Digestibility of nutrients and aspects of the digestive physiology of the greater cane rat,journalThryonomys swinderianus journalin two seasons

The greater cane rat, Thryonomys swinderianus, utilizes high fibrous plant material and is an important meat source in West Africa. An insight in its digestive physiology will enhance our understanding of its feeding habits. Digestibility coefficients of the food were determined during two seasons before the animals were euthanased. The distribution and concentrations of nutrients and energy in different parts of the gastrointestinal tract were determined at the time of day when animals practised coprophagy. Trial 1 diet in the wet season consisted of 36% neutral detergent fibre (NDF), 11% protein and 49% dry matter, while the Trial 2 diet in the dry season consisted of 53% NDF, 8–9% protein and 89% dry matter. The Trial 2 animals on the poor diet increased their daily nutrient intake, possibly increased the volume of digesta and practised frequently cophrophagy, so that faecal production was reduced and digestibility coefficients were relatively high. Coprophagy increased both protein and energy intake as soft pellets in the distal colon had higher protein and energy content than the hard faeces. Energy, protein and acid-detergent fibre were retained in the caecum of Trial 1 females and the caecum and proximal colon of the Trial 2 animals 16 hours after feeding, illustrating the importance of these two regions in the fermentation process. Water was absorbed in the distal colon as dry matter content of digesta increased 53%, 4% and 56% from the proximal colon to the distal colon. Animals produced hard faeces with only 16% and 5% lower moisture content in the dry season, compared to that produced in the wet season, as water was not a limiting factor during the trials. It was concluded that an increase in daily food intake, an increase in coprophagy and the presence of a colonic separation mechanism (that retains small particles) enable the greater cane rat to utilize high fibrous plant material. These digestive strategies seem to be comparable to those observed in other hystricomorph rodents.     

Coprophagy in animals: a review

Coprophagy is performed by rodents and lagomorphs and to a lesser degree by piglets, foals, dogs and nonhuman primates. Due to the construction of the digestive system of rodents and rabbits, coprophagy is necessary to supply many essential nutrients. Bacterial synthesis of nutrients occurs in the lower gastrointestinal tract in these animals where little absorption is realized. The eating of their feces provides a method for obtaining these nutrients.     

Reproductive performance and factors that decrease pregnancy rate in heavy draft horses bred at the foal heat

Reproductive performance and factors that decrease the pregnancy rate in heavy draft horses bred at the foal heat were investigated. The study was based on a total of 422 mares varying from 4 to 20 years in age, which had foaled during the period 1991 to 1994. Over the four years, the percentage of the mares bred at the foal heat was 62.6% and the pregnancy rate was 60.2%. The pregnancy rate following breeding at the foal heat in 1991 (67.7%) was significantly higher than that in 1992 (44.1%). Significant correlation was observed between the pregnancy rate and the mean placental retention time and also between the pregnancy rate and the mean temperature during the winter season. When compared on a monthly basis, the pregnancy rate following breeding at the foal heat in February was 53.3% and in May, 48.2%. The mean number of covers per mare at the foal heat was 2.3; this figure decreased to 1.8 for those bred in May. The mean number of days from parturition to the first breeding date was 11.3 days and the number of days from parturition to the last breeding day at the foal heat was 14.0 days. The number of days from parturition to the last breeding day at the foal heat decreased to 12.5 days in May. The latter may have been influenced by factors involving the stallion. When compared on a monthly basis, the mean placental retention time was longest in January (219 min.) following which it decreased gradually up to mid-summer. The mean placental retention time of mares which were not bred at the foal heat was significantly longer (197 min.) than in mares bred at the foaling heat (143 min.) and also in mares that conceived following breeding at the foal heat (135 min.). The pregnancy rate was less in mares bred shortly after parturition. The findings of this study would suggest that certain factors decrease the pregnancy rate in mares bred at the foal heat. The stress of low temperature in winter, prolonged placental retention time, breeding too early after parturition and factors pertaining to individual stallions may be involved. Expulsion of the placenta as soon as possible after foaling and appropriate breeding timing are significant factors that can influence the pregnancy rate following breeding at the foal heat.     

