The nutrition of grazing ewes during pregnancy and lactation: relationships between herbage, supplement and milk intakes, and ewe and lamb liveweight and body composition

2018 ◽  
Vol 58 (7) ◽  
pp. 1253 ◽  
Author(s):  
H. Dove ◽  
M. Freer ◽  
J. Z. Foot

This paper reports results from a study of ewes in pregnancy and lactation, during which times they grazed at a high versus medium stocking rate and either received or did not receive a pelleted supplement. We measured ewe liveweight, condition score and body composition; intakes by ewes of pasture and supplementary feed; milk production by ewes, and; birthweight, milk intake, liveweight gain and body composition of single and twin lambs. Ewes grazing at the medium stocking rate consumed more pasture in late pregnancy and the intake of supplement significantly reduced pasture intake. Nevertheless, total intakes of organic matter or digestible organic matter were unaffected by supplementation and were significantly higher at the medium stocking rate. Effects of stocking rate on intake persisted into early and mid-lactation, but supplement intake did not affect pasture intake in lactation. Pasture intakes in pregnancy were not markedly different between twin-bearing and single-bearing ewes, nor were pasture intakes in lactation affected by the number of lambs suckled. Ewes suckling twins produced much more milk. There were significant effects of birth type, ewe stocking rate and supplementation on lamb milk intake and liveweight gain. The data were reanalysed by regression, to explore the effects of actual herbage masses and ewe intakes, and the possible effects of non-treatment terms such as ewe age, condition score and dentition score at allocation. These analyses confirmed the above effects of treatment, but also demonstrated that ewes in better condition at the start of the experiment ate less pasture in both pregnancy and lactation, and produced significantly less milk. Ewe organic matter intakes in pregnancy were not related to dentition score at allocation, but in early and mid-lactation were reduced by ~170 g organic matter/day and 280–380 g organic matter/day, respectively, per unit increase in dentition score. There was no significant effect of ewe dentition score on lamb milk intake, but there was a significant penalty of ~19 g lamb liveweight gain/unit increase in ewe dentition score at allocation. Future studies of this kind thus need to include estimates of the condition score and dentition score of ewes when they commence the experiment.

1985 ◽  
Vol 40 (1) ◽  
pp. 101-109 ◽  
Author(s):  
R. J. Orr ◽  
T. T. Treacher ◽  
V. C. Mason

ABSTRACTFinnish Landrace × Dorset Horn ewes were offered 300, 600 or 900 g fresh weight per day of concentrates and forage ad libitum from day 105 of pregnancy until lambing. Spring barley straw (S) or hay (H) was offered either untreated (U) or following treatment with anhydrous ammonia in an oven (T). Organic matter digestibilities (in vitro) were 0·42, 0·58, 0·42 and 0·60 and nitrogen contents were 7·2, 18·6, 12·0 and 25·0 g/kg dry matter for US, TS, UH and TH respectively. Forage intake did not differ between ewes carrying two or more foetuses but the small number of ewes carrying one foetus ate more straw (6·8 v. 4·5 g organic matter (OM) per kg live weight) than ewes carrying two or more foetuses. Ammonia treatment increased intake; the increase was larger on straw (4·6 v. 100 g OM per kg live weight) than on hay (9·0 v. 10·7 g OM per kg live weight). Replacement rates of forage by concentrates were -0·21, +0·06, -0·48 and +0·08 kg forage per kg concentrates for treatments US, TS, UH and TH respectively; only the value for treatment UH differed significantly from zero. On most treatments forage intake decreased as pregnancy progressed and the declines were greater when treated forages were offered. Concentrate level had a large effect on most aspects of ewe performance. Ewes offered treated forage gained slightly more weight in pregnancy (138 v. 104 g/day), had a slightly smaller decrease in body condition score (-0·54 v. -0·68) between day 105 and lambing but did not have greater lamb birth weights than ewes on untreated forage.


2011 ◽  
Vol 51 (9) ◽  
pp. 794 ◽  
Author(s):  
A. N. Thompson ◽  
M. B. Ferguson ◽  
D. J. Gordon ◽  
G. A. Kearney ◽  
C. M. Oldham ◽  
...  

