Studies on the age of puberty of male camels (Camelus dromedaries) in Saudi Arabia.

Aspects of sexual development and attainment of sexual and breeding maturity were studied in two groups of Najdi camels (Mojaheem and Wadah), maintained in stalls under good nutritional conditions. Body weight, testes diameter and degree of penile freedom were recorded weekly. Sexual maturity was assessed by the examination of semen collected by an artificial vagina. Puberty was defined as the stage when the animal was able to produce viable sperms. Mating, followed by strong jerks and ejaculation of mature sperms, was taken to indicate onset of breeding maturity. Mojaheem camels reached sexual maturity at a significantly younger age and heavier weight (164 weeks and 360 kg) than Wadah camels (182 weeks and 336.5 kg) (P < 0.001). Complete separation of the penis from preputial adhesions occurred at an average age of 138.6 weeks in both breeds. At the point of sexual maturity, the mean percentage of live spermatozoa was 65.1 +/- 5.2 while percentage of abnormal sperms was 17.6 +/- 2.2; total motility was 40 +/- 16% and progressive motility (48 +/- 2.2% (semen pH range 7.8-8.2). The percentage of live sperm was 65 +/- 1.5 (normal sperms 82 +/- 4). It is suggested that the encouragement of rapid growth during the pubertal period in camels managed under good nutritional and environmental conditions could assist early sexual development and breeding maturity.

The use of milk progesterone analysis to monitor reproductive activity in the camel (Camelus dromedarius).

Milk progesterone profiles were used to monitor the ovarian changes during the post-partum period of five she-camels. Milk samples were collected daily for 60 days from four suckling camels (1-4) and from one animal whose calf died on day 3. Progesterone was determined using the Ovucheck Bovine progesterone kits. The first increase of progesterone level in the five animals occurred on days 28, 26, 21, 24 and 20 respectively. At least two progesterone peaks of 6 +/- 2 SD days' duration occurred during the 60 days. An early one day peak was also noticed in three animals.

The lymphatic drainage of the cranial part of the sheep's uterus and its possible functional significance.

The lymphatic drainage of the cranial part of the uterus is described. Some of the uterine lymphatic vessels are closely associated with the ovarian arterial supply. It is proposed that the uterine lymphatics form part of the local pathway for the transfer of uterine prostaglandin F2 alpha to the ovary for luteolysis.

Surgical separation of the uterus and ovaries with simultaneous cannulation of the uterine vein extends luteal function in sheep.

The insertion of a glass cannula into the uterine branch of the utero-ovarian vein, followed by disconnection of all other tissues between the uterus and the ovary containing the luteal tissue in non-pregnant sheep, was followed by a prolongation of luteal function. A pathway involving uterine venous blood alone is therefore insufficient to explain the transfer of PGF-2 alpha from the uterus to the ipsilateral ovary. We suggest that lymph is also involved.

Sequential changes in the concentration of prostaglandins and steroids in uterine lymph in sheep during the oestrous cycle.

Sequential samples of uterine lymph were collected from 9 conscious sheep at 4 or 5 h intervals. The mean PGF2 concentration in uterine lymph increased significantly on days 10 and 11 but then fell again, only to increase once more (P less than 0.001) for the 4 days prior to oestrus. PGE2 concentrations in uterine lymph showed no significant changes during the cycle. Lymphatic oestradiol-17 beta concentrations fluctuated throughout the cycle, with peak values considerably higher than those found in peripheral or uterine venous blood.

Prostaglandin F2 alpha and PGE2 in uterine lymph during the oestrous cycle in sheep.

The concentration of prostaglandin F2 alpha (PGF2 alpha) in uterine lymph remained low (less than 1 ng/ml) during the first two-thirds of the oestrous cycle in the non-pregnant sheep. However increased amounts of PGF2 alpha were present from day 12 onwards. The concentration of prostaglandin E2 in uterine lymph remained low (less than 0.43 ng/ml) throughout the cycle.

Milk progesterone profiles and the double injection of cloprostenol in post partum beef cows.

The time to resumption of ovarian cycles was determined in 27 post partum beef suckler cows by twice weekly milk progesterone analysis and was 24.5 +/ 1.6 (SEM) days. Treatment of 87 cows with a double injection of 500 micrograms cloprostenol at an interval of 11 days resulted in 55 cows (63.2 per cent) responding by a fall in progesterone levels and ovulation. Thirty-eight of these cows (43.7 per cent of total) subsequently conceived to a timed double insemination. Eight (9.2 per cent) had high progesterone levels at the second injection had failed to respond; three (3.4 per cent) had a prolonged period of low progesterone levels after the first injection which were still low when the second was given. A further 21 cows (24.1 per cent) had low progesterone levels at the time of the second injection but could not be categorised further with certainty because of lack of previous samples. These cows were treated at a significantly earlier stage post partum than the rest and in fact were treated earlier than the recommended day 42. However, four of the 21 cows conceived to the timed insemination resulting in a total conception rate of 48.3 per cent.

Clinical application of milk progesterone in the diagnosis of subfertility in suckled cows.

The potential value of milk progesterone profiles in conjunction with rectal examination in the diagnosis of subfertility in beef suckler cows was investigated. Ten of 20 cows suckled their calves three times per day and the other 10 suckled their calves continuously. Milk samples were collected twice weekly during the 21 days prior to first service and up to day 50 post mating in cows confirmed pregnant. The uterine and ovarian states of the cows were examined per rectum weekly between calving and first service. Progesterone profiles of cows conceiving to first service showed a typical smooth curve, while those of cows failing to conceive were irregular and indicated disturbances in the normal functioning of the corpus luteum.