The timing of melatonin treatment affects the seasonal onset of ovarian activity, coat growth and live weight in young red deer hinds

ABSTRACTMelatonin was fed daily at 14.00 h to eight non-lactating and six lactating hinds. Feeding was begun on 27 July 1983 (day 1) and continued until 21 September (day 57). Six non-lactating hinds were used as controls. Blood samples were taken about every 10 days from day 42 until day 73. Plasma progesterone and prolactin were determined by radioimmunoassay. Progesterone values of greater than 0·63 μg/1 were taken to indicate the presence of a corpus luteum and that the animal had ovulated. In the melatonintreated, non-lactating group seven of the eight hinds showed ovarian activity compared with two of the six controls (P < 0·01). None of the lactating hinds treated with melatonin showed evidence of ovarian activity. In both the lactating and non-lactating hinds treated with melatonin, prolactin levels were never greater than the detection limit of the assay (7·4 μg/l), while, in the control hinds mean prolactin levels were elevated on all but the last sampling day. It is, therefore, possible to induce early ovarian activity in non-lactating red deer hinds by feeding melatonin. However, although melatonin treatment similarly depressed plasma prolactin levels in both lactating and non-lactating hinds, it was unable to overcome the inhibitory effect of lactation on reproduction.

Download Full-text

The influence of the stag on pubertal development in the red deer hind

Animal Science ◽

10.1017/s1357729800013394 ◽

1995 ◽

Vol 60 (3) ◽

pp. 503-508 ◽

Cited By ~ 12

Author(s):

M. W. Fisher ◽

L. M. Meikle ◽

P. D. Johnstone

Keyword(s):

Breeding Season ◽

Social Factors ◽

Red Deer ◽

Pubertal Development ◽

Ovarian Activity ◽

Melatonin Treatment ◽

Timing Of Puberty

AbstractThe possible influence of social factors on the timing of puberty in the hind was investigated utilizing seasonally advanced (melatonin-treated) hinds and stags. Melatonin treatment of both sexes resulted in a significant advancement in the onset of pubertal ovarian activity (26 days, P < 0·001) and calving (27 days, P < 0·001) in the treated hinds and antler casting (25 days, P < 0·001) in the treated stags. Ovarian activity and calving were not influenced by melatonin treatment of the stags alone and similarly, antler casting was not affected by melatonin treatment of the hinds alone. However, a group of hinds without stags until after the onset of the breeding season, reached puberty later (5 days, P < 0·05) than hinds with stags, suggesting the presence of the male is important in determining the timing of puberty.

Download Full-text

Effects of treatment with melatonin on the response of seasonally anovular ewes to the introduction of rams

Animal Science ◽

10.1017/s0003356100020134 ◽

1991 ◽

Vol 53 (2) ◽

pp. 203-207 ◽

Cited By ~ 6

Author(s):

M. Rekik ◽

M. J. Bryant ◽

F. J. Cunningham

Keyword(s):

Factorial Design ◽

Pregnancy Rate ◽

Jugular Vein ◽

Live Weight ◽

Response To Treatment ◽

Ovarian Activity ◽

Melatonin Treatment ◽

Plasma Melatonin ◽

The Mean

AbstractSixty-four mature ewes (equal numbers of Bluefaced Leicester ♂ × Swaledale ♀ and Suffolk ♂ × (Bluefaced Leicester ♂ × Swaledale ♀) which had lambed in March were separated from their lambs on 1 fune. They were randomly allocated from breed and live-weight blocks to one of four treatments arranged in a 2 × 2 factorial design. All received vaginal implants, with or without melatonin, on 1 June. The implants were removed, all ewes given 20 mg progesterone in oil intramuscularly and equal numbers isolated or introduced to rams on 12 July. Ovarian activity was monitored by progesterone concentrations in blood taken three times weekly from the jugular vein. Four ewes receiving melatonin and four control ewes were bled for 24 h on 6 July to determine plasma melatonin concentrations.Melatonin treatment increased plasma melatonin concentrations during the day. All ewes were anovular prior to 12 July. There were no differences between the two ewe types in their response to treatment. The number of ewes ovulating before 27 August was: control 1; melatonin 6; ram 16; melatonin + ram 16. The mean date of emulation for both the ram and melatonin + ram groups was 21 July. The number of ewes showing oestrous behaviour was 16 and 15 for the ram and melatonin + ram treatments respectively. The proportion of ewes responding to ram introduction was judged as unusually high, possibly as a result of the favourable male:female ratio. Pregnancy rate was in excess of 80% for both treatments, with resulting litter sizes of 14 for the ram and 1·8 for the melatonin + ram treatments respectively (P > 0·05).

