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[Fundamental ethological and ecological aspects for the husbandry of domestic animals, especially for hens].

The significance of ethology applied to farm animals is demonstrated from 1. a broader point of view and 2. focussed on the management of poultry. The topic of animal ethology is the study of their behaviour. Basic functions of animal behaviour are satisfaction of their requirements and needs including reproduction and avoidance of harm. A significant task for ethologists is the scientific elaboration of the animals' interactions with their surrounding, in their keeping system. The documented information aim to show how to satisfy the basic behavioural and physiological needs of hens and how to produce eggs of high quality in adequate quantity in respect also to the environment.

Animal Husbandry↗

Pathological and biochemical observations on subclinical cases of fatty liver-haemorrhagic syndrome in the fowl.

A high incidence of subclinical fatty liver-haemorrhagic syndrome (FLHS) was found in three flocks of laying hens in which deaths from FLHS had occurred. There was so significant difference between the affected hens and the remainder of the block in egg production or quality, but the former were more obese and had higher concentrations of lipids in their livers, suggesting a pathogenic relationship between hepatic steatosis and haemorrhage. Soluble protein tended to accumulate with the fat in the livers. Reticulolysis had occurred in over half the haemorrhagic livers examined. Histological examination and DNA estimations provided no evidence of generalised hyperplasia. From the composition of the liver lipids it was concluded that the steatosis resulted mainly from an increase in lipogenesis from dietary carbohydrate. Lipid levels in the plasma were weakly correlated with those in the liver. No change was detected in the plasma protein pattern.

Animals↗

Influence of dietary cereal and energy content on the accumulation of lipids in the liver in fatty liver-haemorrhagic syndrome in the fowl.

Isocaloric diets supplying about 2900 kcal/kg and based on maize, wheat and barley respectively, were fed to pullets for 13 weeks from point of lay. The number of cases of subclinical fatty liver-haemorrhagic syndrome and the mean total lipid, triglyceride and monoglyceride content of the liver decreased in the above order of diets. The final body weight, weight gain and abdominal fat score followed the order wheat greater than maize greater than barley. Reduction of the energy content of the wheat and barley diets to 2670 and 2490 kcal/kg respectively by the omission of animal fat was associated with a reduction in the lipid content of the liver only in the case of the wheat diets. Egg production and quality were uniformly high and no difference was detected in plasma triglyceride and free fatty acid levels.

Animal Feed↗

Bovine egg transplantation. Superovulation, non-surgical recoveries and transfers.

Lactating dairy cows were superovulated with a pregnant mare serum gonadotrophin (PMSG)/cloprostenol (PG) regimen in their mid-luteal phase (day 10). The average interval from the PMSG injection to heat was 4.1 +/- 0.05 days. First insemination occurred 18--24 hrs after standing heat and the second insemination 12--18 hrs later. Six to eight days later (the day of recovery) the superovulatory response was assessed. The variation in number of ovulation points (corpora lutea, C.L.) was sizable, and right ovary (4.1 C.L./donor) appeared more active than left ovary (3.3 C.L./donor). The non-surgical embryo collection equipment was developed for practical use on the farms and it was possible to recover 6.0 +/- 0.6 eggs per donor (54 +/- 5% recovery rate). Approximately half of these (54.2%) were considered viable, and suitable for either direct transfer or freezing, Other eggs were retarded (5.8%), degenerated (25.7%) or unfertilized (16.3%). Several influential factors were examined and there was only little conclusive evidence for any specific effect on the superovulatory response and/or egg number and quality. The non-surgical transfer experiments with a common insemination gun was encouraging and gave rise to a pregnancy rate of 56%.

Animals↗

Precision and accuracy of an assay for detecting Ascaris eggs in various biosolid matrices.

This paper presents quality assurance data and quality control data on the recovery of Ascaris suum eggs from various biosolid matrices: acid-treated, alkaline-treated, amended-soil blended, and lagoon stored biosolids. Over a period of years, the same procedure, the "Tulane Method," was performed on different matrices, and in this work, the data collected on the recovery of the eggs from the different matrices is examined and compared. The egg recoveries are discussed in terms of precision (the comparison of the recovery of eggs from a sample processed in duplicate) and in terms of accuracy (the percentage of eggs recovered from a sample to which eggs were added at the beginning of the extraction procedure). This form of quality analysis/control is typically called the "Split/Spike" method. This method of biosolid processing for helminth egg recovery had an overall accuracy of about 60% or greater and a percent variation from the mean density (an indirect method of assessing precision) of only 3-35%.