Cryptosporidium parvum infection in a mare and her foal with foal heat diarrhoea

Cryptosporidium infection was molecularly investigated in mares and in their neonatal foals for which the occurrence of foal heat diarrhoea was also assessed. Thirty-seven mare/foal pairs were included in the study. All foals were born in the same stud farm during 2006-2008 breeding seasons. Two faecal samples, one prior to and one after delivery were collected from each mare, whereas three faecal samples were taken from each foal, i.e. at 8, 10 and 12 days of age. All samples (74 from mares and 111 from foals) were divided into two aliquots, one of which was examined for the presence of Cryptosporidium by a commercially available microplate ELISA kit, while the second aliquot of all ELISA-positive samples was molecularly examined. Nine out of 37 examined foals presented foal heat diarrhoea and one of them scored positive for Cryptosporidium, together with its mare. More specifically, four samples belonging to the same mare/foal pair resulted positive for Cryptosporidium upon both ELISA and PCR. The sequence analysis of the COWP gene showed the occurrence of the zoonotic species Cryptosporidium parvum. The possibility that foal heat diarrhoea-like episodes may be due to neonatal cryptosporidiosis and their relevance for the health of horses and of humans handling diarrhoeic neonatal foals and their mares are discussed.     

Amino acid,mineral and vitamin levels in hydrous faeces obtained from coprophagy-prevented rats

Amino acid, mineral and vitamin levels in hydrous faeces obtained from coprophagy-prevented rats were examined. Two experiments were conducted with rats of different age, 4 weeks and 10 weeks. Six rats each were fed under coprophagy-prevented and coprophagy-allowed (conventional feeding) conditions, respectively. In the first experiment using 4-week-old rats, amino acid values were determined for hydrous faeces and usual faeces obtained in the above-mentioned conditions. In the second experiment using 10-week-old rats, mineral values were determined for both types of faeces. Vitamin values were determined in both experiments. In a comparison of amino acid values and their patterns, specific kinds of amino acids in hydrous faeces were not recognized as growth factors. Sodium and potassium levels in hydrous faeces were significantly higher than those for usual faeces, but those levels were 1/(18-20) of those derived from feed. Although cyanocobalamin and folic acid levels in hydrous faeces were two to three times higher than those for usual faeces, folic acid supplements from coprophagy were 1/8 of those derived from feed. Cyanocobalamin supplements from hydrous faeces were five times larger than those from feed. Therefore, it appears that cyanocobalamin was supplied by the ingestion of hydrous faeces and that this cyanocobalamin supports conventional growth in rats.     

The role of Penicillia in ryegrass staggers

Tremorgenic strains of Penicillium verrucosum var cyclopium, P canescens, P janthinellum, P novaezeelandiae and P estinogenum were isolated from the faeces of 15 of 23 affected sheep and cattle in eight of nine field outbreaks of ryegrass staggers. One tremorgenic strain of P griseofulvum was isolated from the faeces of one of 25 sheep grazing in unaffected flocks. Tremorgenic strains of P verrucosum var cyclopium, P canescens, P janthinellum and P estinogenum were also isolated from the A horizon of New Zealand soils. Since a large proportion of experimentally dosed live P verrucosum var cyclopium died during passage through the gut, the faecal evidence from naturally staggering animals suggests that at least some outbreaks of ryegrass staggers are caused by tremorgenic Penicillia and that their source may be soil.     

Coxofemoral luxation in two foals wearing hindlimb casts

Two foals wearing hindlimb casts developed coxofemoral luxations 6 days and 9 days after the casts were applied. One foal had a cast on one hindlimb up to the proximal portion of the tibia and the other foal had tube casts on all 4 limbs. Although the incidents that resulted in the luxations were not observed, they probably occurred during awkward attempts to stand or from being pushed by the mare, with the affected limb being caught under the body in a forward extended and adducted position.     