Download Full-text

The rôles of photoperiod and nutrition in the seasonal increases in growth and insulin-like growth factor-1 secretion in male red deer

Animal Science ◽

10.1017/s1357729800058288 ◽

2001 ◽

Vol 73 (2) ◽

pp. 305-311 ◽

Cited By ~ 8

Author(s):

J. R. Webster ◽

I. D. Corson ◽

R. P. Littlejohn ◽

S. K. Martin ◽

J. M. Suttie

Keyword(s):

Growth Factor ◽

Food Intake ◽

Growth Rates ◽

Energy Demand ◽

Red Deer ◽

Young Male ◽

Live Weight ◽

Metabolizable Energy ◽

Plasma Prolactin ◽

Insulin Like Growth Factor

AbstractYoung male red deer follow a seasonal growth pattern that can be shifted by altering the photoperiod they experience. An increase in photoperiod to 16 h of light per day (16L : 8D) during winter advances the onset of rapid growth and high food intake that normally commences in spring. These changes are associated with increased growth hormone (GH) and insulin-like growth factor-1 (IGF-1) secretion. The GH/IGF-1 axis is acutely sensitive to the level of nutrition and the relative rôles of photoperiod and nutrition in determining the spring IGF-1 rise is unknown. The present experiment set out to examine this by exposing two groups of deer (no. = 8 per group) to a photoperiod shift during their 1st year of life (16L : 8D from 2 June), designed to cause accelerated growth and increased food intake after approximately 7 weeks. However, after 6 weeks the food intake (pellets containing 11 MJ metabolizable energy and 160 g crude protein per kg dry matter (DM)) of one group (LDRES) was clamped, thereby preventing the intake component of the response. The intake of the other group (LDAL) remained ad libitum for a further 12 weeks until 6 October, when the experiment concluded.During the first 6 weeks of 16L : 8D, growth rate (118 (s.e. 15·4) g/day) and food intake (1·37 (s.e. 0·031) kg DM per head per day) did not differ between the groups. Food intake following the clamp in LDRES averaged 1·40 (s.e. 0·015) kg per head per day. The intake of LDAL increased 2 weeks after the clamp and thereafter was higher than LDRES (P < 0·001). Food intake of LDAL averaged 2·13 (s.e. 0·051) kg during the nutritional clamp period. Growth rates increased in both groups during the first 3 weeks of the clamp, averaging 237 (s.e. 25·0) g/day, then growth slowed in LDRES and live weights diverged. Growth rates until the end of the experiment (147 (s.e.23·0) g/ day v. 299 (s.e. 12·5) g/day, P < 0·001) and mean live weight over the last 5 weeks of the experiment were lower (P < 0·05) in LDRES than LDAL, weights reaching 88·3 (s.e. 1·86) kg and 97·9 (s.e. 2·74) kg respectively on the final sampling date. Metatarsal bone length grew more in LDAL than in LDRES (3·1 v. 2·2 cm, s.e.d. = 0·23, P < 0·01). Prior to the nutritional clamp, mean plasma prolactin and IGF-1 concentrations increased at 3 and 6 weeks after 16L : 8D respectively, in both groups. Prolactin concentrations were lower in LDRES than LDAL on two occasions, at weeks 3 and 7 after the onset of the nutritional clamp, and IGF-1 concentrations were lower in LDRES than LDAL (676 v. 872 ng/ml, s.e.d. = 73·8, P < 0·05) over the last 7 weeks of sampling.In summary, a photoperiodically driven increase in IGF-1 occurred even when the usual associated increase in food intake was prevented. This indicates that the seasonal IGF-1 rise in red deer is not a consequence of the increased food intake, although the latter appears necessary to maintain elevated IGF-1 concentrations. The rise in IGF-1 may therefore be considered as a component of the photoperiodically entrained seasonal drive to grow, and the increase in food intake a response to satisfy the increased energy demand.

Download Full-text

Precision Betacarotene Supplementation Enhanced Ovarian Function and the LH Release Pattern in Yearling Crossbred Anestrous Goats

Animals ◽

10.3390/ani10040659 ◽

2020 ◽

Vol 10 (4) ◽

pp. 659

Author(s):

Noé M. Lopez-Flores ◽

César A. Meza-Herrera ◽

Carlos Perez-Marin ◽

Dominique Blache ◽

Gerardo Arellano-Rodríguez ◽

...

