bluuebunny/crossref_metadata_2025 huggingface dataset:
The use of fish meal and monensin as supplements to grass silage and their effect on body composition changes in steers from 5 months of age to slaughter
Authors: Gibb M. J. , Baker R. D.
Published: September 2010

Fish meal and monensin, as supplements to grass silage, were offered either separately or together to Friesian steers from 5 to 9 months of age (period 1). At 9 months, six steers from each of the supplemented treatments were slaughtered to determine body composition. Of the remaining steers, from 9 months of age to slaughter at 490 kg live weight (LW) (period 2), six continued on each of the same treatments, whilst six received silage unsupplemented. A further group of six steers which had received fish meal and monensin during period 1, received monensin only as a supplement to their silage.

During period 1 fish-meal supplementation increased LW, empty body and carcass weight gains, and tissues gains, while monensin had no apparent effect. During period 2, continued supplementation with both fish meal and monensin significantly increased LW, empty body and carcass gains compared with the continuously unsupplemented steers, whilst fish meal and monensin separately produced intermediate increased gains. All three supplement regimes significantly reduced the time taken to reach slaughter.

The only significant effect on body composition was that steers receiving fish meal and monensin had a higher crude protein concentration in the empty body than those receiving only fish meal as a supplement. They also had the highest crude protein concentration in the carcass, although this was not significant. Steers which had their supplements withdrawn after 9 months of age generally maintained gains intermediate between those continuing to receive supplements and those steers unsupplemented throughout. Only those not continuing to receive fish meal and monensin together appeared to perform appreciably worse. Nevertheless, although time taken to reach slaughter from 4 months of age varied by as much as 96 days, there were no other significant differences in body or carcass composition, hi terms of cost effectiveness, use of monensin showed distinct advantages over fish meal.
Effect of feeding frequency on diurnal variation in plasma and urinary purine derivatives in steers
Authors: Chen X. B. , Grubic G. , Ørskov E. R. , Osuji P.
Published: September 2010

The diurnal changes in plasma concentration and urinary excretion of purine derivatives (PD) were examined in four steers given their food in either one or two meals daily in two 18-day periods. In period 1, two steers were fed once daily (at 08.00 h) and the other two twice daily (at 08.00 and 16.00 h). In period 2, the treatments were switched. In the last 4 days of each period, plasma samples were taken from 08.00 to 24.00 h at 2 to 3 h intervals, and daily urine was collected in several 4 to 8h periods. With once daily feeding, allantoin concentration in plasma varied from 090 to 1·07 of the daily mean and with twice daily feeding, from 0·97 to 1·05 of mean. The coefficient of variation (CV) for total variation was 0·14. In urine, the concentration and hourly excretion of PD varied with sampling times (P < 0·05) but the ratio of PD to creatinine was relatively constant even for once-daily feeding (CV, 0·02 for measurements at different times). The CV for total variation in the ratio was 0·19. The results suggest that diurnal variation in plasma allantoin concentration and in the ratio of allantoin (or total PD) to creatinine are relatively small even for once daily feeding. It thus seems that these measurements in spot samples may be suitable for use as a simple index of microbial protein supply if they are correlated with the daily PD excretion. The results also indicate that measurements in samples of plasma and urine taken between 15.00 and 20.00 h tended to give a better representation of the daily mean.
Calcium hydroxide treatment of malt distillers' grains 1. Effects on chemical composition and digestibility measuredin vitroandin sacco
Authors: Offer J. E. , Offer N. W.
Published: September 2010

Experiment 1 investigated the effects of calcium hydroxide (Ca(OH)2)treatment (80 g/kg malt distillers' grains (MDG) dry matter (DM) at ambient temperature (L) and at 60°C (LH). Organic matter digestibilitiesin vitro(1V0MD) were 0·30, 0·50 and 0·56 (s.e. 0·023) for untreated (C), L and LH respectively. The increase in IVOMD was less with MDG that had previously been ether-extracted (corresponding values 0·47, 0·53 and 0·54). The proportion of lipid in soap form was 0·03, 0·35 and 0·46 (s.e. 0·03) for C, L and LH respectively. Experiment 2 investigated the effects of treatment time, temperature and Ca(OH)2concentration on composition, IVOMD and organic matter digestibility in sacco (ISOMD). Response was most dependent on Ca(OH)2concentration. Mean values for 0, 40, 80 and 120 g Ca(OH)2per kg DM were for neutral-detergent fibre (NDF) (g/kg DM) 704, 586, 422 and 382; for water-soluble carbohydrate (g/kg DM) 2, 4,40 and 44; for ISOMD 0 h (without incubation) 0·25, 0·25, 0·51 and 0·57; for ISOMD 24 h (24-h rumen incubation) 0·63, 0·66, 0·84 and 0·86 and for IVOMD 0·51, 0·55, 0·65 and 0·65. Increasing treatment temperature from 20 to 80°C increased mean ISOMD 0 h from 0·31 to 0·49 but had less effect on ISOMD 24 h (0·74 and 0·79 respectively). Experiment 3 investigated the effects of treatment with 80 g Ca(OH)2per kg DM at 60°C for 16 h on rumen degradation in sacco. Instantaneous losses (a values%) for OM and NDF were increased by treatment from 14·6 to 45·5 and from 8·6 to 18·6 respectively. Treatment increased effective degradability (at 0·06 per h rumen outflow rate) from 0·43 to 0·66 for OM and from 0·40 to 0·46 for NDF. Total potentially digestible OM (a + b) increased from 0·65 to 0·91 for OM and from 0·58 to 0·84 for NDF. Ca(OH)2treatment enhances the nutritional value of MDG. Its mode of action involves reduction of the toxicity to rumen micro-organisms of unsaturated lipid by soap formation and the effect of alkali on the composition of the carbohydrate fraction.
Serum concentrations of insulin-like growth factor 1 and cholesterol in relation to protein and fat deposition in growing pigs
Authors: Taylor J. A. , Salter D. N. , Close W. H. , Laswai G. H.
Published: September 2010

