Plasma 1,25-dihydroxyvitamin D, insulin-like growth factor-1, calcium, magnesium and phosphorus concentrations in pregnant beef cows and calves from a herd with a known history of congenital joint laxity and dwarfism.

An investigation was undertaken to ascertain the possibility of a relationship between calcium, inorganic phosphorus, magnesium, 1,25-dihydroxyvitamin D [1,25(OH)2D], and insulin-like growth factor-1 (IGF-1) concentrations in blood plasma and occurrence of congenital joint laxity and dwarfism (CJLD) in young cattle. Pregnant cows were fed hay (30 cows) or grass silage (122 cows) during winter months (October 15 to calving in March). Blood samples were taken from cows on seven occasions during the experiment and 48 hours after calving, and from calves at birth, and at seven, 14 and 56 days old. Five per cent of calves born (six of 122) to cows fed grass silage and none born to cows fed hay were affected by CJLD. The diet and health status of calves were not significantly (P greater than 0.05) associated with the plasma concentration of 1,25(OH)2D. The plasma calcium concentration declined with age of the calves (P less than 0.05) but was not affected by the occurrence of CJLD. Plasma phosphorus and magnesium concentrations in calves born to cows fed silage were higher (P less than 0.05) than in those born to cows fed hay. At birth and seven days old, plasma phosphorus concentrations were higher (P less than 0.05) in CJLD-affected calves than in healthy calves but the plasma concentration of IGF-1 was not different (P greater than 0.05). It was concluded that the high plasma phosphorus concentrations in CJLD-affected calves and their dams could be related to the aetiology of the CJLD condition in calves.     

Clinical, biochemical and pathological study of perinatal lambs in a commercial flock

The birth and fate of 818 lambs born to 571 ewes on a low-ground farm in the Scottish Borders with a history of substantial perinatal mortality were monitored with a range of physiological, biochemical and pathological measurements. In lambs which survived, the rectal temperature, birthweight and plasma concentrations of fructose, insulin, thyroxine and the third component of complement at birth, and the weight at four months of age, decreased with litter size. One hundred and thirty-seven lambs were stillborn or died within four days and seven others died later. The mothers of 77 per cent of these lambs had low condition scores, but the lamb deaths did not correlate significantly with the condition scores. From data relating to birthweight, temperature, packed cell volume and plasma composition it was deduced that placental insufficiency was involved in 24 per cent of these deaths; acute hypoxaemia at birth accounted for 35 per cent, inadequate thermogenesis for 12 per cent and starvation for 13 per cent. The remaining 16 per cent of dead lambs could not be assigned to any of these categories. Using only clinicopathological criteria, 37 per cent of the lamb deaths were attributed to antenatal influences which included immaturity, developmental anomalies, and degenerative or inflammatory changes. Thirty-three per cent of the deaths were due to post natal factors which included, in declining order of frequency, starvation, enteritis, misadventure, pneumonia, navel infections and septicaemia. No conclusions could be drawn from the pathological examinations alone in the remaining 30 per cent, although almost half of these had low rectal temperatures after birth, death being attributed to hypothermia.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effect of experimental Ostertagia circumcincta infection on the performance of grazing lambs

Groups of 10 three-and-a-half-month-old Suffolkcross lambs were infected daily, five times a week, for 12 weeks with either zero, 500, 1500, 3000 or 5000 larvae of Ostertagia circumcincta and grazed together on a series of 'clean' paddocks. All the lambs were moved at seven to 10 day intervals to a fresh paddock to prevent autoinfection and were killed after 14 weeks. Another group was killed at the outset as a control for carcase analysis. Mean O circumcincta populations were 34 (grazing control) and 1224, 473, 1092 and 4331 for the groups receiving 500, 1500, 3000 and 5000 larvae per day respectively. The percentage of fourth stage larvae increased with increasing larval intake. Extensive abomasal damage with mucosal hypertrophy and depletion of parietal cells occurred in the lambs receiving 3000 and 5000 O circumcincta larvae per day. Intakes of 1500 larvae per day and above depressed growth rate by 24 to 37 per cent, reduced the deposition of protein in the carcase by 34 to 52 per cent and lowered calcium/phosphorus deposition by 23 to 48 per cent. Plasma pepsinogen concentrations were consistently elevated in lambs receiving 3000 or 5000 larvae per day and may be a useful aid to recognising abomasal damage sufficient to affect productivity.     

