The effect of feeding supplements in the autumn on the reproductive performance of grazing ewes 2. Feeding supplements in relation to sward height

1992 ◽  
Vol 54 (2) ◽  
pp. 249-258 ◽  
Author(s):  
R. G. Gunn ◽  
J. R. Jones ◽  
D. A. Sim
Keyword(s):  
Body Condition ◽  
Reproductive Performance ◽  
Live Weight ◽  
Corpora Lutea ◽  
Mating Period ◽  
Sward Height ◽  
Negative Effect ◽  
Repeated Experiment ◽  
Effect Of Feeding ◽  
Lambing Rate

AbstractThe effects of feeding supplements in relation to sward height in the autumn on the reproductive performance of ewes grazing predominantly perennial ryegrass swards were studied in four experiments with three genotypes. Treatments in which either no supplements were given or supplements were offered according to the height of the sward were compared when ewes were grazed on swards which were managed to decline in height from > 5 cm to 2·5 cm either before or after mating. At a sward height of < 3·5 cm, 400 g ground and pelleted barley was offered per head per day; at < 3·0 cm, 700 g was offered; and, at < 2·5 cm, hay was offered in addition to the barley. Responses to these treatments were compared with that of a treatment in which a sward was maintained at > 5 cm. Sward heights were controlled by varying stocking rate. In experiment 1, with 305 Scottish Blackface ewes, supplementation was not necessary until after the start of the mating period. In experiment 2, with 200 Brecknock Cheviot ewes, the supplementation protocol was examined on swards declining in height either before or after a synchronized mating. Experiment 3 repeated experiment 2 with 200 Beulah Speckled-face ewes and experiment 4 repeated only the pre-mating phase of experiment 3 with 195 Beulah Speckled-face ewes.In experiment 1, ovulation, ova loss and potential lambing rates were determined from the number of corpora lutea and viable embryos at slaughter at 8 to 10 weeks after the start of mating in 103 ewes and lambing rate was determined from the number of lambs at lambing in the remaining 202 ewes. In experiments 2, 3 and 4, ovulation, ova loss and potential lambing rates were determined from the number of corpora lutea and viable embryos at slaughter at return to service or at 4 weeks after a synchronized first mating.Grazing a sward declining in height below 3·5 cm in the pre-mating period significantly reduced ewe live weight, body condition and reproductive performance, particularly in the relatively prolific Beulah Speckled-face breed, compared with grazing a sward maintained at > 5 cm. Supplementation at the levels offered overcame some of the effects of the lower sward height treatment in the pre-mating period but did not compensate fully. Grazing a sward declining in height below 3·5 cm in the post-mating period, although reducing ewe live weight and body condition, had little effect on reproductive performance, compared with that achieved on a sward maintained above 4 cm. Supplementation at the levels offered at the lower sward height during the post-mating period produced no increase in overall reproductive performance and had a negative effect on some reproductive parameters.

The effect of feeding supplements in the autumn on the reproductive performance of grazing ewes 1. Feeding fixed amounts of supplement before and during mating

1992 ◽  
Vol 54 (2) ◽  
pp. 243-248 ◽  
Author(s):  
R. G. Gunn ◽  
J. A. Milne ◽  
A. J. Senior ◽  
A. M. Sibbald
Keyword(s):  
Organic Matter ◽  
Body Condition ◽  
Reproductive Performance ◽  
Fish Meal ◽  
Live Weight ◽  
Stocking Rate ◽  
Mating Period ◽  
Sward Height ◽  
Stocking Rates ◽  
Effect Of Feeding