The nutrient partitioning of growing pigs was altered through nutrition and castration in order to investigate the relationship between serum insulin-like growth factor 1 (IGFl) and protein deposition and serum cholesterol and fat deposition. In a 2 × 2 factorial experiment 18 entire and 18 castrated male pigs, of 20 kg initial live weight, were given either 2·25 (low) or 3·4 (high) times maintenance energy requirements to a scale based on live weight. Nitrogen and energy balances were measured over 7-day periods when the pigs reached about 30, 60 and 90 kg. Fasting blood samples were taken at each weight and serum was analysed for IGFl and insulin and total- and high density lipoprotein (HDL)-cholesterol. Protein and fat deposition, IGFl and cholesterol concentrations were higher for pigs given the high, as opposed to the low, feeding level. Protein deposition and IGFl concentrations were higher for entire males, as opposed to castrated males, whereas fat deposition and cholesterol concentrations were higher in castrated than in entire males. IGFl and protein deposition increased with age for entire but not for castrated males. Conversely, fat deposition increased with age in castrated but not in entire males. There was no effect of age on serum cholesterol. Serum IGFl was correlated with protein deposition at 30, 60 and 90 kg (r = 0·40, r = 0·63 and r = 0·67; P < 0·05, P < 0·002 and P < 0001 respectively, no. = 36). Serum total cholesterol and low density lipoprotein (LDL)-cholesterol were correlated with fat deposition at 60 and 90 kg (r = 0·65 and r = 0·54; both P < 0·001 for total cholesterol; r = 0·66 and r = 0·50; both P < 0·001 for LDL-cholesterol). Insulin levels were similar for pigs in all treatment groups. It is concluded that serum IGFl and cholesterol may give a useful indication of protein and fat deposition in pigs of between 60 and 90 kg live weight.
Growth and reproductive development of red deer calves (Cervus elaphus) born out-of-season
Authors: Adam C. L. , Kyle C. E. , Young P.
Published: September 2010

Since the productivity of farmed red deer is constrained by their inherent seasonal biology, the potential advantages of breeding out-of-season following melatonin administration were investigated. Calves born in February (F; no. = 8) were heavier at weaning in September of the same year than calves born with normal birth dates in June (}; no. = 8) (73·2 v. 441 (s.e.d. 3·59) kg; P < 0·001) and at the end of April of the next year (88·0 v. 67·6 (s.e.d. 6·44) kg; P < 0·02) although their suckled live-weight gain to 100 days of age was lower (304 v. 361 (s.e.d. 21·4) g/day; P < 0·05). After weaning, F calves had higher voluntary food intake than / calves (g dry matter per head per day) from September to November (1643 v. 2224 (s.e.d. 92·6); P < 0·002), November to February (1435 v. 926 (s.e.d. 67·9); P < 0·002), and February to April (1487 v. 2059 (s.e.d. 115·5); P < 0·02).

Unlike J calves, F calves showed puberty in their first autumn. F male calves (no. = 3) grew antlers which hardened in November, whereas J males (no. = 3) did not, and F males, aged 8 months, had significantly higher mean plasma concentrations of testosterone than J males, aged 4 months (1·35 v. 0·28 (s.e.d. 0·154) fj.g/1, P < 0·001). Oestrous cyclicity was observed in 3/5 group F females, aged 9 months, but in 0/5 group ] females, aged 5 months. Although the dams of F and ] calves had similar live weights at mating, birth and 100 days pos t partum, F dams were heavier (P < 0·05) at weaning. Following parturition, F dams had a mean voluntary food intake of 2700 (s.e. 110) g dry matter per head per day from February to April.
A note on the apparent digestibility and nutritive value of whole cottonseed given to sheep
Authors: Karalazos A. , Dotas D. , Bikos J.
Published: September 2010

Four castrated crossbred (Karagouniki♂ × Friesian♀) rams were used in a 4 × 4 Latin-square design to determine the apparent digestibility of four diets based on alfalfa hay and maize grain and containing varying proportions of whole cottonseed (WCS). The proportions of WCS studied were 0, 175, 355 and 530 g/kg diet dry matter (DM) and the respective apparent digestibility coefficients of DM were 0·744, 0·716, 0·689 and 0·625; of organic matter, 0·772, 0·739, 0·718 and 0·643; and of neutral-detergent fibre (NDF), 0·409, 0·481, 0·522 and 0·472. The gross energy (GE) apparent digestibility coefficients were 0·745, 0·722, 0·704 and 0·641, for the same order of treatments. The effect of the incorporation of WCS instead of maize grain in the diet in significantly reducing DM, OM and GE digestibility was evident. The lowest digestible energy value of WCS was observed in the treatment with the highest level of WCS.
A note on production responses of lactating ewes to calcium soaps of fatty acids
Authors: Sklan D.
Published: September 2010

Productive and metabolic responses were determined in ewes given diets containing calcium soaps of fatty acids for a period of 90 days after lambing as compared with ewes given a control diet.