Keyword(s):

Ovarian Function ◽

Body Condition Score ◽

Area Under The Curve ◽

Live Weight ◽

Beta Carotene ◽

Ovarian Activity ◽

Release Pattern ◽

Time Treatment ◽

Condition Score ◽

Lh Release

The possible out-of-season effect of beta-carotene supplementation on ovulation rate (OR), antral follicles (AFN), and total ovarian activity (TOA = OR + AFN) as related to the LH release pattern in yearling anestrous goats was evaluated. In late April, Alpine-Saanen-Nubian x Criollo goats (n = 22, 26 N) were randomly allotted to: (1) Beta-carotene (BETA; n = 10, orally supplemented with 50 mg/goat/d; 36.4 ± 1.07 kg live weight (LW), 3.5 ± 0.20 units, body condition score (BCS) or (2) Non-supplemented (CONT; n = 12, 35.2 ± 1.07 kg LW, 3.4 ± 0.2 units BCS). Upon estrus synchronization, an intensive blood sampling (6 h × 15 min) was accomplished in May for LH quantifications; response variables included (pulsatility-PULSE, time to first pulse-TTFP, amplitude-AMPL, nadir-NAD and area under the curve-AUC). Thereafter, an ultrasonography scanning was completed to assess OR and AFN. The Munro algorithm was used to quantify LH pulsatility; if significant effects of time, treatment or interaction were identified, data were compared across time. Neither LW nor BCS (p > 0.05) or even the LH (p > 0.05); PULSE (4.1 ± 0.9 pulses/6 h), NAD (0.47 ± 0.13 ng) and AUC (51.7 ± 18.6 units) differed between treatments. Nonetheless, OR (1.57 vs. 0.87 ± 0.18 units) and TOA (3.44 vs. 1.87 ± 0.45 units) escorted by a reduced TTFP (33 vs. 126 ± 31.9 min) and an increased AMPL (0.55 vs. 0.24 ± 0.9 ng), favored to the BETA supplemented group (p < 0.05), possibly through a GnRH-LH enhanced pathway and(or) a direct effect at ovarian level. Results are relevant to speed-up the out-of-season reproductive outcomes in goats while may embrace translational applications.

Download Full-text

Increased winter growth in male red deer calves under an extended photoperiod

Animal Science ◽

10.1017/s1357729800016623 ◽

1997 ◽

Vol 65 (2) ◽

pp. 305-310 ◽

Cited By ~ 2

Author(s):

J. R. Webster ◽

I. D. Corsor ◽

R. P. Littlejohn ◽

J. M. Suttie

Keyword(s):

Dry Matter ◽

Red Deer ◽

Live Weight ◽

Natural Increase ◽

Metabolizable Energy ◽

The Other ◽

Abrupt Increase ◽

Winter Solstice ◽

The Mean ◽

Autumn And Winter

AbstractThe growth of male red deer slows during the first winter of life before increasing again during spring. This study aimed to determine if this period of slow growth could be minimized using artificial photoperiods during autumn and winter (10 April (week 1) to 11 September (week 23), southern hemisphere). Four groups of deer (no. = 10) were housed indoors as follows. Two groups were placed on a winter solstice photoperiod (8·5 light (L): 15·5 dark (D)) and given either a natural increase in photoperiod to 11·25L: 12·75D (WSN) or held on 8·5L: 15·5D for 7 weeks followed by an abrupt increase to 11·25L: 12·75D (WSH). One group was exposed to a summer solstice photoperiod of 16L: 8D (SS) and one group exposed to a natural photoperiodic pattern (IC). A fifth group of deer (no. = 10) was maintained outside on a gravelled enclosure under natural changes in photoperiod (OC). All groups were given a diet containing 160 g protein per kg and 11·0 MJ metabolizable energy per kg dry matter (DM) ad libitum. All animals were weighed weekly and group food intake recorded daily. Metatarsal length was measured at weeks 3,17 and 22 from the start of treatments.The major differences occurred between SS and the other groups. After a period of slower growth (weeks 1 to 5, SS = 88 g/day v. 168 g/day other groups, s.e.d. 31·2, P < 0·05), SS grew more rapidly from week 10 (P < 0·01). As a result, SS was heaviest from week 17 (P < 0·05) until the end of the experiment (P < 0·01). The mean growth rate of SS animals from weeks 10 to 23 was 346 g/day compared with 173 g/day (s.e.d. 15·3; P < 0·001) for the other groups. Over the whole experiment, SS animals gained 42·3 kg live weight, compared with 31·1 kg for WSN, 26·6 kg for WSH, 25·1 kg for OC and 23·7 kg for IC (s.e.d. 2·08 kg P < 0·01). The DM intake of SS from week 9 until the end of the experiment averaged 2·04 kg DM per head per day compared with 1·48 (s.e. 0·041) kg DM per head per day for the mean of the other groups. Metatarsal length increased more in SS than the other groups (P < 0·001) between weeks 3 and 17 and was longest in SS at weeks 17 and 22 (P < 0·01). Exposure to a 16L: 8D photoperiod during winter advanced the rapid growth of red deer calves normally associated with spring and summer. This response may be used to advance slaughter dates for venison production.

