Effect of pelvic suspension on the instrumental meat quality characteristics of red deer (Cervus elaphus) and fallow deer (Dama dama) venison.

The effect of pelvic and Achilles tendon suspension of red and fallow deer carcasses on meat quality parameters were compared. Venison was evaluated from red deer stags (n=14), bucks (n=14) and fallow deer does (n=10) between 12 and 36months old. Immediately after slaughter, carcasses were split down the dorsal midline and assigned to one of the two hanging methods and pH and core body temperature measured. Twenty-four hours post-slaughter muscles were excised. Venison from fallow deer and red deer stags pelvic-suspended had significantly lower (P<0.001) cooked shear force values than Achilles hung carcasses. There was no significant difference between hanging technique for other characteristics measured. These data indicated that pelvic suspension should be adopted by the deer industry to increase tenderness of venison.

Effect of concentrate feeding on instrumental meat quality and sensory characteristics of fallow deer venison.

Venison from twenty four hybrid fallow deer does, 36months old with an initial body condition score (BCS) of 2, was tested to determine the influence of feed type on meat quality. Feeding with concentrates increased BCS (P<0.01) but did not affect ultimate pH (P>0.05). BCS 4 animals had higher intra muscular fat (IMF) (P<0.01), and more tender meat (P<0.05). Venison from does fed over 24weeks exhibited less redness (P<0.01) than those fed for 19weeks regardless of feed type. Panellists evaluated samples for colour, flavour, tenderness, juiciness and overall liking. They detected significantly (P<0.05) stronger flavour in meat from animals fed concentrates. Male panellists detected flavour differences within meat from animals fed concentrates (P<0.05), with longer feeding periods resulting in stronger flavour. There was no difference in overall liking, therefore finishing fallow deer on grain-based concentrate feeds prior to slaughter provided little commercial advantage.

Consumer evaluation of venison sensory quality: effects of sex, body condition score and carcase suspension method.

Intact fallow bucks (n=20) and non-pregnant fallow does (n=24) (Dama dama), in the body condition score (BCS) of 2, 3 and 4 (lean, prime and fat) and rising 2 year old red deer stags (n=26) (Cervus elaphus) of the same BCS range (2-4) were used in this study to determine the impact of sex, BCS and method of carcase suspension on consumer perception of venison quality. Consumers were asked to evaluate cooked meat samples (M. gluteus medius) on an unstructured line scale for colour, flavour, tenderness, juiciness and overall liking. Meat from both fallow deer and red deer was preferred by consumers when carcases had hung by the pelvic suspension (PS) method compared with the Achilles tendon (AT) method of hanging (p<0.001). Consumers also noted a difference in colour between sexes in fallow deer venison, with venison from 36 month-old does being darker (p=0.015), and preferred venison from does over 18-24 month-old bucks. There was a significant difference in the consumer scores for tenderness in red deer stags of BCSs 2 and 4 (p=0.05) with panellists determining BCS 4 animals to be more tender; however no tenderness differences were observed for fallow deer does compared with bucks.

Rate of blood loss and timing of exsanguination on prevalence of ecchymosis in fallow deer (Dama dama).

Blood loss associated with four combinations of stunning and exsanguination methods was determined as part of studying prevalence of ecchymosis in slaughtered fallow deer (Dama dama). A fifth treatment simulated incomplete severance of the extended neck after captive bolt stunning. Predicted mean weights of blood collected from the five slaughter treatments, including electrical stunning followed by the thoracic stick method of exsanguination, captive bolt stunning followed by the thoracic stick, captive bolt stunning followed by the gash cut method of exsanguination, electrical stunning followed by the gash cut, and captive bolt stunning followed by incomplete severance of the extended neck, were 1458.7, 1072.7, 684.5, 463.7, and 228.5 g, respectively. The overall effect of exsanguination method was highly significant (p<0.001) with the thoracic stick resulting in the greatest weight of blood collection in the 10s period immediately after initiation. The overall effect of stunning method on blood loss was not significant, although there was a significant (p<0.05) stunning method by exsanguination method interaction. Ecchymosis of varying severity occurred in some carcases from all treatment groups. Using the total loin and round ecchymosis scores, when little or no ecchymosis (grades 0 or 1) was compared with some ecchymosis (grade 2) by logistic regression, castrated bucks were 9.8 times more likely (p=0.002) and does 4.2 times more likely (p=0.06) to have some ecchymosis than entire bucks. The results indicate that ecchymosis can be reduced in fallow deer carcases by thoracic stick exsanguination incorporated less than 10s after stunning.