The association between weather, frenzied behaviour, percutaneous invasion by Strongyloides westeri larvae and Rhodococcus equi disease in foals

Episodes of frenzy lasting approximately 30 minutes were observed among horses confined to enclosures surfaced with sand or soil. The probability of sighting these episodes increased by a factor of three when within 24 hours there was 0.2mm or more of rain, a maximum air temperature between 16.7 - 26.6 degrees C and a soil temperature of 16.3 - 23.9 degrees C at 30 cm. High egg counts of Strongyloides westeri appeared in faeces four to five days later and persisted for several days. Rhodococcus equi was recovered from all soil samples, and from the faeces of 76% of mares and 82% of foals. The youngest foal was five days old when the organism was isolated from rectal faeces. In contrast to the majority of reports, the lesions of R. equi in the foals were confined to limbs and peripheral lymph nodes. It is proposed that the percutaneous invasion of these foals by third stage larvae of S. westeri facilitated invasion of R. equi, and ubiquitous saprophytic opportunist pathogen.     

A pilot study to investigate the measurement of immunoglobulin A in Welsh Cob and Welsh Pony foals’ faeces and their dam’s milk

ABSTRACT

Aims: To determine if an ELISA for measurement of IgA in equine serum could be used to measure concentrations of IgA in foal faeces and to determine correlations with concentrations in the milk of the dam.

Methods: Faeces from 20 Welsh Cob and Welsh Pony foals and milk from their dams were collected within 12?hours (Day 0) and at 6 days after parturition (Day 6). On Day 6, faeces could not be collected from 2/20 foals, and milk samples could not be collected from 3/20 mares. An equine IgA ELISA validated for serum and plasma was used to measure concentrations of IgA in all samples in triplicate. The precision of the assay for each sample type was determined using modified CV.

Results: IgA was not detectable in 7/20 Day 0 faecal samples and in 2/18 Day 6 faecal samples. For samples with detectable IgA, the mean modified CV was 10.5 (95% CI?=?6.0–15.0)% for Day 0 faecal samples, and was 6.8 (95% CI?=?4.3–9.4)% for Day 6 faecal samples. Median concentrations of IgA in faeces on Day 0 were lower than concentrations on Day 6 (0.7?mg/g vs. 37?mg/g dry matter; p?=?0.003). Concentrations of IgA in milk and faeces on Day 6 were statistically correlated (r?=?0.59; p?=?0.006).

Conclusions and clinical relevance: The IgA ELISA showed acceptable precision when used to estimate concentrations of IgA in foal faeces during the first week of life, but IgA could not be detected in 37% of meconium samples collected on Day 0. This assay may be useful for investigation of the role of maternal milk IgA in the gastrointestinal tract of neonatal foals, but further assessment of both accuracy and precision of the ELISA is required.     

Nutritional support for neonatal foals.

In recent years, equine neonatal medicine has made significant advances. The importance of nutritional support for the sick neonatal foal has been recognized, and methods of providing that sup-port have been developed. Today, the clinician has many options when designing a nutritional plan for the neonatal foal. When the foal's gut permits, enteral diets are an inexpensive source of nutrients. Under conditions where the gut requires rest, methods for delivering nutrients by the parenteral route have also been developed. In this article, the nutrition of the normal and sick foal is described. Guidelines for designing a nutritional plan are also reviewed.     

Role of feeding in the treatment of dogs with pancreatic degenerative atrophy

Fourteen dogs with pancreatic degenerative atrophy (PDA) were fed their original diets or a special diet for 2 periods of 4 weeks to compare the severity of clinical signs in relation to different types of diet. During the first period, the dogs were given ordinary food, and in the second period, the dogs were given only the special diet that consisted of a commercial moderate-fat, low-fiber, highly-digestible food. In addition, equal amounts of pancreatic enzymes were added into the food during highly-digestible food. In addition, equal amounts of pancreatic enzymes were added into the food during both periods. The owners were given a questionnaire covering 9 typical signs of PDA. They were asked to assess the severity of signs daily for the 2 periods using a scale provided with the questionnaire. The general well-being of the dogs was significantly (p less than 0.05) better during the period when the dogs were fed a special diet. Of the individual clinical signs associated with PDA the severity of flatulence, borborygmi, volume of faeces and frequency of defecation were significantly (p less than 0.05) decreased on the special diet. There were no significant differences in appetite, drinking, colour and consistency of the faeces or in coprophagy between the 2 feeding periods. The costs of the special diet were almost double compared to the ordinary diets.     