Animals↗

Survival and transport of bacteria in egg washwater.

An evaluation of methods for monitoring the quality of water used to wash eggs at grading stations was undertaken to improve maintenance of bacterial viability during overnight sample transport. Bacterial content of samples at analysis would then better reflect conditions at the time eggs were washed. The interactive effects of temperature and the highly alkaline water conditions upon viability were the subjects of this study. Nine transport methods were examined for their efficacy in recovering total and coliform bacteria from recycled water used to wash eggs, and these were compared with samples analyzed at two commercial egg grading stations. Samples were shipped under test to the laboratory for analysis the following day. The survival of Staphylococcus aureus and Escherichia coli was also examined, but in a synthetic washwater matrix under various combinations of temperature (6 to 32 degrees C) and pH (9.5 to 10.5) to determine whether there was likely to be a different response to variations in transport treatment among gram-positive and -negative bacteria. S. aureus was much more resistant to the lethal effects of high pH and moderate temperature than E. coli. These results indicated that samples of high pH should be held (transported) at less than or equal to 13 degrees C to optimize bacterial survival. Considering cost, ease of manipulation, and the ability to protect both coliforms and the bacterial population as a whole, the method of choice for transport of industrial samples was the direct addition of washwater to containers in which powdered KH2PO4 and Na2S2O3 had been placed to yield final concentrations, when dissolved, of 0.2 and 0.05% (wt/vol), respectively.

Animals↗

Egg size-number trade-off and a decline in oviposition site choice quality: female Pararge aegeria butterflies pay a cost of having males present at oviposition.

Once mated, the optimal strategy for females of the monandrous butterfly, Pararge aegeria, is to avoid male contact and devote as much time as possible to ovipositing, as there is little advantage for females to engage in multiple matings. In other butterfly species the presence of males during egg laying has been shown to affect aspects of oviposition behavior and it has been suggested that repeated interference from males has the potential to reduce reproductive output. The aim of this study was to assess the effects of male presence during oviposition on reproductive output and behavior of a population of P. aegeria obtained from Madeira Island, Portugal, and maintained in the laboratory. Two experiments were performed where females were housed individually in small cages. Experiment 1 examined how social factors influenced the egg laying behavior of females. To do this the presence or absence of males was manipulated and egg size and number was measured over the first 14 days of oviposition. It was observed that when males were present during oviposition females made a trade-off between egg size and number. Experiment 2 examined how social factors affected oviposition site choice. Again, male presence/absence was manipulated, but in this experiment where the female laid her egg in relation to host quality was scored, and the size of the egg laid was measured. In the absence of males females selectively positioned their larger eggs on good quality host plants. However, selective oviposition was no longer observed when females were in the presence of males. We suggest that P. aegeria females from the Madeira Island population are adapted for a flexible oviposition strategy, governed by external cues, allowing a trade-off between egg size and number when the time available for egg laying is limiting.

Animals↗

Influence of vitamin D3, 1 alpha-hydroxyvitamin D3, and 1,25-dihydroxyvitamin D3 on eggshell quality, tibia strength, and various production parameters in commercial laying hens.

