Species diversity and size ranges of cephalopods in the diet of jackass penguins from Algoa Bay,South Africa

An analysis of cephalopod remains collected from jackass penguin Spheniscus demersus regurgitations and stomachs at St Croix Island, Algoa Bay, in 1976 and 1977 revealed the presence of three cephalopod species. Most common was Loligo reynaudi, with Heterotuthus sp. and Argonauta argo constituting trace items. Beak measurements were used to estimate dorsal mantle lengths and wet masses of cephalopods taken by penguins. The dominant cephalopod taken by penguins was the same species as that harvested by commercial fisheries. Despite an overlap in the size range of squid taken by penguins and trawlers, penguins tended to take smaller squid and did not take the larger squid landed by trawlers. The seasonal occurrence of squid in the penguin diet in 1976 and 1977 was the opposite of the abundance of squid in the area as reflected by trawler landings. This is explained in terms of the abundance and preference for other prey items. It is suggested that penguins take fish in preference to squid because of the relatively higher energy content and food value of fish.     

Heat production studies on normal and oil-covered jackass penguins (Spheniscus demersus) in air and water

Heat productiorf and the importance of intact feathers for insulation were studied in jackass penguins Spheniscus demersus at various temperatures (5-25°C) by comparing their oxygen consumption in air and water with that of birds whose feather insulation was impaired when they were accidentally covered in partially weathered crude oil. Special attention was given to employing an experimental procedure that could relate oxygen consumption to level of activity. The mean ± SD metabolic rate recorded for normal inactive birds (188 ± 24 kJ kg-1 day-¹) was the same in air and water but only 80% of the mass specific rates predicted for non-passerine birds. Wetting a bird increased the inactive rate in air 1,33 times while slow swimming in water above 10°C caused a 1,76-fold increase. At low air temperatures (5°C) postural changes and feather fluffing were associated with a very low rate of 122 ± 29 kJ kg-¹ day-¹, which we interpret as behavioural control of penguins over energy expenditure. Jackass penguins in sea water at 10°C and above were within their thermal neutral range thus indicating that the water phase of their life cycle is not energetically more expensive than the terrestrial phase. Activity c level of the birds was an important influence on oxygen consumption; we suggest it is the main reason for the variations in metabolic rates within closely related species "? reported in the literature.     

Plasma vitamins A and E, total lipid and cholesterol concentrations in captive jackass penguins (Spheniscus demersus)

The concentrations of vitamins A and E in the plasma of captive jackass penguins was studied in birds fed defined quantities of the vitamins. For a year, each of the 17 adult birds in the colony received a daily diet of 340 g of sprats and a vitamin supplement tablet, together providing 2.04 mg per day retinol equivalent and 185 mg per day alpha-tocopherol equivalent. The concentrations of plasma retinol and alpha-tocopherol and the alpha-tocopherol/total lipid ratio compared well with those recorded in wild populations of related species of penguin and the birds moulted and bred successfully.     

Influence of frame size and zeranol on growth, compositional growth and plasma hormone characteristics

A 2 X 2 factorially arranged trial was conducted to compare effects of implant (zeranol) and frame size on weight and compositional gain, and plasma hormone concentrations. Angus, Charolais X Hereford and Hereford X Angus yearling steers (34 steers averaging 270 kg body weight) were randomly assigned to treatments of small (SF) vs large frame (LF) and implant (I) vs no implant (NI). Steers were implanted at 0 and 97 d and individually fed an 81% whole shelled corn and 11.5% corn silage-based diet (dry basis) for a 175-d period. Shrunk weights and body measurements for frame size determination were taken initially and at approximately 28-d intervals; blood was collected via venipuncture at 14-d intervals for analyses of insulin (IN), triiodothyronine (T3), thyroxine (T4) and glucose concentrations. Steers were also counted in a whole body counter for measurement of 40K content and prediction of whole body protein and fat. The I steers showed an improvement (P less than .05) in daily gain regardless of frame size for the total trial. The I LF steers required 18% more dry matter to attain higher daily gain for 97 to 175 d; I steers were more efficient (P less than .05) at converting dry matter to gain during 0 to 97 d and 0 to 175 d. Daily fat deposition was increased (P less than .05) in I steers, while protein deposition was not affected by I. Plasma IN concentrations were numerically elevated (P less than .10) in I steers regardless of frame size, during the initial 97 d. Implant did not influence (P greater than .10) plasma T3, T4 and glucose concentrations regardless of frame size. Steers responded differently to zeranol implant over time regarding plasma T4 concentrations (P less than .003). Steers differing in frame size responded similarly in rate of gain, in feed conversion and in patterns of plasma insulin concentrations to zeranol implants.     