AbstractThe effects on reproductive performance offeeding supplements to ewes grazing predominantly perennial ryegrass swards before and during mating which started in mid November were examined with approximately 200 Scottish Blackface ewes in each of three experiments. In two experiments, ewes were offered no supplement (C), 600 g barley (S(B)) or 500 g barley + 100 g white-fish meal (S(B + FM)) per head per day from 3 weeks before until 3 weeks after the start of the mating period. Ewes in experiment 1 were grazed on different areas and in experiment 2 were rotated around these areas on a 12-day cycle. Initial herbage allowance in both experiments was 40 to 50 kg organic matter per ewe and stocking rates ranged from 10 to 14 ewes per ha. Ewes in experiment 3 were rotated around the same areas on a 10-day cycle at a stocking rate of 18 ewes per ha and offered either no supplement (C) or 600 g barley (S(B)) per head per day when live weight started to decrease or sward height declined to 3·5 cm, whichever occurred first. Both of these occurred shortly after the start of mating. Sward height fell from mid October and throughout November and was between 3 and 4 cm at the start of mating in all experiments.There were no differences in response to the (S(B)) and (S(B + FM)) treatments in live weight, body condition or reproductive performance in experiments 1 and 2 and the effects of supplementation were examined with these treatments pooled.Supplementation had very little effect on live weight, resulting in higher values only in experiment 1 but did produce higher body condition in all experiments. This occurred by the start of mating in experiment 1 but not until mid December in experiment 3 and early January in experiment 2.A significant increase in the number of lambs born per ewe lambing was obtained from supplementation when the data from experiments 1 and 2 were combined (P < 0·05). There was no response in reproductive performance to supplementation in experiment 3. It was concluded that supplementation in the pre-mating period can improve reproductive performance when sward height declines from 6 to 3·5 cm but that supplementation in the post-mating period may not, even when the sward height is below 3·5 cm.

The effect of different durations and times of high- level feeding prior to mating on the reproductive performance of Scottish Blackface ewes

1984 ◽  
Vol 39 (1) ◽  
pp. 99-105 ◽  
Author(s):  
R. G. Gunn ◽  
J. M. Doney ◽  
W. F. Smith
Keyword(s):  
Body Condition ◽  
Reproductive Performance ◽  
Differential Effect ◽  
Weight Maintenance ◽  
Live Weight ◽  
Economic Advantage ◽  
Corpora Lutea ◽  
Mating Period ◽  
High Level ◽  
Lambing Rate

ABSTRACTOne hundred and sixty-four Scottish Blackface ewes from two different farm sources were brought into a uniform moderately-poor level of body condition by early November. Five groups of approximately 33 ewes were then fed different amounts of pelleted dried grass and hay on pasture to achieve either high (H) or live-weight maintenance (M) levels of intake for different durations and at different times in the 36 days prior to mating at a synchronized oestrus. One group of ewes was fed the M level throughout, two groups were fed the H level for 18 days either preceded or followed by 18 days of the M level and two groups were fed the H level for 27 days either preceded or followed by 9 days of the M level. After mating, all ewes were fed the M level until slaughtered on return to service or at 28 (± 8) days after mating for counts of corpora lutea and viable embryos relating to first mating.The gain in body condition and live weight after 18 days of H feeding was about half that achieved after 27 days. Time of H feeding had no differential effect on gain in condition or live weight. H feeding increased ovulation rate only if fed immediately prior to mating. When a period of M feeding preceded mating, most of the advantage was lost, particularly with 18 days of M feeding after 18 days of H feeding. Embryo mortality measured as ova loss was not significantly affected by either the duration or time of H feeding, although there was a trend for loss to decrease with increasing duration. Potential lambing rate to first mating was therefore significantly increased by H feeding for 27 days even when followed by 9 days of M feeding prior to mating but was not significantly increased by H feeding for only 18 days even when fed immediately prior to mating.Differences in response were obtained from the ewes from the two sources. H feeding only produced a significant improvement in reproductive performance when potential was high and this was partly related to greater size. In populations with low potential, the provision of H feeding in the pre-mating period is therefore of doubtful economic advantage.

A note on the effect of post-mating stocking rate on reproductive performance of Greyface ewes

1991 ◽  
Vol 52 (3) ◽  
pp. 548-550 ◽  
Author(s):  
R. G. Gunn ◽  
T. J. Maxwell ◽  
W. F. Smith ◽  
R. D. M. Agnew ◽  
C. D. Kerr ◽  
...  
Keyword(s):  
Body Condition ◽  
Reproductive Performance ◽  
Live Weight ◽  
Conception Rate ◽  
Stocking Rate ◽  
Mating Period ◽  
Sward Height ◽  
Stocking Rates ◽  
Lambing Rate

Continuously grazed rye grassl clover swards with surface heights of 8 to 10 cm at 5 weeks before a synchronized mating and 7·5 cm at mating were grazed by 151 Greyface ewes stocked at 12 per ha until mating. The effects of two stocking rates (eight and 16 ewes per ha) for 6 weeks over the mating and post-mating period were then studied on live weight, body condition and reproductive peformance. Sward height fell more rapidly post mating when stocked at 16 ewes per ha than at eight ewes per ha, but remained above 3·5 cm until 4 weeks after first mating under both rates. Ewes stocked at 16 per ha became significantly lighter and leaner than ewes stocked at eight per ha. There was no significant effect of post-mating stocking rate on reproductive performance in terms of conception rate and lambing rate to first mating or lambing rate to all matings. Reproductive performance of Greyface ewes is therefore unlikely to be adversely affected by post-mating stocking rate on swards of 7 to 8 cm which do not fall below 3·5 to 4·0 cm until 3 to 4 weeks after mating.

