bluuebunny/crossref_metadata_2025 huggingface dataset:
Prediction of energy status in first lactation dairy heifers
Authors: Ducker M. J. , Haggett Rosemary A. , Fisher W. J. , Morant S. V.
Published: September 2010

Data from a large controlled experiment to investigate the effect of level of nutrition on reproductive performance were used to assess the value of production and blood measures as indicators of energy status in lactating dairy heifers. Live-weight change showed the strongest and most consistent relationship to mean energy balance (the difference between metabolizable energy intake and that used for milk production and maintenance) (P< 0·01 toP< 0·001). Body-condition score at a particular time was more closely related to mean energy balance in the preceding 4-week period (P< 0·05) than current energy balance. There was also a lag in the relationship between energy balance and live-weight change and mean body-condition score. Ultrasonic back fat measurements were significantly correlated with both loin and tailhead body-condition score (P< 0·001) but were more strongly related to mean energy balance in the preceding period (P< 0·05 toP< 0·001) than the body-condition scores.

Blood samples were taken from all heifers 2 weeks before calving and 1, 5, 9, 13 and 18 weeks after calving and were analysed for 13 constituents. Concentrations of blood metabolites did not show consistently strong correlations with mean energy balance. The only blood metabolite to be measurably affected by the nutritional treatments applied in lactation was β-hydroxybutyrate.

At best, combinations of production measures and blood metabolites were only able to predict the mean daily energy balance with a 95% confidence interval of ±20 MJ for an individual animal although this confidence interval was reduced to ±3 MJ for 100 animals.
Retention of copper in the liver of sheep genetically selected for high and low concentrations of copper in plasma
Authors: Woolliams J. A. , Wiener G. , Woolliams Carol , Suttle N. F.
Published: September 2010

The extent to which genetic selection to change the concentration of copper (Cu) in plasma also affected the retention of Cu in the liver was assessed in three experiments. In each, the concentration of Cu was measured in samples of liver (taken by biopsy) and of plasma from female sheep of lines selected from a Scottish Blackface × Welsh Mountain population (which had previously been interbred for several generations) for high and low plasma Cu levels (high line and low line) and from purebred Scottish Blackface and Welsh Mountain females.

The concentration of Cu in the liver and plasma was found to be consistently greater in high-line and Welsh Mountain than in low-line and Scottish Blackface females (P< 0·01) in the first experiment in which grazing animals were sampled at both 6 and 10 months of age and in the second, where sampling' was at 6 months only. Mean Cu concentrations in the liver ranged from 13 to 115 mg/kg dry matter (DM) and the correlations with those in plasma varied from 0·28 to 0·53 (allP< 0·05) and was highest when the concentration of Cu in the liver was lowest. The correlation between the concentrations of Cu in liver at different ages was 0·57 (P< 0·05).

In the third experiment, 10-month-old high- and low-line females were given complete diets containing either 5, 10, 22 or 28 mg Cu per kg DM for 12 weeks. Liver samples were obtained at the beginning and end of this period and blood samples were taken every 3 weeks. The concentration of Cu in the liver was greater in high- than in low-line sheep on all diets and increased linearly with the Cu concentration of the diet but at a greater rate in the high line. At the end, the high line had significantly greater concentrations of Cu in plasma on the 5 and 10 mg Cu per kg DM diets.

The experiments showed that high-line females retained more Cu in the liver than low-line females. It is most likely that this was caused by a positive genetic correlation between concentration of Cu in plasma and the efficiency of absorption of Cu.
Growth, food intake and development in broiler cockerels raised to maturity
Authors: Prescott Nicola J. , Wathes C. M. , Kirkwood J. K. , Perry G. C.
Published: September 2010

The food intake, growth and development of Ross broiler cockerels were recorded from 1 day old to maturity. At regular intervals, the body composition of these birds was determined and the eviscerated carcasses were chemically analysed. Allometric relationships of component weights and live weight were examined. Historical comparisons with fowl reared during the last 60 years did not reveal any significant changes in the pattern of development, despite faster absolute growth rates and heavier mature weights.
A note on the ability of three portable ultrasonic probes to predict backfat thickness in cattle
Authors: Eveleigh C. S. , Thwaites C. J. , Hassab P. B. , Paton D. G. , Smith R. J. , Upton W. H.
Published: September 2010

Three portable ultrasonic probes (Scanoprobe, Meritronics and Krautkramer), each used by the one experienced operator, were found to be superior to the visual and tactile assessments of two experienced judges in predicting carcass backfat depth (range 4 to 20 mm) in 132 live steers. Residual standard deviations for the three probe/operator combinations were 2·01, 2·16 and 2·77 mm respectively; those for the judges were 2·96 and 3·09 mm. Combining ultrasonic estimates by multiple regression improved slightly the accuracy of prediction (residual s.d. = 1·87 mm), the level of which was comparable to that previously reported for scanning ultrasonic instruments used on pigs.
A note on the acceptance of several types of cereal grain by young sheep with and without prior experience of wheat
Authors: Mottershead B. E. , Lynch J. J. , Elwin R. L. , Green G. C.
Published: September 2010

Sixteen sheep which had previously eaten wheat only (eaters) were offered wheat, barley, oats and maize separately in a Latin-square design with two sheep per cell and two replicates of the Latin square. Another 16 sheep which had never previously been offered wheat (non-eaters) were offered the same cereal grains in two more Latin squares with two sheep per cell.