Yield of milk and milk fat, milk protein and milk lactose were increased over the experimental period by feeding calcium soaps. Live-weight changes after lambing were not different in the two experimental treatments. No changes in rumen metabolism were observed when calcium soaps were offered whereas plasma concentrations of protein, glucose, triglycerides, phospholipids and cholesterol were enhanced.

It is concluded that calcium soaps of fatty acids can be included in diets of ewes to increase production of milk and milk solids.
Intensive beef production VII. The effect on nitrogen retention of diets containing barley processed by four different methods
Authors: Kay M. , Preston T. R. , MacLeod N. A. , Philip Euphemia B.
Published: September 2010

1. Nitrogen balance studies were conducted on 16 steers in two separate trials. The steers were fed on four diets containing respectively dry rolled barley; dried, steamed and rolled barley; dried, crimped barley and barley that had been stored in a sealed silo and rolled.

2. There were no significant differences in the dry-matter intake of any of the diets.

3. No consistent differences between the diets in dry-matter digestibility or nitrogen retention were observed.
A note on hepatic vitamin A and carotene stores in West African cattle
Authors: Wharton F. D.
Published: September 2010

Conditions exist in Ghana which could implicate vitamin A deficiency as a factor in causing the poor growth and breeding difficulties observed in local cattle. Lansbury (1960) reviewed some of the limiting factors in the nutrition of cattle on the Accra plains, and stated ‘the bleached dried up appearance of the Accra plains over much of the year is due to the fact that most of the grassland is little more than standing hay from which most, if not all, of the vitamin A or its precursors are likely to have been lost’. Northern Ghana, with its longer dry season, presents such an appearance for a more extended period.
Intensive beef production. 8. The effect of chlortetracycline on growth, feed utilisation and incidence of liver abscesses in barley beef cattle
Authors: Wieser M. F. , Preston T. R. , Macdearmid A. , Rowland A. C.
Published: September 2010

An experiment was conducted on 13 commercial barley beef units in Scotland, using a total of 301 early-weaned Friesian male calves. On each unit the trial batch of calves was divided into two groups, which were then allocated to a control diet (85% barley + 15% protein supplement) or the same diet supplemented with 20 mg. chlortetracycline per kg. of feed. The experiment was conducted over the live-weight range 115 to 360 kg.

The chlortetracycline significantly (P<0·01) improved live-weight gain ( + 4·9%) and feed utilisation ( + 4·8%). This overall effect was largely due to a high response during the first 12 weeks. From 13 to 28 weeks the chlortetracycline had only a marginal effect, which was not significant. There was no significant difference in the feed intakes of the two groups. There was a significant (P<0·01) negative correlation between the effect of the chlortetracycline on live-weight gain at each unit and the growth rate of the control animals at that unit; the response was greatest on farms with poor hygiene. The animals given chlortetracycline showed a significantly (P<0·05) lower incidence of liver abscesses (11·8%) than the controls (28·2%). Macroscopic examination of the rumens showed that rumenitis is common among intensively fed cattle, but no correlation could be found between incidence of liver abscesses and rumen lesions.
A comparison of semi-intensively reared Charolais × Ayrshire and Shorthorn × Ayrshire cattle
Authors: Broadbent P. J. , Dodsworth T. L. , Ball C. , Sampford M. R.
Published: September 2010

The growth and carcass characteristics of semi-intensively reared Charolais × Ayrshire and Beef Shorthorn × Ayrshire cattle were studied. Charolais × Ayrshires grew faster while grazing, achieved slaughter condition at a higher live-weight and age and had leaner carcasses than Beef Shorthorn × Ayrshires. The practical significance of these results is discussed.
A note on goitre in lambs grazing rape (Brassica napus)
Authors: Russel A. J. F.
Published: September 2010

Forage crops of the genus Brassica are known to contain goitrogens which under certain conditions can cause severe incidences of neonatal mortality in lambs and goitre in older sheep (Shand, 1952; Sinclair and Andrews, 1958, 1959, 1961; Andrews and Sinclair, 1962).

In the course of studies of certain aspects of lamb growth it was noted that lambs grazing rape (Brassica napus) had heavier thyroid glands than comparable lambs grazing grass. Pipes, Premachandra and Turner (1958) found that a degree of hypothyroidism increased the rate of fattening and influenced the carcass quality of cattle, and in view of this and other evidence it was decided to test the hypothesis that changes in the weight of the thyroid glands of lambs grazing rape were associated with changes in the rate of live-weight gain.
Sewage-grown algae as a protein supplement for swine
Authors: Hintz H. F. , Heitman H.
Published: September 2010

In two trials with 48 pigs it was found that when algae supplemented with certain B-vitamins replaced fish meal on an equal-nitrogen basis in a diet based on barley and fish meal there was no decrease in rate of gain or feed conversion efficiency. When vitamin B12 was omitted from the algal diet, there was a decrease in rate of gain. There were no consistent differences in carcass characteristics between pigs fed on the algal diets and those fed ondiets containing fish meal. Digestibility studies indicated that algae are low in digestible energy, but their protein is 70% digestible.
The protein requirement of the ruminant calf. III. The ability of the calf weaned at five weeks of age to utilise urea given as a supplement to a low-protein concentrate
Authors: Stobo I.J.F. , Roy J.H.B. , Gaston Helen J.
Published: September 2010

(1) Forty-five Ayrshire and Shorthorn bull calves were used in an experiment to study the ability of the calf weaned at 5 weeks on to concentrates, hay and water, to utilise urea added to a low-protein concentrate.