Influence of feeding different types feed blocks as supplementary feed on the reproductive performance of Awassi ewes grazing cereal stubble

2005 ◽  
Vol 29 (1) ◽  
pp. 143-151
Author(s):  
A. D. Salman
Keyword(s):  
Cottonseed Meal ◽  
Body Condition ◽  
Reproductive Performance ◽  
Body Condition Score ◽  
Live Weight ◽  
Mating Period ◽  
Different Types ◽  
Condition Score ◽  
Supplementary Feed ◽  
Lambing Rate

This study was conducted to investigate the Influence of feeding different types feed blocks as supplementary feed on the reproductive performance of Awassi ewes grazing cereal stubble. These types were feed blocks enriched with cottonseed meal (CSM) or Brewers’ grain (BG) as sources undegradable protein (UDP). Ninety-six Awassi ewes (mean live weight 42.2 Kg), aged 3-4 years were allocated into three groups according to ewes live weight and body condition score.Group (C): Control (No Supplement) stubble grazing only.Group (FBC): FB enriched with CSM supplement plus stubble grazing.Group (FBB): FB enriched with BG supplement plus stubble grazing.All ewes were run as one flock during cereal stubble grazing. The feed blocks were fed to animals (supplementary groups) after their return from grazing wheat and barley stubble (28 days prior to mating and 54 days after introduction of rams). Rams run with the flock during the mating period. The results showed that feeding feed blocks enriched with CSM and BG as supplementary feed resulted considerable improvement in weight gain (P<0.05), body condition score (P<0.05), conception rate (13-16), lambing percentage (25-33%), twinning percentage (13-18%) and decreased the proportion of barren ewes (19 vs. 6 and 3%). Inclusion of small amount of high moisture brewers grain by-product (9%) as sources of undegradable protein in the feed blocks formula as replacement for costly cottonseed meal resulted a dramatic effects on the reproductive performance of Awassi ewes especially twinning rates and lambing rate.

The effect of supplementary feeding in relation to sward height during the pre- and post-mating periods on reproductive performance of brecon cheviot ewes

1988 ◽  
Vol 1988 ◽  
pp. 100-100 ◽  
Author(s):  
R.G. Gunn ◽  
T.J. Maxwell ◽  
D.A. Sim ◽  
J.R. Jones ◽  
M.E. James
Keyword(s):  
Growth Rate ◽  
Body Weight ◽  
Body Condition ◽  
Reproductive Performance ◽  
Live Weight ◽  
Supplementary Feeding ◽  
Management Decision ◽  
Mating Period ◽  
Sward Height ◽  
The Uk

Sward growth rate and height decline under autumn grazing in the UK. This eventually depresses ewe intake, live weight and body condition and may, as a consequence, reduce reproductive performance. The provision of supplementary feeding is a strategic measure to avoid this but requires quantification in relation to measurable variables such as sward height and stage of the reproductive cycle.A management decision rule for supplementary feeding over the mating period, which is currently operated in the MLURI upland system studies, requires that, in order to maintain both body weight and condition until the completion of the second cycle of mating, concentrated feed be introduced when sward height (herbage mass) is ≤3.5 cm (≤1200 kg DM/ha), be increased when height is ≤3.0 cm ( ≤ 1000 kg DM/ha) and ad lib, hay be introduced when height is ≤ 2.5 cm (≤ 750 kg DM/ha).

The effect of sward height and active immunization against androstenedione on reproductive performance of ewes of two Welsh breeds in different body conditions

1988 ◽  
Vol 46 (3) ◽  
pp. 417-426 ◽  
Author(s):  
R. G. Gunn ◽  
S. M. Rhind ◽  
T. J. Maxwell ◽  
D. A. Sim ◽  
J. R. Jones ◽  
...  
Keyword(s):  
Body Condition ◽  
Reproductive Performance ◽  
Body Condition Score ◽  
Live Weight ◽  
Active Immunization ◽  
Corpora Lutea ◽  
Stocking Rate ◽  
Sward Height ◽  
Period 2 ◽  
Condition Score

