Metabolic and anatomical adaptations of light‐bodied chicks to intermittent feeding

1. Chicks of a light‐bodied strain were deprived of food on alternate days from 15 to 46 d of age.

2. Hyperphagia, amounting to twice the intake of control birds early in the experiment, occurred on the repletion day.

3. Final body weight attained 80% of that of the controls.

4. Body fat concentration decreased at first but returned to that of controls after 3 weeks.

5. A consistent hyperlipaemia was observed after food deprivation or restoration.

6. There was a marked increase in the digestive enzymes found in the small intestine, but not in the pancreas during the repletion day.

7. These responses may be considered as mechanisms to reduce the physiological manifestations of starvation.     

Selection for food conversion in broilers: Direct and correlated responses to selection for body‐weight gain,food consumption and food conversion ratio

1. Direct and correlated responses were determined after five generations in four lines of chickens selected either for increased body‐weight gain (line W), for increased food consumption (line F), for decreased food conversion ratio (line E), or at random (line C).

2. Realised heritability estimates calculated after five generations of selection were : 0–37 + 0.04 for weight gain (WG); 0.44 + 0.05 for food consumption (FC); 0.21 + 0.04 for food conversion ratio (FCR).

3. Realised genetic correlation estimates were: WG and FC, +0.71 ±006; WG and FCR, ‐0.40±0.09; FC and FCR, +0.27 + 0.09.

4. Zero‐generation heritability and genetic correlation estimates were greater than the realised estimates, and sex linkage appeared to be important in the expression of all three traits.

5. The genetic correlation between FC and FCR was asymmetrical with considerable positive response in FCR in line F (r_g = +0.79) but negligible response in FC in line E (r_g = —0.01).

6. There was an apparent plateau in response in FCR in line E from the third to the fifth selected generations.     

The hen's egg: Evidence on the mechanism relating shell strength to loading rate

1. The decrease in strength of an egg shell which is known to accompany an increase in the period of time over which a load is applied might come about by either of two mechanisms: a decrease in the strength of the material constituting the strong, outer layer of the mineral shell, or a decrease in the thickness of this layer brought about by deepening of the crevices that are normally present between adjacent crystal columns in the weak, inner layer of the shell.

2. Experiments designed to discriminate between these mechanisms are described: the results indicate the second mechanism.

3. This mechanism offers explanations for various other shell phenomena, including delayed fracture under a static, cyclical or recurrent load.

4. The main implication for the poultry industry is that any external insult to a shell is likely to weaken it by doing damage that is local, internal, irreparable and cumulative, even though it may be invisible from the outside.     

AN OESOPHAGEAL DIVERTICULUM IN A DOG

An 11-month-old male Miniature Poodle was found to regurgitate small volumes of fluid and food particles due to a diverticulum in the thoracic oesophagus. The diverticulum was removed surgically. Histologically the wall contained extensive scar tissue. Longterm recovery was uneventful and 5 months after surgery the dog is in good health     

Newcastle disease in Cyprus: A review

Summary The first Newcastle disease epidemic in Cyprus was reported in 1949 to 1950 and between 1953 and 1959 there was a second. In November 1977 another Newcastle disease outbreak occurred. Measures implemented immediately were: quarantine of all foci of infection, destruction of diseased and in-contact birds, disinfection of premises and island-wide (Government controlled) vaccination. Within a month the epidemic was brought under control. In all 47 outbreaks were recorded with the loss of about 35,000 birds. Only 2 commercial units were affected, the remaining outbreaks occurring in premises of back-yard poultry keepers. The virus was the Asiatic type.

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La Enfermedad De Newcastle En Chipre: Revisión De La Literatura

Resumen La primera epidemia de Newcastle en Chipre se describio en 1949–50 y la segunda entre 1953 y 1959. En Noviembre de 1977 ocurrio otro brote. Las medidas tomadas fueron: cuarentena de todos los focos de infección, destrucción de todas las aves enfermas y en contacto, desinfección de los galpones y vacunación general. La epidemia se controló en un mes. En los 47 brotes diagnosticados, hubo una pérdida calculada de 35 000 aves. La enfermedad se diagnosticó en dos empresas comerciales y en unidades pequeñas familiares. El virus aislado fue el tipo Asiático.