(2) Calves given the concentrate containing 20% crude protein gained weight significantly faster from 3 to 12 weeks than those given concentrates containing either 12% crude protein, or 18% crude protein of which 33% was in the form of urea. There was a tendency for calves given the urea supplement to gain weight at a slightly faster rate to 8 weeks than those given the low-protein diet, but this tendency was reversed between 8 and 12 weeks of age.

(3) At 15 weeks, the coefficients of apparent digestibility of dry matter, crude protein, crude fibre and nitrogen-free extract were significantly greater when an all-concentrate diet containing 19·6% crude protein was given, than with a concentrate containing 12·2% crude protein. When the lowprotein concentrate supplemented with urea was given (18·5% crude protein) the apparent digestibility of dry matter, crude protein and ether extract was significantly greater than on the low-protein concentrate. The digestibility of crude fibre in the urea-supplemented diet was intermediate between the values obtained on the high- and low-protein diets.

(4) Despite marked differences between treatments in the intakes of apparently digested nitrogen, similar amounts of nitrogen were retained, because of large differences in the amounts of nitrogen excreted in the urine. However, the amount of nitrogen stored per unit of body-weight gain was 27% higher in calves given the concentrate containing 19·6% crude protein than in those given either the low-protein concentrate or the urea-supplemented diet.
Studies on the nutritive value of the diet selected by grazing sheep. II. Some sources of error when sampling oesophageally fistulated sheep at pasture
Authors: Langlands J. P.
Published: September 2010

Some possible sources of error when sampling oesophageally fistulated sheep at pasture were examined in eleven trials. Samples collected from sheep asted for varying periods of up to 22 hours did not differ significantly in nitrogen content from samples collected from unfasted sheep. There was no significant difference between the nitrogen content of extrusa collected at the start of a 30-minute period and that of extrusa collected at the end of the period. Sheep transferred from a perennial ryegrass/clover pasture to a native pasture for three months ingested herbage containing 3·80% nitrogen when returned to the original pasture. Control sheep which had remained on the ryegrass/clover pasture selected material containing 3·33% nitrogen. In a further trial sheep transferred from a ryegrass/clover pasture to a Phalaris/ clover pasture consumed herbage with an organic matter digestibility of 70·8 % which contained 3·44 % nitrogen. The material consumed by similar sheep which had grazed the Phalaris/clover pasture for 18 months was 71·5% digestible and contained 3·63% nitrogen.

Diurnal changes in the digestibility and nitrogen content of the diet of free-grazing sheep were observed in two trials. Diurnal changes in nitrogen content were similar on different days but changes in digestibility were relatively smaller and less repeatable between days.

Consistent differences in the composition of the diet selected by individual sheep and selected on different days were observed in a further five trials. Variation between sheep and between days in the nitrogen content of the diet was ±5·6% and ±7·4% respectively, both estimates being expressed as coefficients of variation. Corresponding estimates for digestibility, calculated as standard deviations, were ±1·6 and ±1·3 units. The implications of these results when sampling oesophageally fistulated sheep at pasture are considered.
Changes in body composition of the sow during pregnancy
Authors: Heap F. C. , Lodge G. A.
Published: September 2010

The body composition of four sows slaughtered on the 110th day of pregnancy was compared with that of four non-pregnant sows slaughtered after 110 days on the same feeding regime and with four sows slaughtered at the beginning of the 110-day period. Mean weight gains in 110 days of the pregnant and non-pregnant sows were 35·9 and 4·3 kg. respectively; the extra gain of pregnant sows over that of the non-pregnant was located in the carcass and reproductive organs. The extra carcass gain of pregnant sows was in muscle, fat and mammary tissue. The greatest proportion of the extra fat of the pregnant sows was in the back region while the greatest proportion of extra muscle was in the belly. There was considerable variation between individuals in moisture, nitrogen and fat contents of sample muscles and treatment differences were not significant.
Studies on the nutritive value of the diet selected by grazing sheep. III. A Comparison of oesophageal fistula and faecal index techniques for the indirect estimation of digestibility
Authors: Langlands J. P.
Published: September 2010

Regression equations relating the intake factor to the dissolved faeces fraction, faecal nitrogen and faecal cellulose contents were derived in a continous digestibility trial with cut herbage, and also with sheep fitted with oesophageal fistulae grazing the pasture from which the herbage was cut. In the grazing trial the intake factor was calculated from the in vitro digestibility of the fistula samples.

The relationships established in the digestiblity trial differed significantly (P<0·001) from those in the grazing trial. These differences may have arisen from selective grazing or from bias in estimating digestibility from fistula samples.

The digestibility of the diet selected in the grazing trial was estimated from the various faecal index relationships established. These estimates were very variable. In contrast there was reasonable agreement between estimates derived by the fistula technique and those predicted from a ‘general’ relationship between the intake factor and faecal nitrogen as established at this Laboratory with a wide range of herbages.