蛋重对蛋鸭孵化效果的影响

将三个品种(攸县麻鸭、麻旺鸭和三穗鸭)种鸭蛋按蛋重各分5个组在相同的条件下孵化,研究蛋重对不同品种孵化效果的影响。结果表明,种蛋受精率和入孵蛋孵化率:攸县麻鸭蛋重在65~73 g最高,麻旺鸭蛋重在66~70 g最高,三穗鸭蛋重在66~74 g最高,种蛋过重或过轻均不利于种蛋孵化。胚胎死亡率:攸县麻鸭在蛋重61~65 g最低,三穗鸭在蛋重小于62 g时最低,麻旺鸭在蛋重小于58 g时最低,攸县麻鸭种蛋重量适中有利于胚胎成活,三穗鸭和麻旺鸭种蛋重量较轻时有利于胚胎成活。     

Influence of litter size and creep feeding on preweaning gain and influence of preweaning growth on growth to slaughter in barrows

The importance of birth-to-weaning average daily gain as a determinant of weight at a final age and yield of marketable pork was investigated. Treatments were imposed to create variation in birth-to-weaning ADG independent of birth weight. Newborn pigs were cross-fostered to create litters of four through 14 pigs/litter. Creep feed was offered to pigs from 5 d of age or during last 2 d before weaning at 13 to 20 d (average = 17 d). Growth rate and carcass dissection data were obtained from 195 barrows that were slaughtered at an average age of 170 d (SD = 7.5), weight of 109 kg (SD = 10.5). All traits measured were influenced by birth dam and sire (P < 0.01). Quadratic and cubic effects (P < 0.09) of litter size on birth-to-weaning ADG and weaning weight were different between the creep feeding treatments. Data revealed a positive influence (P < 0.04) of creep feeding from 5 d of age on birth-to-weaning ADG and weaning weight in larger size (> 8) litters. Importance of the independent variables birth weight, birth-to-weaning ADG, weaning weight, and birth weight plus birth-to-weaning ADG in determination of measures of postweaning growth and yield of marketable pork were examined by step-down regression analysis. Initial models included the linear and quadratic effects of the independent variables. In general, R2 for models ranked birth weight < birth-to-weaning ADG < d-17 weaning weight < birth weight + birth-to-weaning ADG. The R2 of models for BW at 170 d of age were 0.11 (P < 0.01) using birth weight as the independent variable, 0.16 (P < 0.01) using birth-to-weaning ADG, 0.19 (P < 0.01) using d-17 weaning weight, and 0.21 (P < 0.01) using birth weight + birth-to-weaning ADG. The model for effect of birth-to-weaning ADG on BW at 170 d of age indicated that a 10-g advantage in birth-to-weaning ADG produced a 0.94-kg advantage in BW at 170 d of age. Positive relationships (P < 0.05) between birth-to-weaning ADG and measures of postweaning growth and carcass yield suggest management practices that increase birth-to-weaning ADG may be advantageous in pork production.     

