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

1997 ◽  
Vol 65 (2) ◽  
pp. 305-310 ◽  
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.

The voluntary intake by cattle of four silages differing in dry matter content

1970 ◽  
Vol 12 (4) ◽  
pp. 591-599 ◽  
Author(s):  
N. Jackson ◽  
T. J. Forbes
Keyword(s):  
Dry Matter ◽  
Live Weight ◽  
Matter Content ◽  
Metabolizable Energy ◽  
Dry Matter Content ◽  
Meadow Fescue ◽  
Digestible Organic Matter ◽  
The Mean ◽  
Voluntary Intake ◽  
Daily Intakes

SUMMARYHerbage from the same timothy/meadow fescue/white clover sward was ensiled at four different dry matter contents. The resulting silages had dry matter contents of 19·0, 27·3, 32·3 and 43·2%, the dry matter content increasing with the length of the wilting period. An experiment was carried out to determine the voluntary intake of the silages. Each silage was given to 7 animals individually, the mean live weight of these being 334 kg.Although the silages made from wilted herbage were lower in digestibility than that made from unwilted herbage, wilting increased dry matter intake and metabolizable energy (ME) intake. The mean daily intakes of digestible organic matter were 53·0, 58·1, 59·6 and 59·6 g/kgW0·73, for silages of increasing dry matter content. The corresponding ME intakes, expressed as a multiple of the ME requirement for maintenance, were 1·17, 1·29, 1·30 and 1·28. The percentage of acetic acid in the silage dry matter was significantly (r= −0·56) and linearly related to voluntary intake. The relationship between lactic acid concentration and voluntary intake was significantly curvilinear (r= 0·48).

A study of the effect of supplementing a concentrate diet with roughages of different quality on the performance of Friesian steers. I. Voluntary food intake and food utilization

1970 ◽  
Vol 75 (2) ◽  
pp. 327-335 ◽  
Author(s):  
T. A. McCullough
Keyword(s):  
Dry Matter ◽  
Nitrogen Retention ◽  
Live Weight ◽  
Metabolizable Energy ◽  
Food Utilization ◽  
Stages Of Growth ◽  
Gross Energy ◽  
The Mean ◽  
Metabolizable Energy Intake

SUMMARYConcentrate diets supplemented with 5, 20 and 40% of a high- and a low-quality hay were given ad libitum to British Friesian steers from 9 weeks of age to slaughter. The intake of dry matter and metabolizable energy was studied over weight ranges from 91 to 363 kg live weight. The quality of hay did not significantly affect the drymatter intake at any of the weight ranges studied. From 91 to 182 kg live weight the daily dry-matter intake decreased as the proportion of hay in the diet increased. Over the weight range from 182 to 272 kg live weight, intake was maximum at the 20% level of hay supplementation, while from 272 to 363 kg live weight, intake increased with increasing levels of hay in the diet. The supplementation of high-quality hay significantly increased the intake of metabolizable energy by animals weighing 91–182 kg. Increasing proportions of hay in the diet significantly affected the metabolizable energy intake at all stages of growth studied.At 18 and 36 weeks of age digestibility and N balance studies were carried out. The metabolizable energy expressed as a percentage of the gross energy and the mean retention time of the diets were significantly affected by the age of animal, quality of the hay and the level of hay supplementation. Nitrogen retention was also affected by the age of the animal but not by the quality of the hay.The relationships between the voluntary intake of dry matter and the metabolizable energy of the diet expressed as a percentage of the gross energy, for different stages of growth, are also presented.The change in the digestibility and the mean time of retention of the diets in the digestive tract with age and the effect of this on the point where physical regulation to intake gives way to physiological regulation are discussed.

Effects of diet calcium: phosporus ratio and metabolizable energy content on development of osteochondrosis, foot bending and performance in blue foxes

2005 ◽  
Vol 80 (3) ◽  
pp. 325-331 ◽  
Author(s):  
H. T. Korhonen ◽  
M. Happo ◽  
T. Rekilä ◽  
J. Valaja ◽  
I. Pölönen
Keyword(s):  
Dry Matter ◽  
Energy Content ◽  
Live Weight ◽  
Metabolizable Energy ◽  
Low Energy ◽  
Alopex Lagopus ◽  
Body Weights ◽  
The Mean ◽  
Calcium And Phosphorus ◽  
And Performance

