Effects of testicular status and feeding diets containing date palm by-product on the sensory attributes of Omani lamb meat.

The effects of testicular status and diet on the tenderness and flavour intensity of Omani lamb meat were evaluated. Thirty male lambs were divided into three testicular status treatments shortly after birth, entire, castrated or induced to cryptorchidism. The animals were fed a maize and soya bean meal based diet, isocalorically supplemented with either palm fronds or Rhodesgrass hay.

The effect of undernutrition of beef cows on blood hormone and metabolite concentrations post partum.

Twelve Hereford Friesian cows were allocated to either a high plane (HP) or a low plane of nutrition (LP) post-partum. HP animals received rations supplying sufficient energy and protein for maintenance plus 10 kg/day milk yield. LP cows were offered approximately 70% of their maintenance needs for 63 days post-partum.

Effect of diet and season on steroid hormones in the ruminant.

The effects of diet and season on blood concentrations of progesterone and glucocorticoids in sheep and cattle are reviewed. Underfeeding tends to increase progesterone in sheep but the effects in cattle are equivocal. Sheep undergo seasonal anoestrus but there is very little evidence for circannual variations in progesterone in cattle.

Effects of season, lactation and plane of nutrition on prolactin concentrations in ovine plasma and the role of prolactin in the control of ewe fertility.

Plasma prolactin concentrations during the first 2 months after lambing, at oestrus, and during early pregnancy were investigated in 2 experiments in which Finn x Dorset Horn ewes were mated at an induced oestrus approximately 9 weeks after lambing. Mean prolactin concentrations between lambing and mating were dependent on seasons, being greater than 260 ng/ml plasma in lactating ewes mated in July and less than 150 ng/ml in those mated in October. Within 8 days of weaning of the lambs at 50 days post partum values declined to 122 and 30 ng/ml respectively.

Effects of season, lactation and plane of nutrition on the reproductive performance and associated plasma LH and progesterone profiles in hormonally treated ewes.

Two experiments were designed to determine the effects of duration of lactation and plane of nutrition on the reproductive performance of Finn x Dorset Horn ewes mated at a hormonally induced oestrus 9 weeks after lambing. In Exp. 1, ewes were mated on 4 December or 19 March and lactation was terminated at 35 or 15 days before mating or 7 or 35 days after mating.

A seasonal difference in ovine peripheral plasma prolactin and progesterone concentrations in early pregnancy and in the relationship between the two hormones.

In the first 11 days of pregnancy, progesterone and prolactin levels were significantly correlated (P less than 0.05), positively in December-mated animals (r = 0.889) and negatively in those mated in March (r = 0.

A simple and sensitive radioimmunoassay for pregnancy-specific beta1-glycoprotein.

A simple, sensitive and relatively rapid radioimmunoassay for pregnancy-specific beta1-glycoprotein (PSbetaG) is described. The concentrations of PSbetaG in plasma from cord blood and in amniotic fluid were approximately 0-1% and 1-0% respectively of the maternal plasma levels. The amniotic fluid PSbetaG levels in pregnancies associated with an anencephalic fetus were not significantly different from normal levels.