It is concluded that faecal index relationships must be derived with material similar to that selected by the sheep when grazing.
Improvement of metric traits through specific genetic loci
Authors: Smith Charles
Published: September 2010

Known genetic loci that affect metric traits may be useful in livestock improvement. Their value depends on the proportion (R) of the total additive genetic variation due to the known loci relative to the heritability of the trait concerned and on the form of selection practised. When normal selection is effective, further information on known loci can add only a little to the rate of improvement. But if normal selection is not very effective, as for characters of low heritability, or if indirect selection on relatives must be used (as for sex-limited or carcass traits) then known loci may add significantly to the rate of improvement possible.

Sampling errors in the estimated effects and in the proportion (R) may cause selection effort to be misdirected and may even lead to losses rather than gains in improvement. Such errors are most likely to occur when the heritability of the character is low.

Reports on several loci with large effects in the various farm species have been summarised, but the evidence is often inconsistent and contradictory. At present, there appear to be no loci that could be used with confidence in the improvement of economic traits in farm animals.
Variation in the absorption of a colostrally secreted marker antibody in piglets
Authors: Perry G. C. , Watson J. H.
Published: September 2010

1. Sixteen sows were immunised in late pregnancy withSalmonella pullorumantigen. Sows showed marked differences in serum antibody titre at parturition.

2. Twelve hours after birth, serum antibody titres in the 173 piglets born to the 16 sows were measured. They were positively related to the serum titres of their mother.

3. Marked variation existed in the antibody titres of colostra from different teats and from different sows. No relationship was found between colostral titres and the titres in sow or piglet sera.

4. Sow and piglet serum titres were negatively related to piglet and litter weight gain from birth to 7 days of age.

5. Those piglets with high serum antibody titres at 12 hr. after birth displayed better growth rates and enjoyed lower mortality than piglets with low antibody titres.
Silage as a feed for pregnant ewes
Authors: Forbes J. M. , Rees J. K. S. , Boaz T. G.
Published: September 2010

1. Four experiments are described in which silages or kale were given to groups of ewes in the later stages of pregnancy and their voluntary intake recorded. A concentrate supplement was given in the last few weeks of pregnancy in each experiment. In experiments 1, 3 and 4 the ewes were housed in a semi-covered yard.

2. In the first experiment, three groups of 10 Scottish Halfbred ewes were offered one of three silages. A fourth group was offered all three in equal amounts. The silage with a low DM content, low crude-protein content, low pH and high crude-fibre content was eaten in smaller quantities than the other two silages. The ewes fed on this poor silage gained less weight during the latter half of pregnancy.

3. In a second experiment four groups of 15 ewes were offered either silage or kale and housed in a Dutch barn or left in a small paddock. There was no difference between the results from the two silage-fed groups in any respect. The ewes offered kale outside ate less than those offered it inside; they gained less weight and produced lighter lambs.

4. There were two groups of 13 ewes in experiment 3a, one group lambing 5 weeks before the other. Both were fed on the sanie silage; intake was higher in the late lambing group but there was no difference in lamb birth weights.

5. Experiment 3 was repeated with 15 ewes per group; the silage was of much poorer quality, intake being low and the ewes gaining very little weight. Lamb birth weights and growth rates were low.

6. Groups of 15 Scottish Halfbred (90 kg. live-weight) and 15 Speckle-faced Welsh (45 kg.) ewes were fed on yet another silage. The Specklefaced ewes ate more silage DM per unit weight than did the Halfbred ewes and gained in weight, whereas the Halfbreds did not gain.

7. In all experiments there was a decline in silage intake in the last few weeks of pregnancy. This decline did not always coincide with the start of concentrate feeding.

8. The results are discussed and comparisons made between experiments. Suggestions are made for the feeding and management of ewes fed on silage, including the recommendation that a silage for pregnant ewes should have at least 20% DM and 14% crude protein in the DM, but not more than 32% crude fibre in the DM.
Effects on the bacon pig of adding protein and vitamin-mineral supplements to barley without mixing and at different time intervals
Authors: Lawrence T. L. J.
Published: September 2010

1. In a randomized block experiment 72 Large White-type pigs (in pens of six) were individually fed twice daily on six variations of a basic diet containing 80% barley, 15% soya bean meal (S) and 5% of a vitamin-mineral supplement (VM).

2. For treatments 1 to 3 the pigs were given both supplements together. The combined supplement was either mixed with the barley (treatment 1—control), or added to the barley at either both meals of the day (2), or at only the morning meal (3). For treatments 4 to 6 the supplements were given separately. For treatment 4, VM was given at the morning feed and S in the afternoon; for treatment 5, VM was given at both feeds of one day and S at both feeds of the next day, for treatment 6 the supplements were given only at the morning feeds, VM on one day followed by S on the next day.

3. Overall, there were no significant differences between treatments 1 to 5 in growth rate or efficiency of food conversion. The pigs on treatment 6 refused a relatively large percentage of their food, grew significantly more slowly but converted their food significantly more efficiently than did the pigs on any of the other treatments. There were no significant differences between treatments in any of the carcass data recorded.
Studies of pedigree Hereford cattle breeding. 2. Reproductive statistics in bull-breeding herds
Authors: Bichard M. , Özkütük K.
Published: September 2010

1. Analyses are presented of 1628 calvings from 397 pedigree Hereford cows kept in three herds whose records were made available by their owners. In addition a further 541 calvings were examined from a sample of 100 cows taken at random from the herdbook entries.

