Effect of restricted food intake, before and/or after mating, on the reproductive performance of Greyface ewes

1989 ◽  
Vol 48 (1) ◽  
pp. 149-155 ◽  
Author(s):  
S. M. Rhind ◽  
W. A. C. McKelvey ◽  
S. McMillen ◽  
R. G. Gunn ◽  
D. A. Eiston

ABSTRACTThe effect on the reproductive performance of Greyface (Border Leicester × Scottish Blackface) ewes of a low level food intake and associated loss of live weight from either 14 days before mating, or from the time of mating, until 11 to 26 days after mating, was investigated. Ewes (252) were allocated to one of three treatments with ewes within each treatment divided into two flocks (flock A: 16 ewes per treatment; flock B: 68 ewes per treatment). Ewes of treatment LL were given a ration providing proportionately 0·5 estimated metabolizable energy (ME) requirements for maintenance from 2 weeks before mating. Those of treatment HL were given a daily ration providing 1·5 estimated ME requirements for maintenance until mating and the restricted ration thereafter. Ewes of treatment HH were given the higher ration throughout the experimental period. Flock A ewes were slaughtered at 11 days post mating and flock B ewes at between 18 and 26 days post mating. Treatment differences in the ovulation rates of flock A ewes were not statistically significant but in flock B, ewes of treatment LL had a lower mean ovulation rate (1·81) than those of treatments HL (2·23) and HH (2·09) (P < 0·001). The lower ovulation rate of LL ewes relative to HL ewes in flock B was reflected in a lower mean potential lambing rate per ewe pregnant than in the HL treatment (1·58 v. 1·79; P < 0·01) and per ewe put to the ram (1·37 v. 1·65; P < 0·01). HL ewes had a slightly lower mean potential lambing rate per ewe pregnant (1·79 v. 1·97; P < 01) and per ewe put to the ram (1·65 v. 1·82; P < 0·05) than HH ewes. Ova wastage rates of LL + HL and HH ewes were 0·26 and 014 (P < 001) respectively at 24 days post mating. Values for LL and HL ewes (0·27 and 0·25 respectively) were not significantly different.Estimated mean conceptus lengths were 370, 500 and 1400 μin for LL, HL and HH ewes respectively (P < 0·05).It is concluded that low food intake before mating reduced the mean ovulation rate and low intakes after mating compromised embryo growth rate and induced a higher rate of ova wastage; this increase in the incidence of ova wastage was not significantly exacerbated by the low levels of intake prior to mating.

Author(s):  
S.M. Rhind ◽  
J.M. Doney ◽  
R.G. Gunn

Ovulation rate and lambing rate of Cheviot ewes are improved by both increased body condition and premating food intake. The aim of this work was to investigate the endocrine mechanisms by which one of these factors, intake, could influence reproductive performance.Two similar groups of 20 ewes were fed differentially to achieve condition scores of either 2.0 or 2.5 by 4 weeks before mating in November. Low condition animals were then fed ad libitum and achieved a mean condition score of 2.3 and mean liveweight of 58 kg at mating. The remainder were offered a maintenance ration and had a mean condition score of 2.5 and mean liveweight of 55 kg at mating. Blood samples were collected at 20 minute intervals for 10 h approximately 7 days before mating and for 5 h on each of the 3 days immediately prior to the anticipated day of oestrus.