The total intake of wheat for the eaters was significantly greater than for the other cereal grains (P < 0·01) and it took 7 to 9 days for other cereals to be eaten. There was virtually no consumption of cereal grains by the non-eaters until days 10 to 12 when some wheat but little other cereal was being eaten.

The results indicate that sheep learn to eat each type of cereal grain separately but if they know how to eat wheat they learn to eat other cereal grains more rapidly.
Inheritance of linear type traits in dairy cattle and correlations with milk production
Authors: Meyer Karin , Brotherstone Susan , Hill W. G. , Edwards Maureen R.
Published: September 2010

Records on 18 939 Friesian-Holstein cows classified for 16 linear-type traits and total score in first lactation by the British Friesian Cattle Society and similarly on 13 192 cows in second lactation were analysed to estimate heritabilities and genetic correlations among the linear traits. These comprised progeny of 542 and 477 young sires, respectively, together with older sires included to increase connections. Correlations of type with milk production traits and correlations between type in first and second lactations were estimated from subsets (of about one-half) of the data. Effects due to proportion of Holstein in the sires were removed.

Heritabilities of the linear traits were similar in first and second lactations, ranging from under 0·15 for one of the leg traits to about 0·5 for stature. Genetic correlations between traits in first and second lactation were generally over 0·75, whereas phenotypic correlations for most traits ranged from 0·3 to 0·6. Genetic and phenotypic correlations among the linear traits were generally low, except for those involving size.

Phenotypic correlations between linear traits and milk yield and composition were all small, none exceeding 0·3. Genetic correlations were generally almost as small: taking first and second lactations together, the only consistent non-negligible correlations with yield were for angularity (+0·3), fore-udder attachment (–0·2) and udder depth (–0·4). The linear traits are not useful predictors of yield.
Voluntary food intake in a limited time of lambs and calves given diets containing rapeseed meal from different types and varieties of rape, and rapeseed meal treated to reduce the glucosinolate concentration
Authors: Stedman J. A. , Hill R.
Published: September 2010

The voluntary food intake in a limited period, 30 or 60 min after morning and afternoon feeds, and during 24 h, by lambs and calves given diets containing rapeseed meal (RSM) or soya bean meal (SBM) as the only protein supplement was determined. Four rapeseed meals were compared, one from seed of British-grown winter Brassica napus varieties (BRSM), and the others from seeds of the varieties Tower (TRSM) and Loras (LRSM), or from seeds of Canadian spring sown varieties (Canola; CRSM). The effects on food intake of treating BRSM with heat and ammonia, steam, steam and ammonia, or calcium hydroxide and ammonia were also determined.

In lambs, intakes in a limited period of BRSM and CRSM were significantly lower than that of SBM, and there were no differences between intakes of BRSM and CRSM. In calves, intake in a limited period of BRSM was significantly lower than intake of SBM, TRSM and LRSM: those of TRSM and LRSM were lower, but not significantly so, than that of SBM. Treatment of BRSM with steam, steam and ammonia or calcium hydroxide and ammonia, increased food intake significantly but by small amounts: intakes of the treated meal diets were markedly lower than that of the control SBM diet. The glucosinolate concentration of untreated RSM influenced intake in calves but not in lambs. The effects of treatment of RSM on intake were not closely related to changes in glucosinolate concentration.
Effects of dietary protein and energy intakes on growth hormone, insulin, glucose tolerance and fatty acid synthesis in young wether sheep
Authors: Waghorn G. C. , Flux D. S. , Ulyatt M. J.
Published: September 2010

A group of 16 Romney wether sheep fitted with rumen and abomasal cannulae and aged 11 to 12 months was allocated to either high or low crude protein (CP) pelleted diets (220 (HP) and 120 (LP) g CP per kg) to give four daily intakes of dry matter (356, 711, 1067 and 1422 g) within each diet, giving two sheep per treatment. Diets were given hourly for 40 days during which time growth rates, plasma concentrations of insulin (I) and growth hormone (GH) were determined, a glucose tolerance test was performed and relative rates of fatty acid (FA) synthesis were determined.

Live-weight changes ranged from –46 to 215 g/day and wool growth ranged from 86 to 210 mg per 100 cm2daily.

Plasma GH concentrations were significantly higher (P< 0·001) in sheep given LP diets (21·2 (s.e. 4·2) μg/1) than in those given HP diets (10·1 (s.e. 1·8) μg/1) and negatively correlated with both energy (E) (r= –0·62;P< 0·01) and nitrogen (N) (r= –0·63;P< 0·01) intakes which proportionately accounted for 0·47 of the variance in plasma GH concentration (P< 0·01). Plasma I concentrations were higher (P< 0·05) in sheep given HP diets (2·77 (s.e. 0·34) μg/1) than in sheep given LP diets (1·86 (s.e. 0·23) μg/1). Intakes of E and N proportionately accounted for 0·38 of variance in I concentration which was primarily determined by N intake.

After intravenous infusion of glucose (150 mg/min) for 30 min, significant differences in the rate at which plasma glucose and I concentrations declined to pre-infusion levels were evident with different daily intakes of the pelleted diets.