AbstractAbstract The study evaluates the effects of two dietary Ca: P ratios (1·5: 1v. 2·5: 1) and metabolizable energy (ME) contents (17·3 MJ/kg dry matter (DM)v. 19·2 MJ/kg DM) on the development of osteochondrosis, foot bending and performance in juvenile male blue foxes (Alopex lagopus). Four experimental groups (no. = 10 per group) were formed : (1) low energy, lagopus). low Ca: P (LELC); (2) normal energy, low Ca: P (NELC); (3) low energy, normal Ca: P (LENC); and (4) normal energy, normal Ca: P (NENC). The experiment started at weaning in mid July and finished in early October. From mid August onwards, animals on the normal energy diets (NELC, NENC) grew significantly faster (P< 0·001) than animals on the low energy diets (LELC, LENC). The final body weights of the normal energy groups were 1·5 kg higher than those of the low energy groups (P< 0·001). The dietary Ca: P ratio did not affect live-weight gain. Foot bending increased significantly from summer to autumn (P< 0·001). Changes in foot bending between initial and final evaluations showed that bending was significantly greater (P< 0·05) in animals on normal energy (NELC, NENC) than on low energy diets (LELC, LENC). Significant differences were not found in the mean degree of damage in foot and cartilage between the groups. Ulna breaking strength was significantly higher (P< 0·05) in normal energy (NELC, NENC) than in low energy (LELC, LENC) animals. Ulna calcium and phosphorus concentrations of the normal Ca: P (LENC, NENC) groups were significantly higher (P< 0·001,P< 0·05) than those of the lower Ca: P (LELC, NELC) groups. The bone (ulna) calcium and phosphorus concentrations tended to be higher in the normal energy (NELC, NENC) than in the low energy (LELC, LENC) groups (calciumP= 0·07; phosphorusP= 0·06). The bone Ca: P ratio was higher (P< 0·001) in the normal (LENC, NENC) than in the low Ca: P diet (LELC, NELC) animals. The carcass weights of normal energy animals (NELC, NENC) were significantly higher (P< 0·001) than those of low energy (LELC, LENC) animals. The fat : dry matter ratio was higher (P< 0·05) in normal (NELC, NENC) than in low energy (LELC, LENC) carcasses. We conclude that the Ca: P ratio of the diet has no effect on the development of osteochondrosis or bending of the foot. The higher body weight caused by normal as opposed to low metabolizable energy content seems, however, to increase the incidence of foot bending.

Effect of diet energy density and season on voluntary dry-matter and energy intake in male red deer

2000 ◽  
Vol 70 (3) ◽  
pp. 547-554 ◽  
Author(s):  
J.R. Webster ◽  
I.D. Corson ◽  
R.P. Littlejohn ◽  
B.M. Masters ◽  
J.M. Suttie
Keyword(s):  
Food Intake ◽  
Energy Density ◽  
Growth Rates ◽  
Dry Matter ◽  
Red Deer ◽  
Energy Requirement ◽  
Live Weight ◽  
Metabolizable Energy ◽  
Wide Range ◽  
Pelleted Diet

AbstractFood intake and growth of red deer is lower in winter than in spring and this reduces the efficiency of venison production. Rumen capacity is also lower during winter and this may contribute to the reduced food intake and therefore growth. In the present study, we investigated the ability of deer to regulate food intake during winter and spring by feeding diets of differing energy densities.Six groups of eight male red deer calves were housed indoors in separate pens. Each group was given,ad libitum, a pelleted diet of a different energy density (8·5, 9·0, 9·5, 10·0, 10·5 and 11·0 MJ metabolizable energy (ME) per kg dry matter (DM) for groups 1 to 6 respectively) but the same amount of protein (156 g/kg DM). Food intake of each group was recorded every 2nd day and animals were weighed every 6 days from 17 May to 9 December. For seasonal comparisons, winter was defined as 24 May to 31 August and spring as 1 September to 9 December.There was no difference (P> 0·05) between the mean live weights of the groups at any time during the study. Live-weight gain (LWG) reached a minimum on 4 July and was lower in winter than spring (161 v. 308 g/day, s.e.d. = 10·0,P< 0·001). LWG was positively related (P< 0·001) to diet ME during winter. DM intake (g/kg M0·75per day) and ME intake (MJ ME per kg M0·75per day) decreased until 16 July and increased thereafter. Mean DM intake was lower in winter than spring (83·5 v. 97·2 g/kg M0·75per day, s.e.d. = 2·05,P< 0·001). DM intake increased as diet energy decreased (P< 0·001) in winter and spring with a steeper slope (P< 0·05) in spring than winter. ME intake was not related to diet ME (P> 0·005) and was lower in winter than spring (0·82 v. 0·95 MJ/kg M0·75per day, s.e.d. = 0·25,P< 0·001). Maintenance energy requirement (MEm) across groups and seasons was calculated to be 0·45 (s.e. 0·22) MJ ME per kg M0·75and the energy requirement for LWG (MEf) was 53 (s.e. 8·5) MJ/kg LWG. MEfwas related (P< 0·01) negatively to diet ME during winter.In summary, deer consuming diets with a wide range of energy densities, altered their DM intake, resulting in similar energy intakes and growth rates on all diets. Animals seemed less able to achieve this compensation in winter compared with spring when food intake increased to support the natural rise in growth rate at that time. These results indicate that deer have target growth rates and/or energy intakes that change with season, and are defended by adjusting food intake.