2. Mean age at first paternity for 71 homebred bulls was 25·6 mo. Mean age at first calving varied between the three herds from 29·5to 32·8 mo, with 39·7 mo for the random cows.

3. Random herdbook cows produced an average of 3·3 calves per cow compared with 4·2 from those in the three herds; these latter cows had an average calving interval of 13·1 mo.

4. The pattern of cow and calf disposal varied partly according to the differences in herd age and culling policy. While one herd retained more than 80% of heifers and subsequently sold half of them after two or three calvings for breeding, another retained only one-third but kept these for their full working life. Similarly the percentage of bull calves sold for breeding varied between 43 and 83%.

5. The net reproductive rate, or number of calves weaned per 100 cow-herd-years was 74, 88 and 67 for the three herds, and 66 for the random herdbook cows. The mean generation intervals were 4·1 yr for sires and 5·8 yr for dams whose breeding life in the herds had been completed.

6. The biases in reproductive statistics estimated from herdbook entries were examined, and it was concluded that such data can be of use where better herd records are unavailable.
A more precise statistical analysis for certain grazing trials and other large scale animal experiments
Authors: Conniffe D.
Published: September 2010

In some grazing experiments stocking rates are adjusted during the experiment. For these and other experiments in which the initial number of animals per treatment is subsequently reduced a more powerful statistical analysis than the normal analysis of variance may be possible. The methodology of the analysis is presented in this paper and applied to an example.
The effects of two nutritional environments from 6 weeks pre partum to 12 months of age on lifetime performance and reproductive potential of Scottish Blackface ewes in two adult environments
Authors: Gunn R. G.
Published: September 2010

In one experiment, 227 female sheep in two age groups were reared on low (107 sheep) and high (120 sheep) levels of nutrition from birth to 12 mo of age after their dams had been given low and high levels of nutrition during the last 6 weeks of pregnancy. From 12 mo, 47 of the low-level sheep and 51 of the high were grazed on poor hill pasture to provide a low-level adult nutritional environment while 46 of the low level and 52 of the high were grazed on good quality pasture to provide a high-level adult nutritional environment. These treatments were continued for 5 production years for one age group and 4 production years for the other.

Live-weight differences associated with rearing treatment persisted throughout the experiment in both adult environments. Lifetime lamb production was significantly affected by both rearing and adult treatments.

The effects of these treatments on reproductive potential were examined in a second experiment by determination of ovulation rate when the sheep were brought into uniform good body condition at mating after the end of the first experiment. Potential ovulation rate was significantly affected by rearing treatment but not by adult treatment, although live weight and body size were affected by both.

It is concluded that while reproductive potential is related to body size it may also be influenced by the pattern of early growth during unidentified developmental stages.
A survey of the carcass characteristics of the main types of British lamb
Authors: Kempster A. J. , Cuthbertson A.
Published: September 2010

Commercial lamb carcasses were surveyed in 1971/72 as part of the development programme for a national classification scheme for Great Britain. Carcasses of 421 castrated male lambs were evaluated and their left sides dissected. The sample comprised seven groups representing the main breed types in the national population. Within these groups, lambs were selected from three regions on each of three occasions corresponding with the beginning, middle and end of the normal slaughtering season for each group.

The overall means (±SD) for side weight and percentage subcutaneous fat in the side were 8·3 ± 1·8 kg and 12·6 ± 3·2 respectively. When adjusted to the overall mean subcutaneous fat percentage (constant % SF), the breed-type side weight means ranged from 6·4 kg (Welsh Mountain) to 10·8 kg (British Longwool). At constant% SF, lambs slaughtered earlier in the season were lighter than those of the same breed type slaughtered later.

Significant differences (P<0·05) were recorded between breed-type groups in fat distribution and lean/bone ratio. These were reflected as important differences in percentage lean at constant % SF, group means ranging from 54·5 (lambs by Suffolk rams out of Scottish Halfbred ewes) to 56·7 (lambs by British Longwool rams out of hill ewes).

When lambs of the same breed type from different regions were compared at constant % SF and constant side weight, there were few important differences in carcass characteristics.

The results are discussed in relation to the classification scheme which has since been introduced by the Meat and Livestock Commission.
The interpretation and analysis of subjective body condition scores
Authors: Evans D. G.
Published: September 2010

Subjective scoring data may be analysed by ranking methods, ANOVA methods or by inspection of the score distributions. These methods are discussed with particular reference to body condition scores of cows and ewes. A combination of ANOVA and ad hoc inspection was used to analyse data from trials carried out in 1976 to investigate the precision of condition scoring. On the basis of the results, recommendations are made concerning the use of condition scoring on farms and in scoring trials where the object is to monitor assessor bias and inconsistency.
Application of light control to shorten the production cycle in two breeds of sheep
Authors: Vesely J. A.
Published: September 2010

An average of 60 Rambouillet and 60 Suffolk ewes was maintained under an intensive management system to lamb about every 7 months. Decreased daylength was used for oestrus induction in normally anoestrous periods. The experiment lasted 3·7 years, during which time six lamb crops were produced, three of them as a result of out-of-season mating. Ewes of each breed were subdivided into three experimental groups and each breed-group was maintained under one of three different light treatments before and during out-of-season mating. Imposed Treatment 1 consisted of a pre-mating period under natural daylight followed by a mating period of short daylength (8 h/day). Ewes under imposed Treatments 2 and 3 were exposed to 16 h of light during the pre-mating period and to 8 h of daylight during the mating period. This did not affect conception significantly in the Rambouillet but it did in the Suffolk. Different intensities and wavelengths of light during the long daylight period (16 h/day) were used in Treatments 2 and 3 but did not cause different responses.