Download Full-text

Photoperiodic requirements for rapid growth in young male red deer

Animal Science ◽

10.1017/s1357729800010146 ◽

1998 ◽

Vol 67 (2) ◽

pp. 363-370 ◽

Cited By ~ 3

Author(s):

J. R. Webster ◽

I. D. Corson ◽

R. P. Littlejohn ◽

S. K. Stuart ◽

J. M. Suttie

Keyword(s):

Growth Rate ◽

Food Intake ◽

Rapid Growth ◽

Red Deer ◽

Young Male ◽

Live Weight ◽

Reproductive Development ◽

The Other ◽

Plasma Prolactin ◽

Lower Amplitude

AbstractWinter growth of young male red deer can be increased by exposure to 16 h of light (L) and 8 h of dark (D) per day (16L: 8D). This study tested the duration of photoperiod required for this growth response, determined if the time to reach slaughter weight can be reduced and monitored plasma IGF-1, prolactin and reproductive development. Fifty male calves were allocated to five equal groups. Four groups were housed indoors and for 33 weeks from the winter solstice (22 June, southern hemisphere) until 11 February were placed under either 16L: 8D (16L), 13·25L: 10·75D (13L), 10·751:13·25D (111) or 8L: 16D (8L) photoperiods. The fifth group of deer (OC) remained outside in a gravelled enclosure. All groups were given a pelleted diet ad libitum. Group food intake was recorded daily, individual live weight was measured weekly and testes diameter and blood samples taken at weekly or 2-week intervals.Plasma prolactin concentrations in 16L increased within 4 weeks of treatment and were different (P < 0·001) between groups from 14 August to 4 September. IGF-1 increased in both 16L and 13L 4 weeks after treatments and then increased further in 16L above that of 13L (P < 0·01). All groups grew at the same rate for the first 7 weeks. 16L then gained more weight (P < 0·001) than the other groups over the next 19 weeks (50·7 kg v. 38·5 for 13L, 35·7 for 11L, 37·0 for 8L and 37·4 for OC; s.e.d. 3·76). Food intake was positively related to growth rate in a similar way among the inside groups (P < 0·001), however there was a higher energy requirement outdoors (P < 0·05). A target live weight for slaughter of 95 kg was reached 7 weeks earlier for 16L than the other groups (P < 0·01). Testes diameter of 16L was larger than in the other groups from 13 November until 24 December (P < 0·001). The growth oflSL slowed from 1 January while that of OC increased and the live weight ofOC was equal to 16L by the end of the experiment. OC also had the largest testes diameter from 5 February onwards (P < 0·01). The live-weight increase in OC was associated with increases in both prolactin and IGF-1 levels.This study confirmed that 16L: 8D stimulates rapid growth of young male red deer during winter for sufficient time to achieve an earlier slaughter date. The live-weight advantage was lost by late summer however. The increased growth rate was mediated by food intake and associated with increases in IGF-1 and prolactin and earlier reproductive development. Photoperiods of 13 h of light per day or less did not stimulate growth and increases in IGF-1 and prolactin were of a lower amplitude than under 16L: 8D.

Download Full-text

Strategic Feeding Alternating a 2-months’ Feeding Restriction and a Short Boost of the Feeding Level Increases Conception Rate in Sheep

International Journal of Biology ◽

10.5539/ijb.v8n1p80 ◽

2015 ◽

Vol 8 (1) ◽

pp. 80

Author(s):

Narjess Lassoued ◽

Mourad Rekik ◽

Imene Ben Salem ◽

Mariem Rouatbi

Keyword(s):