Four hundred 53-wk-old Hyline W36 laying hens were randomly allocated to 10 treatments. The effects of feeding two vitamin D3 metabolites, 1 alpha-hydroxyvitamin D3 [1 alpha-(OH) D3] and 1,25-dihydroxyvitamin D3 [1,25-(OH)2 D3], each at five dietary levels (0, .75, 1.50, 3.00, and 4.50 micrograms/kg of feed) were determined on eggshell quality and tibia strength in commercial laying hens (Experiment 1). In Experiment 2, 1,440 Hyline W36 65-wk-old laying hens were used to determine the effects of four levels of vitamin D3 (0, 500, 1,000, and 1,500 ICU vitamin D3/kg) and three levels of dietary 1,25-(OH)2 D3 (0, .5, and 1.0 microgram/kg of feed) on eggshell quality, tibia strength, and egg production. In Experiment 1, neither 1,25-(OH)2 D3 nor 1 alpha-(OH) D3 affected eggshell quality or production criteria. Tibia weight was increased by adding either 1,25-(OH)2 D3 or 1 alpha-(OH) D3. In Experiment 2, 1,25-(OH)2 D3 increased percentage of shell, shell weight, and egg breaking strength when 0 ICU D3/kg was fed but had no effect at higher levels of vitamin D3. Egg production, feed consumption, and egg weight were also increased with supplemental 1,25-(OH)2 D3 when 0 ICU D3/kg was fed. Tibia weight and tibia breaking strength were also increased by adding 1,25-(OH)2 D3 to the diet. The commercial laying hen metabolizes sufficient 1,25-(OH)2 D3 from dietary vitamin D3 to maintain shell quality but not enough to maintain tibia strength.

Animals↗

Performance of layers reared and/or kept under different 6-hour light-dark cycles.

Using 60 hens reared and kept on a standard lighting programme (decreasing followed by increasing photoperiod to 22 weeks of age and 14 h continuous light: 10 h continuous dark during lay) as control, the effects of the following intermittent patterns on development and performance were studied. Group 1. The same rearing programme, followed by, between 20 and 36 weeks, 3 h light (L):3 h dark (D) intermittent and then from 36 weeks a regime in which each light period was progressively shortened by 30 min every 8 weeks with corresponding lengthening of the dark period so that the last cycle used between 52 and 60 weeks was 1.5 h L:4.5 h D. Group 2.6-hour light-dark cycles from hatching; the light:dark ratio first decreasing and then increasing, such that total light hours per day varied as in the control group to 20 weeks, and then subsequent lighting as in 1. Group 3. Intermittent lighting of 1.5 h L:4.5 h D unvaryingly from 4 to 60 weeks. Sexual development was essentially the same in all groups. Egg numbers were decreased slightly by the short light-dark cycles but daily egg mass output was the same in all groups. Food utilisation was best in group 1 and worst in the control group. In general egg weight and shell quality were improved by the short light-dark cycles; the effect appearing with the first eggs and being especially marked for group 3. On intermittent regimes ovipositions were equally distributed, between the four daily light-dark periods when the light:dark ratio was near unity but were more numerous during the first half of the solar day when the ratio was 1.5 L:4.5 D.

Animals↗

Life expectancy and egg load affect oviposition decisions of a solitary parasitoid.

Life-history theory predicts that animals should be sensitive to both the amount of resources available and life expectancy in making reproductive decisions. Because it is easier to control the mortality of insect parasitoids (insects whose larva develop in or on another insect) than many other groups of animals, the best tests of these predictions have used them. However, because of the inter-correlation of several of the variables of interest, much of this evidence is equivocal, and experimental manipulations have failed to isolate the most important factors. Here we report an experiment which circumvents such problems by comparing the superparasitism rates of fed and starved parasitoids. By using the asexual solitary hymenopteran parasitoid Venturia canescens, we demonstrate that starved wasps with a reduced life expectancy lay eggs in low-quality hosts more frequently than those with a greater expected lifespan, as do parasitoids with higher egg loads and hence more resources available for reproduction.

Animals↗

[Microbiological aspects of stored hard-boiled eggs].

Hard-bioled eggs in the shell were without any pretreatment stored in air at 20 degrees C and 4 degrees C. Furthermore the keeping quality of varnish-coated eggs stored in air at 20 degrees C and of untreated eggs stored in 100% carbon dioxide at the same temperature was studied. Hard-boiled eggs stored at 4 degrees C and varnish-coated eggs stored at 20 degrees C were of excellent bacteriological quality up to 5 weeks. Untreated eggs stored in air at 20 degrees C showed high microbiological contamination (more than 10(6)/g) already after one week. The CO2 storage atmosphere inhibited the growth of microorganisms during the first week of storage, but in the days to follow counts increased to more than 10(6)/g as well.

Aeromonas↗

Effect of age at molting on postmolting performance.