1970 ◽  
Vol 75 (2) ◽  
pp. 337-345 ◽  
Author(s):  
T. A. McCullough

SUMMARYConcentrate diets supplemented with 5, 20 and 40% high- and low-quality hay were given ad libitum to British Friesian steers from 9 weeks of age to slaughter.The performance of the animals was studied over 91 kg weight ranges from 91 to 363 kg live weight and from 9 weeks of age to slaughter. In the whole experimental period the daily live-weight gain was significantly greater on diets containing high-quality hay. There was also an increase in the daily live-weight gain in each of the weight ranges studied on diets supplemented with high-quality hay but this increase was not significant at the stage of growth from 272 to 363 kg live weight. As the level of concentrate in the diet increased there was a significant increase in the daily live-weight gain at each stage of growth studied and over the complete experimental period.The mean feed conversion ratio was greater for diets containing low-quality hay. Except during the stage of growth from 272 to 363 kg live weight the proportion of hay in the diet significantly affected the mean concentrate conversion ratio. With increasing levels of hay in the diet there was a significant increase in the total dry-matter conversion ratio.The conversion ratio of metabolizable energy was also increased on diets containing low-quality hay. The proportion of concentrate in the diet significantly affected the conversion ratio of metabolizable energy at all stages of growth studied.There were significant differences in the killing-out percentages, weight and contents of the reticulo-rumen and the omasum plus abomasum expressed as a percentage of empty body weight, with increasing levels of hay in the diet. These measurements were not significantly affected by the quality of hay in the diet.Indirect measurements of carcass composition indicated that the level of hay in the diet tended to affect the amount of fat in the carcass but the amount of lean was similar at the different ratios of concentrate to hay. The ratios of the weight of separable lean to the weight of separable bone in the 9–10–11th rib cut were similar at different levels of hay supplementation. The organoleptic appraisal of sample joints indicated that carcass quality was satisfactory.


2001 ◽  
Vol 73 (2) ◽  
pp. 305-311 ◽  
Author(s):  
J. R. Webster ◽  
I. D. Corson ◽  
R. P. Littlejohn ◽  
S. K. Martin ◽  
J. M. Suttie

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.


1989 ◽  
Vol 48 (2) ◽  
pp. 449-457 ◽  
Author(s):  
B. P. Mullan ◽  
I. H. Williams

ABSTRACTThe level of body reserves in first-litter sows was manipulated by giving gilts one of three levels (high (H), medium (M) or low (L)) of food from selection (44 kg live weight) to parturition. The aim of this experiment was either to maintain or to mobilize these reserves during lactation (31·4 days) by feeding sows to appetite (high (H)) or 2·0 kg/day (low (L)).When the level of body reserves was increased prior to farrowing (171 kg live weight, 32 mm backfat) sows had a lower voluntary food intake during lactation than those animals that farrowed with a low level of body reserves (126 kg live weight, 20 mm backfat) (H-H v. L-H, 3·4 v. 4·9 kg/day; P < 0·001). Both groups had a normal return to oestrous activity after weaning (mean interval between weaning and mating of 14 days) but the heavier animals mobilized more of their body reserves (H-H −30·7 kg live weight, -4·3 mm backfat; L-H -3·6 kg live weight +0·9 mm backfat; P < 0·001). When food intake during lactation was restricted to 2·0 kg/day the interval between weaning and mating was increased by 50% regardless of the level of body reserves present at farrowing. For the same animals, there were insufficient body reserves to support milk production at the same level as for those animals given food t o appetite.


1992 ◽  
Vol 54 (2) ◽  
pp. 249-258 ◽  
Author(s):  
R. G. Gunn ◽  
J. R. Jones ◽  
D. A. Sim

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.


Author(s):  
R.M. Waruiru ◽  
C.O. Onyando ◽  
R.O. Machuka

Between June 1999 and August 2000, the effects of feeding medicated urea-molasses supplement blocks on the growth of dairy heifers in a marginal area of central Kenya were assessed by comparing the live-weight gain of supplemented and unsupplemented heifers grazing the same pasture. Thirty-nine heifers with an average age of 9.6 months were initially treated orally with albendazole (10 mg / kg body weight) and assigned to 3 groups : group I was fed urea-molasses blocks with incorporated fenbendazole (MUMB), group II was fed urea-molasses blocks (UMB) and group III heifers (control) received no block supplementation (NBS). Body weights of the heifers and faecal egg counts (FECs) were measured monthly and larval cultures were made of positive faecal samples of each group. The mean cumulative live-weight responses of the MUMB and UMB groups were significantly greater than the NBS group (P < 0.05). However, at the end of the experimental period, the mean weight gain of the MUMB group did not differ from that of the UMB group (P >0.05). The FECs were moderate to low in all groups and decreased progressively with increasing age of the animals; FECs for the urea-molasses-supplemented groups remained significantly lower than those of the NBS group throughout the experimental period (P <0.05). Haemonchus and Trichostrongylus were the predominant nematode genera found in the heifers, but Cooperia, Bunostomum and Oesophagostomum were also present. These results indicate that feeding of urea-molasses blocks substantially reduced production losses attributable to nematode infection of young grazing cattle, and confirms previous observations that well-fed animals are better able to overcome the effects of helminth infections.