Influence of level of nutrition during late pregnancy on reproductive productivity of red deer I. Adult and primiparous hinds gestating red deer calves.

The present study aimed to relate feed intake of red deer hinds during late pregnancy to dam body condition, foetal development and calf growth. Across 3 years, multiparous (n=33) or primiparous (n=18) hinds with known conception dates were housed in individual pens from days 150-220 of pregnancy, during which time they were each offered one of three daily allowances of pelletised rations (11 MJME/kg DM; 16% CP): high (H; ad libitum), medium (M; approximately 30% less; multiparous hinds only) and low (L; approximately 50% less). Restricted intake levels were retrospectively calculated from the mean intake of H hinds in the previous week. Hinds were returned to pasture at day 220 and calving was closely monitored. Liveweights, body condition score (BCS), and lactation score (LS) of hinds were recorded weekly from day 130 of pregnancy until calves were weaned at 12 weeks of age. Calves were tagged and weighed at birth, and subsequently weighed at 7 and 12 weeks of age. Additionally, hinds in the first year of study underwent CT scans on days 150 and 215 of pregnancy to assess compositional changes of the dam and conceptus. Mean daily ad libitum intakes of H hinds increased from 1.8 to 2.0 kg DM (0.6-0.7 MJME/kg0.75) at around day 150 to 2.8-3.2 kg DM (0.8-0.9 MJME/kg0.75) by day 220. Those of M and L hinds peaked at 1.8 and 1.6 kg DM, respectively, by day 220. This was reflected in significant treatment effects on liveweight gain and change in BCS and LS by the time of calving. CT scans indicated a significant treatment effect by day 215 on the mass of hind tissues (fat and lean) and a non-significant trend on conceptus/foetal weights. Despite apparent differences in foetal growth trajectories, there were no discernable treatment effects on sex-adjusted birth weights. However, there was an unexpectedly wide spread in calving dates that reflected considerable variation in gestation length. Furthermore, gestation length was negatively correlated with change in hind liveweight (but not BCS) between days 150 and 220 of pregnancy for all groups of hinds (P<0.05). Of three neonatal calf mortalities, none were related to overweight (dystocia) or underweight (non-viability) calves. Subsequent growth rates (g/day) of surviving calves did not reflect prior treatment of their dams, although variation in birth date influenced weights on specific dates. It is concluded from this study that while variation in nutrition to hinds during the last trimester may strongly influence foetal development, under conditions of modest feed imbalance, variation in gestation length compensates to ensure optimisation of birth weight.

Reproductive cycles of farmed female chital deer (Axis axis).

Studies were conducted on chital deer hinds (Axis axis) living in a temperate region to advance the understanding of the patterns of reproduction of a tropical cervid species. The hinds exhibited regular patterns of oestrus cyclicity throughout the year as evidenced by concentrations of serum progesterone monitored over a 14-month period, and detection of behavioural oestrus by vasectomized stags. The mean length of the oestrous cycle was 18.0+/-0.7 days (range, 12-23 days). Profiles of serum progesterone showed concentrations of <0.5 ng mL(-1) at the time of oestrus, which rose to a peak (range 1.5-5.0 ng mL(-1)) about Day 13, and then declined to low concentrations at the next oestrus. Observations following parturition showed that the first detected oestrus occurred at a mean (+/- SEM) time of 26.9+/-3.0 days later for seven of nine hinds. The mean length of the oestrous cycle after the first post-partum oestrus was 16.6+/-1.0 days (range 7-20 days). The presence of a stag may influence the length of the post-partum period in chital deer hinds, and hinds in contact with a stag in this study had a significantly shorter interval from parturition to first ovulation (P<0.01) compared with hinds not in contact with a stag. By 7 weeks post partum a corpus luteum was detected in 93% of hinds. In comparison only 43% of hinds with no stag contact had a corpus luteum by 7 weeks post partum. It is suggested that the tendency towards seasonal calving in the study population may be related more to male than female factors.

Effect of exogenous gonadotrophins on oestrus, the LH surge and the timing and rate of ovulation in red deer (Cervus elaphus).

