Determination of calcium, phosphorus, and magnesium values in rib bones from clinically normal cattle.

Mean phosphorus (P) content in bovine rib bone was 102.9, 108.3, and 182.7 mg/g of bone on fresh, dry, and ash weight bases, respectively. Values for calcium (Ca) were 194.3, 203.7, and 344.6 mg/g, respectively, and for magnesium (Mg) were 5.3, 5.5, and 9.4 mg/g, respectively. Mean percentage of ash in rib bone was 59.12%. Expected concentrations of Ca, P, and Mg were determined on fresh, dry, and ash weight bases and for 3 age groups, 3 breeds, and bulls, females, and steers. On an ash weight basis, cattle 6 to 18 months old had 185.74 mg of P/g, 372.52 mg of Ca/g, and 12.37 mg of Mg/g. Those 19 to 36 months old had 182.02 mg of P/g, 322.35 mg of P/g, and 8.09 mg of Mg/g. Those > 36 months old had 174.80 mg of P/g, 340.36 mg of Ca/g, and 6.62 mg of Mg/g. Steers had 183.93 mg of P/g, 352.73 mg of Ca/g, and 10.15 mg of Mg/g. Females had 178.47 mg of P/g, 320.28 mg of Ca/g, and 6.5 mg of Mg/g. Males had 176.15 mg of P/g, all on an ash weight basis. Dairy breeds were found to have 186.08 mg of P/g, 351.25 mg of Ca/g, and 10.47 mg of Mg/g. Cattle of mixed breeding had 177.42 mg of P/g, 341.28 mg of Ca/g, and 6.54 mg of Mg/g. The Africander breed of beef cattle had 167.07 mg of P/g, all on an ash weight basis.

Experimental studies with Stronglyloides papillosus in goats.

Unusual clinical and pathological observations in the field in goats and sheep suffering from Strongyloides papillosus infection prompted experimental work on this parasite. Goats were infected percutaneously with either single or multiple, low or high levels of S. papillosus. Young goats up to 12 months of age were found to be the most susceptible. Some animals, however, showed substantial resistance to infective doses. Clinical signs included transient diarrhoea, misshapen, elongated faecal pellets terminally, dehydration, anorexia, cachexia, gnashing of teeth, foaming at the mouth, anaemia and nervous signs such as ataxia, a wide-based stance, stupor and nystagmus. A 'pushing syndrome' was seen in 22% of the animals. The pathological changes are described and included enteritis, status spongiosus in the brain, hepatosis leading to rupture of the liver, nephrosis, pulmonary oedema, interstitial pneumonia and pneumonia. About 6% of the goats died acutely from fatal hepatic rupture. The development of an acquired immunity was determined. The immunity elicited an allergic skin reaction at the application site of larvae or injection sites of larval metabolites. This immunity, however, could be breached by large doses of larvae. The most profound clinicopathological changes induced by the parasites were an anaemia (most pronounced in the young goats) and hypophosphataemia. Trace element analyses provided evidence of Cu, Mn and possibly Se deficiencies in some goats.

A review of mineral imbalances of grazing animals in southern Africa.

A historical review of mineral imbalances recognised in Southern Africa is given. The survey procedures which were followed are described in terms of sample sources, as well as the analytical procedures with emphasis on the problems encountered at each stage of the developments. A concise summary is given of the mineral patterns known to date according to the ten regions currently recognised where specific patterns of mineral imbalances are known to occur.

Acute effects of an anionic diet on bone mineral homeostasis in the bovine.

Fifteen Friesian oxen between 12 and 18 months of age with a mean body mass of 240.7 kg were randomly assigned to diets containing 0.25% phosphorus (P) or less to evaluate the acute effects of an acidiogenic diet of -11.1 meq/100 g of diet dry matter, compared with a basiogenic diet of +25.6 meq/100 g or a control diet of +16.5 meq/100 g of diet dry matter calculated as (Na + K)-(Cl + S), on blood, bone and faecal P, calcium (Ca) and magnesium (Mg) for a period of 9 weeks. Blood, bone and faecal responses to an anionic diet are described. An inverse relationship existed between bone and blood Ca, in which there was resorption from bone with increased blood Ca in response to the anionic diet. The anionic treatment group demonstrated simultaneous increases in bone, blood and faecal P concentrations at various stages of the experiment compared to the cationic and control treatment groups. Results indicate independent absorption and resorption of Ca and P into and out of bone. There was wide variation in the bone Ca:P ratio between 2.02 and 1.51 among animals fed the anionic diet, with the Ca:P ratio following Ca values and not bone P values. Bone and blood P had a linear relationship with dietary cation:anion balance (DCAB), increasing as the diet became more anionic in nature, but faecal P was curvilinear with highest concentrations at -11.1 and +25.6 meq/100 g compared to +16.5 meq/100 g. Concurrent blood, bone and faecal P increases at some stages of the experiment indicate a P-sparing effect of the anionic diet and warrants further research into the long-term effects of anions in the diet, leading to their use as a possible addition to improved licks in P-deficient areas.

The effect of a progesterone/estradiol ear implant on the performance of young beef steers.