Four-year survey of urinary tract infections in calves in Israel

The prevalence of urinary tract infections in calves aged seven days to three months in three dairy cattle herds ranged from 0.5 to 1.6 per cent, with an average of 1.1 per cent. The mortality rate reached 16.1 per cent. The morbidity rate of the female calves was 1.4 per cent and that of the male calves 0.8 per cent. The bacteria isolated from urine, and from vaginal and preputial swabs were Escherichia coli (35 per cent), Corynebacterium renale (14 per cent), plasma coagulase-negative Staphylococcus species (12 per cent), Pseudomonas aeruginosa (12 per cent), Proteus species (12 per cent) and Arcanobacterium pyogenes (5 per cent). The affected calves had a significantly lower serum concentration of inorganic phosphorus (P < 0.01).     

Effect of Ostertagia ostertagi on lamb performance and cross resistance to O circumcincta

Fifteen worm-free lambs (two-and-a-half to three months or four to four-and-a-half months old) were infected with 3500 or 4000 Ostertagia ostertagi larvae on five days each week for six weeks, and their performance compared to that of controls. Eleven lambs were killed after eight weeks and four were challenged with O circumcincta to determine whether any cross resistance had developed. A feature of the O ostertagi infection was the considerable variation in response. Overall liveweight gain was lowered by 24 per cent in the two-and-a-half to three-month-old infected lambs, mainly due to reductions of 27 to 40 per cent in four of the seven lambs. There was no consistent effect in the older lambs. The worm populations consisted mainly of early fourth stage larvae and developing worms, but a small percentage reached sexual maturity and these produced a low faecal egg count (1 to 63 eggs per gram). Numerous intraluminal refractive crystals were present in the gut of both adult worms and developing stages, possibly reflecting degenerative changes. Hypertrophy of the abomasal mucosa with patchy loss of differentiation was a feature of the infection, and in four lambs serum pepsinogen concentrations were elevated. Exposure to O ostertagi did confer some protection against challenge with O circumcincta in that worm counts were reduced to about 60 per cent of those in controls, although no increase was observed in the numbers of arrested larvae. The successful passage of O ostertagi through young lambs could be important in mixed or alternate grazing systems by providing a reservoir of infection for the alternate host.     

Role of thiamine status in sulphur induced polioencephalomalacia in sheep.

The effects of excess dietary sulphur were studied in sheep supplemented and unsupplemented with thiamine. The diets contained either 0.19 per cent sulphur (LS) or 0.63 per cent sulphur (HS) in combinations with 14 mg kg-1 thiamine (LB1) or 243 mg kg-1 thiamine (HB1). A total of 56 two-month-old lambs were used. Groups consisting of nine, nine, 22 and 16 lambs were fed LS-LB1, LS-HB1, HS-LB1 and HS-HB1 diets, respectively for 14 weeks. Out of 22 lambs fed the HS-LB1 diet, seven lambs developed neurological signs between the third and eighth week of the trial. Two of these lambs died, three that were in extremis were euthanased, and two recovered completely. All clinically affected animals had extensive malacic lesions in the cerebral cortex, midbrain and brainstem. None of the lambs from the LS groups or HS-HB1 group developed clinical signs. Several clinically normal lambs from the HS-LB1 group had necrotic lesions in their brains at gross and microscopic examination. Supplementation with dietary thiamine prevented development of clinical signs, but did not totally prevent development of microscopic brain lesions. Brain thiamine concentration, transketolase activity and thiamine pyrophosphate (TPP) effect were not different (P greater than 0.05) among groups. There was a strong effect (P less than 0.0001) of dietary thiamine supplementation on blood thiamine concentration and TPP effect. Blood thiamine concentration was higher whereas TPP effect was lower in the thiamine supplemented sheep. Blood and tissue thiamine concentrations in sheep exposed to high dietary sulphur did not indicate either systemic or local thiamine deficiency per se. Increased TPP effect in sheep fed the HS-LB1 diet indicated mild to moderate metabolic thiamine deficiency. Thiamine inadequacy may be an effect of an increased requirement for thiamine in animals exposed to excess dietary sulphur.     

