1. A low-magnesium diet was fed to four sheep, each of which had been surgically prepared with a rumen fistula, a tube into the cranial one-third of the omasum, a tube to the cranial one-third of the abomasum and a re-entrant duodenal cannula. Mg, as gluconate or acate or acetate, was continuously infused for 12-14 d in turn into (1) the caudal duodenal cannula, (2) the abomasum, (3) the omasum...

Six abomasums of yaks (Bos grunniens) were studied with gross dissection and histological methods. It was found that the mucosa of the yak abomasum was covered with simple columnar epithelium. There were lots of spiral folds (≥10) in the fundic glandular area. The developed membrane of lamina propria was occupied by high density glands. According to the morphological characteristics of the glan...

Computed tomographic (CT) images of the reticulum, rumen, omasum and abomasum of five healthy Holstein-Friesian bull calves were compared with anatomical transverse cadaver sections of the same calves. The calves were scanned in the transverse plane from the 5th thoracic vertebra to the sacrum six times three weeks apart from birth to 105 days of age. Multiplanar reconstruction was used to crea...

Homozygous grey Karakul lambs are born with a lethal genetic factor responsible for death and weaning age. When put on a high roughage diet under field conditions they develop distended, thin-walled rumens and sand impacted abomasa. Homozygous white Karakul lambs have a similar factor but survive for a longer period. Black Karakul lambs are not affected. The present study was undertaken to comp...

Previous studies indicated large, thin-walled, milk-filled rumens in lethal grey and white Karakul lambs. There was also a significant decrease in the number and size of the myenteric plexuses and the number of ganglion cells in these lambs. The purpose of this study was to determine whether the myenteric ganglia of the affected lambs are functional, by testing for the presence of vaso-active i...

Bradykinin is a physiologically active peptide involved in vasodilation and smooth muscle contraction and is previously shown to be increased in gastrointestinal mucus during nematode challenge in sheep. Here, it is shown that bradykinin in the abomasum is positively correlated with both mast cells and globule leukocytes in the abomasum, and that all three of these parameters are negatively ass...

The oesophageal groove reflex was examined in 6 milk-fed Holstein Friesian calves once weekly during the first 17 weeks of life. Additionally, the effect of different feeding methods (bucket, different nipple positions and openings), different milk temperatures (20, 30, 39, 45°C) and milk replacer concentrations (100, 125, 150 grams/litre of water) on oesophageal groove closure was investigated...

Haemonchus parasites are responsible for many losses in animal production. However, few studies are available, especially of zebu cattle. In this study, we investigated mRNA differences of immune response genes in naïve Nellore calves infected with Haemonchus placei, relating these differences to patterns of cellular infiltrate. Calves were infected with 15,000 H. placei L3 larvae and after 7 d...

I . Steers fitted with simple rumen, abomasal and sometimes duodenal cannulas were given isonitrogenous and isoenergetic diets consisting of pellets containing equal amounts of rolled barley and chopped straw together with tapioca alone (B), or with some tapioca replaced by coarse soya-bean meal (M) or finely ground soya-bean flour (F). Diet B had an estimated rumen degradable nitrogen (RDN): m...

Homozygous grey Karakul lambs are born with a lethal genetic factor responsible for death at weaning age. When put on a high roughage diet under field conditions they develop distended, thin-walled rumens and sand impacted abomasa. Homozygous white Karakul lambs have a similar factor but survive for a longer period. Black Karakul lambs are not affected. The present study was undertaken to compa...