Red deer hinds (n = 38) were treated in the breeding season with five different gonadotrophin regimens to investigate the temporal relationship between oestrus, ovulation and the LH surge. All hinds were treated with progesterone-impregnated controlled internal drug release (CIDR) devices to synchronize oestrus. The five treatments were as follows: treatment 1, controls; treatments 2, 3 and 4, 1200 iu pregnant mares' serum gonadotrophin (PMSG) was administered i.m. 72 h before CIDR device withdrawal (treatments 3 an 4 were also injected i.v. with 0.4 mg synthetic GnRH 12 or 18 h after CIDR device withdrawal, respectively); treatment 5, 200 iu PMSG was administered i.m. 72 h before CIDR device withdrawal and 0.5 iu FSH was administered in eight equal doses at intervals of 12 h starting from the time of PMSG injection. The hinds were run with crayon-harnessed stages to determine the time of oestrus onset. Blood samples were collected every 2 days for 26 days after CIDR device removal to determine concentrations of plasma progesterone and every 2 h for 72 h after CIDR device removal to determine plasma LH profiles. Laparoscopy for ovary examination was performed 6 or 12 h after oestrus onset and was repeated twice at intervals of 12 h. Final ovulation rate was determined on day 7 after CIDR device removal. All hinds received 500 micrograms cloprostenol i.m. on day 13. A total of 30 and 34 hinds exhibited oestrus and ovulation, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Characteristics of the oestrous cycle and duration of gestation in chital hinds (Axis axis).

Duration of oestrous cycle and gestation, and characteristics of postpartum oestrus of chital hinds are described. Mean duration of the oestrus cycle of chital hinds was 19.3 +/- 1.3 days, with a range of 17-21 days. Serum progesterone profiles are shown, with minimum progesterone concentrations near oestrus less than 2.7 nmol l-1, and maximum luteal values 16-26 nmol l-1. Mean duration of gestation was 234.5 +/- 3.0 days (n = 17).

Relationship between the onset of oestrus, the preovulatory surge in luteinizing hormone and ovulation following oestrous synchronization and superovulation of farmed red deer (Cervus elaphus).

The timing of ovulation relative to the onset of oestrus and the preovulatory surge in luteinizing hormone (LH) was studied in red deer following treatments to synchronize oestrus and induce either a monovulatory or superovulatory response. Mature hinds (n = 36) were allocated randomly to two mating groups (n = 16 + 20), with respective treatments staggered by 4 weeks during the 1990 rut (March-April). Each hind was treated with an intravaginal controlled internal drug releasing (CIDR)-type S device for 14 days. Treatments to induce a monovulatory response included CIDR device alone (treatment A; n = 4 + 8) and additional injection of 200 iu pregnant mares' serum gonadotrophin (PMSG) at device removal (treatment B; n = 4 + 4). Treatments to induce a superovulatory response included injections of 200 iu PMSG and 0.5 units ovine follicle-stimulating hormone (FSH) at about time of removal of CIDR devices (treatment C; n = 4 + 4) and further treatment with gonadotrophin-releasing hormone (GnRH) analogue 18 h after removal of CIDR devices (treatment D; n = 4 + 4). The hinds were run with crayon-harnessed stags from insertion of CIDR devices (12 March or 9 April) and blood samples were taken every second day to determine plasma progesterone. Further blood samples were collected for determination of plasma LH and progesterone via indwelling jugular cannulae every 2 h for 72 h from removal of CIDR devices. Hinds were allocated randomly to an initial ovarian examination by laparoscopy at either 16 or 20 h (A and B), or 12 or 16 h (C and D) after the onset of oestrus, with laparoscopy repeated at intervals of 8 h until either ovulation was recorded (A and B), or for four successive occasions (C and D). All hinds received cloprostenol injections 15 days after device removal. A total of 28 hinds (78%) exhibited oestrus and a preovulatory LH surge, with mean (+/- SEM) times to onset of oestrus of 44.6 +/- 1.0 h (A; n = 7), 37.4 +/- 2.0 h (B; n = 7), 16.3 +/- 1.7 h (C; n = 6) or 14.0 +/- 1.7 h (D; n = 8). Failure to exhibit oestrus or LH surge was most prevalent among hinds in treatment A early in the rut.(ABSTRACT TRUNCATED AT 400 WORDS)

Causes of perinatal mortality in farmed fallow deer (Dama dama).