Renal function in dogs with lymphosarcoma and associated hypercalcaemia

Renal function was investigated in 12 dogs with lymphosarcoma and accompanying hypercalcaemia. There was no age or breed predilection. Renal function was evaluated using the endogenous clearance of creatinine to estimate glomerular filtration rate and urinary and fractional excretion of endogenous substances. Standard serum biochemical determinations and urinalyses were also employed. Serum calcium concentrations were high (>2·99 mmol/litre) in ail dogs, while serum phosphorus concentrations approximated or were below those of normocal-caemic dogs in most cases. Hypercalcaemic nephropathy and impaired renal function were evident in all 12 dogs studied. Ten of the dogs (83 per cent) were isosthenuria and 11 (92 per cent) were hypercalciuric. Endogenous creatinine clearance was reduced by more than 50 per cent in all dogs examined. Urinary and fractional excretions of calcium, phosphorus, sodium, chloride and potassium were increased over reference values. The observed alterations in renal function could be attributed to the direct effects of a high concentration of intrarenal calcium on renal tubular function and haemodynamics and to the presence of a renotropic factor that interacted specifically with the parathyroid hormone receptor in the kidney.     

An outbreak of gonadal hypoplasia in a sheep flock: clinical, pathological and endocrinological features, and aetiological studies.

In 1984, 31 per cent of 437 ram lambs reared on one property were found to have either bilateral or unilateral testicular hypoplasia. Similar numbers of ram lambs were reared in the next three years and 13, 2 and 0.5 per cent were affected. Severely abnormal testicles typically produced no spermatozoa and presented a 'Sertoli cell only' picture. Sixty-six of 200 ewe lambs born in 1984 were not marked by a harnessed teaser before mating; 12 of these were examined further and eight were found to have bilateral ovarian hypoplasia. The ovaries were very small and contained no oocytes or follicles. Plasma gonadotrophin levels were higher than normal in bilaterally affected rams and ewes but plasma testosterone and inhibin concentrations in rams with bilateral hypoplasia were not significantly different from those in normal rams. A genetic cause of the gonadal hypoplasia was considered unlikely in view of the pattern of occurrence and an examination of the flock pedigrees. No environmental cause was found. Two environmental sources of toxins were considered worthy of further investigation; onion grass (Romulea species) with its leaf spot fungus Helminthosporium biseptatum and the water supply which could have contained high concentrations of arsenic or other toxins during the period when the mothers of the affected lambs were in early pregnancy.     

Subclinical trichostrongylosis in growing lambs produced by continuous larval dosing. The effect on performance and certain plasma constituents.

Three groups of eight-four-month-old worm-free lambs were used to investigate the effect of Trichostrongylus colubriformis infection on growth rate, food intake, and concentration of plasma constituents. Groups ALC and ALI were fed ad libitum, the latter being dosed daily with 2500 infective larvae for 14 weeks. Lambs in group PF were paired to individuals in group ALI and offered the same quantity of food as the infected pair consumed. Hypophosphataemia and hypoalbuminaemia developed in ALI at week 3 and hyperglobulinaemia was present from week 6. There was no significant difference in plasma calcium, protein, urea or glucose concentration between the three groups at any stage. No clinical signs of parasitism were seen in seven of eight ALI lambs and egg counts were generally less than 2000 epg. Worm burdens of 1500-82,900 were found at slaughter. Group weight gain was only 50 per cent of PF lambs which received the same digestible energy intake. Group ALI consumed 15-5 kg dry matter per kg gain in bodyweight compared with 8-6 kg/kg and 9-8 kg/kg for ALC and PF respectively. The infections resulted in extensive villous atrophy and flattening of the intestinal mucosa. Bone growth was arrested and osteoporosis present in five group ALI lambs. The possible use of plasma constituents, particularly phosphorus, as aids for the diagnosis of the early stages of trichostrongylosis in the field is assessed.     

