Spectral sensitivity of the domestic fowl (Gallus g. domesticus).

1. The spectral sensitivity of 7 broiler fowl was determined in a behavioural test. 2. Initially the birds were trained to receive a food reward by pecking at a clear, Perspex panel behind which was a light stimulus (circular, diameter = 9 mm), originating from a tungsten-halogen lamp. Subsequently, they were trained to choose between 2 panels only 1 of which was lit; the assignation of light and dark on each panel was randomly ascribed between trials. The colour of the lit panel was determined by the wavelength of the light transmitted through one of 13 closely defined narrow bandwidth filters between 326相似文献   

Discrimination between individual humans by domestic fowl (Gallus gallus domesticus).

1. We demonstrate that Barred-Rock and Isa-Brown hens can discriminate between the presence of 2 different humans and use this information as a cue for whether or not to make an operant response. 2. This demonstration in domestic fowl, the first of its kind in any avian subject, is consistent with a growing body of evidence that many species, including agricultural animals, are surprisingly adept at differentiating between humans. 3. Such a discriminative ability carries considerable implications for issues related to husbandry, production and welfare.     

Bilateral testicular asymmetry and supernumerary testes in the domestic fowl (Gallus domesticus).

1. The left and right testis weights from 378 males in 7 experiments were recorded. 2. The relationship between the right and left testis weights was similar in males of different ages, strains and body weights. 3. The left as a proportion of total testes weight was approximately normally distributed about a mean of 0.515. 4. The left testis was greater than the right testis weight in 0.67 of males. 5. The linear regression of the natural logarithm of the right on that of the left testis weights was -0.04 + 0.99X (r2 = 0.98) and it was concluded that, in general, the left and right testes were of similar weight. 6. Three cases of triorchidism (two left testes) occurred, suggesting that this may not be a rare condition in the domestic fowl.     

An efficient isolation method for domestic hen (Gallus domesticus) ovarian primary follicles

An enzymatic method of isolating primary follicles in the turkey has been described previously, but no similar work has been done in the hen. In this study, primary follicles from domestic hens (Gallus domesticus) were isolated using an enzymatic method, and the isolated follicular quantity, quality, and development in vitro were assessed. About 400 primary follicles ranging from 60 to 1125 microm in diameter were recovered with trypsin and collagenase from hen ovaries (per ovary). Of these, 76.5% were intact follicles with a complete single layer of granulose cells surrounded by the basement membrane, and their ultrastructures appeared this way in situ. Follicles (351 to 500 microm in diameter) were cultured in vitro, and 46.67% of them survived after 5 days. Ultrastructural examination showed that elongated mitochondria forming a ring were distributed to the periphery of the oocyte, the Golgi was oriented with the maturing face toward the granulosa cell layer, and the oocyte plasma membrane presented a few short microvilli lying on the oocyte surface, which confirmed that the surviving follicles were developmental. These results suggest that a simple, rapid, effective enzymatic method can be used to isolate a great number of intact primary follicles from the hen ovary.     

Effect of non-steroidal aromatase inhibitor on blood plasma ovarian steroid and thyroid hormones in laying hen (Gallus domesticus)

HyLine Brown laying hens at 30 weeks of age were treated twice daily with Fadrozole, a non-steroidal aromatase inhibitor (AI; 1 mg/kg body weight; i.m.) for six consecutive days; control hens received saline. Blood was collected every day 0.5 h after oviposition, i.e. just before AI treatment. Ovarian steroids: progesterone (P4), testosterone (T) and estradiol (E2), and iodothyronines: thyroxine (T4), triiodothyronine (T3) and reverse-triiodothyronine (rT3) were measured in blood plasma by radioimmunoassay methods. In AI-treated hens a gradual delay in oviposition time was observed. AI significantly decreased P4 and E2 levels, maximally by 43% on day 4 and by 74% on day 5, respectively, and elevated T level, maximally by 248% on day 4. Simultaneously, the increases in T4 and T3 levels with no changes in rT3 levels were observed. The maximal effect of AI on T4 and T3 levels was found on day 4 (60% increase) and day 5 (312% increase), respectively. Moreover, statistically significant, negative coefficient of correlation between E2 and T3 (r = -0.51), and positive coefficient of correlation between T and T3 (r = 0.42) in AI-treated hens were found. The results obtained indicate that in mature laying hens there is a strong relationship between ovarian steroids and thyroid hormones, and suppression of E2 synthesis not only disrupts ovarian function but also affects the activity of the thyroid gland and peripheral metabolism of thyroid hormones.     

