Energy expenditure was estimated using the doubly-labelled water (DLW) method in summer in five free-living adult, non-pregnant, non-lactating, red deer (Cervus elaphus) hinds (weight 107 . 3 (SE 0 . 9) kg; age 6 (SE 1) years) on lowland pasture under typical farming conditions. Climatic conditions were monitored throughout the experiment. Errors due to 2 H losses in CH 4 and faeces were calculated from previous estimates of stoichiometries. CH 4 production, fractionated water loss, urinary N and O 2 consumption were estimated using an iterative approach. The water flux (rH 2 O) in these animals consuming only fresh grass was 12 (SE 0 . 5) kg/d, the CO 2 production (rCO 2 ) was 1271 (SE 40) litres/d and the mean energy expenditure was 25 (SE 0 . 8) MJ/d. There were no significant differences in the isotope distribution spaces and flux rates, rH 2 O, rCO 2 or energy expenditure using the multi-point or two-point approaches to calculation. The DLWderived energy expenditure of 25 MJ/d is approximately 20 % higher than the recommended intake of 21 MJ/d for adult hinds kept outdoors (Adam, 1986) and, at 757 kJ/kg 0.75 per d, one third higher than the value of 570 kJ/kg 0.75 per d for stags penned indoors (Key et al. 1984). Energy expenditure: Doubly-labelled water: Red deerDownloaded from https://www.cambridge.org/core. IP address: 44.

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Studies of cervical artificial insemination of ewes at hormone-synchronized oestrus indicate that the cervix remains relatively impenetrable to semen, in contrast to naturally breeding animals. During parturition the inflammatory response plays an important part in cervical dilation and possibly, to a lesser extent, in the non-pregnant cervix at oestrus to facilitate the transcervical transport of semen. The expression of interleukin 8 (IL-8), a pro-inflammatory cytokine in the ovine cervix, has been mapped and quantified, using semi-quantitative in situ hybridization, to ascertain the role played by inflammation in the ovine cervix during natural and artificially induced oestrous cycles. IL-8 gene expression was observed in both the luminal epithelium and fibroblastic cells of the cervix. The presence of IL-8 was confirmed using immunohistochemistry. IL-8 gene expression in the luminal epithelium varied throughout the oestrous cycle and was highest at oestrus and at day 5 of the oestrous cycle. In ewes artificially induced to ovulate, either by the withdrawal of progesterone pessaries after treatment for 12 days, or by two i.m. injections of prostaglandin 9 days apart, IL-8 gene expression at oestrus was significantly lower than it was at natural oestrus. Insemination increased IL-8 gene expression in progesterone-synchronized ewes. These data support the hypothesis that IL-8-induced inflammation is important in normal cervical function and that this process is inhibited during artificial synchronization of the oestrous cycle and is increased by exposure to semen.

Thirty-two Scottish Blackface ewes that lambed outdoors in March and were weaned at the end of April and individually penned indoors under the natural photoperiod at 57 degrees N were used to determine whether the ovine ovary that was deprived of gonadotrophic support was capable of early activation by melatonin. From 5 May (day 0), 16 of the ewes received an oral dose of 3 mg melatonin in a 4:1 (v:v) mixture of water and ethanol daily at 15:00 h. The remaining 16 ewes received the vehicle alone. Within each of these groups, eight were implanted s.c. on day 0 with an osmotic minipump which infused 50 micrograms of the gonadotrophin releasing hormone agonist (GnRHa), buserelin day-1. On day 25, a second minipump was inserted to ensure continued infusion of the agonist and on day 50 (24 June) both minipumps were removed. Ovarian activity was assessed by laparoscopy at intervals of 3 weeks from day 29 until the experiment was terminated on day 200 (21 November). Blood samples taken by jugular venepuncture three times a week for the first 50 days, daily from days 51-78 and thereafter three times a week were analysed for progesterone, prolactin and LH. Samples taken at intervals of 15 min for 10 h on days--1, 14, 28, 49, 56, 70 and 91 were assayed for LH. Treatment with GnRHa reduced LH concentrations and abolished pulsatile LH secretion.(ABSTRACT TRUNCATED AT 250 WORDS)

Results from a series of recent experiments involving superovulated ewes demonstrate the important influence of nutritionally-induced alterations in preovulatory progesterone concentrations on the subsequent in vivo and in vitro development of their fertilized ova (McEvoy et al, 1993 and 1995; Creed et al, 1994). In essence, these show that high-plane feeding can suppress preovulatory progesterone concentrations to such an extent that the subsequent development of the ova is impaired both in vivo and during in vitro culture. An important practical question however remains unanswered in that no attempt has been made to study the effects of dietary energy concentrations, as opposed to plane-of-nutrition, on progesterone concentrations and ovum development. As a result, recommendations regarding which energy sources should be used as supplements to pasture around mating time are a matter of conjecture. Furthermore, in arid environments, roughage feeds are often in short supply and therefore command a much higher price per unit of energy than concentrate diets. Under these conditions it is not unusual to feed all-concentrate diets at mating, yet there are no published data for their effects on ovum development and embryo survival.