Effect of incubation temperature on the gross pathology of turkey embryos     

N. A. French 《British poultry science》1994,35(3):363-371

1. Turkey eggs were incubated at 36.5, 37.5 and 38.5°C. The age of mortality, the incidence of malpositions and the incidence of morphological abnormalities were recorded from all unhatched eggs.

2. Eggs incubated at 36.5°C hatched later than eggs incubated at 37.5°C but did not differ in age of mortality or incidence of malpositions and abnormalities.

3. Eggs incubated at 38.5°C hatched significantly less well than eggs incubated at 37.5°C and showed significant differences in time of embryo mortality. Overheated embryos had a mortality peak between 15 and 20 d of incubation and an increased mortality after 24 d of incubation.

4. Overheated eggs were characterised by a high incidence of embryos with head in small end, with excess albumen, ruptured yolk sacs, oedematous heads, eye cataracts and swollen down‐plumules.  相似文献   

Effect of dietary protein content on growth and body composition of fast and slow feathering broiler chickens     

O. A. Ajang  S. Prijono  W. K. Smith 《British poultry science》1993,34(1):73-91

1. Broilers were produced from two lines of breeders selected for three generations for fast and slow feather growth. The base population foundation stock originated from a commercial pedigree female line, which carried only the dominant sex‐linked late feathering gene K. Three isoenergetic (12.7 MJ AME/kg) starter and grower diets were formulated to contain 280, 240 and 200, and 260, 220 and 180 g/kg protein, respectively, and fed to 156 broilers of each sex to give three starter‐grower combinations.

2. Broiler performance in terms of growth, food conversion ratio, carcase meat, fat and protein content was optimised on the 240 to 220 g/kg protein starter‐grower series of diets.

3. Birds of the slow line were significantly (P<0.05) heavier at 48 d of age and had the same food intake and food conversion ratio as birds of the fast feathering line.

4. The slow line birds had significantly (P<0.01) shorter feathers and less total plumage weight at 48 d. The slow line birds had significantly (P<0.001) less carcase fat and significantly (P<0.05) more carcase protein than the fast line. The slow line had significantly more carcase meat (P<0.01) within which a greater breast meat yield was evident (P<0.001).  相似文献   

Improvement of dietary protein utilisation in chicks by medium chain triglyceride     

R. T. Mabayo  M. Furuse  K. Kita  J. Okumura 《British poultry science》1993,34(1):121-130

1. To improve the influence of variation of ME intake, an experiment was carried out using equalised feeding to investigate the comparative effects on protein and energy utilisation in chicks of diets containing medium chain triglyceride (MCT) and long chain triglyceride (LCT). Experimental diets were given at 3 different food intakes, namely, 100, 120 or 147 g/bird/10 d. The diets contained MCT or LCT on an isoenergetic basis. Maize oil and caprylic acid triglyceride respectively, were used as LCT and MCT sources.

2. Body weight gain and food efficiency of chicks significantly increased with the supplement of dietary MCT compared with dietary LCT at all food intakes. Protein retention and the efficiency of protein utilisation (protein retained/protein intake) at all food intakes also significantly increased with dietary MCT, while body fat and fat retention were significantly reduced. Chicks fed the LCT‐supple‐mented diet, on the other hand, had a lower protein retention, but significantly higher fat retention. The value for energy retention and the efficiency of energy utilisation (energy retained/ME intake) were not significantly different between MCT‐ and LCT‐supplemented diets.

3. It was concluded that supplementing MCT to the chick diet would improve body weight gain and protein utilisation while regulating fat deposition compared to the LCT supplemented diet, under equalised feeding conditions.  相似文献   

Effect of cold stress on performance and immune responses of Bedouin and white leghorn hens     

M. Spinu  A. A. Degen 《British poultry science》1993,34(1):177-185

1. Bedouin chickens are kept in deserts mainly for eggs and are well adapted to arid conditions. However, deserts are also characterised by relatively cold winter nights. As a consequence of cold stress there is an involution of lymphoid organs and a depression of immunological function. We compared the performance and immunological responses of Bedouin and White Leghorn hens kept in outdoor pens in the Negev Desert during the winter.