Effects of incremental changes in forage: concentrate ratio on plasma hormone and metabolite concentrations and products of rumen fermentation in fattening beef steers

2000 ◽  
Vol 71 (1) ◽  
pp. 93-109 ◽  
Author(s):  
C. L. Thorp ◽  
A.R.G. Wylie ◽  
R.W. J. Steen ◽  
C. Shaw ◽  
J. D. McEvoy
Keyword(s):  
Dry Matter ◽  
Plasma Concentrations ◽  
Live Weight ◽  
Open Circuit ◽  
Metabolizable Energy ◽  
Plasma Metabolites ◽  
Beef Steers ◽  
Lower Efficiency ◽  
The Mean ◽  
Sampling Times

AbstractAs part of an investigation of factors responsible for a previously reported lower efficiency of carcass lean gain in steers offered grass silage diets, 16 Simmental × Friesian steers (515 (s.e. 6·4) kg) were offered perennial ryegrass silage ad libitum (C0) or silage plus rolled barley at 200 (C20), 400 (C40) or 600 (C60) g/kg total diet dry matter (DM). Barley-supplemented diets were intake-restricted to provide equal DM and metabolizable energy (ME) intakes to those offered C0. Eight steers were selected at random to determine the ME contents of the diets by open-circuit respiration calorimetry. The other eight steers were offered the same diets and were blood-sampled at 20- to 60-min intervals, for 10 h, to monitor changes in the concentrations of a number of nutritionally related plasma metabolites and hormones. Estimated ME intakes in these steers were 85·7, 83·1, 84·4 and 86·2 (s.e. 0·91) MJ/day from diets C0, C20, C40 and C60 respectively. Rumen-fistulated Hereford × Friesian steers provided 24-h rumen data for the same diets offered at equal amounts of ME per kg metabolic live weight.Mean 24-h plasma concentrations of insulin and insulin-like growth factor 1 (IGF-1) were linearly and positively related (P < 0·01 and P < 0·001 respectively) and glucagon quadratically related (P < 0·05) to the proportion of barley in the diet. Plasma insulin increased after feeding on all diets but concentrations on diets C40 and C60 were significantly higher than those on C0 and C20 at all post-feeding sampling times up to 9 h after feeding. Plasma IGF-1 concentrations increased above pre-feeding levels following feeding of the higher barley diets (C40 and C60; P = 0·053) but remained unchanged in steers offered C0 and C20. Mean plasma concentrations of glucose were unaffected by diet but those of β-hydroxybutyrate (BOHB) and urea were positively and negatively related respectively (both P < 0·001) to the proportion of barley in the diet. Plasma BOHB and urea concentrations also changed with time after feeding (P < 0·001). Amongst the rumen parameters measured (pH; ammonia and volatile fatty acid concentrations and proportions) only the mean 24-h concentrations and proportions of butyrate were positively related to the proportion of barley in the diet (P = 0·051 and P < 0·05 respectively). All rumen parameters were affected by time after feeding (acetate, P < 0·01; others, P < 0·001) but there was no interaction between treatment and time for any parameter.