Influence of maternal frame size and nutritional restriction on growth and development of the postnatal lamb

Pregnant ewes (large frame [LF] and small frame [SF]) were nutritionally stressed in early gestation (EGS), late gestation (LGS) or fed 100% of NRC requirements (unstressed, US) throughout gestation. Lambs (128) from these ewes were slaughtered at birth, weaning (18 kg), 41 kg or 55 kg. Sixty-four lambs received a 13% protein diet from weaning to either 41 or 55 kg. Lambs from SF ewes were fatter at 55 kg, had a higher numerical yield grade and a lower percentage of carcass protein. Lambs from US ewes were youngest at slaughter and had the most carcass weight and protein per day of age at 55 kg. The LGS lambs had the lowest percentage of lean and carcass protein at 41 and 55 kg. However, at birth these lambs had the highest concentration of RNA and DNA in muscle. The EGS lambs had the lowest quality grade, carcass weight per day of age and fat percentage. Muscle DNA and RNA at birth was lowest in EGS lambs. However, EGS lambs produced the highest lean percentage and highest percentage carcass protein at 41 and 55 kg. Shortest metacarpals and metatarsals were also found in these lambs at weaning and 41 kg. Although frame size had little effect on carcass characteristics, the effects of nutritional stress in the first 80 d of gestation were apparent in lambs slaughtered at 31 kg. Stress in the last 50 d of gestation had more effect on lambs slaughtered at 55 kg.     

Influence of management system on litter size, lamb growth, and carcass characteristics in sheep.

Three management systems (winter, spring, and late summer) distinguished by season of lambing and management practices were compared for litter size born and weaned and growth and carcass characteristics of lambs. Three sire breeds (Cheviot, Rambouillet, and Suffolk) and three dam breeds (Florida Native, Native-X, and Synthetic-X) were used in 698 matings over a 3-yr period. System affected (P < .01) litter size born. Spring lambing yielded more lambs (1.62) than winter (1.49) and late summer (1.12). The winter-born lambs were lighter but fatter (P < .05), and spring-born lambs were leaner with higher leg conformation and carcass quality scores. The late summer-born lambs were not different from spring-born lambs. Wethers had higher (P < .01) weights off test than ewe lambs (43.9 vs 42 kg) but had lower (P < .01) leg conformation scores, percentage kidney and pelvic fat, yield grade, and dressing percentages. Dam breed effects were significant (P < .05) for average preweaning daily gains with 249+/-5, 201+/-9, and 191+/-9 g for progeny of Native-X, Florida Native, and Synthetic-X, respectively. Single-born lambs had higher daily gains (P < .05) than twins in a preweaning period in all management systems and higher postweaning and lifetime daily gains for winter and spring management systems.     

Effects of coated hatching eggs obtained from old broiler breeders with chitosan on embryonic growth,hatching results and chick quality

The aim of this research was to determine the effects of coating broiler hatching eggs with chitosan on egg quality, embryonic growth, hatching results and chick quality. Eggs obtained from old broiler breeder, aged 59 weeks, were used. Eggs were divided into two groups (coated with chitosan and uncoated) groups. Each group was divided into three groups according to the storage period. Eggs were stored for periods of 1, 4 and 7 days at 15°C and 80% humidity. Then, they were incubated. Storage period of eggs up to 7 days did not affect the egg quality, egg weight loss, embryo growth, chick properties and hatchability of fertile eggs. However, embryo development, relative residual yolk sac weight and relative chick weight were affected by coating eggs with chitosan. Interaction was not found between storage lengths and coating of eggs with chitosan for all examined parameters. The results of the present study suggested that hatching eggs obtained from old broiler breeder flocks were immersed into chitosan solution once and quickly have negative effect on the embryo weight, yolk sac absorption and relative chick weight. It has been observed that covering the hatching eggs with chitosan is not suitable in this respect even if immersion takes place once and in a short time.     