ABSTRACTIn a 2 × 2 × 2 × 2 factorial experiment, the effects on reproductive performance of active immunization against androstenedione and of two sward heights in two periods, August to October (period 1) and October to November (period 2), were investigated in 144 Beulah Speckled-face and 146 Brecknock Cheviot ewes. Sward heights of either 5 to 6 cm (2200 kg dry matter (DM) per ha) (high) or 2 to 3 cm (650 kg DM per ha) (low) were achieved by adjustment of stocking rate during period 1. Two groups of ewes were balanced for body condition score across breed and sward height and the ewes of one group were actively immunized against androstenedione by injection with Fecundin® at 8 and 5 weeks before mating at the second synchronized oestrus after progestagen pessary withdrawal. Ewes were reallocated to the high (at 15 ewes per ha) and low (at 20 ewes per ha) swards at the start of period 2 by breed and immunization treatment, balanced for live weight, body condition score and sward height in period 1. After mating in mid November, all ewes were run at 19 ewes per ha on the residual pasture of the high sward until slaughtered either at return to service or at 4 weeks after first mating when corpora lutea and embryos were counted.There were no effects or interactions due to sward height in period 1 on the reproductive responses to sward height in period 2. Ovulation and potential lambing rates were greater in the Beulah breed than in the Cheviot, and on the high sward than on the low in period 2. Ovulation rates were higher in immunized ewes than in control ewes but the effects of immunization and sward height on potential lambing rate were not independent. Potential lambing rates were higher in immunized ewes than in control ewes at the low sward height but not at the high sward height.Adjustment of stocking rate during period 1 served to increase the range in ewe body condition at the start of period 2 in mid October. Reproductive response to body condition at this time differed between the breeds, the relationship being strongly positive in the more prolific Beulah control ewes but less so in the less prolific Cheviot control ewes. The response to immunization in both breeds was relatively greater at lower levels of body condition, thereby reducing the effect of body condition in immunized ewes.The use of Fecundin® is therefore unlikely to produce much advantage when pre-mating nutrition or body condition are high but there may be some advantage in using it when nutritional resources are limited in the autumn, particularly in ewes in poorer body condition.

The effect of level of nutrition prior to mating on the reproductive performance of ewes of two welsh breeds in different levels of body condition

1991 ◽  
Vol 52 (1) ◽  
pp. 157-163 ◽  
Author(s):  
R. G. Gunn ◽  
T. J. Maxwell ◽  
D. A. Sim ◽  
J. R. Jones ◽  
M. E. James
Keyword(s):  
Body Condition ◽  
Reproductive Performance ◽  
Body Condition Score ◽  
High Surface ◽  
Live Weight ◽  
Corpora Lutea ◽  
Stocking Rate ◽  
Treatment Groups ◽  
Condition Score ◽  
Body Condition Scores

ABSTRACTThe effects of high-low (HL) and low-high (LH) patterns of nutrition during the 5 weeks prior to a synchronized mating were studied on the reproductive performance of 115 Welsh Mountain and 114 Brecknock Cheviot ewes in a range of body condition at the start of treatment. For 2 months prior to treatment imposition, ewes were grazed in a systematic way at different stocking rates on different sward heights to obtain a range of body condition scores. Target score groupings were 2·00 to 2·25, 2·50 to 2·75 and 3·00 to 3·25 and although scores of 1·50 to 3·25 were obtained, most lay in the 2·00 to 2·75 range. Two treatment groups, balanced for live weight and body condition score, received high and low levels of nutrition for 16 days from mid October, achieved, respectively, by a low stocking rate on a sward with a high surface height plus ad libitum concentrate and a high stocking rate on a sward with a low surface height plus 200 g hay per head per day. Treatments were then reversed for the 17 days prior to mating. Live-weight and body condition-score changes were recorded and reproductive performance at first mating was measured from counts of corpora lutea and viable embryos at slaughter either at return to service or at 4 weeks after first mating. There were no differences due to nutritional pattern in live weight or body condition score at mating. The LH treatment significantly increased the rates of ovulation, conception, multiple ova survival and potential lambing per ewe pregnant and per ewe mated in the Welsh Mountain breed but significantly increased only the rates of ovulation and potential lambing per ewe pregnant in the Brecknock Cheviot breed compared with the HL treatment. The relatively poorer response in the latter breed was partially due to a lower ovulation rate potential coupled with non-significantly lower rates of conception and survival of single-shed ova associated with the LH treatment. Much of this relatively poorer reproductive performance in the Brecknock Cheviot breed was in ewes with body condition scores 3= 2·75. Reproductive performance increased with increasing body condition at the start of treatment over the range of scores =≤ 2·25 to 2·50 in both breeds and, while continuing to improve in scores above 2·50 in the Welsh Mountain breed, in the Brecknock Cheviot breed it started to decline. Ewes with a body condition score of 2·50 in both breeds showed the greatest response in potential lambing rate to the LH treatment.