In Rambouillet ewes the first mating (out-of-season) gave 73% conception. It was followed by two in-season matings with 72 and 85% conceptions. The last three matings (out-of-season, in-season, out-of-season) resulted in 57, 42, and 58% conceptions. In the Suffolk ewes, the conceptions were 30, 88, 77, 3, 77, and 10% in the same order as those for Rambouillet. The average production ofRambouil-lets on the three treatments was 166 lambs per 100 ewes per year (165, 177, 157) whereas Suffolks produced 132 lambs (120, 143, 135). Control Rambouillet and Suffolk ewes maintained under natural daylight year-round produced 139 and 117 lambs.
The effects of selection for high and low body weight on the proportion and distribution of fat in mice
Authors: Allen P. , McCarthy J. C.
Published: September 2010

The growth of adipose tissue was investigated in lines of mice selected for high and low body weight at 5 and 10 weeks of age, by dissecting and weighing individual fat depots from mice aged 5, 7·5, 10 and 15 weeks. At fixed ages most depots were heavier in the High lines and lighter in the Low lines. Depots grew at different rates and the rate of total fat deposition relative to gain in body weight was greater in High than in Low lines. At about 20g live weight High and Low lines had similar proportions of total fat; at lower weights the High lines were relatively leaner. These correlated effects of selection were more pronounced in the faster growing depots of the kidneys and gonads. In consequence, the High an d Low lines had different fat distributions at fixed ages, at fixed body weights and at fixed weights of fat.
The effect of interval between harvests and wilting on silage for milk production
Authors: Gordon F. J.
Published: September 2010

Seventy-two British Friesian cows, with a mean calving date of 21 January, were used in a 3 × 2 factorial design experiment to assess the effects of the interval between harvest and wilting on the value of grass silage for milk production. Three regrowth intervals of 5, 7 and 9 weeks were used with each material ensiled both unwilted and after wilting to a dry-matter content of approximately 450g/kg. The six silages were offered ad libitum in addition to 7·6 kg concentrates per day, from day 8 of lactation until 13 April, with a mean experimental period of 67·5 days. The mean intakes of silage dry matter were 11·2, 9·8 and 8·7 kg/day for the 5-, 7 and 9-week regrowth intervals respectively and 9·6 and 10·2kg/day for the unwilted and wilted silages respectively. Regrowth interval significantly affected milk yield with mean yields of 24·7, 24·2 and 22·5 (s.e. 047) kg/day being obtained for the 5-, 7- and 9-week intervals respectively. Wilting significantly depressed milk yield with mean yields of 24·8 and 227 (s.e. 0·39) kg/day being recorded with the unwilted and wilted materials respectively. Live weight at the end of the experiment was not significantly affected by any of the treatments but the rate of live-weight loss, calculated by linear regression over the experiment, and loss in body condition score both significantly increased with increasing regrowth interval. Wilting had no effect on live weight or body condition. Increasing the regrowth interval also significantly reduced the solids-not-fat and protein contents of the milk produced during the final week of the experiment but no other significant effects were recorded on milk composition.

Blood analysis data are presented: blood urea was the only component affected by the treatments and decreased significantly as regrowth interval increased.
Individual intake variation in ewes given feedblock or trough supplements indoors or at winter grazing
Authors: Kendall P. T. , Ducker M. J. , Hemingway R. G.
Published: September 2010

Individual dry matter intakes were measured using four groups of 16 ewes, indoors or at sparse winter grazing. In periods of varying duration (14 to 35 days) the ewe groups received 14 feedblock supplements competitively, eight trough supplements competitively or two feedblock supplements individually. In each period hay was available ad libitum. All supplements contained chromic oxide and individual supplement intakes were estimated by total faecal collection. Individual hay and total dry-matter intakes were estimated by faecal apportionment according to indigestibility of dietary components.

Metabolizable energy content (0·81 × digestible energy) of the feedblocks ranged from 7·9 to 9·2 MJ/kg dry matter compared with a value of 13·0 MJ metabolizable energy/kg dry matter for concentrates. The variation in individual supplement intake was large, irrespective of type of supplement. However the mean coefficient of intake variation for 14 feedblock supplements (0·56) significantly (P < 0·05) exceeded that (0·39) for eight trough supplements at equivalent mean dry-matter intakes.

Thus, ‘free-access’ feedblocks did not allow a more uniform supplementation than trough supplements. Supplement intake variation was higher outdoors and increased as total feedblock intake reduced.

The variation in individual hay and total dry-matter intake was lower, and generally independent of that for the supplements. Mean coefficient of variation of 0·24 and 0·22 were obtained for hay and total dry matter, respectively, based on 22 collections with competitively fed sheep.