Effects of interaction of incubator CO2 levels and mixing hatching eggs of different embryo growth trajectory on embryo physiological and hatching parameters

1. Two experiments were designed to investigate the effects of mixing eggs of different genotype and incubating with different CO₂ concentrations on embryonic parameters. Half of the eggs were incubated in a CO₂ controlled incubator (VCO₂) during the first 10 d of incubation and the other half was incubated at standard incubation ventilation rate (SV).

2. From 10 to 18 d of incubation, thick albumen and embryos were weighed. Blood samples were collected at d 18 of incubation, at internal pipping and at hatch for determination of triiodothyronine (T₃), thyroxine (T₄) and corticosterone concentration. During the last 2 d of incubation, hatching events of individual eggs were monitored every 2 h.

3. From 4 to 5 d of incubation in the SV group of Experiment 1, pH values of Ross strain chickens were lower than those of Isa Brown. From d 12 of incubation onwards, Ross embryos grew faster than those of Isa Brown. At 14 and 16 d of incubation, Ross eggs in the CO₂ controlled incubator had lower albumen weights compared to all other treatments.

4. T₃ concentrations in Ross embryos were higher than those of Isa Brown embryos. Chicken weight at hatch was in the following order: Isa Brown SV < Isa Brown VCO₂ = Ross SV < Ross VCO₂.

5. In Experiment 2, incubation time of VCO₂ eggs until internal pipping, external pipping and hatch was significantly shorter than that of SV eggs.

6. It was concluded that mixing of hatching eggs of differential embryo developmental trajectory affects their hatching process.     

Sound exposure and its beneficial effects on embryonic growth and hatching of broiler chicks

ABSTRACT

1. The physical factors that involve artificial incubation determine embryonic growth and hatching of broiler chicks, and have important implications for the poultry production chain and chick welfare. This study explored the effects of sound exposure on incubation responses (hatching, embryonic development and chick quality).

2. A 2 × 2 factorial experiment with the factors ‘sound pressure level’ (at 70 and 90 dB) and ‘species-specific vocalisations’ (at 75dB - 85dB) was performed in four experimental incubators (loaded with 90 eggs each) for eight consecutive cycles of incubation, totalling 2880 Cobb-500® broiler breeder eggs.

3. Embryonic growth was not influenced by any experimental factor, but the highest sound pressure level (90 dB) led to earlier hatching, higher hatchability, better chick quality and lower weight at hatching. Additional effects of species-specific vocalisations were found at 70 dB noise, which caused early hatching and better chick quality.

4. It was concluded that the loud noise found in commercial hatcheries (at 90 dB) can be beneficial. Furthermore, the presence of species-specific vocalisations could improve the hatching time and chick quality from experimental incubators (at 70 dB). However, this would not provide additional benefits in commercial hatcheries, due to the machinery noise masking them.     

Ultrasonographic evaluation of sexual glands before and after ejaculation in the jackass

Veterinary Research Communications -     

用不同消毒剂消毒肉鸡种蛋对孵化效果的影响

肉鸡种蛋从母鸡体内产出后经泄殖腔,到产蛋箱接触垫草和粪便,表面就会逐渐沾染细菌.在贮藏、运送、孵化过程中,种蛋上的致病菌在适宜的温度和湿度条件下,就会迅速繁殖.虽然蛋壳表面上的细菌容易被杀死,但还有相当一部分细菌可以直接通过蛋壳上的微小气孔和蛋壳膜进入蛋内,进行生长繁殖.     

Influence of egg storage on hatchability, embryonic development and vitamin status in hatching broiler chicks

Storage of eggs for 14 d prior to incubation depressed hatchability by 10%. Most of the increase in embryonic mortality (64%) occurred during the first week of incubation, with a further 30% taking place during the third week. Chicks hatching from stored eggs did not show any increased incidence of physical abnormalities characteristic of vitamin deficiencies. Chicks from stored eggs showed haematological abnormalities characteristic of mild macrocytic anaemia. Such changes can result from deficiencies of folic acid or cobalamin. Biochemical and haematological data did not suggest impairments in the status of the chicks with respect to a range of other vitamins.     