2. Initial mean body mass was similar for the two breeds: 1525 g for Bedouin hens and 1542 g for White Leghorn hens. White Leghorns lost 7–74 g/d, compared with 0.60 g/d for Bedouin hens and produced 0.36 eggs/d, compared with 0.54 eggs/day for Bedouin hens.

3. The heterophil/lymphocyte ratio for Bedouin hens was 0.28, which was lower than the 0.44 for White Leghorn hens. Phagocytic index was higher in Bedouin hens than in White Leghorns. Furthermore, wattle index measured 24, 48 and 72 h after PHA injections and anti‐SRBC antibody titres determined 10 d after challenge were also higher in Bedouin hens than in White Leghorns.

4. We concluded that the Bedouin hens were less stressed by the cold than were the White Leghorn hens.  相似文献   

Utilisation of raw jackbean (Canavalia ensiformis) and jackbean fractions in diets for broiler chicks     

A. D. Ologhobo  D. F. Apata  A. Oyejide 《British poultry science》1993,34(2):323-337

1. An experiment was conducted to examine the effectiveness of some extraction procedures at eliminating the antinutritional properties of jackbean to the broiler chicken. The most pronounced effects were observed in the base‐ and acid‐soluble protein fractions (BSP and ASP) which contained the bulk of the antinutritional factors.

2. The growth of chickens on all diets were significantly (P<0.05) reduced.

3. Examining the weights of broiler organs as a proportion of body weight showed a significant (P<0.05) decrease in the weight of the liver and an increase in the weights of the kidney, brain and pancreas.

4. Serum urea concentrations were elevated (P<0.05) in all groups receiving base‐soluble protein (BSP), acid‐soluble protein (ASP), defatted jackbean (DJB) and raw jackbean (RJB) diets. Enzyme activities were similarly elevated (P<0.01), but serum protein and albumin concentrations were depressed while uric acid was not influenced by dietary treatment.

5. Histopathological examination revealed several pathological lesions in organs of chicks fed on the BSP, ASP, DJB and RJB diets. The presence of lesions was less marked in the organs of chickens fed on diets containing base‐insoluble residue (BIR), acid‐insoluble residue (AIR) and ethanol‐extracted meal (EEM), while those given the aqueous heated jackbean diet did not show any pathological effects.  相似文献   

Effect of warm drinking water on the performance and immunological responses of broiler breeder hens raised at low air temperatures     

M. Spinu  A. A. Degen  A. Rosenstrauch 《British poultry science》1993,34(2):361-366

1. The effect of warmed drinking water on the performance and immunological responses of broiler breeder hens maintained at low air temperatures (5.0° to 12.9°C) was tested. From 22 weeks of age hens (mean body mass = 2.4 kg) were offered either warm water (27.7°C; WARM; n=24) or tap water (12.7°C; CONR; n=24) twice daily for a total time of 2.5 h or tap water ad libitum (CONA; n = 16). Food was restricted for all hens.

2. Daily water intake in the WARM hens (103 ml/kg) was similar to that of the CONR (93 ml/kg) and CONA hens (106 ml/kg).

3. There were no significant differences in either body mass change or egg production among treatment groups.

4. There was no difference among groups in heterophil/lymphocyte ratios. Similarly, there was no difference among groups in either phagocytic activity or wattle index after phytohaemagglutinin (PHA) injection. Total and IgG antibody titres to SRBC tended to be highest in the WARM hens and these titres were significantly higher than in CONR hens 14 d after challenge.  相似文献   

Associations between body weight and rectal temperature in turkey poults     

P. E. Waibel  M. G. Macleod 《British poultry science》1993,34(2):417-423

1. Associations between body weight and rectal temperature were observed in female turkeys.

2. Turkeys with lower weights between 13 and 30 d of age tended to have higher temperatures.

3. Turkeys with lower weights at 7 d exhibited depressed body temperatures.

4. Higher or lower body temperatures may be associated with poorer performance depending on the time of appearance.  相似文献   

Comparison of the rates of proliferation of adipocyte precursor cells derived from two lines of chicken which differ in their rates of adipose tissue development     

L. E. Donnelly  A. Cryer  S. C. Butterwith 《British poultry science》1993,34(1):187-193

1. Putative adipocyte precursor cells were isolated from the white adipose tissue of young broiler and layer chickens and cultured in vitro.