Synthesis of FA in adipose tissue was on average 1·7 times more rapid in sheep given HP than in sheep given LP diets (P< 0·05) and increased approximately three-fold with increasing intake. Partial correlations showed differences in E and N intakes were able to account for 0·73 (P< 0·01) of the variance in FA synthesis rates, with N intake having a greater influence than E intake (partial correlations:r= 0·53;P< 0·05 andr= 0·35;P> 0·05 respectively).
The influence of dietary protein intake during lactation on the reproductive performance of sows
Authors: MacPherson R. M. , Elsley F. W. H. , Smart R. I.
Published: September 2010

1. Forty-five Large White gilts were given 2·20 kg daily of a diet containing 14·0% crude protein during three successive pregnancies. During a 6-week lactation they received 5·30 kg daily of one of three diets containing 19·0% (HP), 16·5% (MP) or 14·0% (LP) crude protein.

2. Daily milk yield was estimated on the 10th, 20th, 30th and 40th day of lactation. Milk samples were obtained from the same sows for the determination of protein, fat, lactose and total solids on the 11th, 21st, 31st and 41st day.

3. One sow and litter from each treatment in each lactation was placed in metabolism cages during lactation and estimates of nitrogen and dry matter excretion obtained.

4. As the concentration of protein in the diet decreased the average 42-day gain in litter weight from birth increased significantly in the first lactation. This trend continued in the second lactation although it was not significant but did not appear in the third.

5. There was no marked difference in daily milk yield between treatment groups.

6. There was a significantly greater loss of live weight by the sows on the lower levels of protein in the first lactation. These differences were not significant in the second and third lactations.
The effects of dietary supplementation with lysine and methionine on body and tissue composition in the pig
Authors: Ostrowski H.
Published: September 2010

A feeding trial was conducted on 24 individually-fed pigs given either a diet containing plant protein with insufficient Iysine and methionine or the same diet with optimal Iysine and methionine levels. Supplementation of the diet with synthetic amino acids significantly improved daily live-weight gain, feed conversion, nitrogen balance, loin eye muscle area and total yield of lean muscle.

Pigs receiving insufficient Iysine and methionine were characterized by lower haemoglobin and creatinine values accompanied by a decreased level of glutamic oxaloacetic transaminase.

There were highly significant differences in the blood and liver Iysine levels of the two treatments, and significant differences in the fresh muscle and in the pressed muscle juice Iysine levels.

The ratios between liver and blood Iysine levels and between dietary or muscle Iysine levels and % of nitrogen retention were calculated and found to be the same on both treatments.

The accumulation of Iysine in liver and muscle was linearly related to the blood Iysine level and to N retention and Iysine intake.
A note on the growth of pigs in metabolism cages
Authors: Livingston D. M. S. , Fuller M. F. , Livingstone R. M.
Published: September 2010

The growth of pigs kept continuously or intermittently in metabolism cages was compared with that of animals penned in groups. The ten continuously caged grew more slowly and contained more fat at slaughter than their penned littermates.
A note on some aspects of rumen fermentation in Holstein calves changed from an all-concentrate diet to high levels of molasses/urea and forage
Authors: Elías A. , Preston T. R.
Published: September 2010

Two changeover treatments were studied over a 5-week period in eight early-weaned concentrate-fed Holstein calves of initial weight 160 kg. Fresh forage was given ad libitum for one week (A) or two weeks (B); calves on the latter treatment also had 500 g daily of maize meal. All calves received 300 g/100 kg live weight of a protein supplement and had free access to sodium and phosphorus-rich minerals. A rumen inoculation was given after seven days of forage feeding, at which point a liquid molasses/urea mixture was introduced, first in small amounts and then after a further seven days ad libitum. The forage was then restricted to 3 kg/100 kg live weight. Both treatments were effective in raising rumen pH and buffering capacity to the point of allowing the establishment and maintenance of protozoa, chiefly Entodinium and Isotricha spp. Protein N as a percentage of the total N of rumen contents was about 90 with the all-concentrate diet, fell to 35 with the roughage diets and then rose again to 80–90 by the end of the experiment.
A study of protein utilization by weaned lambs
Authors: Robinson J. J. , Forbes T. J.
Published: September 2010

Fifty weaned store lambs approximately 7-month-old were used in an experiment designed to assess their protein requirements and utilization. At the beginning of the experiment a random sample of 10 animals were slaughtered and their loin joints analysed. The remaining 40 were allocated at random to four dietary treatments (T1, T2, T3, T4) comprising four crude protein intakes at a constant energy intake. The experiment was divided into two periods. During period 1 (48 days) the dietary crude protein intakes were 58 (T1), 111 (T2), 170 (T3), and 198 (T4) g/day with a mean digestible organic matter intake (DOMI) of 578 g/day. During period 2 (55 days) the corresponding crude protein intakes were 89, 157, 215, 251 and the DOMI was 678 g/day.

Digestibility and nitrogen balance trials were carried out on two animals from each treatment in period 1 and on six animals on each treatment in period 2. At slaughter the loin joints from five animals on each dietary treatment were chemically analysed.