Gentamicin-induced nephrotoxicosis in lambs

Lambs injected with gentamicin sulphate remained bright and continued to eat, but their plasma creatinine and urinary microprotein concentrations and activities of alkaline phosphatase, gamma glutamyltransferase, leucine aminopeptidase, and N-acetyl-β-glucosaminidase were significantly increased. Urinary creatinine and specific gravity were significantly decreased. The kidneys of lambs killed shortly after the last treatment with gentamicin were pale and oedematous and microscopic changes included marked tubular necrosis and dilation. Mild tubular dilation was the only lesion in lambs killed later. Reduced enzyme activity was observed histochemically in cells of the convoluted tubules. The lambs showed little clinical evidence of gentamicin toxicity, but the urinary enzyme activity and protein content were sensitive and reliable markers of renal injury, in agreement with the pathological findings. The lesions were different from those reported in naturally occurring tubular nephrosis of lambs.     

Clinical and clinicopathologic features of transport tetany of feedlot lambs

Clinical and clinicopathologic features of transport tetany in 9 feedlot lambs were investigated. The lambs became recumbent within 10 days after arrival in the feedlot. The mean serum calcium concentration, mean magnesium concentration, and calcium:phosphorus ratio were significantly (P less than 0.01) less in affected lambs than in 6 unaffected lambs from the same feedlot. The mean serum phosphorus concentration was significantly (P less than 0.05) greater in the group of affected lambs. High activities of serum glutamic oxalacetic transaminase, creatine kinase, and lactate dehydrogenase in the serum of affected lambs indicated muscle necrosis, which was confirmed by histologic examination. Blood pH, HCO-3, and total carbon dioxide were significantly greater in affected lambs (P less than 0.01) than in unaffected lambs.     

Effect of concurrent infection with Ostertagia circumcincta and Trichostrongylus vitrinus on the performance of lambs

The interaction between Ostertagia circumcincta and Trichostrongylus vitrinus was investigated in lambs continuously infected over 12 weeks. Four groups of seven lambs were given either zero, 1000 T vitrinus larvae per day, 2500 O circumcincta larvae per day or infected concurrently. Overall liveweight gain was reduced by 17, 20 and 30 per cent in T vitrinus, O circumcincta and concurrent infection, respectively. T vitrinus infection significantly lowered serum phosphorus concentrations by week 4. In the concurrent infection the decline in phosphorus concentration was more gradual and only differed significantly from the controls during the final four weeks of the trial. There were no significant differences between the total numbers of T vitrinus or O circumcincta recovered from single or combined infections. The lack of an additive effect on performance may be due to a delayed establishment of T vitrinus in the presence of O circumcincta.     

Calcium metabolism in eight dogs with hypoadrenocorticism

Hypoadrenocorticism is a well-described endocrinopathy in dogs that results from deficient production and secretion of glucocorticoids and/or mineralocorticoids. Although hyperkalaemia, hyponatraemia and hypochloraemia are the most common electrolyte disturbances, hypercalcaemia also occurs in approximately 30 per cent of cases. The pathogenesis of hypercalcaemia in dogs with hypoadrenocorticism is unknown. This case series reports ionised calcium, parathyroid hormone, parathyroid hormone-related protein and vitamin D metabolite concentrations that were measured in eight dogs with concurrent hypercalcaemia and hypoadrenocorticism. Ionised calcium was increased in five of seven dogs with hypercalcaemia associated with hypoadrenocorticism. Parathyroid hormone, parathyroid hormone-related protein and 1,25 dihydroxyvitamin D concentrations were within their reference ranges in seven of eight dogs, six of seven cases and six of seven dogs, respectively. This case series highlights that hypercalcaemia associated with hypoadrenocorticism is rarely associated with increases in plasma parathyroid hormone, parathyroid hormone-related protein or serum 1,25 dihydroxyvitamin D concentrations.     

