Supplementation of prebiotics in fish feed: a review

Aquaculture is one of the fastest growing industries in the world. There is a need for enhanced disease resistance, feed efficiency and growth performance of cultured fish species. The cost of production are likely to be reduced if growth performance and feed efficiency are increased in commercial aquaculture. Also if the survivility of the fishes increase, then their overall production cost would be remarkably reduced. Dietary supplementation of different feed additives e.g. immunostimulants, probiotics and prebiotics usually in small quantities for the purpose of fortifying it with certain nutrients have been found to be beneficial for improving immune status, feed efficiency and growth performance of crustaceans and finfishes. The present article was constructed to highlight the effect of dietary prebiotics on different body growth parameters of fish. However, the application of prebiotics and supplementary enzymes in fish feed is now gradually gaining importance in commercial aquaculture practices, the article stresses on the effect of prebiotics on live body weight gain, dressing percentage, weight of vital organs and muscles and mean villus lengths in digestive tract of fish along with their application as growth promoters in commercial aquafeed (Gatesoupe in Aqua Feeds Formul Beyond 2(3):3–5, 2005; Ganguly et al. in Israeli J Aquac Bamidgeh 62(3):130–138, 2010a, Fish Chimes 30(7):64, 2010b).     

The costs of autotomy and regeneration in animals: a review and framework for future research

Many organisms have the ability to shed an appendage (autotomy)to escape a predator or fouled molting event. Despite its immediateadvantage on survivorship, autotomy can have important consequencesfor locomotion, foraging, survivorship, and/or reproduction.Thus, regeneration is a way that animals alleviate some of thecosts associated with losing an appendage. Like autotomy, however,appendage regeneration can have important consequences for avariety of aspects of fitness; in a wide range of amphibians,reptiles, fishes, and arthropods, the allocation of resourcesto regenerate a lost appendage negatively affects somatic orreproductive growth. Previous research into the costs associatedwith regeneration has provided a strong framework to explorehow trade-offs associated with regeneration may have influencedits evolution. However, all research to date describing thecosts and benefits associated with autotomy and regenerationhave compared individuals autotomizing and regenerating an appendagewith individuals that have never lost an appendage. I suggestthat for studies of the evolutionary significance of regeneration,an alternative comparison is between individuals experiencingautotomy without regeneration and individuals experiencing autotomywith regeneration. Future work in this direction promises newinsights into the evolution of regenerative tendencies, as wellas how regeneration may be influencing animal form and function.     

Exclusion probabilities for pedigree testing farm animals

Pedigree testing, using genetic markers, may be undertaken for a variety of situations, of which the classical paternity testing is only one. This has not always been made clear in the literature. Exclusion probabilities associated with various testing situations, including the use of autosomal or X-linked codominant marker systems with any number of alleles, are presented. These formulae can be used to determine the appropriate exclusion probability for the situation being investigated. One such situation is where sire groups of progeny are to be verified without knowledge of the dams' genotypes, in which case the classical paternity exclusion probability is too high, and if used may result in an optimistic declaration about the progeny that have not been excluded. On the other hand, if mating pairs are known then incorrect progeny can be excluded at a higher rate than suggested by paternity exclusion calculations. The formulae also assist in determining the usefulness of X-linked markers, particularly if the pedigree checks involve progeny of only one sex. A system of notation that is useful for the algebraic manipulation of genetic probabilities, including exclusion probabilities as presented here, is also given.     

Lice of farm animals in Libya

Abstract. This first report on the lice of farm animals in Libya lists a total of fifteen species, as follows: Haematopinus quadripertusus and Linognathus vituli from cattle, Bovicola ovis, Linognathus pedalis, L.afrlcanus and L.ovillus from sheep, L.stenopsis, L.africanus and Bovicola caprae from goats. Poultry harboured Lipeurus caponis, L.heterographus, Menacanthus stramineus, Menopon gallinae, Goniocotes gallinae, Goniodes gigas and G.dissimilis.     

Control of ovulation in farm animals

Examination of hormonal changes occurring in farm species at the onset of puberty, during the follicular phase of the oestrous cycle, and at those times when ovarian activity is re-established after periods of seasonal or lactational anoestrus, provides circumstantial evidence that the final phases of follicular development are dependent on a pattern of tonic (episodic) LH secretion. A suppression of episodic LH secretion is associated with periods of anovulation. Stimulation of tonic LH secretion by repeated injections of small doses of synthetic Gn-RH or purified LH restores normal reproductive function in all but deeply anoestrous animals. Continuous infusion of Gn-RH is as effective as repeated injections. It is suggested that an additional inadequacy, possibly endocrine, contributes to the anovulatory state in deep anoestrus.     

Comparative mapping in farm animals.

This paper summarises the current status of comparative mapping in farm animals. For most of the major farm animal species, a wide range of genomic tools are now available to create high-resolution genetic and physical maps of the genome. For many farm animals, the use of radiation hybrid panels and sequence data from expressed sequence tag (EST) projects has accelerated the development of high-resolution comparative maps, with human--the model species for farm animals. These tools and comparative maps are being used to map and identify the genes at the loci for simple and complex traits. The development of detailed physical maps in farm animals based on radiation hybrid panels and bacterial artificial chromosome (BAC) contigs provides a direct link between the 'information-poor' maps of farm animals and the 'information-rich' genomes of human and other model organisms.     

Relationship of embryo sexing to other methods of prenatal sex determination in farm animals: A review

Cloprostenol (ICI 80, 996) was administered to a cow with hydrallantois and a cow with hydramnios to induce parturition. In both cases circulating plasma progesterone levels at parturition were decreased from pretreatment levels. Circulating estradiol-17β levels in the case of hydramnios did not change post treatment. A 64 kg dead fetus with pituitary and adrenal defects was delivered via cesarean section. Circulating estradiol-17β levels in the case of hydrallantois rose from 200 pg/ml pre-treatment to 450 pg/ml at parturition. A live 37 kg heifer calf was delivered via forced extraction. In both cases cloprostenol was effective in reducing plasma progesterone levels, dilating the cervix and initiating labor.     