1977 ◽  
Vol 24 (3) ◽  
pp. 377-385 ◽  
Author(s):  
M. J. Ducker ◽  
J. S. Boyd

SUMMARYBody size was estimated for 255 Greyface ewes using five linear body dimensions. On the basis of this calculated measure combined with a subjective measure of body size 50 small and 50 large ewes were selected for use in the experiment. Precise ovulation data were obtained by endoscopy and this technique allowed the ewes to be mated subsequently.Body size did not affect the mean ovulation rate of the ewes although, at the same level of body condition, the large ewes were 25% heavier than the small ewes. The ovulation rates and the numbers of lambs born were influenced by changes in live weight and body condition. For these reasons live weight per se was not a good indicator of ovulation rate as ewe live weight was a combination of both body size and body condition. At the same live weight small ewes in improving body condition had a significantly higher ovulation rate than large ewes in reducing body condition.The onset of the breeding season of the ewes was not affected by their body size. The mean date of onset of oestrous activity for both large and small ewes was 17 October 1972 at a latitude 55° 52′ N.


1979 ◽  
Vol 29 (3) ◽  
pp. 393-399 ◽  
Author(s):  
A. M. Khalaf ◽  
D. L. Doxey ◽  
J. T. Baxter ◽  
W. J. M. Black ◽  
J. FitzSimons ◽  
...  

ABSTRACTOne hundred and thirty-nine Scottish Half bred ewes were studied during the last 8 weeks of pregnancy, through parturition and early lactation. They were divided, on the basis of their metabolizable energy intake during this period, into low (483 MJ/ewe; L), medium (742 MJ/ewe; M) or high (974 MJ/ewe; H) feeding groups.Ewe weight change (from mating to 12 h post lambing) was directly related to nutritional level and the number of lambs born, e.g. L ewes with triplets lost a mean 13·8 kg, while H ewes with single lambs gained 14·3 kg.Lamb birth weight and perinatal lamb mortality levels were affected by ewe nutrition and litter size. L twins weighed 19% less at birth than H twins; L triplets weighed 26% less than H triplets. The mortality rate of L twins was 23% greater than M twins; L triplets exceeded the H triplet mortality rate by 87%.Ewe energy feeding during late pregnancy affected the mean daily weight gain of lambs for at least 3 weeks after birth. H single, twin and triplet lambs grew 12%, 15% and 16% faster than M lambs and 19%, 31 % and 31 % faster than L lambs respectively.The H group produced 33 % more lamb live weight at 3 weeks of age for every lamb born than did the L group.Lamb serum immunoglobulin levels were related to litter size but did not reflect the differences in ewe feeding during late pregnancy.


1997 ◽  
Vol 65 (2) ◽  
pp. 305-310 ◽  
Author(s):  
J. R. Webster ◽  
I. D. Corsor ◽  
R. P. Littlejohn ◽  
J. M. Suttie

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.


1969 ◽  
Vol 9 (39) ◽  
pp. 381
Author(s):  
PD Mullaney

Observations were carried out on one Polwarth, three Corriedale, and four Merino flocks in Western Victoria to investigate the influence of a ewe's own live weight at birth and weaning on her subsequent reproductive performance, when lambing for the first time. Weaning weights were adjusted to 140 days of age. The mean adjusted weaning weights were 26-35 lb (Merino), 27-48 lb (Corriedale), and 37 lb (Polwarth). Variation in the live weight of ewes at birth had little or no effect on either the number of lambs born per ewe joined (LBJ) or the number of lambs weaned per ewe joined (LW]), when the ewes lambed for the first time at either two or three years old. Variation in the live weight of ewes at weaning generally had only a small effect on both LBJ and LWJ at first lambing. On three properties, there was, however, an increase of about 3 per cent in LBJ and about 2 per cent in LWJ for each 10 lb increase in the ewe's own live weight at weaning.


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