Nutrition of ewes during pregnancy can have permanent impacts on the production potential of their progeny. The hypothesis tested in the experiments reported in this paper was that improving the nutrition of Merino ewes during pregnancy and lactation increases the fleece weight and reduces the fibre diameter of their progeny’s wool during their lifetime. In addition, that these effects on the progeny’s wool production can be predicted from the ewe’s liveweight profile. At sites in Victoria and Western Australia in each of 2 years, a wide range in the liveweight and condition score profiles of Merino ewes was generated by varying the amount of supplements fed from joining to Day 100 of pregnancy and the amount of feed on offer grazed from Day 100 to weaning. The site in Victoria was based on perennial pastures and included both single- and twin-bearing ewes whereas the site in Western Australia was based on annual pastures and included single-bearing ewes only. The production and characteristics of wool from the progeny were measured until 51 months of age at the site in Victoria and 33 months of age at the site in Western Australia. The nutritional treatments and the resulting changes in ewe liveweight had significant impacts on the fleece weight and to a lesser extent the fibre diameter of wool produced by their progeny, but there were no consistent effects on other characteristics of progeny fleece wool. The fleece weight of the progeny was related to the liveweight change during pregnancy of their mothers (P < 0.05) and the relationships were similar for the two experiments at each site. At the site in Victoria, a loss of 10 kg in ewe liveweight between joining and Day 100 of pregnancy reduced fleece weight by ~0.2 kg at each shearing until 51 months of age whereas gaining 10 kg from Day 100 of pregnancy to lambing had the opposite effect. The effect of changes in ewe liveweight during late pregnancy on the fleece weight of their progeny at each shearing was of similar magnitude at the site in Western Australia. When evident, the effect of the ewe liveweight profile on the fibre diameter of progeny wool was opposite to the effect on clean fleece weight and the effect of poor nutrition in early to mid pregnancy could be completely overcome by improving nutrition during late pregnancy. Twin-born and reared progeny produced ~0.3 kg less clean wool at each shearing (P < 0.001) that was 0.3-μm broader (P < 0.001) than that from single-born progeny at the site in Victoria. However, the effects of varying ewe nutrition and ewe liveweight change during pregnancy on fleece weight and fibre diameter of progeny wool were similar (P > 0.05) for both single- and twin-born or reared progeny. Overall, these results supported our hypothesis and it is clear that the nutritional management of Merino ewes during pregnancy is important for optimal wool production from their progeny during their lifetime.


2014 ◽  
Vol 54 (8) ◽  
pp. 1023 ◽  
Author(s):  
M. C. Raeside ◽  
Z. N. Nie ◽  
M. Robertson ◽  
D. L. Partington ◽  
R. Behrendt

Ewe nutrition during pregnancy and lactation is a key determinant of ewe and lamb performance. A paddock-scale field experiment in western Victoria, Australia, tested the hypothesis that grazing maiden ewes on plantain (Plantago lanceolata L.) from mid-pregnancy until lamb weaning (July 2010–January 2011) would increase ewe liveweight and condition score during this period, reduce worm egg counts, and increase lamb liveweights at birth, marking and weaning, relative to tetraploid perennial ryegrass (Lolium perenne L.), but that further increases would be achieved by offering a spatially arranged sward of plantain and perennial ryegrass. The experiment tested three treatments: plantain (PL), perennial ryegrass (PR), and a 50 : 50 (by area) spatially separated mixture of perennial ryegrass and plantain (PR + PL). Plots were ~1 ha in size arranged in a randomised complete block design with four replications. The ewes were Coopworth composites joined at 8 months of age. Feed-on-offer levels (kg DM/ha) did not differ (P > 0.05) between treatments, with 2.3–3.0 t DM/ha being available pre-grazing. Twin-bearing ewes had higher (P < 0.05) liveweights when offered PR + PL compared with PR or PL at late-pregnancy and higher (P < 0.05) liveweights than PR but not PL (P > 0.05) at lamb marking. At weaning, single-born lambs were heavier (P < 0.05) on PR than PR + PL, with the PL being intermediate. There were no other significant differences (P > 0.05). This experiment has found that feeding plantain to ewes during pregnancy and lactation, or offering ewes spatially separated mixes of plantain and perennial ryegrass, offers no clear liveweight or worm egg count improvement for ewes and lambs relative to a tetraploid perennial ryegrass under Western Victorian conditions.


2011 ◽  
Vol 51 (9) ◽  
pp. 776 ◽  
Author(s):  
C. M. Oldham ◽  
A. N. Thompson ◽  
M. B. Ferguson ◽  
D. J. Gordon ◽  
G. A. Kearney ◽  
...  