The only significant effect on live-weight gain of varying protein intake was a lower gain on the lowest protein intake (T1) in period 1. It was estimated that the optimum ratio of digestible protein intake (g) to digestible energy intake (meals) for live-weight gain in period 1 was approximately 30 : 1 and in period 2 approximately 21 : 1. There was a significant increase in killing-out percentage with increasing crude protein intake. The digestibility of dry matter and nitrogen increased with increasing crude protein intake. There was a significant quadratic relationship between the apparently digested nitrogen intake in g/day (X) and nitrogen retained in g/day (Y). The regression equation was

Y= −0·008X2+ 0·537X+ 0·682

Liver copper levels decreased with increasing crude protein con-centration in the diets.
A note on the protein requirement for maintenance of adult rams
Authors: Singh Manohar , Mahadevan V.
Published: September 2010

Nitrogen balance studies of latin square design were conducted on six adult rams receiving diets with approximately 4, 8 and 16% crude protein. The diets were almost isocaloric and contained groundnut cake, wheat bran, maize starch, and chopped wheat straw. Metabolic faecal and endogenous urinary N were 0·24 ± 0·003 g/100 g dry-matter intake and 0·038 ± 0·01 g/kg body weight per day. Biological value, true digestibility and coefficient of net utilization were 86·9 ± 8·68, 93·4 ± 1·94 and 79·6 ± 2·47, respectively.

Daily digestible crude protein requirements for maintenance estimated by the factorial method (0·875 + 0·;06 g/kg W0·734) and from N balance and the net utilization of protein (0·893 + 0·03 g/kg W0·734) were similar but slightly higher than the requirement estimated from N balance alone (0·738 ± 0·04 g/kg W0·734). All values are lower than the conventional recommendations.
Photoperiodism in the ewe: 4. A note on the effect on onset of oestrus in Clun Forest ewes of applying the same decrease in daylength at two different times of the year
Authors: Ducker M. J. , Bowman J. C.
Published: September 2010

Experiments were carried out with Clun Forest ewes to determine the effect on the onset of oestrus of applying the same abrupt decrease in daylength at two different times of the year. An abrupt decrease in daylength of 3·75 hr was applied to the ewes on 1 July 1968 and on 24 April 1969. The mean number of days from the commencement of the light treatment to the onset of oestrous activity was 59·5 and 87·0 days, respectively. It is concluded that the time of year at which the light treatments were applied, or the previous light treatment of the Clun Forest ewes, or both, significantly (P<0·001) affected the date of onset of oestrus.
A note on the repeatability of parameters of the lactation curve in cattle
Authors: Wood P. D. P.
Published: September 2010

A study of 1567 lactations of 336 Friesian cows in 10 herds has been undertaken to establish to what extent the shape of the lactation curve varies between parities, cows and herds, and to assess the importance of variations in seasonality from year to year, with particular reference to herd production forecasts.

In general, cows calving the same parity at the samé time of year showed similar curves, modified only by total yield and abnormal seasonality of production. Production forecasts based on month/parity subclasses are therefore adequate, provided due account is taken of extréme variations in weather conditions or forage growth.
The selection of dairy bulls for artificial insemination
Authors: Hinks C. J. M.
Published: September 2010

A numerical model of AI selection procedures has been constructed in an attempt to assess the efficiency of current selection methods and to examine possibilities for their improvement. The results indicate that (1) present selection methods are relatively efficient in their utilization of test resources, but much less efficient in their usage of tested bulls. Additional investments in bull testing are likely to profit the dairy industry. (2) The main effects of improved bull utilization are (a) to permit increases in selection pressure with no increase in cost over current selection procedures and (b) to extend the limits to profitable selection. (3) The adoption of alternative stud management systems, in which bulls are slaughtered early in life, are likely to require excessively large investments in semen processing and storage.
An experiment on the selection of bacon pigs by high and low carcass densities
Authors: Hale R. W.
Published: September 2010

Selection based on average carcass densities of sibs was effective in breeding for leanness and for fatness in Large White pigs. Four herds were established for the five-year experiment, in which 615 pigs were slaughtered at bacon weights. Responses were obtained with both feeding to appetite and restricted feeding, but it was not possible to decide which was the preferable method.
A note on feed-lot performance of Grey Shirazi sheep
Authors: Ghorban K. , Mozafar A. A. , Sefidbakht N. , Simhaee E.
Published: September 2010

Identical group-feeding experiments (each of 90 days duration) were conducted in the summer and in the winter of 1968. The purpose was to study the feed-lot performance of the Grey Shirazi breed on high- and low-concentrate diets with or without diethylstilboestrol (DES) in two different seasons of the year. Lambs on the high-concentrate diet gained more than those on the low-concentrate diet both in summer and in winter. On both diets lambs performed better under cold than under warm conditions. There was no difference when DES was given orally with the above two rations.
Growth of pigs fed cool whey at two ambient temperatures
Authors: Holmes C. W.
Published: September 2010

1. Two experiments have been performed to compare the performance of pigs given cool ‘whey’ (15°C) with that of pigs fed warm ‘whey’ (40°C). Pigs were penned individually and the ‘whey’ was reconstituted from concentrated materials.

2. In both experiments pigs offered cool ‘whey’ grew at a slower rate and required more dry matter/kg live-weight gain than pigs offered warm ‘whey’; the differences in rate of gain were 11 % at 16°C air temperature in Experiment 1 and 5% at 22°C air temperature in Experiment 2.