Hypothyroidism in the foal

Hypothyroidism in the foal occurs as two entities because of the separate actions of thyroid hormones in regulation of metabolic rate and in cell differentiation. The hypometabolic state which results in inadequate thermogenesis and lethargy, occurs concurrently with a period when thyroid hormone secretion is inadequate. Also the severity of the concurrent symptoms is related to the degree of hormone inadequacy as measured by plasma concentrations of free T4 and T3. By contrast, the developmental lesions caused by hypothyroidism are often observed during periods when plasma thyroid hormone concentrations are normal. This is because during the development of most tissues there is a period during which deprivation of thyroid hormones leads to developmental defects which may first appear weeks or months later, by which time thyroid hormone levels may have returned to normal. In the foal the critical period for some developmental processes, eg, myelination, is before birth so it is difficult to confirm a pre-natal hypothyroid state as the cause of neonatal neuromuscular incompetence. Post natal developmental lesions of the epiphyses or ossification centres, for example, may also manifest themselves some weeks subsequent to the period during which hypothyroidism existed. Because confirmation of diagnosis using plasma hormone measurements is very difficult in the foal, and because the symptoms of hypothyroidism are not specific, the incidence of confirmed hypothyroidism in foals is low. However there is suggestive evidence that where awareness of the condition exists it is diagnosed frequently. The aetiology is obscure although diet has been implicated.(ABSTRACT TRUNCATED AT 250 WORDS)     

A case of transplacental transmission of Theileria equi in a foal in Trinidad

Equine piroplasmosis due to Theileria equi and Babesia caballi is endemic in Trinidad. A case of equine piroplasmosis due to T. equi was diagnosed in a thoroughbred foal at 10h post-partum. A high parasitaemia (63%) of piroplasms was observed in a Wright-Giemsa(?) stained thin blood smear from the foal. In addition, the 18S rRNA gene for Babesia/Theileria was amplified from DNA extracted from the blood of the foal and the mare. Amplified products were subjected to a reverse line blot hybridization assay (RLB), which confirmed the presence of T. equi DNA in the foal. The mare was negative by RLB but was positive for T. equi using a nested PCR and sequence analysis. In areas where equine piroplasmosis is endemic, severe jaundice in a post-partum foal may be easily misdiagnosed as neonatal isoerythrolysis. Foals with post-partum jaundice should be screened for equine piroplasmosis, which may be confirmed using molecular methods if available.     

A preliminary investigation of the use of a foal image to reduce mare stress during mare–foal separation

The data for this study were collected from 7 mares (10 ± 1.6 years old) when their foals were 4-, 15-, 30-, 45-, or 60-days-old. On each occasion, the foals were anesthetized and placed out of sight of the mare and the mares’ behavior, heart rate, and cortisol response to foal separation in either the presence of a foal phantom, a square shape, or no visual stimuli were measured. In the presence of the foal phantom, anxious (P = 0.119) and agitated (P = 0.524) mare behavior was not significantly different from baseline values. The mares had significantly elevated behavior scores for 5 out of 6 criteria when the square phantom was presented and were significantly more active (higher scores for fidgety and active criteria) when no visual stimuli (control) were provided. Based on the data presented in this study, the use of a phantom image of a foal with neutral ear and tail position may be an effective nonchemical method of calming mares during separation from their foal.     

Toxocara eggs shed by dogs and cats and their molecular and morphometric species-specific identification: is the finding of T. cati eggs shed by dogs of epidemiological relevance?

Intestinal infections with Toxocara cati and Toxocara canis in their definitive host (felids and canids, respectively) are diagnosed by egg identification in faeces using coproscopical techniques. The Toxocara species is assumed to comply with the species from which the examined faeces were obtained, i.e. T. cati in cats and T. canis in dogs. We isolated and measured Toxocara eggs from faecal samples of 36 cats and 35 dogs from Switzerland and identified the Toxocara species by PCR. Amongst the isolates originating from dogs, 24 (68.5%) were determined as T. canis and 11 (31.5%) as T. cati. In all samples originating from cats, only T. cati was identified. Based on PCR identification, eggs of T. canis (n=241) and T. cati (n=442) were measured, revealing statistically significant different (p<0.001) mean sizes of 62.3 by 72.7 μm for T. cati and 74.8 by 86.0 μm for T. canis eggs. Considering that coprophagy is not unusual for dogs, a considerable percentage of Toxocara infections coproscopically diagnosed in dogs, as well as assumptions on anthelminthic resistance in regularly treated dogs, might in fact relate to intestinal passages of eggs following the uptake of other animals' faeces.     