Clinical features of renal tubular dysplasia, a new hereditary disease in Japanese Black cattle

A new hereditary disease characterised by renal failure, poor growth and long hooves in Japanese Black cattle (wagyu) has been recognised in a region of central Japan since 1990. The number of calves affected has increased gradually, with the incidence reaching 17 of 485 (3.51 per cent) in 1995. Almost all the calves were slightly undersized at birth, and repeatedly had diarrhoea during the neonatal period. They began to show signs of growth retardation with proportional body and elongation of the hooves from about two to five months of age, but they had an almost normal or only slightly decreased appetite. The concentrations of urea nitrogen, creatinine and inorganic phosphorus in serum were high, and the affected calves excreted diluted urine frequently. Among 25 cases, the urine of 21 contained occult blood, 24 contained protein and two contained glucose. In 29 calves observed for 30 to 130 days, the course of the disease varied; in 21 of them it remained unchanged, six became gradually worse and two became severely debilitated and died. The disease was diagnosed as renal tubular dysplasia by histopathological examination.     

Influence of insulin and substrate concentration on protein synthetic rate in fetal tissues

The influence of fetal plasma substrate and insulin concentrations on the fractional synthesis rate or turnover of the mixed proteins in the organs of fetal lambs was calculated from measurements of the rate of uptake of L-14C lysine by the protein in the steady state in utero. The control values for protein synthesis rate in the fetal organs of Welsh mountain ewes, 130 to 140 days' pregnant, were similar to those previously observed in the fetuses of Border Leicester ewes: the mean turnover rates were 38, 72, 40 and 63 per cent per day for the brain, liver, cardiac muscle and the placenta respectively; that for skeletal muscles was 6.8 per cent per day; the corresponding half lives were 2.15, 1.27, 1.8 and 1.42 days respectively and 11.3 days for skeletal muscle. A fivefold increase in the plasma glucose levels had no influence on protein turnover rate over a six hour period. A fourfold increase in the concentration of some amino acids, following a mixed infusion, decreased turnover rate in brain, heart and liver. The half life was increased by 30 per cent, but a small reduction in half life was observed in skeletal muscle. Insulin caused a fall in intracellular lysine concentration in skeletal muscle and in plasma, which suggests that the hormone can reduce muscle protein catabolism in the fetal lamb in the last trimester of gestation. Enhancement of synthesis rate occurred in the presence of the amino acid infusions only; the half life of the proteins was reduced by a factor of three. Insulin also increased placental protein synthesis rate by 50 per cent but had no influence on the other tissues studied.     

Effects of iron dextran injections on the incidence of abomasal bloat, clinical pathology and growth rates in lambs

A preliminary study revealed significantly lower serum iron concentrations in lambs that developed abomasal bloat about one week later, than in lambs that did not develop bloat. In a subsequent trial, with 754 naturally reared twin lambs from five flocks, iron dextran injections were found to have a preventive effect on the development of abomasal bloat. Clinical signs of abomasal bloat were observed in the placebo-treated lamb of 16 couples and in the iron-treated lamb of six couples (P<0.05). In three further couples, both lambs developed bloat. The iron-treated group had significantly (P<0.001) better average weight gains, both from birth to summer, and from birth to autumn of approximately 0.5 and 1 kg, respectively. There was a reduction in red blood cell values and iron saturation in the placebo group 14 days after treatment but not in the iron-treated lambs. In one of the flocks, there was a decrease in the cumulative incidence of abomasal bloat from 37 per cent to 3 per cent during the period of four years after measures such as later lambing, earlier turnout and iron injections were introduced.     