Clostridium difficile in young farm animals and slaughter animals in Belgium

Faecal carriage of Clostridium difficile in healthy animals has been reported recently, especially in piglets and calves. However there is limited data about carriage in animals just prior to slaughter in Europe. The main objective of this study was to determine the presence of C. difficile in pigs and cattle at the slaughterhouse. C. difficile was isolated in 6.9% of the cattle at the slaughterhouse. None of the pig slaughter samples were positive for C. difficile after an enrichment time of 72 h. For complementary data, a short study was conducted in piglets and calves at farms. C. difficile was more prevalent in piglets (78.3%) than in calves (22.2%) on the farms. Regarding the piglet samples, 27.8% of the positive samples were detected without enrichment of stools. The PCR ribotype 078 was predominant in farm animals. Samples isolated from slaughter cattle presented the widest range in PCR-ribotype variety, and the most prevalent PCR ribotype was 118a UCL. The results of this study confirm that C. difficile is present in slaughter animals in Belgium with a large percentage of toxigenic strains also commonly found in humans.     

Plasmodium: experimental animals for human malaria and research needs. A review.

The literature on experimental animals for human malaria has been selectively reviewed. Criteria for the selection of host animals and the experimental approaches for establishing malarial infections in them are discussed and analyzed on the bases of previous work. It is suggested that the research experiments of other countries, where feasible and applicable, should be adopted in attempts to establish animal models for human malaria indigenous to the People's Republic of China.     

Emotions in farm animals: a new approach to animal welfare in applied ethology

One of the major topics of applied ethology is the welfare of animals reared by humans. Welfare can be defined as a state of harmony between an individual and its environment. Any marked deviation from this state, if perceived by the individual, results in a welfare deficit due to negative emotional experiences. In humans, verbal language helps to assess emotional experiences. In animals, only behavioural and physiological measurements help to detect emotions. However, how to interpret these responses in terms of emotional experiences remains an open question. The information on the cognitive abilities of farm animals, which are available but scattered, could help the understanding of their emotions. We propose a behavioural approach based on cognitive psychology: emotions can be investigated in farm animals in terms of the individual's appraisal of the situation. This evaluative process depends on: (a) the intrinsic characteristics of the eliciting event (suddenness, novelty, pleasantness); (b) the degree of conflict of that event with the individual's needs or expectations; and (c) the individual's coping possibilities offered by the environment. The result of such an evaluation determines the negative versus positive emotions. We propose an analysis of the emotional repertoire of farm animals in terms of the relationship between the evaluative process of the event on the one hand and the behavioural and physiological responses on the other hand.     

Survey of aflatoxicosis in farm animals.

Over a 22-month period, 278 submissions of farm animals were made to the North Carolina Diagnostic Laboratory for suspected aflatoxicosis, and 94 cases were confirmed on the basis of finding aflatoxin in the feed and the occurrence of bile ductule proliferation. There was an annual variation in the incidence of aflatoxicosis, as well as a seasonal variation: the peak incidence occurred in the winter, and the minimum incidence occurred during the summer. The annual increase coincided with the corn harvest. All confirmed cases occurred on farms that raised and stored their own corn, and 88% were in swine. The cases were geographically localized in the eastern section of North Carolina (94% of the total cases) where 82% of the swine and 79% of the corn are produced. Mean concentration of aflatoxin in feed samples from the confirmed cases was 3,890 mug/kg, and the mean value for corn used in making the feed was 5,180 mug/kg. Only aflatoxin B1 was found in the samples. These data were interpreted to mean that the incidence and severity of aflatoxicosis is greater than previously suspected, that poor on-farm storage of corn is a primary contributing factor, that aflatoxin formation continues during and after the milling process, and that mycotoxicoses other than aflatoxicosis may cause equal or greater problems.     

Correlates of psychosomatic stress symptoms among farm women: a research note on farm and family functioning

The relationship between self-reported psychosomatic stress symptoms and dimensions of family and farm functioning were examined in a sample of New York State dairy farm wives (N = 126). The farm women completed a questionnaire assessing home and farm task loads, farm complexity, intrapersonal role conflict, interpersonal role conflict, husband support, and marital satisfaction. The psychosomatic stress symptoms included nervousness, restlessness, insomnia, shortness-of-breath, and fainting. In general, stress symptoms showed little relationship to task loads, farm complexity, and intrapersonal role conflict. Much stronger relationships were found for interpersonal role conflict, husband support, and marital satisfaction. Thus, these findings point to the greater importance of family relationships in preventing or buffering stress in comparison with simple role-related task expectations of farm systems.     

Pain detection and amelioration in animals on the farm: issues and options

Pain in nonhuman animals is a difficult concept to identify and measure. This article briefly describes the consequences of pain in animals on the farm and explains the reasons for the minimal use of analgesics in farmed animals. Pain can have implications for both animal welfare and economics. The reasons for a low use of analgesics in farmed animals include the lack of recognition of animal pain owing to the apparent lack of anthropomorphically identifiable behavioral changes, concern over human food safety, and lack of research efforts to develop safe analgesics for farm use. Treatment cost relative to the benefits expected is another hindering factor. Interventions to minimize pain must begin with developing objective and practical measures for pain identification and measurement at the farm level. A suggested use of a combination of different behavioral and physiological indicators would help to identify pain in animals. To facilitate continued usage of the methodologies on the farm it also is necessary to evaluate the economic implication of the pain alleviation intervention.