Total daily metabolizable energy intakes of individual ewes outdoors ranged from 5 to 22 MJ per collection.
Changes in body composition relative to weight and maturity in large and small strains of Australian Merino rams 1. Muscle, bone and fat
Authors: Butterfield R. M. , Griffiths D. A. , Thompson J. M. , Zamora J. , James A. M.
Published: September 2010

Maturing patterns of carcass muscle, bone and fat were established using dissection data from 20 large mature size strain and 19 small mature size strain Merino rams. The rams were fed a pelleted ration soon after weaning and individual rams from both strains slaughtered at 6 kg increments in live weight from 18 kg to maturity at 116 and 91 kg for the large and small strains respectively.

Composition of mature rams of both strains was similar for the proportion of muscle and bone but there was a slightly greater proportion of fat in the larger strain.

The progress of each carcass tissue to maturity was assessed relative to progress of shorn full live weight to maturity. Maturing patterns of the three carcass tissues were not significantly different in the two strains. Muscle and bone were early maturing relative to live weight and fat late maturing.

The composition of the large and small mature size strains at the same live weight and at the same proportion of maturity was predicted from the maturity patterns of the carcass tissues and the composition of the mature rams. At the same live weight the large mature size strain had a greater proportion of bone and a smaller proportion of fat than the small mature size strain. At the same proportion of mature live weight, differences between the strains in proportional composition were reduced, and the large mature size strain had slightly more fat.

Some guidelines for comparison of strains of animals of different mature size are developed.
An analysis of seasonality of milk production
Authors: Goodall E. A.
Published: September 2010

The lactation model of Wood, y = Anbe−cn was fitted, using a logarithmic transformation, to two sets of lactation data obtained from the Agricultural Research Institute of Northern Ireland. The first set was from animals calving in the autumn and the second set from animals calving in winter and early spring. A categorical variable was added to the transformed model to investigate the effect on the parameters of the animals going out to grass. The technique proved more useful with the autumn-calving herd.
Gut fill in cattle: effect of pasture quality on fasting losses
Authors: Goodchild A. V.
Published: September 2010

An abrupt fall in live weight of grazing cattle occurs at the beginning of the growing season in the seasonally dry tropics. In an experiment with grazing crossbred bulls in central Tanzania designed to monitor changes in gut fill, 16 were slaughtered in the dry season and 14 in the early wet season. Bulls were measured and weighed before, and weighed after, a 20-h fast and then slaughtered. Gut fill was measured and empty body weight (EBW) calculated.

During fasting, the ratio gut fill/EBW fell from 0·291 to 0·217 in the dry season and from 0·207 to 0·119 in the wet season. Heart girth/EBW1/3 was 0·2577 and 0·2567 m/kg1/3 in the dry and wet seasons respectively.

It was concluded that live weight before or after fasting is seriously affected by season and can give biased predictions of EBW change. On the other hand, heart girth is little affected by season and can be used to monitor relative increases or decreases of EBW within animals.
Observed energy intake of weaned piglets and its effect on temperature requirements
Authors: Robertson A. M. , Clark J. J. , Bruce J. M.
Published: September 2010

Energy intake was recorded for two batches of 12 individually-penned piglets weaned at 5 kg live weight and fed milk-based diets of 18·7 MJ metabolizable energy (ME) per kg up to 8 kg live weight and 15.4 MJ ME per kg thereafter. The piglets were kept within their thermoneutral zone throughout the experiments. Regression equations describing the relationship between energy intake and days after weaning were developed for each piglet and the means of the regression coefficients and constants were incorporated in an equation for estimating energy intakes for piglets of 5 to 15 kg live weight. The lower and upper critical temperatures were calculated for each piglet on every day of the trial. These values were extrapolated to give temperature recommendations for piglets of 5 to 15 kg live weight kept in groups of 20. The temperatures ranged from 30°C at weaning to 19°C, 23 days after weaning. This represented a reduction in temperature equivalent to 0·5°C per day.
The influence of feeding level on the protein requirement of pigs between 20 and 45 kg live weight
Authors: Campbell R. G. , Taverner M. R. , Curic D. M.
Published: September 2010

One hundred entire male pigs growing between 20 and 45 kg live weight were used to investigate the effects on growth performance and carcass composition of eight concentrations of dietary crude protein (CP), ranging from 93 to 238 g/kg and three levels of food intake (giving mean daily digestible energy 15·6, 18·7 and 22·4 MJ).

Growth rate improved with each increase in food intake and with increase in dietary CP up to 175 g/kg (10·5 g lysine per kg) at all food intakes. Food:gain ratio (g food per g growth) improved with increase in dietary CP up to 175 g/kg and with the first increase in food intake.

The rate of protein deposition in the carcass (excluding viscera) increased with each increase in level of feeding, and with increases in dietary CP up to 175 g/kg. The results showed that for pigs given diets deficient in protein, the rate of protein deposition was linearly related to protein intake and independent of energy intake. For pigs given diets adequate in protein, the rate of protein deposition was related to energy intake, and independent of protein intake.

The carcass fat of pigs killed at 45 kg live weight decreased on all feeding treatments with increase in dietary CP up to 175 g/kg, and was higher in pigs given the two higher levels of feeding than in those fed at the lowest level. The effect of feeding level on carcass fat content declined as the protein adequacy of the diet was reduced.