3. It was estimated that the ‘heat of warming’ for the cool ‘whey’ might have accounted for its entire effect on rate of gain.
Reproductive performance and growth of Shorthorn purebred and crossbred cows
Authors: Fahmy M. H. , Lalande G. , Hidiroglou M.
Published: September 2010

Data were obtained from 27 pure Shorthorn, 22 Angus × Shorthorn, 31 Charolais × Shorthorn and 27 Hereford × Shorthorn cows, during 10 years. Angus × Shorthorn cows required the least number of services per conception (1·17), had the shortest average gestation lengths (280·6 days), and had a calving percentage of 88·2% and birth weight of calf of 29·8 kg. The respective figures for Charolais × Shorthorn were 1·21 services, 281·6 days, 88·3% (the highest) and 32·9 kg (the heaviest), for Hereford × Shorthorn 1·23 services, 283·6 days, 84·4% and 31·6 kg, and for pure Shorthorn 1·20 services, 282·2 days, 82·7% and 29·6 kg. Average calf weight at birth increased with the advance in age of cow up to 5 years, then showed little change. Seventy-two per cent of the crossbred cows calved for the first time at 2 years old compared with 65% of the Shorthorns. On the other hand, Shorthorn cows had the highest twinning percentage (2·9%) and the lowest single calf mortality at birth (1·4%). The maximum body weights of Angus, Charolais, and Hereford crossbreds and Shorthorn cows were 576·8, 655·8, 6254 and 553·8 kg respectively at 7–8 years of age.
Freeze-branding of young beef animals
Authors: Day Norman , Jenkinson D. McEwan , Walker-Love J.
Published: September 2010

The effects of freeze-branding young beef animals using two coolants were investigated and an attempt was made to avoid hide damage.

1. Branding with irons cooled in liquid nitrogen gave good markings but resulted in severe hide damage.

2. CO2-branding caused much less hide damage but gave fewer legible brands.

3. Legible brands with both coolants always resulted in some marking of the hide.

4. Branding on the jaw provided a satisfactory means of identification without loss of hide value.
Crossbreeding beef cattle in Western Uganda. 1. Performance of Ankole, Boran and Zebu Cows
Authors: Trail J. C. M. , Sacker G. D. , Fisher I. L.
Published: September 2010

In a new ranching area of Uganda recently cleared of trypanosomiasis, with a high level of disease control, adequate water supplies and extensive grazing on free range, three dam breeds, the indigenous Ankole and Zebu, and the Boran from Kenya, were mated to Boran, Angus and Red Poll sires.

Under artificial insemination, at least 10 % fewer cows were detected on heat than under natural service, and 15% fewer artificially inseminated cows actually produced calves than did naturally served cows. The introduced Boran females were not inferior in calving percentage to the indigenous Ankole and Zebu.

Relationships between dam body weight and progeny performance were investigated. The introduced Boran breeding cows were able to maintain their body weight as least as well as the indigenous Ankole and Zebu cows. While cows which calved regularly and reared their calves could not maintain body weight, it was found that heavier cows conceived at a higher rate than lighter cows, cows heavier at parturition weaned heavier calves than lighter cows, and cows that reared heavier calves lost more, or gained less, body weight than cows that reared lighter calves. It was therefore indicated that investigations into the reduction of lactation stress on cows by such methods as earlier weaning of calves, mating at the most suitable time of year, and possible nutritional supplementation at a stage in the cycle, should be commenced.
Response to within-family selection in a small closed pig herd
Authors: MacIver R. M.
Published: September 2010

Two lines of Large White pigs were selected for increased rate of growth and decreased backfat thickness respectively over five generations. Each line was bred from four boars, each mated to four gilts per generation, these being selected on a within-family basis to minimize inbreeding. Response to selection was measured by direct comparison with contemporary control stock. The control line, originating from the same foundation stock as the selection lines, consisted of 15 groups of one boar and two gilts, mating between groups being designed to reduce the rate of inbreeding.

Over three generations the control stock exhibited random variation in the traits measured except rate of daily live-weight gain and backfat thickness ‘K’. The evidence suggests that the time trend in these was mainly, if not entirely, non-genetic in nature.

The low rate of progress achieved in both lines is ascribed to the selection method adopted and to losses of potential breeding stock. It is concluded that the success of such a small-scale breeding operation is dependent on achieving optimum husbandry conditions, and even then it cannot achieve the same rate of progress as in larger herds. The necessity of using a control strain to assess genetic progress in experiments of this nature is emphasized.
The effect of pattern of food intake in pregnancy upon sow productivity
Authors: Elsley F. W. H. , Bathurst E. V. J. , Bracewell A. G. , Cunningham J. M. M. , Dent J. B. , Dodsworth T. L. , MacPherson R. M. , Walker N.
Published: September 2010

Seven research and teaching centres have co-operated in an experiment involving 154 sows. The experiment compared the effect of feeding four different patterns of feed intake during pregnancy upon reproductive performance of sows. In each case approximately 220 kg of feed were given during each gestation according to four patterns of intake designated Constant (C), Low-High (L-H), High-Low (H-L) and High-Low-High (H-L-H). During lactation all animals were given a daily ration of 3·7 kg of feed for litters of five pigs or less, and 0·4 kg for each additional piglet. Wherever possible the sows remained on the same nutritional regimes for three parities.