Effect of flushing on reproductive performance of ewes

1966 ◽  
Vol 67 (3) ◽  
pp. 305-323 ◽  
Author(s):  
I. E. Coop
Keyword(s):  
Body Condition ◽  
Reproductive Performance ◽  
Live Weight ◽  
Dynamic Effect ◽  
Mating Period ◽  
Weight Effect ◽  
Grazing Sheep

Eight flushing experiments were conducted with grazing sheep over a 4-year period, the responses being measured at lambing. In the first 2 years mobs of 600-750 ewes were employed. Those experiments were designed to separate, identify and measure the two components postulated as comprising the flushing response—a static live-weight effect not specifically related in time to the mating period, and a dynamic effect of the rising or falling body condition which is specific to the mating period.

scholarly journals Reproductive performance of Santa Inês ewes fed protected fat diet

2011 ◽  
Vol 46 (6) ◽  
pp. 663-668 ◽  
Author(s):  
Ricardo Lopes Dias da Costa ◽  
Reginaldo da Silva Fontes ◽  
Eduardo Antonio da Cunha ◽  
Mauro Sartori Bueno ◽  
Celia Raquel Quirino ◽  
...  
Keyword(s):  
Body Weight ◽  
Body Condition ◽  
Reproductive Performance ◽  
Control Diet ◽  
Live Weight ◽  
Conception Rate ◽  
Santa Inês ◽  
Lambing Rate ◽  
Diet Supplementation

The objective of this work was to evaluate the reproductive performance of Santa Inês ewes fed a diet supplemented with protected fat. Intervals from lambing to first clinical estrus and to conception, conception rate, prolificacy, live weight and body condition were determined. After lambing, 60 ewes and their offsprings were weighted and randomly assigned to three treatments, based on age, body weight and number of born lambs. Treatments consisted of: control diet, or control diet plus 30 g of protected fat, from lambing to day 25 of post-lambing (Sup25), or to day 60 of post-lambing (Sup60). Out of 60 evaluated ewes, 93.3% returned to estrus, and 74.5% got pregnant, with 73.53% lambing rate and 196.5 days lambing interval. The average periods from lambing to first estrus were 32.4, 27.2 and 35.5 days for ewes fed the control diet, Sup25, and Sup60, respectively. The intervals from lambing to conception were 45.2, 46.5 and 45.2 days, and the supplemented diets did not show differences in comparison to the control diet. Supplementation with protected fat to well-nourished Santa Inês ewes does not improve their reproductive performance.

A note on reproductive performance and plasma progesterone level during early pregnancy of Scottish Blackface and Cheviot ewes in relation to body condition and level of nutrition prior to mating

1983 ◽  
Vol 37 (3) ◽  
pp. 455-458 ◽  
Author(s):  
S. M. Rhind ◽  
R. G. Gunn ◽  
J. M. Doney
Keyword(s):  
Treatment Group ◽  
Body Condition ◽  
Early Pregnancy ◽  
Reproductive Performance ◽  
Weight Maintenance ◽  
Live Weight ◽  
Corpora Lutea ◽  
Plasma Progesterone ◽  
Condition Score ◽  
Maintenance Ration

ABSTRACTSeventy-nine Scottish Blackface and 79 North × South Country Cheviot ewes were fed to increase their mean condition score by 0·5 over periods of either 4 (M/H group) or 8 (I group) weeks prior to mating. Thereafter, they were fed a live-weight maintenance ration until they were slaughtered at 50 to 65 days after mating. Reproductive tracts were recovered, corpora lutea counted and embryos counted and examined. Plasma progesterone levels were monitored at selected times after mating. The proportion of ewes in each treatment group that were pregnant at the time of slaughter was similar (0·75 to 0·83) but there was evidence of differences in the pattern of reproductive failure with treatment. The proportion of non-pregnant ewes which had apparently been pregnant initially was 0·55 in the M/H group compared with only 0·27 in the I group. Circulating progesterone levels were not affected by premating nutritional treatments but differed with breed.

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