Effects of genotype and dietary forage to concentrate ratio during the finishing period on carcass characteristics and meat quality of lambs from hill sheep systems

2001 ◽  
Vol 137 (2) ◽  
pp. 205-220 ◽  
Author(s):  
A. F. CARSON ◽  
B. W. MOSS ◽  
L. E. R. DAWSON ◽  
D. J. KILPATRICK
Keyword(s):  
Meat Quality ◽  
Dry Matter ◽  
Carcass Characteristics ◽  
Live Weight ◽  
The Other ◽  
Grass Silage ◽  
Classification Score ◽  
Forage:Concentrate Ratio ◽  
Matter Basis

The study investigated the effects of lamb genotype produced from hill flocks on feed efficiency, carcass characteristics and meat quality in animals finished on either a high forage:concentrate ratio diet (HFC) or a low forage:concentrate ratio diet (LFC). Purebred Scottish Blackface (BXB) lambs were compared with Blue-Faced Leicester×Scottish Blackface (BLXB) and Texel×Scottish Blackface (TXB) lambs. Purebred Cheviot (CXC), Suffolk×Cheviot (SXC) and Texel×Cheviot (TXC) lambs were also investigated. Lambs on the LFC diet were offered grass silage and concentrates mixed in the proportion of 0·80 silage and 0·20 concentrates on a dry matter basis. The LFC diet consisted of 0·20 grass silage and 0·80 concentrates on a dry matter basis. Representative lambs were slaughtered at the start of the experiment and on reaching 38 and 46 kg live weight. Averaged over the two slaughter weights, within the Blackface cross lambs, BXB had a lower liveweight gain (P < 0·01) than either BLXB or TXB (138, 207 and 203 (S.E. 11·1) g/day, respectively). Within the Cheviot cross lambs, CXC had a lower liveweight gain (P < 0·05) than SXC (188 v. 220 (S.E. 11·1) g/day), while SXC and TXC (204 g/day) had similar liveweight gains. Lambs on the LFC diet had a higher dressing proportion (P < 0·001) compared with lambs finished on the HFC diet (0·466 v. 0·434 (S.E. 0·0018) kg carcass per kg live weight). Averaged over the two slaughter weights BXB lambs had a lower (P < 0·05) dressing proportion than the other genotypes. Carcass conformation classification (assessed on a five-point scale) was higher (P < 0·001) in lambs finished on the LFC diet (3·0 v. 2·4 (S.E. 0·04)). Conformation classification was higher in lambs produced from Cheviot compared with Blackface ewes (P < 0·05). Within the Blackface cross lambs, BXB and BLXB lambs had a lower conformation classification (P < 0·001) than TXB lambs (2·4, 2·4 and 2·9 (S.E. 0·08) respectively). Within the Cheviot ewes, TXC lambs had a higher (P < 0·001) classification than either CXC or SXC (3·1, 2·7 and 2·7 (S.E. 0·08) respectively). Lambs finished on the LFC diet had a higher fat classification score compared with lambs on the HFC diet (P < 0·001) (3·4 v. 2·8 (S.E. 0·04)). Fat classification was similar across all genotypes. Lambs finished on the LFC diet had a lower ash content in the carcass than lambs finished on a HFC diet (P < 0·01) (44 v. 47 (S.E. 0·8) g/kg). Lamb genotype and dietary forage:concentrate ratio had no significant effect on cooking loss, sarcomere length, Warner–Bratzler shear force and L* values. Ultimate pH (pHU) was not influenced by dietary forage:concentrate ratio, but was significantly (P < 0·01) higher in BXB lambs compared with BLXB, TXB, CXC and TXC lambs. Lambs offered the LFC diet during the finishing period had significantly higher values for a* (P < 0·05), b* (P < 0·001), C* (P < 0·001) and H0 (P < 0·05) than lambs offered a HFC diet. Of these parameters only b* was significantly affected by lamb genotype, with BXB lambs having a lower value (P < 0·05) than the other genotypes.

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

2001 ◽  
Vol 73 (2) ◽  
pp. 305-311 ◽  
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.