Long-term vasoligation in the domestic fowl (Gallus domesticus)

The effects of long-term (14 months) unilateral vasoligation on the tests and their excurrent ducts of the domestic fowl were studied histologically and ultrastructurally. Severe testicular degeneration and epididymal atrophy were observed in the ipsilateral organs while the contralateral control organs were normal. Massive macrophage activity was observed in the epididymal regions and to a lesser extent in some severely degenerated seminiferous tubules. Several granulomata occurred in the epididymal regions and the ducti deferentes, and most were resorbed or were undergoing resorption at the time of examination.     

Uterine adenocarcinoma with transcoelomic metastases in breeder hens (Gallus domesticus)

Hens involved in a Newcastle disease study were euthanased at regular intervals according to a designed protocol. Of these, 7.14 % (n = 42) of the 82-week-old specific pathogen-free breeder hens were found to have well-delineated firm white to yellowish nodules of varying sizes in the abdominal cavity. Histologically, the nodules were identified as an adenocarcinoma originating in the uterus. Transcoelomic spread was evidenced by the presence of similar neoplastic cells embedded in the serosa and outer longitudinal muscle layer of the intestines as well as the liver.     

Lecithin--cholesterol--acyltransferase activity in the plasma of immature, oestrogenised and laying fowl (Gallus domesticus).

A study was made of the role of the lecithin-cholesterol-acyltransferase (LCAT) enzyme in the changes in the concentrations and fatty acid composition of the plasma cholesteryl esters of the fowl associated with oestrogen treatment and sexual maturity. Although there was a considerable increase in the concentration of free cholesterol in the plasma of oestrogen treated and laying birds, only in the oestrogen treated birds was it associated with an increased rate of cholesterol esterification. In both laying and oestrogen treated birds, changes in the fatty acid composition of the plasma cholesterol esters could be attributed to related changes in the fatty acid specificity of the LCAT enzyme. Evidence is provided to indicate that the cholesterol esters in the plasma of the fowl are synthesised mainly by the plasma LCAT system. The changes in the rates and fatty acid specificity of the LCAT system in the plasma of the fowl associated with sexual maturity or oestrogen treatment are discussed in relation to the extensive alterations shown to occur in the lipoprotein pattern of the plasma.     

Histotopics of glycosidases in the oviduct of domestic chicken (Gallus domesticus)]

The histochemical patterns of distribution of six glycosidases were examined in the oviduct of mature hens (white Leghorn, Heysdorf — Nelson — Lohmann ). The significance of the glycosidases possibly forming an antibacterial protective mechanism is discussed.     

Evaluation of putative appetite suppressants in the domestic fowl (Gallus domesticus)

1. The effectiveness of the appetite suppressants fenflur‐amine, furanone and crotonolactone were evaluated in a series of experiments with adult male layers and growing broilers of both sexes fed on diets with concentrations of up to 1000 mg/kg.

2. Fenfluramine produced a curvilinear decrease in food intake and body weight in adult layers and growing broilers.

3. Inconsistent responses to furanone and crotonolactone were obtained with adult layers and broilers in cages, but a similar decrease in food intake and body weight for both drugs was recorded in male broilers raised in floor pens.

4. The responses to subcutaneous injection of 20 mg/kg of each drug on food intake over 24 h were comparable to those for dietary inclusion. Fenfluramine, however, produced a greater response in male compared with female broilers and induced signs of hyper‐thermia in broilers and layers.

5. Subcutaneous injection of 50 mg crotonolactone/kg was associated with decreases in the food intakes of 4 strains and there was evidence of different responses between lines.

6. It was concluded that none of the drugs used were likely to be suitable for the control of food intake in broiler breeder flocks.     

Bilateral apex pubis distance：a novel index for follicular development and egg laying status in domestic hens (Gallus gallus domesticus)

ABSTRACT

1. Measures of the bilateral apex pubis (BAP) in White Leghorn (WLH) hens aged from 16 to 64 weeks (from the time ovaries were completely undeveloped to senility) were ranked into various groups so the relationship between external traits (BAP distance, comb length, comb height, wattle length, wattle height, body weight) and internal traits (largest ovarian follicle diameter (LFD) and oviduct weight and length) could be determined.

2. Using correlation and regression analysis with data from 16 weeks of age to the onset of lay, measurements of the apex pubis showed a strong correlation with LFD (r = 0.80, P < 0.01) and oviduct weight (r = 0.80, P < 0.01).

3. Multiple comparisons among WLH hens from 16 to 43 weeks of age showed that the BAP distance increased in all groups ranked by LFD or by laying period.

4. In the late laying period (>60 weeks of age), BAP distance showed a significant decrease (P < 0.01) in long-term non-laying hens compared to laying hens.

5. These findings suggest BAP distance can serve as an index for evaluating the onset and probable stages of follicular development during sexual maturation and/or aid in the identification and selection of non-laying hens during reproduction.     