A progesterone/estradiol ear implant was tested over a 84 d feedlot period on 96 young Bonsmara steers which were randomly allocated to implant and control groups. Animals were adapted over 5 d to a complete feed formulated to South African feedlot standards. Health aberrations were observed and feed intake, mass gain and slaughter data were recorded. The implant group elicited a 23.2 kg gain per animal (P less than 0.01). Mean treatment feed intakes varied marginally but the implant group showed a 14.91% feed to gain improvement over controls. Warm carcass dressing percentage showed an overall improvement of 4.96% for both groups. Bloat incidence was calculated at 0.98% over 8,064 cattle feedlot days. Mortality was 2.08% and 12 animals were considered to be chronic bloaters. This may have been due to the high proportion of fine particles in the diet. A composite feed sample revealed that 62.48% consisted of particle lengths of 0.5-4mm. The effect of this on ruminal health is briefly discussed. It is concluded that the progesterone/estradiol implant provided greater mass gain and improved feed to gain ratios for treated steers over a control group.

Short-term effects of dietary cation:anion balance on bone mineral homeostasis in the bovine.

Fifteen Friesian oxen between 12 and 18 months of age with a mean body mass of 240.7 kg, were randomly assigned to diets containing 0.25% phosphorus (P) or less, to evaluate the acute effects of a dietary cation:anion balance (DCAB) of either -11.1, +16.5 or +25.6 mmol 100 g-1 diet dry matter calculated as (Na+K) - (Cl+S), on blood, bone and faecal P, calcium (Ca) and magnesium (Mg) for a period of 9 weeks. Bone and faecal P concentrations were significantly (P < 0.05) higher in the anionic treatment group compared with the cationic and control treatment groups. The same was true for blood P, but significant (P < 0.05) only when compared with the cationic treatment group. Bone Ca was lower (NS) and blood Ca was significantly (P < 0.05) higher in the cationic compared to the anionic and control treatment groups, but faecal Ca was significantly (P < 0.05) higher in the anionic compared to the cationic, and control treatments groups. There was little difference in blood and bone Mg content among treatment groups, but faecal Mg was significantly (P < 0.05) higher in the anionic treatment group compared to the other 2 treatment groups. Whether this was due to the anionic nature of the diet or dietary concentration of Mg is unclear. Results from this research indicate a P sparing effect in which a low DCAB may improve the availability of P in animals where dietary P is limiting. In critical evaluations, weekly sampling of rib bone should be used to give a more accurate assessment of acute changes in bone mineral.

Causes of variation of copper, iron, manganese, zinc and magnesium levels in bovine livers. 3. The effects of locality.

The effects of locality on the copper, iron, manganese, zinc and magnesium levels in 407 bovine caudate lobe liver samples preserved in formalin for differing storage periods were examined. The mineral determinations, expressed on the wet basis (WB), were made by atomic absorption spectrophotometry after wet ashing of the liver. Two hundred and ten of the liver samples were from cattle from one farm (Farm 1) the remaining 197 cattle being from another farm (Farm 2). The copper, iron and magnesium levels were taken as indicative of the hepatic concentrations at slaughter. Locality had a significant effect (P less than 0,05) on the copper, iron and magnesium levels. All copper levels on Farm 1 fell well below the accepted minimum (33,0 mg/kg). The deficiency appeared to be secondary with the possible implication of sewage effluent. In terms of biological variation the different iron levels appeared of minor importance and no inverse relationship was found between iron and copper. The manganese and zinc levels were interpreted with caution due to the significant differences reported in their hepatic concentrations after six months of storage in formalin. Extremely high zinc levels in individual animals could have been associated with sewage effluent.

Out-of-season breeding of milk goats--the effect of light treatment, melatonin and breed.

The purpose of this study was to evaluate the effectivity of melatonin in addition to light treatment (exposure to 2 hours of light during the night = a long-day photoperiod) to modify the breeding season of Saanen and cross-bred milk goats and to compare the difference between the breeds. Twenty-two Saanen and 22 cross-bred does were randomly divided into 3 treatment groups. Group 1 (controls) received no treatment, Group 2 received light treatment for 37 days and Group 3 received light treatment plus melatonin implants after the light treatment. After a further 35 days the 3 groups were brought together and a billy goat that had also been exposed to the extra light at night, had received a melatonin implant and had been isolated from the does during the treatment period, was introduced to the does for natural mating. Ultrasound scanning was used to diagnose pregnancy and all the pregnant goats kidded. Significantly more Saanen does compared to cross-bred does (P = 0.018) became pregnant and kidded after natural mating, when the group that received melatonin as well as light treatment was compared to the group that received light treatment only. Compared to light treatment only, the addition of melatonin to light treatment improved (P = 0.0028) conception after natural mating, in both the Saanen and the cross-bred does.

Use of bovine rib bone in serial sampling for mineral analysis.

A total of 2160 samples of rib bone were used in a split-plot design analysis of variance to show that, on an ash weight basis, P content is not different among the right and left 9th, 10th, 11th, and 12th ribs of cattle above 6 mo of age. Results were similar for Ca on a fresh or dry weight basis. Some differences existed in Mg content among some of the ribs. Location on the rib from which samples were taken was responsible for significant differences in mineral concentrations. Based on results reported herein, ribs 9, 10, 11, and 12 of the right and left side may be used in the serial sampling of bone tissue in the bovine for the purpose of comparing the content of P, Ca, and--to some extent--Mg. Serial sampling makes possible comparison of bovine mineral status based on bone tissue over an extended experimental period that includes eight sampling dates.