The causes of perinatal mortality in farmed fallow deer in the Camden region of New South Wales were determined between 1982 and 1987. The results of 144 necropsies on fawns showed that ante-parturient and parturient deaths occurred in 33 (22.9%) of cases, with post-parturient deaths accounting for 99 (69.8%), and undiagnosed causes the remaining 12 (8.3%). The most common cause of post-parturient death (43.1%) was exposure/starvation of fawns that had birthweights lower than the average for surviving fawns on these same farms (3.01 kg and 4.12 kg, respectively). These results provide good evidence of the correlation between low birthweight and perinatal mortality in fallow deer on Australian deer farms.

Laparoscopic intra-uterine insemination of fallow deer with frozen-thawed or fresh semen after synchronisation with CIDR devices.

This study investigated the efficacy of fixed-time laparoscopic intra-uterine insemination of farmed fallow deer (Dama dama) with frozen-thawed or fresh semen. In the trials with frozen-thawed semen, a total of 547 mature non-lactating does across five New Zealand farms were used. For oestrous synchronisation and artificial insemination, a standard control regimen was applied to at least 30% of the does on each farm, involving the insertion of single CIDR type-G devices intravaginally for 14 days, deposition of 50 x 10(6) frozen-thawed spermatozoa at 65 hours after withdrawal of the CIDR device and the continuous presence of vasectomised bucks from the insertion of the CIDR device until 10 days after insemination. Various aspects of this protocol were changed for the remaining does on each farm, including inseminations at 60 or 70 hours, the absence of vasectomised bucks, insemination with 25 x 10(6) or 10 x 10(6) spermatozoa, synchronisation with CIDR type-S devices and synchronisation with prostaglandin. The conception rate, based on rectal ultrasonography at 45 days after insemination, was 67% across all treatments (n=547). Corrected conception rates (+/-s.e.), calculated following between-farm adjustments, were 67+/- 3% for the control regimen, 67+/- 9% and 73 +/- 8% for inseminations at 60 and 70 hours respectively, 61 +/- 9% for absence of bucks, 80 +/- 8% and 74 +/- 9% for inseminations with 25 x 10(6) and 10 x 10(6) spermatozoa respectively, 62 +/- 10% for CIDR type-S device synchronisation, and 49 +/- 10% for prostaglandin synchronisation. Despite apparent differences, none of the treatments resulted in adjusted conception rates that were significantly different from the control regimen (P>0.01). In the trials with fresh semen, 216 does in the USA were inseminated at 69-71 hours after withdrawal of the CIDR device using either cryopreserved semen from New Zealand (n=158; 25 x 10(6) spermatozoa per inseminate) or fresh semen (n=58; 7.5 x10(6) to 20 x 10(6) spermatozoa per inseminate) collected less than 10 hours earlier. The overall conception rates were 77% and 81% respectively, with no significant differences between semen type (frozen v. fresh) or fresh spermatozoa number per inseminate (P>0.01). A further 102 does in New Zealand similarly received fresh semen from 3/4 Mesopotamian buck. Doses of 10 x 10(6) (n=35), 5 x 10(6) (n=32) or 2.5 x 10(6) (n=35) spermatozoa per inseminate were delivered at 69-71 hours after withdrawal of the CIDR device. The conception rates were 77%, 66% and 51% respectively, reflecting a dose effect (P<0.05). However, 1/4 Mesopotamian does in the group (n=19) exhibited higher conception rates (95% overall) irrespective of semen dose, possibly indicating a semen/recipient genotype interaction. It is concluded that laparoscopic intra-uterine insemination of fallow deer with frozen-thawed or fresh semen at fixed intervals after removal of a CIDR device can give acceptable conception rates under a range of on-farm management options and semen doses.

Haematology and serum biochemistry of captive unsedated chital deer (Axis axis) in Australia.