Molt was induced at the 431, 501, or 571 d, in Lohmann (L) and Hy-Line W-77 (H) hens, by 8 or 14 d, respectively, of feed withdrawal followed by a rest period of 16 d. Induced molt resulted in increases in egg production, numbers of intact eggs, egg mass per housed or surviving hen, and shell quality and in decreases in egg breakage (not significant), mortality, and culling. Egg weight was only slightly affected by molt, and the EW of hens induced to molt at 431 or 501 d of age were slightly lower than those of the unmolted hens or of those induced to molt at 571 d. Both strains reacted similarly to molt, although the L hens responded better, and expressed their responses more intensively when induced to molt earlier (431 d). This finding suggests that although different breeds have some effects of molt in common, molt protocols should be finely tuned for each breed. Total intact egg production and egg mass of the molted hens became higher than those of the unmolted hens at 650 to 728 d, which suggests that no benefit would be achieved by rearing molted hens for less than 700 to 730 d.

Aging↗

Variations in external and internal microbial populations in shell eggs during extended storage.

The current project was conducted to determine the microbial quality of commercially processed shell eggs during extended storage. Unwashed eggs were collected at the accumulator before entering the processing line. Washed eggs were retrieved after placement in flats. All eggs were stored on pulp flats at 4 degrees C for 10 weeks. Twelve eggs from each treatment were rinsed on the day of collection and during each week of storage. After rinsing, eggs were sanitized in ethanol, and contents were aseptically collected. Total aerobes, yeasts and molds, Enterobacteriaceae, and pseudomonads were enumerated from shell rinses and pooled egg contents. During storage, no differences were found between unwashed and washed eggs for Enterobacteriaceae and pseudomonads in either shell rinses or contents. No differences were found between treatments for population levels of total aerobes or yeasts and molds in the egg contents throughout the storage period. Significant differences between treatments were found at each week of storage for external shell contamination by total aerobes. The highest unwashed egg contamination occurred at week 8 of storage and the lowest was at weeks 0 and 1 of storage. The highest shell contamination with aerobic bacteria on the washed eggs was found at week 0 of storage and the lowest was at week 7. Yeast and mold contamination determined by shell rinses was also significantly different between treatments at each week of storage. Commercially washed eggs were significantly less contaminated than were unwashed eggs for the populations monitored.

Animals↗

Stressed mothers lay eggs with high corticosterone levels which produce low-quality offspring.

Organisms frequently encounter stressful ecological conditions. In vertebrates, a major mechanism of physiological response to stress is mediated by the hypothalamic-pituitary-adrenal axis and results in increased secretion of glucocorticosteroids, which can have adverse consequences on diverse phenotypic traits affecting fitness. Maternal stress may thus have carry-over effects on progeny if it influences pre-natal offspring environment in terms of glucocorticosteroid concentration, although this hypothesis has never been tested in any species under field conditions. We manipulated stress experienced by female barn swallows Hirundo rustica, by exposing them to a predator during laying and measured egg corticosterone concentration. Stressed females laid eggs with greater corticosterone concentration than controls exposed to a herbivore. In another experiment, we injected physiological doses of corticosterone in the egg albumen and compared the phenotype of offspring originating from these eggs with their control siblings originating from either sham-inoculated or unmanipulated eggs and reared in the same nest. Eggs injected with corticosterone had lower hatchability and produced fledglings with smaller body size and slower plumage development than did control eggs. Nestling body size in our study population predicts long-term survival. Thus, maternal stress impaired offspring phenotype and viability by increasing transmission of glucocorticosteroids to the eggs. This study identifies a novel mechanism mediating early maternal effects whereby maternal stress affects offspring quality. These results are relevant to biological conservation because they disclose a mechanism that can link environmental conditions to population productivity and viability.

Analysis of Variance↗

Protein quality of supplements and meal replacements. Amino acids and calculated indicators of protein quality.

The amino acid composition of several types of dietary supplements and meal replacements was measured and compared with label values when available and to published values for egg. Calculated indicators of protein quality, such as chemical score, protein calorie:total calorie ratio, individual essential amino acid:total essential amino acid ratio, and total essential amino acid:total amino acid ratio were also compared for products, egg, and the estimated pattern of adult requirements. Predigested liquid protein products were notably lower in protein quality than other products. All non-predigested products compared favorably with egg in terms of protein quality, but were more expensive and had no advantages over regular meals in terms of protein quality as reducing aids or protein supplements.

