Nutrient intake and efficiency of calf production by two-breed cross cows

Individual consumption of total digestible nutrients (TDN) was measured on 105 two-breed cross cows (Hereford X Angus reciprocal crosses, HA; Simmental X Angus, SA; Simmental X Hereford, SH; Brown Swiss X Angus, BA; Brown Swiss X Hereford BH; Jersey X Angus, JA and Jersey X Hereford, JH) and their three-breed cross calves managed in drylot. Cows were 4 to 6 yr of age and mated to Charolais or Limousin bulls. Cows remained in the drylot for a period of approximately 1 yr (from weaning one year to weaning the next year). Ad libitum consumption of corn silage was allowed for about 4 h each day and fixed amounts of grain and protein supplement were fed as needed. Calf creep feed was provided during the latter portion of lactation. Compared with the average weight of HA cows (454 kg), SA cows were 7% heavier, SH, BA and BH cows were similar, while JH and JA cows were 15 and 22% lighter in weight, respectively. Total intake of TDN by cow and calf for the 365-d drylot period was greatest for the SA group (2,309 kg), exceeding that of the HA group by 11.2%. The JA group consumed 7.2% less than HA, while other groups were similar to HA in TDN intake. Daily intake of TDN for the 365-d period, expressed as a percentage of cow weight and cow weight .75, was highest for the smaller J crosses. The ratio of 365-d TDN intake to 205-d calf weight, a measure of weaning efficiency, averaged 10.0 kg/kg for JH, BH and SH, 10.5 kg/kg for HA and BA and 10.9 kg/kg for JA and SA. When TDN intake was adjusted for cow weight change, crossbred cow group was not a significant source of variation for kg TDN/205-d calf weight.     

The absorption behavior of chemotherapeutics after intrauterine administration in cattle

The uterus of cattle is an organ of excellent absorptive properties, as has been demonstrated by the examples of a sulphonamide and of penicillin. This is true for all cyclic phases. Absorption was somewhat delayed, when animals were in di-oestrus or pro-oestrus. A comparison between rates of absorption by clinically intact and pathomorphologically altered uteri showed absorption of Solupront and Ursopen 40,000 to be much faster in cases of disease. Experimental results as well as knowledge so far obtained on protein binding capacity are likely to support the conclusion that in the pathologically altered uterus bacteriostatic effects of sulphonamides are low due to the high amount of p-aminobenzoic acid which is present as a direct antagonist in pus and cellular detritus.     

Genetic variation among native chicken breeds of Iran based on biochemical polymorphisms

(1) Genetic distances and heterozygosity were determined in 5 Iranian native chickens: Dashtyary, Lary, Marandy, Naked neck and Common breed, using three blood group systems (A, B and D) and 4 serum protein loci (albumin, transferrin, alkaline phosphatase and esterase). (2) The highest D(A) and D(S) were obtained between Dashtyary and Lary breeds. (3) The average heterozygosity for each breed in all loci ranged from 0.330 for Dashtyary to 0.370 for Common breed. (4) Dendrograms based on an unweighted pair-group method using an arithmetic average (UPGMA) showed two distinct clusters. One cluster included Dashtyary and the other contained the remaining 4 breeds.     

Remission of the clinical signs of atopic dermatitis in dogs after cessation of treatment with cyclosporin A or methylprednisolone

Seventy-eight dogs with atopic dermatitis were treated for four months with either cyclosporin A or methylprednisolone. During the two months after the treatment ceased, 87 per cent of the dogs treated with methylprednisolone relapsed after a mean period of 27.9 days, whereas only 62 per cent of the dogs treated with cyclosporin A relapsed after a mean period of 40.7 days (P < .0.001). The clinical condition of the dogs was evaluated either when they relapsed, or two months after the treatment ceased if they had not relapsed. Both the skin lesions and pruritus increased significantly more markedly in the dogs treated with methylprednisolone than in those treated with cyclosporin A. At the end of the study the skin lesions were markedly less severe than before the therapy; in the dogs in both groups that did not relapse, the lesion score was improved by 77 per cent two months after the treatment had stopped, and in the dogs that did relapse the lesion scores had improved by 45 per cent and 35 per cent in the dogs treated with cyclosporin A and methylprednisolone, respectively. Pruritus remained well controlled in the dogs that did not relapse, but increased to baseline levels or close to baseline in the dogs that relapsed.     

Effects of prolonged exposure to low-dose fumonisin B1 in pigs

From the point of view of human exposure, fumonisins (FB1, FB2, FB1, FB4), a relatively recently (1988) discovered and identified group of mycotoxins, represent one of the five most important mycotoxin groups causing human disease. In an earlier experiment studying the effects of relatively low doses (10, 20 and 40 p.p.m.) of FB1 in weaned piglets, it was established that the 4-week feeding of 10 p.p.m. (mg/kg feed) FB1 produced mild pulmonary oedema. This suggested the importance of studies with even lower doses of the toxin to determine the tolerable limits. The objective of this experiment was therefore to study the effects of prolonged (8-week) exposure to still lower concentrations (0, 1, 5 and 10 mg/kg feed) of FB1. The 8-week feeding of FB1 in low concentrations (1-10 p.p.m.) did not cause clinical signs and significant performance impairment in pigs, but rendered irreversible the chronic changes that had already developed in the animals in a dose-dependent manner. Dissection revealed pathological alterations of the lungs in one of the animals given 1 p.p.m. (n = 4), in two animals exposed to 5 p.p.m. (n = 5), and in three animals given 10 p.p.m. (n = 4). In all three treatment groups, proliferation of the connective tissue fibres, primarily of those around the lymphatic vessels, in the subpleural and interlobular connective tissue of the lungs, extending to the peribronchial and peribronchiolar areas, was seen. The results of this experiment call attention to the risk of prolonged low-dose toxin exposure, which has very important public health implications.     

Chronic gypsum fertiliser ingestion as a significant contributor to a multifactorial cattle mortality

Objective To assess the validity of claims that heavy metal contamination from an open-cut mine caused the death of 226 cattle on a nearby farm over a period of 18 months, and to investigate other possible contributing factors.
Procedure A retrospective assessment of previous investigations combinded with additional chemical analyses.
Results Extensive chemical analyses produced no evidence of heavy metal contamination associated with the mine. Analysis of bones indicated exposure to fluoride in greater than normal amounts. The main source of fluoride seems to have been gypsum that was included in a feed supplement and also ingested from fertiliser dumps on paddocks. The gypsum itself may have contributed significantly to the ill health. Other factors probably affected some classes of animals, notably the young calves.
Conclusions What originally seemed to be a disease problem of single aetiology probably was an expression of interacting multifactorial causes. This investigation has highlighted the potential toxicity of gypsum to livestock and the need for further studies to establish its basis.     

Disseminated Mycobacterium avium infection in a dog with chronic diarrhoea

A 3-year-old Maltese-cross dog presented with a 4-month history of chronic diarrhoea and inappetence. Poorly regenerative anaemia, leukocytosis and hypoproteinaemia were evident on several occasions. Biopsies of stomach, duodenum and colon revealed marked infiltration of mucosae by macrophages containing many acid-fast bacilli. Similar organisms were numerous in a faecal smear. Melaena, hematochezia and severe abdominal pain developed and were unresponsive to therapy. Following euthanasia and necropsy, histiocytic cells containing acid-fast bacilli were found throughout the gastrointestinal tract, mesenteric and peripheral lymph nodes, spleen, liver, kidney and lungs. The organism was identified as Mycobacterium avium by bacterial culture and polymerase chain reaction testing.