Haematological and serum biochemical values were measured in blood samples collected over a 12-mo period from 37 unsedated chital deer (Axis axis). Stags and hinds, ranging in age from birth to maturity, were sampled. Haemoglobin, total erythrocyte and haematocrit values were low at birth and sex differences were not apparent in neonates and juveniles, but were in adults. Chital stags had higher erythrocyte parameters (P less than 0.001) and lower erythrocyte indices than hinds, and the total leucocyte count was higher in stags (P less than 0.01). Some parameters (erythrocytes, muscle enzymes, glucose, cortisol) decreased over successive serial sampling. The differential leucocyte count of older stags decreased during the initial handling period. The major rutting period in February and March was characterised by changes in the differential leucocyte count, elevations in serum muscle enzymes, and lower serum cortisol levels. Alkaline phosphatase activity in serum reflected the annual antler cycle of chital stags. Serial sampling over many weeks, either weekly or tri-weekly, produced haematological and biochemical changes in successive samples which may have reflected a reduction in stress and excitement associated with restraint.

Rearing performance of farmed fallow deer (Dama dama).

The ability of fallow does to rear fawns to weaning age was examined in a group of 243 adult does of known age (Group 1) and 509 adult does of unknown age (Group 2). All does had between 1 and 8 opportunities to rear fawns. There was an increasing proportion of does that failed to rear a fawn to weaning age as the number of rearing opportunities increased, although most does (93.6%) only failed on one occasion. A small percentage of does in groups 1 and 2 failed repeatedly to rear fawns to weaning. At slaughter, the presumed causes of failure in chronic non-breeders included pyometron, cystic ovaries, cervical cysts, a vulval neoplasm and salpingitis. The overall rearing success of both groups of deer was 82.4% and there was no consistent pattern of rearing failure relating to parity or previous rearing history.

The reproductive performance of farmed fallow deer (Dama dama) in New South Wales.

Observations on the reproductive performance of fallow deer on 47 farms in New South Wales were made over 6 consecutive years. The minimum fawning rate for does varied significantly (p less than 0.001) between years, the corresponding fawning percentages varying from 75.0% to 96.4%, with an overall mean of 88.8%. The weaning rate also varied significantly (p less than 0.001) between years, the corresponding percentages varying from 65.0% to 89.1% with a mean over 6 years of 81.4%. Weaning rates were low given the known high fertility of fallow deer. The ratio of male to female fawns at weaning varied significantly (p less than 0.05) between years, although the ratio was exactly 1:1 for all births recorded over the 6-year period. The mean birthweights for female and male fawns were 4.01 kg +/- 0.61 (n = 330) and 4.23 kg +/- 0.72 (n = 348) respectively. Mean birthweights varied significantly (p less than 0.001) between the sexes and between years. There was a greater difference between birthweights of male and female fawns in years with higher mean fawn birthweight. Fawn birthweights generally approximated 10% of the pre-rut weight of their mother. Handling of newborn fawns for tagging and weighting did not increase the chance of mismothering and rejection. The mean weaning weight for doe fawns and buck fawns over 6 years was 18.7 kg (n = 227) and 21.2 kg (n = 231) respectively, with a mean birth to weaning interval of 108.4 +/- 4.89 (n = 458). Growth rates of male fawns from birth to weaning were significantly higher (p less than 0.01) than for female fawns, and the growth rates of fawns were significantly different (p less than 0.01) between years.(ABSTRACT TRUNCATED AT 250 WORDS)

Dirofilaria immitis in the dingo (Canis familiaris dingo) in a tropical region of the Northern Territory, Australia.

The heart and lungs from 32 adult dingoes (Canis familiaris dingo) were examined for canine heartworm (Dirofilaria immitis) infection. Eighteen of 32 (56%) samples were infected, with intensity of infection ranging from 1 to 31 worms per animal. Seven of 18 (39%) infections were single sex infections. Large numbers of circulating microfilariae were present in blood from all dingoes infected with both sexes of worms.

Successful uterine insemination of fallow deer with fresh and frozen semen.

Six fallow does were inseminated directly into the uterine horns 72 h (three does) or 78 h (three does) after the removal of progestagen intravaginal sponges. Three does were inseminated with fresh (two at 72 h and one at 78 h) or frozen-thawed (one at 72 h and two at 78 h) semen. The semen used had been collected by electroejaculation and had been stored for 2 yr in liquid nitrogen in a Tris, citric acid, glycerol diluent containing 2.25% egg yolk. Three does each produced a live fawn to insemination and all does had been inseminated 72 h after removal of sponges; two with fresh semen and one with frozen semen. The remaining three does failed to conceive to insemination, but did produce fawns to mating at a subsequent estrus.