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La Maladie De Newcastle A Chypre—Revue

Résumé La première appartition de la maladie de Newcastle à Chypre, a eu lieu en 1949–1950, avec une seconde vague entre 1953 et 1959.La maladie est répparue en 1977. Les mesures assitôt prises ont été: la mise en quarantaine des foyers d'infection, la destruction des animaux malades et des animaux contaminés, la désinfection des locaux et une large vaccination, sous contrôle officiel, des volailles de l'Ile. En l'espace d'un mois la maladie a été enrayée. Pour les 47 foyers constatés les pertes se sont élevées à environ 35 000 têtes. Deux élevages commerciaux ont seulement été atteints, les autres foyers étant apparus dans les poulaillers des petits éleveurs.

     

Plasma concentration of sulphadimethoxine in pigs after multiple dosing and during injections of Escherichia coli endotoxin

The effect of endotoxin induced fever on the steady state concentration of sulphadimethoxine in pigs has been studied.Sulphadimethoxine 20 mg/kg b.wt. was injected at 9 a.m. in an ear vein each day for eleven days. From day 6 until the end of the experiment, endotoxin fromEscherichia coli 1.5 g/kg b.wt. was injected at 9 a.m. and at 3 p.m. The plasma concentration versus time curves were calculated by means of a computer program, assuming a two-compartment model. During the endotoxin injections the plasma concentrations were simulated and compared with those calculated.It was not possible to show any clinically significant changes in pharmacokinetics of sulphadimethoxine after the start of endotoxin injections.     

Tom-cat odour and other pheromones in feline reproduction

The function and suppression of urine spraying by cats is discussed as also is the source of tom-cat odour. It seems unlikely that tom-cat odour is derived from the lipid in the proximal convoluted tubule of the kidney, however its production by the anal glands has not yet been proven. Although male cats show a flehmen response when sniffing urine, smell seems to play a more important role in reproduction in the female than the male. The available data suggests that valeric acid may function as a female/female pheromone in cats by inducing or facilitating oestrus. Nepetalactone, the active ingredient of catnip, is probably not related to any naturally occurring pheromone in the cat but simply acts as an hallucinogenic drug.     

小麦丛矮病研究之三:灰飞虱同发病的关系

1976—1977年河北晋县贺家寨大队小麦春季灰飞虱的传带病毒率为31—52%,不同地块同代灰飞虱的带毒率异差较大:而秋苗期则为12—35.4%,其中不同地块上同代(四代成虫)灰飞虱的带毒率的差异从33.3%至35.4%则不太大。灰飞虱的有效传毒指数(即虫口数×自然带毒率)同田间小麦发病率的相关性是非常显著的,其r=0.9769。1975—1976两年调查及计算分析结果,其直线回归公式如y=4.12x-2.577。在有效传毒指数0.7—20.9之间用于予测发病率有效。人工分期侵染试验证明小麦在生长发育过程中受侵愈早,病情愈重,其中死株率也愈大。秋季侵染的死株率达95.6%,病指为99.6;夏季侵染的死株率为0,病指为57.6。秋季小麦出苗前后的大量虫口形成小麦10月中下旬的一个发病高峰,第二年春季4月中旬的虫口高峰形成5月上旬的一个发病高峰。3月下旬的一个发病高峰是越冬前受侵的。病毒在小麦植株中的潜育期的长短随小麦的生长速度而异。温度不过其中因素之一,最短5—8天,最长30—40天。侵染后如小麦进入越冬期,即不表现症状,一直要到返青以后。介体灰飞虱在河北晋县以第五代3—4龄若虫在冬麦地及草荒中越冬。夏季在玉米上可以产卵并孵化,但不能长期存活,主要在地头沟边及夏作物荫蔽下的禾草上越夏。冬麦治虫防病的重点应在秋季麦苗出土前,春季则应在3月中旬左右。冬麦适当推迟播种有利于减少发病率。棉间作麦比平作的病情重六倍而粮麦间作的病情比平作的重九倍。