白鹅、籽鹅蛋重和蛋形指数对孵化率的影响

随机选取白鹅和籽鹅种蛋各251枚,测量蛋重和蛋形指数,研究蛋重和蛋形指数对种鹅孵化率的影响,结果表明:白鹅和籽鹅的蛋重分别为128.11±12.04 g,129.25±13.07 g;蛋形指数分别为1.457±0.065,1.457±0.068;白鹅和籽鹅的蛋重、蛋形指数无明显差异;白鹅和籽鹅种蛋孵化率随蛋重、蛋形指数的增加呈现先增大后减小的趋势,白鹅蛋重在131.16～144.88 g范围内,蛋形指数在1.387～1.496范围内种蛋孵化率最高;籽鹅蛋重在137.08～151.04 g范围内,蛋形指数在1.349～1.449范围内种蛋孵化率最高.     

犊牛前胸腺素α基因的克隆及表达载体的构建和鉴定

胸腺是机体免疫系统的中枢器官,它所分泌的胸腺素是一组活性肽类物质,分为α族胸腺素和β族胸腺素.胸腺素α族包括前胸腺素α（prothymosin-α,ProT-α）和胸腺素α1、α2、α5、α7.胸腺素能提高机体溶菌酶、补体C3和调理素水平,活化吞噬和巨噬细胞,促进干扰素和白细胞介素的分泌,可用于癌症的治疗.     

Influence of prenatal and postnatal fraternity size on reproduction in swine

Hypotheses of a negative association between fraternity size (size of litter in which an individual develops prior to birth or is reared following birth) and ovulation rate or litter size were tested by examining reproduction of females born or reared in varying prenatal and postnatal fraternities. Gifts were randomly assigned to develop prenatally and be reared postnatal in small or large fraternities. Dams of experimental animals were randomly assigned to one of two prenatal fraternity size treatments, either unilateral oviductal ligation (to bear a small prenatal litter) or no ligation (to bear a normal prenatal litter). Whereas this did result in differences (P less than .01) in litter size at birth (small = 6.2 +/- .4 vs large = 9.6 +/- .9), there was considerable overlap in observed litter sizes between ligated and nonligated dams. Consequently, effects of prenatal fraternity size were examined by regression. Distinct differences in postnatal fraternity size were created by randomly assigning piglets to small (5 piglets) or large (10 piglets) postnatal fraternities within 24 h of birth. Differences in postnatal fraternity size were maintained through weaning at 3 wk (small = 4.9 +/- .1 vs large = 9.4 +/- .2). Weights at birth (regression of birth weight on prenatal fraternity size = -.07 +/- .02, P less than .01) and weaning (small = 6.09 +/- .15 vs large = 5.46 +/- .17 kg, P less than .01) were heavier for gilts from small prenatal and postnatal fraternities, respectively, compared with gilts from large fraternities. Effects of prenatal and postnatal size on BW did not persist following weaning (P greater than .20).     

Influence of race and crossbreeding on casein micelles size

Casein (CN) micelles are colloidal aggregates of protein dispersed in milk, the importance of which in the dairy industry is related to functionality and yield in dairy products. The objective of this work was to investigate the correlation of milk CN micelles diameter from Holstein and Zebu crossbreds with milk composition (protein, fat, lactose, total and nonfat solids and milk urea nitrogen), somatic cell count (SCC), age, lactation stage and production. Average casein micelles diameters of milk samples obtained from 200 cows were measured using photon correlation spectroscopy and multiple regression analysis was used to find relationship between variables. CN micelle diameter, SCC and nonfat solids were different between animals with different Holstein crossbreed ratios, which suggests influence of genetic factors, mammary gland health and milk composition. Overall, results indicate the potential use of CN micelle diameter as a tool to select animals to produce milk more suitable to cheese production.