Effects of nutrition in utero and in early life on the subsequent lifetime reproductive performance of Scottish Blackface ewes in two management systems

1995 ◽  
Vol 60 (2) ◽  
pp. 223-230 ◽  
Author(s):  
R. G. Gunn ◽  
D. A. Sim ◽  
E. A. Hunter

AbstractOver 3 years, a flock of Scottish Blackface ewes was managed so that one-third of the ewes received a high level of nutrition during the last 100 days of pregnancy (P), one-third received a high level of nutrition during the first 100 days of lactation (L) and one-third received a low level of nutrition as derived from a hill grazing over the same two periods (C). From these ewes, 496 ewe lambs were retained at weaning (19 to 22 weeks of age), balanced for treatment, year and birth type. At 6 months of age half of the lambs, similarly balanced, were transferred to an upland grazing system (U) for three breeding years. The other half was retained on the same hill grazing as their mothers for the same period (H). At the end of the study, all ewes were fed to reduce the range in body condition at a synchronized mating and ovulation rates were determined at slaughter.Differences in live weight of ewes due to treatment between groups P, L and C had disappeared by 18 months. There were no pre-mating differences between treatments in live weight or body condition score except that ewes in group P had higher live weights than those in group C at condition scores greater than 2·75. There was little effect of grazing system on the differences between treatments in live weight or body condition score at 30 and 42 months but H ewes were heavier and fatter at 18 months of age. Ewe mortality was consistently less in group L than in groups P and C and on system H than on system U, although the differences were not statistically significant. Group L had fewer barren ewes than groups P and C, and barrenness was significantly greater in the U than the H system. Group C had proportionally more single than multiple births than either groups P or L.At the end of the study there were no differences between the treatments in the proportion of ewes successfully mated at the final mating nor in their ovulation rates in relation to pre-mating body condition.It is concluded that nutrition during either the lactation period or late pregnancy period can influence subsequent lifetime reproductive performance and that this was expressed through an effect on embryo or foetal loss since there were neither residual differences apparent in live weight or condition score nor in ovulation rate potential.

1991 ◽  
Vol 52 (1) ◽  
pp. 157-163 ◽  
Author(s):  
R. G. Gunn ◽  
T. J. Maxwell ◽  
D. A. Sim ◽  
J. R. Jones ◽  
M. E. James

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.


1998 ◽  
Vol 66 (3) ◽  
pp. 667-673 ◽  
Author(s):  
P. Frutos ◽  
O. Buratovich ◽  
F. J. Giràldez ◽  
A. R. Mantecòn ◽  
I. A. Wright

AbstractThirty single-bearing Merino ewes were used to examine the effect of feeding supplement, from 91 to 140 days of gestation, on changes in chemical composition of the ewes, on the relationships with live weight and body condition score and on the foetus. Ewes grazed a perennial ryegrass pasture and were offered either no supplement or 500 g per head per day of a concentrate supplement from days 30 to 90 and (or) from days 91 to 140 of pregnancy. Maternal carcass and non-carcass components, uterine wall, foetus and placenta plus cotyledons were chemically analysed. Live weight (LW) and body condition score (BCS) on day 140 were both affected by supplementation during late pregnancy, mobilization of protein and fat being lower in animals receiving supplement. BCS accounted for more variation than LW in the carcass fat depot. Because this depot was the most important source of energy from days 91 to 140 of gestation, this suggests that BCS is a useful estimator of mobilization of maternal fat reserves during this stage of pregnancy. The ability to mobilize reserves and protect foetal growth by Merino ewes in southern Europe, where large fluctuations in grass growth rate exposes them to considerable undernutrition as pregnancy proceeds, was confirmed in this experiment. However, when the nutritional regime is extreme, supplementary feeding to the ewes is recommended, in order to make the whole system economically profitable.


2005 ◽  
Vol 29 (1) ◽  
pp. 143-151
Author(s):  
A. D. Salman

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.


1988 ◽  
Vol 46 (3) ◽  
pp. 417-426 ◽  
Author(s):  
R. G. Gunn ◽  
S. M. Rhind ◽  
T. J. Maxwell ◽  
D. A. Sim ◽  
J. R. Jones ◽  
...  

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.