Adult↗

Effects of ascorbic acid on plasma thyroxine concentrations and eggshell quality of Leghorn chickens treated with dietary thiouracil.

Because ascorbic acid (AA) and the thyroid hormones are known to influence eggshell formation, the effects of AA on body weight, total plasma thyroxine (T4), egg production, and eggshell quality of Single Comb White Leghorn (SCWL) hens concurrently and previously treated with thiouracil (TU) were determined. Hens were provided feed containing either 0 or 100 ppm AA from 47 to 67 wk of age and either 0 or .1% TU from 47 to 57 wk of age. A three-way split-plot analysis was employed to test for the effects of AA, TU, and time, and their interactions. Dietary TU increased body weight between 53 and 59 wk, and increased thyroid weight at 67 wk; however, TU only depressed plasma T4 level at 51 wk. Dietary TU depressed egg production from 50 to 56 wk and egg weight at 49, 51, and 57 wk. Dietary TU depressed eggshell weight per unit surface area at 49 wk. There was no significant effect due to AA and no AA by TU interaction for any of the parameters examined. It was concluded that .1% dietary TU from 47 to 57 wk of age did not alter eggshell quality and that dietary AA at the 100 ppm level did not influence the effects of .1% TU on body weight, egg production, or egg weight of SCWL hens.

Animals↗

The quality properties and saturated and unsaturated fatty acid profiles of quail egg: the alterations of fatty acids with process effects.

The nutritional composition (moisture, ash, crude protein, available carbohydrates, total lipids), energy value, some quality characteristics (yolk weight, albumen weight and shell weight), cholesterol level and fatty acid profiles of quail egg were determined (p<0.01). The protein content of quail egg was higher than laying hen's egg. The fatty acid composition of quail egg yolk consisted of 24 fatty acids including saturated fatty acids (C14:0, C16:0, C17:0, C18:0, C20:0, C22:0, C24:0), monounsaturated fatty acids (C15:1, C16:1, C17:1, C18:1n9, C18:1n7, C22:1n9, C24:1) and polyunsaturated fatty acids (C18:2n6t , C18:2n6c , C18:3n6, C18:3n3, C20:2, C20:3n6, C20:3n3, C20:4n6, C22:2, C20:5n3, C22:6n3). The total cholesterol level of quail egg was found to be 73.45+/-1.07 mg/100 g. Linoleic acid (C18:2n6c) (10.28%), arachidonic acid (C20:4n6) (1.92%) and cis-5,8,11,14,17-eicosapentaenoic acid (C20:5n3) (0.63%) were the major polyunsaturated fatty acids in the fatty acid content of quail egg yolk, whereas oleic acid (C18:1n9c) was the major monounsaturated fatty acid comprising 26.71% in the yolk. The palmitic acid (C16:0) and stearic acid (C18:0) levels were 16.62% and 6.89%, respectively. Total omega-3 was detected as 1.16% in raw egg whereas it was 0.82% in soft-boiled (rafadan) egg. The polyunsaturated fatty acid/saturated fatty acid proportion was 0.58 and 0.64 for raw and processed yolk, respectively.

Animals↗

Influence of sequence length on the response to ahemeral lighting late in lay.

1. An experiment is described in which 96 individually-caged SCWL hens in two rooms were used to investigate the response to changing to a 28-h cycle using a reverse treatment design. 2. The application of the 28-h cycle did not affect mean rate of lay but increased mean egg weight and egg output. 3. Grouping the birds according to their preliminary sequence length yielded an interesting outcome. In both rooms, birds with short sequences (< or = 6 eggs) produced significantly more eggs under the 28-h cycle, while those with long sequences (> 6 eggs) produced marginally fewer eggs. The same trend was also evident with egg output. 4. Changing from 24-h to 28-h increased yolk and albumen weights as well as shell quality. However, relative to egg weight, no measurable effect was detected due to light cycle, age or sequence length on yolk and albumen weights. 5. The paper provides new evidence suggesting that long ahemeral cycles could be used to improve egg production as well as shell thickness in flocks with modest rates of lay.

Animals↗