Although the pattern of feed intake slightly affected the live-weight changes of the sows during the course of pregnancy, the treatments had no significant effects on overall change in weight of the sows in pregnancy or in lactation in any of the three parities. The live weights of the sows at the end of the third parity were very similar for all treatment groups.

The patterns of feed intake had no appreciable or significant effect on the numbers of pigs born, their average weight at birth or upon the numbers of pigs which survived to weaning at 6 weeks or their live weight. The health and breeding regularity of the sows were also unaffected by the treatments.

There were differences between the centres in many of the variables which were compared, but there was no evidence of any important centre × treatment interactions.

It is concluded that, at the levels of intake given in pregnancy and lactation in this experiment, there are no beneficial or detrimental effects of changing the pattern of intake during pregnancy.
The influence of environmental temperature and plane of nutrition on heat losses from groups of growing pigs
Authors: Close W. H. , Mount L. E. , Start I. B.
Published: September 2010

1. Rates of heat loss from 12 groups of pigs were measured over 4-week periods in a large direct calorimeter equipped as a pig pen.

2. The levels of feeding in different groups were 34, 39, 45 and 52g/kg body weight per day, and the calorimeter temperatures were 7°, 12°, 20° and 30°C.

3. At 12°, 20° and 30°C the rates of heat loss were related to the level of feeding.

4. At 7°C the mean rate of heat loss was higher than at the other temperatures, and was not related to the level of feeding.
A note on dried poultry manure in the diet of the growing pig
Authors: Perez-Aleman S. , Dempster D. G. , English P. R. , Topps J. H.
Published: September 2010

Dried poultry manure, produced locally by sterilization and drying, was evaluated as an addition to a conventional diet, at levels of 10, 20 and 30%, for growing pigs from 23 to 85 kg live weight. The 32 pigs remained healthy and the dried manure had no apparent adverse effect on the carcasses.

There were significant linear relationships between the amount of manure added to the conventional diet and growth rate, feed conversion efficiency and certain carcass characteristics. For every 10% addition of manure, growth was reduced by 0·02 kg/day, feed conversion efficiency by 0·25 units and killing-out percentage by 0·96. The dried manure contained about 30% crude protein and was a rich source of minerals.
Changes in plasma and milk tocopherol levels in beef cattle turned out to pasture
Authors: Hidiroglou M. , Jenkins K. J. , Wauthy J. M. , Proulx J. E.
Published: September 2010

Changes in tocopherol concentrations in the milk of Shorthorn cows, and blood of their calves associated with a change from a winter diet of hay to lush spring pasture were examined. During the winter feeding period the tocopherol levels in the colostrum (108 μg/100 ml) and milk (40 μg/100 ml) were low. A significant increase occurred in the milk tocopherol concentrations after the cows were turned out to spring pasture. Immediately before the animals were turned out to pasture the tocopherol levels were lower in calves with high serum levels of glutamic oxalacetic transaminase, indicative of muscular dystrophy. Plasma tocopherol levels in all calves increased throughout the grazing period, reaching a maximum average value of 919 μg tocopherol/100 ml after 63 days. Six Limousin × Shorthorn calves out of a total of 41 died with nutritional muscular dystrophy but no mortalities occurred among 26 purebred Shorthorn calves.
The effects of pelleting various diets on intake and digestibility in sheep and cattle
Authors: Greenhalgh J. F. D. , Reid G. W.
Published: September 2010

1. Three groups of six castrated male cattle aged 6,18 and 36 months and three corresponding groups of sheep received in turn three diets consisting of high-quality dried grass (A), low-quality grass (B) or 60% of B with 40% barley (C). For one-half of each 6-week period the grass was eaten in the long form (L) and for the other half, it was ground and pelleted (P).

2. Pelleting increased intake by 45% in sheep, from 56·8 to 82·4 g dry matter per kg W-75 per day, but only by 11% in cattle, from 81·8 to 90·7. The increase was greater for diet B (44%) than for A (19%) or C (15%), and greater for the youngest animals (38%) than for the middle-aged (17%) or oldest (20%).

3. Dry-matter digestibility was reduced by pelleting from 67·2% to 58·6% in sheep and from 69·9% to 56·9% in cattle. The reduction was greater for diets A (71·2% to 56·1%) and B (65·7% to 54·1%) than for diet C (68·7% to 63·2%).

4. A hypothesis based on the importance of particle size of digesta leaving the rumen provides a possible explanation ofthese interactions between form of roughage on the one hand, and species and age of animal or diet composition on the other.
A population study of apparent embryonic mortality in cattle, with special reference to genetic factors
Authors: Wijeratne W. V. S.
Published: September 2010

Apparent mortality among 280 215 embryos from the 4th to 16th week of gestation was studied from returns to service records following first inseminations with fresh semen from 100 bulls of five dairy and three beef breeds of cattle over a period of 8 years.

The average incidence of apparent mortality was 20·3% for embryos conceived by fresh semen first inseminations. Differences in rates of apparent embryonic mortality between breeds of sire and also between sires within the Guernsey, Ayrshire and Dairy Shorthorn were statistically significant although confounded with the breed of dam. The highest incidence was from matings by bulls of the Channel Island breeds. These results suggest that hereditary factors influenced embryonic mortality in cattle.

The rate of apparent mortality was higher among embryos conceived by frozen semen than by fresh semen. Ageing of fresh semen extra-corporeally also increased the rate of apparent embryonic mortality but to a lesser extent than frozen semen.