The effects of progesterone on oviposition and ovulation in the domestic fowl (Gallus domesticus)

1. Following an injection of 0.5 or 0.1 mg progesterone/kg between 0 and 6 h after ovulation, oviposition of the resulting egg was delayed by 1 to 11 h and occurred 26 to 31 h after injection, depending on the dose. The injection terminated the laying of a sequence of eggs by causing the next ovulation to occur a day late. The delayed ovulation occurred at the time normally expected for the first ovulation of a sequence and became the first of a new sequence.

2. Following an injection of 0.5 or (H mg progesterone/kg between 6 and 15 h after ovulation, oviposition of the resulting egg was generally delayed by between 15 and 28 h and occurred at the same time of day as the next ovulation, which was delayed as in the first experimental situation. Subsequent ovulations were resynchronised and followed at intervals according to the normal sequence established before the injection.

3. Injection of 0.5, 0.1 or 0.05 mg progesterone/kg between 12 and 9 h before an expected ovulation advanced the oviposition of the egg already in the uterus (shell gland) by about 3 h. The succeeding ovulation was either advanced or blocked.

4. These observations suggest that the pre‐ovulatory surge of progesterone is directly or indirectly involved in the timing of oviposition and ovulation.     

Utilisation of energy substrates in treadmill-exercised domestic fowl (Gallus gallus domesticus): blood plasma free fatty acids

1. Plasma free fatty acid (FFA) concentration, FFA turnover and gas exchange were measured in adult male domestic fowl at rest and during 90 min continuous treadmill exercise at a work load of approximately three times the resting metabolic rate. 2. Plasma FFA concentration and turnover increased 7-fold and 4-fold respectively during exercise. Of the FFA turnover 0.54 was oxidised at rest and this increased to 0.70 during exercise. The fraction of the total carbon dioxide production derived from plasma FFA oxidation rose from 0.33 at rest to 0.55 during exercise. 3. It is concluded that plasma FFA are the most important source of energy for the working muscles of domestic fowl during treadmill exercise of this intensity and duration.     

Effects of temperature and pH on osmotic fragility of erythrocytes of the domestic fowl (Gallus domesticus) and guinea-fowl (Numida meleagris).

The effects of temperature and pH on the osmotic behaviour of erythrocytes of the domestic fowl and guinea-fowl were studied. Erythrocytes of the guinea-fowl were observed to be more osmotically fragile than those of the domestic fowl at 29 degrees C and pH 7.7. The osmotic fragility of erythrocytes of both species decreased as the temperature (at constant pH of 7.7) or pH (at constant temperature of 29 degrees C) increased. The erythrocyte count, packed cell volume, haemoglobin concentration and mean corpuscular volume were identical in both species.     

Follicle stimulating hormone increases serum oestradiol-17 beta concentrations, number of growing follicles and yolk deposition in aging hens (Gallus gallus domesticus) with decreased egg production.

1. The aims of this study were to determine if the number of small yellow follicles (SYF) and large white follicles (LWF) in ovaries of young and old hens differed; and if injection of old hens with follicle stimulating hormone (FSH) changed growth of and yolk deposition into follicles of old hens. 2. Ovaries were removed and follicles were divided according to size and condition and counted. The number of normal SYF and LWF was decreased in old hens compared to young hens, whereas the number of atretic follicles was greater in old hens compared to young hens. 3. Old hens were injected subcutaneously with saline containing 0.1% bovine serum albumin (BSA, vehicle) or 12.5, 50, 200, 400 micrograms porcine (p) FSH or 25 or 50 IU pregnant mare's serum gonadotropin (PMSG) for 5 consecutive days. Blood samples were taken on days 1 and 5 before FSH and PMSG injection and 2 h after FSH and PMSG injection on day 5. Sudan black and Sudan red dyes were injected intravenously on alternative days to monitor yolk deposition into follicles of the hierarchy removed after the fifth day of FSH treatment. 4. Treatment with 200 micrograms pFSH or 25 IU PMSG for 5 d increased serum progesterone (P4) concentrations as compared to controls. Injection of hens with FSH caused a linear dose dependent increase in serum oestradiol-17 beta (E2) concentrations, dose dependent increase in SYF and LWF, and dose related decrease in number of atretic SYF and LWF. The hierarchy of the ovary was disrupted with PMSG, but not FSH. Larger doses of FSH increased the number of small follicles (10 mm diameter) and yolk deposition. 5. We conclude that small follicles which have not entered the rapid growth phase are responsive to FSH. The increased yolk deposition following FSH treatment may have been a direct effect of FSH or may have been caused by the elevation of serum E2 concentrations in response to FSH treatment. It is possible that old chickens may produce inadequate amounts of FSH which result in decreased rate of follicular growth and ultimately decreased egg production.