Food Restriction ◽

Statistical Significance ◽

Live Weight ◽

Conception Rate ◽

Ovarian Activity ◽

Continuous Increase ◽

Treatment Groups ◽

Regime Changes ◽

Strategic Feeding ◽

High Treatment

<p class="1Body">This study aimed to investigate if feeding patterns prior to and after artificial insemination (AI) affect the reproductive performances of ewes. Two breeds were used; the Barbarine (n = 133) and Queue Fine de l’Ouest (QFO; n = 129). For each breed, 2 experimental groups balanced for age and live weight were formed. For 75 days before AI, ewes in treatment High daily grazed for 6 hours and were supplemented with 0.6 kg of concentrate. For those in treatment Low-High, grazing was restricted to 3 hours only. From 21 days before insemination and the following 20 days, feeding pattern for Low-High ewes was switched to the High feeding regime. Changes in live weight and ovarian activity were monitored; conception rate and litter size were recorded. At the end of the restriction period and for both breeds, Low-High ewes reached lower live weights than High ewes (p < 0.05). Prior to AI and for both breeds, Low-High ewes weighed less than those in the High treatment group but no statistical differences were observed. At the end of the restriction period, more QFO ewes were cycling than for the Barbarine breed (75/129 vs. 55/133; p < 0.01). Further, less QFO ewes in the Low-High treatment were cycling than High ewes (30/65 vs. 45/64; p < 0.01). More QFO ewes conceived to AI than Barbarine counterparts (77/112 vs. 73/130; p < 0.05). For both breeds, higher proportions of ewes in the Low-High treatment groups conceived to AI but differences reached statistical significance only for Barbarine breed. Following a food-restriction period between weaning and mating, improved conception rates are achieved if the plane of nutrition is increased few weeks prior to and after AI in comparison to a continuous increase in live weight during the same period.</p>

Download Full-text

The effects of liveweight at weaning, date of weaning and winter nutrition on the subsequent performance of red deer

Proceedings of the British Society of Animal Production (1972) ◽

10.1017/s0308229600016469 ◽

1986 ◽

Vol 1986 ◽

pp. 140-140

Author(s):

J A Milne ◽

Angela M Sibbald

Keyword(s):

Birth Weight ◽

Growth Rates ◽

Red Deer ◽

Live Weight ◽

Meat Production ◽

Weaning Weight ◽

Calf Growth ◽

Subsequent Performance ◽

Number Of Factors

A desirable liveweight for red deer at 15 months of age is approximately 80 kg. This will provide a saleable carcase and a liveweight at which yearling hinds will successfully breed. Live-weight at 15 months will be influenced by a large number of factors including date of birth, birth-weight, liveweight gain to weaning, date of weaning, liveweight gain during the first winter and subsequent summer, and the interactions between weaning weight and subsequent levels of nutrition and between winter levels of nutrition and liveweight gain at pasture in the following summer. These latter two aspects were examined in two experiments and the effect of date of weaning on contemporary calf growth rates and on hind calving date in the following year were studied in a third experiment. The objective was to provide information which would allow the development of effective systems of deer meat production based on slaughter at 15 months of age.

Download Full-text

The lactation performance of red deer on hill and improved species pastures

The Journal of Agricultural Science ◽

10.1017/s0021859600041587 ◽

1984 ◽

Vol 102 (1) ◽

pp. 149-158 ◽

Cited By ~ 34

Author(s):

A. S. I. Loudon ◽

A. D. Darroch ◽

J. A. Milne

Keyword(s):

Growth Rates ◽

Red Deer ◽

Live Weight ◽

Lactation Period ◽

Weight Changes ◽

Lactation Performance ◽

Calf Growth ◽

Grass Sward ◽

The Hill ◽

Grazing Behaviour

SummaryThree groups of red deer hinds of 9–10 years of age were grazed upon an indigenous hill pasture (A), an improved species grass sward (predominantly perennial ryegrass) maintained at < 1500 kg D.M./ha (B), and one maintained at 2000 kg D.M./ha (C) from immediately after calving on 29 May until weaning on 22 September. Numbers of hinds in each treatment were 8, 6 and 9 respectively. Milk yields of hinds were estimated on swards A and C by the calf-suckling technique and hind and calf live-weight changes and hind grazing behaviour were recorded on all three swards during lactation.Hinds on award C yielded on average 60% more milk over the lactation period than hinds on sward A, day 40 yields being 2·2 and 1·5 kg/day respectively. Calf growth rates (treatment A, 257 ± 9·5, B, 324 ± 12·1 and C, 369 ± 14·5 g/day) were higher on the improved species sward than on the hill sward and higher on the improved sward with the greater herbage mass. On treatments A and C calf growth rates were significantly (P < 0·05, r = 0·69) correlated with milk yield throughout lactation. At weaning, calves on sward C were 7·5 and 4·5 kg heavier than those on swards A and B respectively. Biting rates were lower (33 v. 56 bites/min) and grazing times higher (11.7 v. 6.0 h) on sward A than swards B and C. The poorer performance of hinds and their calves on sward A was considered to be due to a lower quality of diet ingested, and to behavioural limitations on intake occurring when hinds graze indigenous swards of relatively high species diversity. These results are discussed in relation to the grazing behaviour of cattle and sheep on similar swards.The significance of the results to red deer farming in the U.K. is briefly discussed.

Download Full-text