Eight groups of five farmed red deer were transported by road for three hours, after which they were either slaughtered immediately (TO) or held in lairage for three, six or 18 hours (T3, T6 and T18). Liveweight loss increased with lairage time but hot carcase weight was unaffected. Deer spent much of the initial period in lairage standing stationary in 'alert' postures. After eight to 10 hours the proportions of time spent in various postures (standing stationary, moving and lying down) were similar to pre-journey values. None of the blood components associated with dehydration (packed cell volume, osmolality, total protein and sodium) changed significantly with lairage time. Compared with T0 deer, plasma creatine kinase activity was significantly decreased in T18 deer. Lairage time had no effect on skin damage, bruising or muscle glycogen content, although liver glycogen content increased with longer lairage time. Although lairage time had a statistically significant effect on muscle pHu (with T6 deer having the lowest values), the differences were small and none of the carcases had a pHu greater than 6-0.

Superovulation of red deer hinds with eCG causes premature luteal regression by inducing follicular hypersecretion of estrogen that activates the luteolytic mechanism. Six groups of hinds (n = 8 per group) were treated with progesterone-impregnated intravaginal controlled internal drug-releasing (CIDR) devices for 14 days to synchronize estrus (CIDR device withdrawal = Day 0). Group 1 served as controls; group 2 received an i.m. injection of 1200 IU eCG at -72 h; group 3 received similar eCG treatment as well as i.m. injections of 0.25 mg estradiol benzoate (EDB) at 72, 84, 96, and 108 h; group 4 received twice-daily i.m. injections of 4 mg recombinant bovine interferon-alpha(I)1 (IFN) from Days 2 to 7; group 5 received IFN and eCG as above; group 6 received IFN, eCG, and EDB. Ovarian response was determined by laparoscopy on Days 14 and 15. Progesterone profiles were determined from thrice-weekly plasma samples from Days -14 to 28. Both the incidence of visible signs of luteal regression and the variation in the time of termination of the luteal phase (plasma progesterone < 1 ng/ml) were greater in eCG+EDB-treated hinds than in control, IFN-, IFN+eCG-, and IFN+eCG+EDB-treated hinds (p < 0.05). The ovulation rate in the eCG+EDB-treated hinds was less than that in the eCG-, IFN+eCG-, and IFN+eCG+EDB-treated hinds (p < 0.05). These results suggest that treatment with interferon, the putative embryonic pregnancy recognition signal, suppresses premature luteal regression induced by hypersecretion of estrogen following treatment with eCG.

The behaviour of farmed red deer was studied while they were being loaded on to a transporter. In experiment 1, the effects of previous overnight housing conditions (indoors, at a space allowance of either 4 or 8 m2 per deer, or in an outdoor raceway) on the ease of loading were investigated. The number of attempts required to load the deer was not significantly affected by their housing conditions or their sex, but there was a significant increase in the number of attempts required after the first day (P < 0.05), suggesting that some aspect of the loading procedure was aversive to the deer. In experiment 2, the effects of illumination inside the vehicle (bright or dim) and the shape of the loading race (straight or curved) were examined. Neither factor significantly influenced the time taken by deer to enter the trailer. However, deer took significantly (P < 0.05) less time to load as the number of trials increased. It is concluded that the loading of deer may be facilitated if the loading raceway is wide enough to allow the deer to move as a group, but narrow enough to prevent the deer from turning round.

No abstract

The role of interferon in early pregnancy in red deer was investigated by (a) measuring production of interferon by the conceptus, (b) testing the anti-luteolytic effect of recombinant interferon-tau in non-pregnant hinds, and (c) treatment of hinds with interferon after asynchronous embryo transfer. Blastocysts were collected from 34 hinds by uterine flushing 14 (n = 2), 16 (n = 2), 18 (n = 8), 20 (n = 13) or 22 (n = 9) days after synchronization of oestrus with progesterone withdrawal. Interferon anti-viral activity was detectable in uterine flushings from day 16 to day 22, and increased with duration of gestation (P < 0.01) and developmental stage (P < 0.01). When interferon-tau was administered daily between day 14 and day 20 to non-pregnant hinds to mimic natural blastocyst production, luteolysis was delayed by a dose of 0.2 mg day(-1) (27.3 +/- 1.3 days after synchronization, n = 4 versus 21 +/- 0 days in control hinds, n = 3; P < 0.05). Interferon-tau was administered to hinds after asynchronous embryo transfer to determine whether it protects the conceptus against early pregnancy loss. Embryos (n = 24) collected on day 6 from naturally mated, superovulated donors (n = 15) were transferred into synchronized recipients on day 10 or day 11. Interferon-tau treatment (0.2 mg daily from day 14 to 20) increased calving rate from 0 to 64% in all recipients (0/11 versus 7/11, P < 0.005), and from 0 to 67% in day 10 recipients (0/8 versus 6/9, P < 0.01). The increased success rate of asynchronous embryo transfer after interferon-tau treatment in cervids may be of benefit where mismatched embryo-maternal signalling leads to failure in the establishment of pregnancy.