The rate of apparent embryonic mortality increased with the greater number of inseminations required for conception possibly because of a deteriorating maternal environment.
Some nutritional implications of group-feeding hill sheep
Authors: Foot Janet Z. , Russel A. J. F.
Published: September 2010

In the first experiment two groups of 11 Scottish Blackface ewes were given either 6·10 kg dried grass pellets plus 1·63 kg chopped dried grass daily (Group A) or 8·17 kg hay plus 1·32 kg oat pellets (Group B). During a 10-day experimental period individual dry-matter intakes ranged from 484 to 939 g/day (CV 22·3%) in Group A and from 613 to 883 g/day (CV 13·3%) in Group B. In Group B dry-matter intakes from oats were much more variable (10 to 149 g/day; CV 35·8%) than those from hay (530 to 762 g/day; CV 12·9%). Plasma protein-bound iodine (PBI) concentrations were significantly higher in the Group A sheep.

In the second experiment the treatments were: group-penned, group-fed (GG); group-penned, individually fed (GI); and individually penned, individually fed (II). Within each treatment there were two groups of 12 ewes; one group was given a high level of feeding (H) and the other a low level (L) for a 7-week experimental period. Allowances of pelleted concentrates ranged from 7 to 15 g/kg in the L groups and from 18 to 26 g/kg in the H groups. The same mean quantities per kg were given to GG sheep, and food intakes ranged from 5·7 to 17·7 g/kg (CV 25·3%) in GGL and from 12·5 to 30·8 g/kg (CV 24·8%) in GGH. Plasma PBI concentrations were significantly higher in L sheep than in H sheep, and higher in GG than in II. Plasma non-esterified fatty acid concentrations were significantly higher in L sheep than in H sheep and higher in GG than in GI and II.

The principal factors determining variations in food intakes between individual animals fed in groups and some of the nutritional implications of group-feeding sheep are discussed.
A note on the failure of thyroxine to restore wool growth to inactive follicles
Authors: Ryder M. L.
Published: September 2010

Two experiments were carried out in which subcutaneous implants of thyroxine pellets were made into Soay sheep in autumn after the wool follicles had become inactive. This hormonal treatment failed to restore wool growth or to shorten the winter period of follicle inactivity.
Milk production and herbage intake of dairy cows kept on a leader and follower grazing system
Authors: Archibald K. A. E. , Campling R. C. , Holmes W.
Published: September 2010

Three groups each of 14 cows, balanced for stage of lactation and potential milk yield, were kept either on a control treatment C, grazing within a rigid rotational grazing system, or on a leader (L) and follower (F) grazing system operated within a similar system. The stocking rate of treatment C was 5·76 cows/ha, the same as the overall stocking rate of treatments L and F. In Experiment 1, a 10-week continuous-type randomized block experiment was preceded by a 4-week uniformity period; in Experiment 2, a 3 × 3 Latin square design was adopted with periods of 4 weeks. Herbage intake and milk yield were only slightly, and not significantly (P > 0·05), higher in the leader than control cows, whilst the performance of cows on treatment F fell significantly (P< 0·001) below the other treatments. In treatment L, cows in early lactation responded to the extra opportunity for herbage selection with significantly (P< 0·01) more milk than those in late lactation. The mean milk production of the leader and follower cows was similar to that of the control cows. It is suggested that the potential value of a ‘leader and follower’ grazing system is unlikely to be greater than that of a conventional rotational grazing system.
Factors affecting the cessation of oestrous activity in ewes
Authors: Speedy A. W. , Owen J. B.
Published: September 2010

In the first experiment, 10 ewes (¼ Finnish Landrace: ¾ Clun Forest) were maintained under natural daylength conditions and 10 were exposed to a constant daylength of 8 hr from 22 December until 1 June. No difference was demonstrated between treatments in dates of cessation of oestrous activity. It was concluded that oestrous activity will eventually cease, whether or not daylength increases after the shortest day.

In the second experiment, 40 similar ewes were mated at first oestrus of the natural breeding season (mean 7 September) and lambed in January. Twenty ewes suckled lambs and 20 had lambs removed within 24 hr of birth. No sucked ewes showed oestrus before the end of the breeding season, but 9 non-sucked ewes showed oestrus at a mean interval of 37·5 days after lambing and 4 of these subsequently lambed. Suckling appeared to inhibit oestrous activity and conception in ewes at this time of year.
Propionic acid-treated barley in the diets of bacon pigs
Authors: Cole D. J. A. , Brooks P. H. , English P. R. , Livingstone R. M. , Luscombe J. R.
Published: September 2010

Growth performance and carcass quality (linear measurements) were studied in pigs grown from 25 to 90 kg on barley stored and prepared in different ways. Half the barley was dried to about 14% moisture content for storage and half was not dried but treated with 0·8% propionic acid. Each was given after hammer-milling (3·2 mm screen) or rolling. A total of 144 pigs was used at four centres.

