loss during incubation. These two factors still account for a high (87%) proportion of the variation in chick weight at 21 d after setting when chicks would normally be removed from the hatcher.

3. The water content of the true chick and the residual yolk sac are both affected by water loss from the egg during incubation and account for the differences in the weight of the whole chick at hatch from eggs of the same size.

4. When the fluid reserves within the egg become exhausted in the few days before hatch, the water: dry weight ratio of the yolk rather than embryo is maintained despite variation in water losses between eggs.     

Genetic basis of the Melanotic Prat phenotype

1. The genetics of plumage colour of a melanotic columbian‐restricted male called ‘Melanotic Prat’ is described. It was found among the F₂ progeny of crosses between the Castellana and Prat breeds, and is very similar to the ‘quail’ phenotype.

2. Results of crosses involving this male indicate that its plumage colour pattern is the result of the Ml/Ml genotype adding black pigment to the Columbian plumage pattern produced by the e ^Wh and Co genes.

3. The melanotic gene (Ml) is recessive in the presence of the colum‐bian‐restricted genotype. It has no effect on the chick down colour although it could be a modifier to produce greyish or black back colourations when Co is present in the genotype.

4. It is suggested that the quail plumage colour is due to the same melanotic factor interacting with the primary pattern of a Columbian‐restricted genotype.     

Effect of in ovo threonine supplementation on early growth,immunological responses and digestive enzyme activities in broiler chickens

1.?The effects of injecting threonine in ovo on early growth, some immunological responses and the activity of digestive enzymes of broiler chicks were investigated. Fertile eggs were distributed into 6 groups, each of 60. These were: untreated control, sham control, 10, 20, 30 or 40 mg threonine. Threonine was dissolved in 0·5 ml sterile saline and inoculated into the yolk sac of the 14-d-old embryo through the narrow end of the egg.

2.?The ratio of chick to egg weight was 1·6% higher in the group given 30 mg threonine and at 28 d of age chicks receiving threonine were 29 to 79 g heavier than untreated controls.

3.?Food conversion ratio until 7 d after hatching was improved in those chicks receiving 10, 20 or 40 mg threonine but there was no significant effect on the activities of amylase, pepsin or trypsin.

4.?The humoral response to sheep red blood cells was significantly greater in those groups receiving 10, 20 or 30 mg threonine supplementation than in untreated controls.

5.?The response to phytohaemagglutinin-P, a measure of the cell-mediated immune response, was not affected, however.

6.?It is concluded that injections of 20 to 30 mg threonine into yolk sac can improve post-hatching growth and humoral responses of broiler chicks.     

Incremental changes in and distribution of chick weight with hen age in four poultry species

1. It is proposed that a general biological pattern exists for chick weight increase with hen age for the various commercial species of poultry and that one general equation can be used for the estimation of chick weight increment.

2. The parameters estimated for this equation are based on (a) chick weights as a percentage of annual mean chick weight, and (b) age, from onset of lay, as a percentage of maximum age of the hen; both serving as common denominators. Hence, if the annual mean chick weight is known for any species, breed or strain, then the increase in chick weight can be predicted for the whole season, or for any particular hen age.

3. For early prediction, first‐month chick weight can be used to estimate the annual mean weight and consequently the chick weight curve for the full season. Although such prediction will be somewhat less accurate, it still can be used for general planning.

4. Results indicate that chick weights of various avian species are normally distributed. Therefore, at each point of hen age, the chick weight distribution can be estimated by employing the computerised Burr's (1967) equation. This may be useful for segregating chicks by size, thus improving uniformity and reducing competition within the flock.

5. Computation results show that coefficient of variation (CV) of chick weights, originating from 22 and 62 week dam ages, is increased by up to about 75%. The CV may thus be used as a quality indicator.