The single largest influence on the survival of lambs in the first few days of life is their birthweight. Fetal growth and birthweight are regulated by genotype of the fetus, maternal genotype, maternal nutrition and the external environment. In this paper we report the extent to which the changes in maternal liveweight during pregnancy and lactation (liveweight profile) of Merino ewes can be used to predict the birthweight and survival of their progeny to weaning. At two sites [Victoria (Vic.) ~700 ewes and Western Australia (WA) ~300 ewes] in each of 2 years, a similar experiment used adult Merino ewes to explore effects of nutrition from joining to Day 100 of pregnancy and from Day 100 of pregnancy to weaning. The average difference between extreme treatments at Day 100 of pregnancy were 7 kg in ewe liveweight and 0.7 of a condition score (CS) and at lambing 11.9 kg and 1.3 of a CS. This resulted in average birthweights of progeny from different treatments ranging from 4.0 to 5.4 kg and survival to weaning ranging from 68 to 92%. Across the four experiments between 68 and 85% of all lamb deaths to weaning occurred within 48 h of birth. Lambs born to ewes in CS 2 at Day 100 of pregnancy were lighter (P < 0.05) in both years at the Vic. site than those from ewes in CS 3 at Day 100 of pregnancy. Lambs born to the ewes grazing a feed on offer of 800 kg DM/ha during late pregnancy were also lighter than those from other levels of feed on offer between 1100 and 3000 kg DM/ha at the Vic. site in both years and at the WA site in 1 year (P < 0.001). Lambs from the 800 kg DM/ha treatment during late pregnancy at the Vic. site had a lower survival than other treatments, especially in the second year. There were no significant effects of treatments on lamb survival at the WA site; however, the results were in the same direction. The birthweight of individual lambs was significantly related to the liveweight profile of their mothers. Their liveweight at joining, change in liveweight to Day 100 of pregnancy and change in liveweight from Day 100 to lambing all contributed (P < 0.05) to the prediction of the birthweight of their lambs. The responses were consistent across experimental sites and years, lamb birth rank and sex, and confirmed that the effects of poor nutrition up until Day 100 of pregnancy could be completely overcome by improving nutrition during late pregnancy. At the Vic. site, survival to 48 h was most influenced by the birthweight of the lamb and survival was significantly higher in single- than twin-born lambs and female than male lambs after adjusting for differences in birthweight. A higher chill index during the 48 h after birth reduced survival of both single and twin lambs to a similar extent, but reduced survival of male lambs more than female lambs. There were no effects of birthweight or chill index on lamb survival at the WA site where most lambs weighed more than 4 kg at birth and climatic conditions during lambing were less extreme. Overall, these results supported our hypothesis that improving the nutrition of Merino ewes during pregnancy increases birthweight and this leads to improved survival of their progeny.


1985 ◽  
Vol 10 ◽  
pp. 85-94 ◽  
Author(s):  
T. H. McClelland ◽  
R. H. Armstrong ◽  
J. R. Thompson ◽  
T. L. Powell

AbstractFollowing the evolution of the “Two Pasture System” of hill sheep management by the Hill Farming Research Organisation (HFRO) at their Sourhope and Lephinmore stations, the model was adopted by the Agricultural Development and Advisory Service at Redesdale experimental husbandry farm (EHF) and by the Scottish Agricultural Colleges at the West College Hill Farm of Kirkton in West Perthshire. At the time, the ADAS Pwllpeiran EHF in mid-Wales was engaged in an exercise based on the traditional Welsh management system in which ewes are kept on enclosed better grazings from tupping until after lambing and then ewes and lambs are summered on the hill.The paper describes the developments at Sourhope, Redesdale, Kirkton and Pwllpeiran from the mid/late 1960's until the present time (1980 for Kirkton). The four farms differ considerably in climate, topography, soil type, vegetation and size. In all cases, however, between 20-30% of the total resource was subjected to some degree of pasture improvement over the course of the development. In the case of Kirkton and Sourhope, 9% of the resource was reseeded, whilst at Redesdale the corresponding figure was 17%. At Pwllpeiran, most of the improvement involved surface treatment but of a fairly costly nature almost equal to that of reseeding.In all cases, the improved pasture was used to provide ewe and lamb grazing during lactation and ewe grazing around mating and lambing. Supplementary feed inputs per ewe during late pregnancy increased significantly on all farms. There was an increase in ewe numbers carried, being 99, 139, 42 and 3% greater for Sourhope, Redesdale, Kirkton and Pwllpeiran, respectively. Weaning percentages (lambs weaned per 100 ewes put to the ram) also increased, by 26, 48, 48 and 36% for Sourhope, Redesdale, Kirkton and Pwllpeiran, respectively. Taken together, there was a significant corresponding increase in the number of lambs weaned of the order of 121, 297, 129 and 47%.Lamb weaning weights were improved in all cases in spite of increased twinning. This weight increase was most significant at Pwllpeiran where a major effort had been made to change breed type with the specific purpose of producing a heavier lamb.Gross margin data were available for Sourhope, Redesdale and Kirkton and when plotted on a per ewe and per hectare basis follow remarkably similar pathways over the development for the three centres. The gross margin figures per ewe, when discounted to base, show no significant increase and in some cases were reduced up until the introduction of the EEC sheep meat regime in 1981, after which time significant real increases occurred for those developments still in progress (Sourhope and Redesdale). The real increase there occurred as a result of increased stocking rate. On Pwllpeiran, however, where stocking rate increase was low, it is still considered that the exercise was profitable as measured by Internal Rate of Return.The various increases confirm that investment in land improvement, coupled with an enlightened approach to sheep management, has improved the overall efficiency of pasture utilisation and economic viability.