1990 ◽  
Vol 51 (1) ◽  
pp. 143-153 ◽  
Author(s):  
R. J. Orr ◽  
T. T. Treacher

ABSTRACTFinn Dorset ewes were offered forage ad libitum from week 16 of pregnancy until lambing and were either unsupplemented (U) or given 600 g/day of concentrates (S). Grass silage and white clover silage, ensiled separately and having similar dry matter concentrations, were offered in four mixtures with white clover proportions of 0, 0·20, 0·40 and 0·60 on a fresh basis. Forage intake was significantly higher for mixtures containing higher proportions of clover (9·1, 10·5, 12·3 and 13·6 g organic matter (OM) per kg live weight) and the ewes gained more weight (33, 65, 178 and 174 g/day) and had smaller losses in body condition score (–0·59, –0·49, –0·39 and –0·17). Higher proportions of clover in the diet in late pregnancy also resulted in significantly higher growth rates of lambs during lactation, when a common diet was offered.The number of foetuses carried in pregnancy had significant effects on intake and some aspects of performance. For ewes carrying singles, twins and multiples respectively, mean daily forage intakes were 12·2, 11·9 and 10·4 g OM per kg live weight and losses in body condition score were –0·05, –0·40 and –0·62.Offering the supplement reduced forage intake and for treatments U and S respectively, mean daily values were 12·6 and 10·2 g OM per kg live weight. Whilst the supplemented ewes had smaller losses in body condition score in late pregnancy (–0·54 v. –0·28), lamb birth weights and growth rates were significantly increased only for ewes which had carried three or more foetuses in pregnancy and reared their two heaviest lambs.


2012 ◽  
Vol 7 (9) ◽  
pp. 904-909 ◽  
Author(s):  
Davoud Aliyari ◽  
Mohammad Mahdi Moei ◽  
Mohammad Hossein Sh ◽  
Mohammad Ali Sirjan

1986 ◽  
Vol 43 (3) ◽  
pp. 391-396 ◽  
Author(s):  
I. A. Wright ◽  
A. J. F. Russel ◽  
E. A. Hunter

ABSTRACTForty-eight Hereford × Friesian and Blue Grey cows ranging in body condition score from 1·75 to 4·0, 12 weeks before calving, were fed to achieve three levels of body condition score at calving. Half the cows were fed on an increasing plane of nutrition as pregnancy advanced and half were fed on a flat-rate feeding system. The condition scores achieved by the three groups at calving were 2·28, 2·47 and 2·70 (s.e.d. 0·071; P < 0·001). Differences in cow body condition at calving were reflected in cow live weight and condition 6 weeks later, but there was no effect on calf performance. Hereford × Friesian cows lost more weight in early lactation, tended to produce more milk and their calves were heavier. Pattern of feeding had no effect on cow condition score or weight at calving or on subsequent performance.It was calculated that each unit of body condition-score loss in late pregnancy contributes the equivalent of 3200 MJ dietary metabolizable energy while 6600 MJ dietary metabolizable energy are required for 1 unit of condition-score gain.


1987 ◽  
Vol 44 (1) ◽  
pp. 107-116 ◽  
Author(s):  
D. Zygoyiannis

ABSTRACTTwo groups, A and B, each consisting of 12 Greek indigenous goats suckling single kids were traditionally fed during a 36-week lactation period. During the suckling period (6 and 12 weeks for the groups A and B, respectively) milk production was estimated at 7-day intervals. During the milking period (30 and 24 weeks for the groups A and B, respectively) the goats were hand milked twice daily and their milk production was measured at intervals of 4 weeks. Milk samples were analysed for fat, protein, lactose, ash and dry matter concentration. Solids-not-fat and energy concentration were calculated. During lactation the goats were weighed weekly up to week 12 and monthly thereafter and body condition score was assessed at each weighing.Goats with a 6-week suckling period produced significantly less milk throughout lactation but significantly more marketable milk than those with a 12-week suckling period. Yield peaked at the 6th and 10th weeks of lactation respectively, then declined rapidly and tailed off gradually from weeks 7 and 16 respectively. Milk composition was affected only occasionally by the duration of the suckling period. Thus, fat concentration was higher for the group with the 6-week suckling period between weeks 7 and 16, whilst protein was higher between weeks 8 and 12. Lactose concentration was lower for the same group between weeks 7 and 11, whilst ash concentration was similar in both groups. Live weight and body condition of the goats throughout lactation showed similar changes in both treatment groups.


1966 ◽  
Vol 6 (23) ◽  
pp. 455 ◽  
Author(s):  
P McInnes ◽  
MD Smith

A factorially designed trial was used to study the effects of level of nutrition on the reproductive performance of Merino ewes. A high level of nutrition from three weeks before joining to conception (flushing) increased the percentage of twin births independently of the effects of previous levels of nutrition. Levels of nutrition did not affect the number of ewes that lambed. Flushing increased body weight and body condition score. Re-analysis of the results showed that there was an association between both body weight gain and body condition score and percentage of twin births. However, body weight gain and body condition score increase during flushing were associated with levels of nutrition before flushing. Although flushing increased body weight of groups at conception, on re-analysis of the results, the percentage of twin births could not be associated with weight at conception. Possible reasons for this result are suggested. As there was no indication of a significant relation between weight at conception and percentage of ewes that lambed, it is suggested that the critical weight for mating these ewes was below 38.7 kg.


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