A note recording the occurrence of bovine viral vaginitis in New Zealand

Episodes of frenzy lasting approximately 30 minutes were observed among horses confined to enclosures surfaced with sand or soil. The probability of sighting these episodes increased by a factor of three when within 24 hours there was 0.2mm or more of rain, a maximum air temperature between 16.7 – 26.6°and a soil temperature of 16.3 – 23.9°C at 30 cm. High egg counts of Strongyloides westeri appeared in faeces four to five days later and persisted for several days.

Rhodococcus equi was recovered from all soil samples, and from the faeces of 76% of mares and 82% of foals. The youngest foal was five days old when the organism was isolated from rectal faeces. In contrast to the majority of reports, the lesions of R. equi in the foals were confined to limbs and peripheral lymph nodes.

It is proposed that the percutaneous invasion of these foals by third stage larvae of S. westeri facilitated invasion of R. equi, and ubiquitous saprophytic opportunist pathogen.⁽²⁾     

Maternal behavior

Parturition in mares is rapid and is followed by a brief period of sensitivity to imprinting on a foal. There is large individual variation in normal maternal style, but normal mothers actively defend their foal, remain near the foal when it is sleeping, tolerate or assist nursing, and do not injure their own foal. Disturbance of a mare and foal during the early imprinting period can predispose a mare to rejection of her foal; therefore, it should be avoided. There are a variety of forms of foal rejection and numerous etiologies. Therefore, each case should be evaluated individually.     

ENTERITIS IN FOALS INDUCED BY ROTAVIRUS AND ENTEROTOXIGENIC ESCHERICHIA COLI

Colostrum-deprived, colostrum-fed or suckling foals were orally inoculated with foal rotavirus and enterotoxigenic Escherichia coli derived from a calf. Neither agent given alone caused diarrhoea in foals aged 1 or 2 days, although with rotavirus, 2 of the 3 inoculated foals became depressed 3 days after inoculation and all 3 were excreting rotavirus in the faeces. Inoculation of both agents induced diarrhoea in colostrum-deprived, colostrum-fed or suckling foals aged up to 16 days. There was an apparent age-related resistance to diarrhoea which developed between 2 and 3 weeks of age. It was related to failure of rotavirus to establish apparent infection in older foals and was independent of preinoculation maternal antibody.     

Pilobolus species and rapid translation of Dictyocaulus viviparus from cattle faeces

In a series of five laboratory experiments observations were made on the role of Pilobolus in the translation of infective lungworm larvae from faeces of cattle. The results indicated that a substantial proportion of the lungworm larvae present in the faeces may be translated from the faeces by this fungus within eight days at a temperature of 15 degrees C. No clear relationship was observed between the numbers of Pilobolus and the translation of lungworm larvae. Further a longitudinal study on the occurrence of Pilobolus on faecal pats of grazing calves showed that between the beginning of July and the middle of September peak emergence of sporangia generally occurred within one week and most sporangia emerged within three weeks. From faecal pats which had been deposited at the end of September and the middle of October emergence of sporangia was lower and mainly occurred after two to four weeks.     

ISOLATION OF AN ADENOVIRUS FROM AN ARAB FOAL WITH A COMBINED IMMUNODEFICIENCY DISEASE

Some details of the clinical and postmortem findings of an Arab foal that died as a consequence of adenoviral pneumonia superimposed on a combined immunodeficiency disease are provided. The foal was the 17th in a series of similar deaths that occurred on a farm since 1959. An adenovirus, which by haemagglutination inhibition and serum neutralisation tests was antigenically similar to 2 other equine adenoviruses isolated in Australia, was isolated from a nasal swab taken from the foal when it was 23 days of age.