The performance and carcass quality of pigs given acid-treated barley were as good as those given dried barley. While feed utilization, expressed on the basis of air-dry feed, was poorer for pigs fed on acid-treated barley this difference disappeared when account was taken of the different moisture contents of the barley samples. Pigs fed on diets based on milled barley grew more quickly, had better feed utilization but greater fat measurements than pigs fed on rolled barley. There was a significant interaction between storage method and feed preparation (milling or rolling). Pigs given the acid-treated barley grew more quickly when it was in the milled form than when it was rolled, whereas for the dried barley there was a small, non-significant difference in favour of the rolled form.
Effect of twin birth on growth of cattle
Authors: Russell W. S.
Published: September 2010

About 350 single- and 250 twin-born female Ayrshire cattle were compared on the same feeding regime in respect of 12 linear body measurements at 3-monthly intervals up to 36 mo of age, and some two-thirds of them up to 48 mo. The twins were purchased from a wide variety of farms, and it is unlikely that their dams were significantly better fed, in pregnancy, than the dams of single calves.

The effects of month and year of birth and age at first calving (including some pregnancy and lactation effects) were estimated by least-squares procedures. The trends of the differences between single and twin-born animals were analysed as percentages of current and of mature size. Earliness of maturing had no apparent effect. For the traits of height and girth, twin-born animals were smaller than single-born by nearly 2 % of mature size (3 % of current size) at 3 mo of age and for the other traits the difference was around 1 %. By 12 mo the differences were generally about half their initial value and remained at this level, except for head width where the difference declined to zero around 2 years of age.

It is concluded that twin-, compared to single-born, cattle are subject to a small degree of permanent stunting in most linear measurements.
Energy exchanges of veal calves in relation to body weight, food intake and air temperature
Authors: Webster A. J. F. , Gordon J. G. , Smith J. S.
Published: September 2010

1. Two series of energy balance trials were conducted with British Friesian veal calves. In the first, calves were given a milk replacer diet at three different planes of nutrition. In the second, calves were raised from about 80 to 180 kg at four air temperatures, 5°, 10°, 15° and 20°.

2. The net efficiency of utilization of the milk replacer diet for growth was 0·72. The effect of body size on heat production in growing calves was best expressed by an exponent of body weight slightly but not significantly below W0·75.

3. Measurements of heat production estimated from respiratory exchange and heat loss measured by direct calorimetry agreed exactly at all planes of nutrition. Heat production at zero energy retention was 675 kJ/kg W0·75 per 24 hr.

4. Average daily live-weight gain and total heat loss were the same at all air temperatures. Changes during growth in the partition of heat loss into its sensible and evaporative components indicated that calves acclimated progressively to the air temperatures to which they were exposed.
The energy metabolism of young Jersey and Friesian calves fed fresh milk
Authors: Holmes C. W. , Davey A. W. F.
Published: September 2010

1. Eight British Friesian and eight Jersey calves were fed fresh milk during the period from 3 days to 40 days of age, at two levels of feeding.

2. Energy and nitrogen balances were measured twice for each calf.

3. Fasting heat production (FHP) (MJ/day), which was measured on these occasions, was related to live weight (kg) by FHP = 0·435 W0·75. There was no significant difference in FHP/kg0·75 between the breeds but previous level of feeding and the duration of fast had significant effects.

4. The data for heat production, metabolizable energy (ME) intake and energy retention were interpreted to provide estimates of ‘true’ net energy required for maintenance of 0·23–0·27 MJ/kg0·75 daily.

5. Pooled values for ME required for maintenance and for the net efficiency of utilization of ME above maintenance were 0·39 or 0·42 MJ ME/kg0·75 daily, and 0·67 or 0·72 determined by simple or multiple regression techniques respectively; there were no significant differences between the breeds. Pooled values for the partial net efficiencies of utilization of ME for the synthesis of protein and fat were 0·54 and 0·79 respectively.

6. ME required above maintenance was estimated to be 11·3 and 13·6 MJ ME/kg of live-weight gain for the lower and higher rates of gain respectively.

7. A small experiment revealed no major differences between diets of milk alone or milk plus solid food, with regard to maintenance requirement or net efficiency of utilization of ME by calves.
Reproductive performance of Zebu compared with Charolais × Zebu females in a humid tropical environment
Authors: Madalena F. E. , A. Hinojosa C.
Published: September 2010

Components of reproductive efficiency of Zebu-type and Charolais × Zebu-type (1/2, 3/4 and 7/8) females were compared. Zebus had longer mean intervals from calving to first service (57·8 days) and from calving to conception (46·0 days). Least squares means for both traits were respectively 129·8 and 145·1 days. Correspondingly, in the Charolais cross group 26·4% more cows were detected in oestrus within 180 days of calving, and 31·4% more conceived in the same period. Least squares means for these traits were respectively 80·7 and 50·5%.

No significant differences were found between the two breeding types either in number of services per conception or in the percentage conceiving by artificial insemination (of those showing oestrus) both for lactating and dry females. A higher percentage of oestrus cycles of normal duration was found in Charolais cross (72·9 %) than in Zebus (63·1%). Gestation lengths of Zebus (Indu-Brasil sires) and Charolais cross (Charolais and Simmental sires) were respectively 288·8 and 283·1 days.

The main difference between breed types was the longer lactation anoestrus shown by Zebus. These were very sensitive to seasonal effects, showing a cyclical time trend with peaks of shorter anoestrous periods for cows calving in January–February–March, and longer ones for cows calving in July–August–September. Related traits followed parallel cycles. Charolais cross cows showed less variation than Zebus.