2. The cells from both sources were shown to have the characteristics of adipocyte precursor cells. On reaching confluence, lipoprotein lipase activity was induced and the cells from both strains accumulated large amounts of lipid in the presence of chicken serum.

3. Measurement of cell number over time in culture and calculation of cell doubling times showed that cells from broilers proliferated at a faster rate than those derived from layer‐strain chickens. This was the case whether primary or secondary cell cultures were used. Primary cultures of broiler cells had a doubling time of 22 h versus 39 h for layer cells.

4. The contribution of such a difference in proliferative rate to the differential rate of adipose tissue growth between broiler and layer strains observed in vivo is discussed.  相似文献   

Feeding behaviour in chickens given diets containing medium chain triglyceride     

M. Furuse  R. T. Mabayo  Y. H. Choi  D. M. Denbow  J. Okumura 《British poultry science》1993,34(1):211-217

1. The effect of dietary medium chain triglyceride (MCT) on short‐term food intake was compared with the effect of long chain triglyceride (LCT) in chickens. Maize oil was used as the LCT while glyceryl tricaprylate (C 8) and glyceryl tricaprate (C 10) were used as MCT. Cumulative food intake was determined during the 6 h after the start of feeding.

2. Chicks were given diets containing 200 g C 8/kg diet, 200 g C 10/kg diet or 200 g LCT/kg diet in experiment 1. As early as 30 min after feeding, cumulative food intake in both MCT‐supplemented diets decreased significantly compared with the diet containing LCT.

3. To determine if endogenous cholecystokinin (CCK) was responsible for the decrease in food intake caused by MCT, birds were injected with the CCK‐A receptor antagonist devazepide (DVZ, 1 mg/kg BW) before diet presentation. DVZ had no effect on food intake with either LCT‐ or MCT‐supplemented diets.

4. In experiment 3, chicks were given a choice between either diets containing LCT and C 8, LCT and C 10, or C 8 and C 10 to confirm whether or not the palatability of the diets was influenced by the dietary fat sources. There was no difference in food intake between C 8 and C 10‐supplemented diets. However, chicks preferred the LCT‐supplemented diet compared with either of the diets containing MCT.  相似文献   

Nesting and dust bathing by hens in cages: Matching and mis‐matching between behaviour and environment     

S. F. Smith  M. C. Appleby  B. O. Hughes 《British poultry science》1993,34(1):21-33

1. Medium hybrid hens were housed as groups of 4 at 18 weeks of age in cages of 4 different types: control battery cages allowing 675 cm2/bird; similar cages with a rear‐mounted dust bath, 290×345×240 mm, containing sand (D); cages with a rear‐mounted nest box of the same size, containing wood shavings (N); cages with both (DN). In half the experimental cages access to nests was restricted to the morning and access to baths was restricted to the afternoon, by automatic sliding doors.

2. During the first 24 weeks of lay about 95% of eggs were laid in nest boxes in treatments N and DN. Slightly fewer were laid in boxes where doors were present. Over 90% were laid in dust baths in D cages without doors and 67% with doors, which birds learned to open. Prelaying behaviour was least disturbed in nest boxes, most disturbed on the floor and intermediate in dust baths.

3. Fully developed dust bathing occurred in D and DN as bouts lasting 5 to 10 minutes; its incidence, surprisingly, was greater when doors were present and greater still when nest boxes were present, even though it was not performed in them. It was also performed by some hens in nest boxes in N (without doors). In N with doors and in control cages, dust bathing occurred on the bare floor in truncated form, as serial bouts each lasting only about 10 s. This truncated dust bathing was also occasionally observed in D and DN.

4. Plumage, foot and claw damage were less in hens from modified cages than from controls. Egg production was very good in all treatments but more eggs from control cages were downgraded because they were dirty or cracked.

5. When a choice was available birds generally partitioned their behaviour appropriately between nest box and dust bath. In N and DN virtually all prelaying and nesting behaviour took place in the nest boxes. Matching between dust bathing and the environment was less close; the reasons for its relatively low incidence and occurrence in truncated form outside dust baths remain to be established.  相似文献