Effect of dietary protein on the regulation of populations of Nematodirus battus by lambs

Two groups of seven and two groups of six lambs were offered either a complete basal ruminant diet (13·2 per cent crude protein [ ]) (groups 2 and 4) or the same diet supplemented with fish meal (18·3 per cent ) (groups 1 and 3). Groups 1 and 2 were infected daily for seven weeks with Nematodirus battus larvae (L₃) and groups 3 and 4 served as uninfected challenge controls. All the groups were treated with anthelmintic in the eighth week, challenged with a single dose of 30,000 N battus L₃ one week later and killed nine days after the challenge. Although protein supplementation tended to enhance the regulation of the population of N battus in the lambs which had been infected continuously, the effect was not statistically significant. The worm burdens in both the groups of previously infected lambs were significantly reduced both in number and size (P<0·001) and they had a lower proportion of male worms than the uninfected challenge controls. The lambs could be segregated into high or low responders on the basis of their worm burdens, and there was a significant reduction in worm burdens (P<0·001) and size (P<0·01) in parallel with the lambs' responsiveness. The identification of high and low responders shows that when the dietary protein supply is adequate the predominant effect of the host on the pathogenicity of its parasites is the host's genetically-determined susceptibility.     

Natamycin treatment of ringworm in cattle in the United Kingdom.

A total of 258 cattle clinically affected with Trichophyton verrucosum (ringworm) were treated twice by spraying with a suspension containing the fungicidal antibiotic natamycin. One-hundred-and-forty-seven in-contact, but unaffected cattle were also similarly treated. Forty-one of the affected animals were examined mycologically and clinically as they were taken to be representative of the whole group. At eight weeks after the last treatment 93 per cent of the affected animals had completely recovered and the remaining 7 per cent had improved markedly; 70 per cent of the mycologically examined animals proved negative at the same time. No reinfection of the recovered animals or spread of the disease to the treated in-contact animals was seen up to six months after treatment.     

Use of sentinel lambs for early monitoring of the South Powys Hydatidosis Control Scheme: prevalence of Echinococcus granulosus and some other helminths.

Sentinel lambs were used to identify young Echinococcus granulosus infections in sheep, to provide an early indication of the progress of the South Powys Hydatidosis Control Scheme. Four sentinel lambs were purchased on each of 60 farms, from inside and outside the control area; they were examined when approximately six, 10 and 15 months of age. Gross examination, thin slicing of organs and histological examination of the lesions in the viscera revealed no E granulosus hydatid cysts in lambs born within the control area, whereas 25 per cent of the 15-month-old lambs from outside the area harboured E granulosus cysts (less than 1 to 2 mm in diameter). Lambs from E granulosus infected farms had significantly higher anti-E granulosus ELISA antibody titres than lambs from uninfected farms. It was concluded that within one year of beginning to treat dogs with praziquantel every six weeks the transmission of E granulosus to sheep had ceased. In contrast, this treatment did not prevent infections with Taenia hydatigena or T ovis; an examination of the 240 lambs revealed T hydatigena in 33.3 per cent of them, Tovis in 4.2 per cent, Dictyocaulus filaria in 12.1 per cent and Meullerius capillaris in 49.2 per cent.     

Microscopic and ultrastructural renal pathology of oosporein-induced toxicosis in broiler chicks

Kidneys from broiler chicks receiving 300 micrograms of oosporein K salt per gram of feed continuously from 0 to 21 days of age were examined by light and electron microscopy. Chicks that died at 3 days had nephrosis of initial proximal tubular segments with an early pyogranulomatous interstitial response. Macula densa cells had cytoplasmic accumulations of periodic-acid-Schiff-positive granules. Kidneys from chicks surviving 21 days had hypercellular or atrophic glomeruli and hyperplastic dilated proximal tubules. Centrilobular distal tubules were dilated and filled with hyaline basophilic casts. Interstitial fibrosis was prominent in cortical and medullary zones. These findings indicate that oral oosporein is a severe nephrotoxin which can cause visceral urate deposition and severe nephrosis of initial proximal tubular segments. The histopathology of this mycotoxicosis was compared with those of infectious-bronchitis-induced nephrosis and avian urolithiasis syndrome.