Biomedical subjects

J H Topps

Publications and source records attributed to J H Topps.

At least 19 recordsLinked to original sources

PubMed2001

Condensed tannin and saponin content of Vigna unguiculata (L.) Walp, Desmodium uncinatum, Stylosanthes guianensis and Stylosanthes scabra grown in Zimbabwe.

Samples of the tropical forage legumes Vigna unguiculata (L.) Walp (cowpea), Desmodium uncinatum (silverleaf desmodium), Stylosanthes guianensis (oxley fine stem stylo) and Stylosanthes scabra (fitzroy) and of natural pasture (veld) hay were analysed and ranked according to their proanthocyanidin (PA) and saponin content. Silverleaf desmodium and fitzroy leaf and stem samples of different ages were also separately analysed for the PA contents. All the samples analysed contained some PA but no saponins. High levels of PA were detected in silverleaf desmodium and very low levels in veld hay and cowpea. In all samples, more of the tannins were bound to protein or neutral detergent fibre (NDF) than were extractable, most being bound to proteins. The proportion of the unextractable PA was greater in younger than in mature materials.

Animal Feed↗

PubMed2000

Effects of supplementing a basal diet of Chloris gayana hay with one of three protein-rich legume hays of Cassia rotundifolia, Lablab purpureus and Macroptilium atropurpureum forage on some nutritional parameters in goats.

Growth and digestibility experiments were conducted on growing East African type goats offered Chloris gayana hay supplemented with one of three high-protein (119-128 g CP/kg DM) legume hays, Cassia rotundifolia (cassia), Lablab purpureus (lablab) or Macroptilium atropurpureum (siratro), and crushed maize to investigate the feed intake, digestibility, growth and urinary excretion of purine derivatives. Goats in the supplemented groups had higher total dry matter and nitrogen intakes and higher N retention and body mass gains than unsupplemented counterparts. The digestibility of dry matter, organic matter and neutral detergent fibre were increased by protein supplementation. Animals on supplemented diets had higher fractional outflow rates of particulate matter from the rumen. The production of protein by ruminal microbes and the efficiency of microbial N production were increased by supplementation. It was concluded that a mixture of low-quality grass hay (61.9 CP/kg DM) and either cassia, lablab or siratro hay, and maize grain can provide a productive balanced diet for growing goats.

Animal Feed↗

PubMed1993

Lactational performance of Jersey cows given Napier fodder (Pennisetum purpureum) with and without protein concentrates in the semi-humid tropics.

Two experiments with 12 and 18 lactating Jersey cows respectively were carried out in the coastal semi-humid zone of Kenya to assess the performance arising from the feeding of chopped Napier fodder (Pennisetum purpureum) given ad libitum with and without one of three sources of protein; fishmeal, copra cake and freshly cut Leucaena (Leucaena leucocephala). Each source supplied approximately 300 g crude protein daily. Dry matter intakes of Napier fodder fed alone averaged 7.1 and 5.5 kg in Experiments 1 and 2 respectively. Additional protein did not affect Napier fodder intake, but total intakes of dry matter were higher for the cows receiving the protein supplements, differences which were significant (P < 0.05) in Experiment 2. Average daily milk production from cows fed Napier fodder alone was 6.4 and 4.2 kg in Experiments 1 and 2 respectively. The additional 300 g crude protein increased milk production by 1.0 to 1.6 kg/day, increases which, except that for fishmeal, were significant (P < 0.05). Weight losses of the cows were either reduced or changed to weight gains by the provision of protein. The results are assessed in relation to the energy and protein requirements for milk production.

Animal Feed↗

PubMed1983

Losses in weight and body water in sows after weaning.

The loss of body water of eight sows in the 7 d following weaning was determined using the deuterium oxide dilution technique. Four of the sows had received a concentrate diet in restricted amounts while the other four had been given the same diet mixed with two-thirds its weight of oat husks ad lib. during the whole of the preceding lactation. Certain blood and urine constituents were also measured. Loss of body water was significantly less (P less than 0.05) than weight loss of fasted animals, but body water losses were considerable in six of the eight animals. Excretion of urinary nitrogen, urea and creatinine and levels of plasma urea were higher, while levels of plasma non-esterified fatty acids and the hydroxyproline index were lower 1 week after weaning compared with values obtained on the day following weaning. These results indicate that in addition to water loss, depletion of body tissue, including protein, occurs in the newly-weaned sow.

Animals↗

PubMed1981

Metabolism of the nucleic acids of rumen bacteria by preruminant and ruminant lambs.

1. A rumen bacterial culture containing specifically labelled nucleic acids was prepared using [8-14C]adenine. 2. The labelled preparation was given in a liquid diet to two preruminant lambs and via a rumen tube to two ruminant lambs. The radioactivity excreted in exhaled gases, faeces and urine and that incorporated into tissues was determined. 3. The preruminant lambs absorbed 58.3% of the total radioactivity measured after 24 h and the ruminant lambs 66.6% of the total activity measured after 48 h. 4. Of the total radioactivity absorbed the preruminant lambs exhaled 38%, excreted 34% in urine and retained 29% in tissues. The corresponding values for the ruminant lambs were 12, 41 and 47% respectively. 5. There was a close relationship between total nucleic acid content and radioactivity per g of tissues of both preruminant and ruminant lambs. 6. Of the radioactivity in the urine, the ruminant and one preruminant lamb excreted most in the fraction containing allantoin, while the other lamb excreted most activity in the uric acid fraction. 7. The salvaging of the breakdown products of bacterial nucleic acids to make tissue nucleic acids appears to be an important synthesis in preruminant and ruminant lambs and of the likely precursors the purine base may be more important than the nucleoside.

Animals↗

PubMed1980