COMPARISON OF INTACT, LATE-CASTRATED, AND DIETHYLSTILBESTROL (DES)-IMPLANTED BOARS WITH BARROWS AND GILTS: NITROGEN AND ENERGY DIGESTIBILITY, NITROGEN RETENTION, CARCASS MEASUREMENTS, MUSCLE ANALYSES, AND RESIDUAL DES IN MUSCLE TISSUE

1973 ◽  
Vol 53 (3) ◽  
pp. 579-585 ◽  
Author(s):  
J. A. NEWELL ◽  
J. P. BOWLAND
Keyword(s):  
Muscle Tissue ◽  
Dry Matter ◽  
General Trend ◽  
Nitrogen Retention ◽  
Carcass Characteristics ◽  
Ash Content ◽  
Metabolizable Energy ◽  
The Other ◽  
Average Weight ◽  
Grade Index

Forty boars, eight barrows, and eight gilts were allotted in groups of four pigs each at an average weight of 13.1 kg. Metabolism studies with a portion of the animals were conducted at 15 and 50 kg liveweight. Although no statistical differences between sexes were found in these studies, barrows tended to digest more nitrogen (N) but to retain less than boars and gilts. N digestibility (DN) and retention (NR) values at 50 kg were higher than those at 15 kg. The three sexes were found to be similar in energy digestibility (DE) and metabolizable energy (ME). Significant differences were found for boars in DE and ME coefficients between the two periods, averaging 83.2 and 85.6% DE in the 15- and 50-kg periods, respectively. At 70 kg, 16 boars were implanted with 96 mg of diethylstilbestrol (DES), 16 boars were castrated, and 8 boars were left intact. Barrows had thicker backfat (P < 0.05) and lower (P < 0.05) grade index than any of the other treatments. Late-castrated boars showed a general trend to revert to the carcass characteristics of barrows but were still superior to barrows at market weight. No significant differences between treatments were found for dry matter, protein, fat, or ash content of the longissimus muscle. No residual DES was found in the muscle tissue of the implanted boars.

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
Keyword(s):  
Food Intake ◽  
Reproductive Performance ◽  
Live Weight ◽  
Experimental Period ◽  
Metabolizable Energy ◽  
Ovulation Rate ◽  
Daily Ration ◽  
The Mean ◽  
Low Levels ◽  
Lambing Rate

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.

scholarly journals Copper, iron, manganese and zinc concentrations in the carcases of lambs and calves and the relationship to trace element requirements for growth

1979 ◽  
Vol 42 (1) ◽  
pp. 89-96 ◽  
Author(s):  
N. F. Suttle
Keyword(s):  
Dry Matter ◽  
Live Weight ◽  
Tissue Storage ◽  
Growth Requirements ◽  
Fe And Mn ◽  
Zinc Concentrations ◽  
The Mean ◽  
Daily Intakes ◽  
Iron Manganese ◽  
The Relationship

1. The minced carcases of twenty-seven lambs, ranging from 18 to 69 kg in live weight, and twenty-five calves (30–90 kg) were analysed for copper, iron, manganese and zinc. The lambs were weaned whereas the calves were reared exclusively on milk.2. Mean concentrations of Fe, Mn and Zn for groups of lamb carcases fell within the ranges 52.6–75.1, 0.7–1.2 and 20.8–25.6 mg/kg fresh carcase weight respectively. The concentrations of Fe and Mn decreased while that of Zn increased slightly with age at slaughter. The concentrations of Fe, Mn and Zn in calves were close to thosein lambs.3. For both species, the concentration of Cu in the carcase varied erratically: variation in hepatic Cu storage was implicated. In an additional study of ten full-term foetuses from Cu-depleted or Cu-supplemented ewes, a dietary Cu supplement (10 mg/kg dry matter (DM)) increased foetal Cu status 10-fold, due largely to an increase in foetal liver Cu.4. The mean retentions of trace elements in the lamb carcases (%intake) were approximately: Cu 2.0, Fe 1.3, Mn 0.08, Zn 4.0. The corresponding values for the milk-fed calves were all probably much higher (Cu 23, Fe 43.7, Mn 4.9, Zn 34.0) but Cu intake was not accurately measured.5. After allowing for tissue storage of Fe and Mn, values of 55, 0.85 and 24 mg/kg carcase gain were taken to represent the approximate net growth requirements of lambs for Fe, Mn and Zn respectively: the corresponding value for Cu was probably < 1.0 mg/kg. Values for calves were similar to those for lambs.6. It was concluded that the total net requirements of ruminants for Fe and Zn shouldbe considered in terms of daily intakes of the metans rather than dietary concentrationsbecause of the relatively large and constant contribution of the growth component to thetotal requirement.

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