Animals ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 295 ◽  
Author(s):  
José Luis Pesántez-Pacheco ◽  
Ana Heras-Molina ◽  
Laura Torres-Rovira ◽  
María Victoria Sanz-Fernández ◽  
Consolación García-Contreras ◽  
...  

Pregnancy and lactation, especially when concurrent, create a rather metabolically demanding situation in dairy ruminants, but little is known about their effects on offspring phenotype and milk yield. Here, we evaluated the impact of pregnancy and lactation on the metabolic traits and productive performance of Lacaune dairy sheep and their offspring. Productive performance was measured in terms of milk yield, body weight (BW), body condition score (BCS), and size. Productivity was assessed during mid-pregnancy (75 ± 5 d) and late pregnancy (142 ± 4 d) and at 52 ± 5 d in the postpartum period. During pregnancy, high-yielding ewes had higher BW, BCS, plasma glucose, cholesterol, β-OHB, and NEFA than low-yielding ewes, but lower levels of lactate and urea. High-yielding animals had lower BCS after lambing, but their lambs showed greater growth. Productivity during lactation was affected by ewe age and parity: Mature ewes (but not maiden sheep) whose BCS increased steeply during pregnancy yielded more milk in the subsequent lactation than those whose BCS did not increase. Lamb BW and size were positively associated with milk yield in the subsequent lactation. Mature ewes had higher yields than maiden sheep, and mature ewes with multiple pregnancies produced more milk than those with singleton pregnancies. Ewes with male singleton pregnancies also showed higher yield than those with female singletons. These results demonstrate that high-yielding dairy sheep, when appropriately fed and managed, can adequately cover the metabolic demands of pregnancy and high milk production (even when concurrent) without losing productivity.


2011 ◽  
Vol 51 (9) ◽  
pp. 763 ◽  
Author(s):  
M. B. Ferguson ◽  
A. N. Thompson ◽  
D. J. Gordon ◽  
M. W. Hyder ◽  
G. A. Kearney ◽  
...  

Defining the nature of the relationship between change in liveweight throughout a breeding cycle and ewe wool production and reproduction would be useful for developing management guidelines for Merino ewes. In this paper we tested the hypotheses that (1) feed on offer has variable effects on liveweight profiles of individual ewes; and (2) liveweight profiles of individual ewes can be used to predict their fleece wool production and reproductive performance. At sites in Victoria and Western Australia in 2001 and 2002, pregnant Merino ewes were exposed to 10 nutritional treatments. In each of the four experiments, ewes in average condition score 3 at artificial insemination were fed to achieve either maintenance or loss of a condition score over the first 100 days of pregnancy before grazing one of five levels of feed on offer between Day 100 and lamb weaning. Across all four experiments, the average difference in ewe liveweight between extreme treatments was: 7.0 kg (range 4.7–8.7 kg) at Day 100 of pregnancy; 11.9 kg (range 4.9–17.8 kg) at lambing; and by weaning was 13.9 kg (range 8.8–22.7 kg). Liveweight at joining and liveweight change during pregnancy and lactation of individual Merino ewes were significantly related to their clean fleece weight, fibre diameter and staple length and thus the second hypothesis was supported. Heavier ewes at joining produced more wool that was longer and broader and this effect was consistent across both sites and years. A 10-kg loss in ewe liveweight between joining and mid pregnancy, mid pregnancy and lambing or during lactation reduced clean fleece weight by 0.4–0.7 kg and fibre diameter by 0.5–1.4 um. At the Victorian site, where ewes were shorn in summer, a loss of 10 kg in liveweight between joining and Day 100 of pregnancy reduced staple strength by 5 N/ktex. As expected the influence of food on offer on changes in ewe liveweight was different between years and sites and between late pregnancy and lactation due to a complex group of pasture and animal factors. Therefore, managing changes in ewe liveweight itself rather than feed on offer will achieve more predictable outcomes. A higher liveweight at joining resulted in a predictable improvement in ewe reproductive rate and liveweight at joining was more important than the liveweight profile leading up to joining. This paper has shown that it is possible to predict the differences in wool production and reproductive rate of flocks of Merino ewes if ewe liveweight records at key times are known.


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.


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