bluuebunny/crossref_metadata_2025 huggingface dataset:
An assessment of the biological and economic efficiency in conversion of milk to growth in N'Dama calves
Authors: Agyemang K. , Clifford D. , Little D. A.
Published: September 2010

Two groups of eight N'Dama calves were fed different quantities of milk from birth to 10 months of age to compare efficiencies of converting milk to live-weight gain, and to assess the economic efficiencies of the two feeding regimes. Group 1 received an average of 347 (s.e. 2·4) kg per calf, with a daily and seasonal pattern of feeding designed to simulate a village production system where calves have access to only part of the milk produced by their dams, the rest being extracted for human consumption. Group 2 received an average of 617 (s.e. 5·1) kg per calf, and simulated situations where no milk is extracted such as in a ranch or station-type of operation.

During the first 6 months, when growth was certainly mediated only by milk, and live-weight gains were consistently positive at 151 and 262 g/day in groups 1 and 2 respectively, the biological conversion of milk to live weight did not differ between groups (8·7 v. 8·8 kg milk per kg live-weight gain). When the two groups were compared over the same weight range to remove possible effects of variable maintenance requirements, the conversion efficiencies again did not differ significantly. Over the whole 10-month period the biological conversion factors were slightly less favourable but still not different between groups (9·5 v. 9·4 kg/kg). When monetary values of milk and live weight at farmgate prices were applied to quantities of milk consumed and calf live-weight increases, the cost efficiency of group 1 was superior to that of group 2.

Based on these findings and results from other on-farm experiments in The Gambia, it was concluded that the current practice of partial milk extraction as occurs in the village production system is a logical approach for profit maximization.
Lamb mortality in Scottish hill flocks
Authors: Gunn R. G. , Robinson J. F.
Published: September 2010

1. Records on lamb mortality from birth to marking at approximately 6 weeks are summarised for four seasons in one Cheviot and three Scottish Blackface flocks and discussed in relation to the breed, environmental and management differences existing on the three farms of Sourhope, Roxburghshire; Lephinmore, Argyllshire and Glensaugh, Kincardineshire.

2. The mortality rates in single-born lambs from three-year-old and older ewes, following hill lambings, were 12% and 6% respectively in the Cheviot and Blackface flocks at Sourhope and 14% in the Blackface flock at Lephinmore. In the Blackface flock at Glensaugh, the mortality rate following regular pre-lambing feeding and lambing on cultivated pastures was 5%.

3. There was considerably heavier mortality in twin-born lambs, and in single-born lambs from two-year-old ewes, notably as a result of increased loss subsequent to birth.

4. Among single-born lambs, more males were lost than females, the difference being between 1% and 8% according to the farm and being largely due to a greater frequency of difficult births among males.

5. Lambs with birth weights markedly heavier or lighter than average had a higher percentage of mortality.

6. An abnormal incidence of loss from difficult birth in a Cheviot sub-flock in 1957 is described.
A comparison of cubes and meal for growing and fattening pigs
Authors: Laird R. , Robertson J. B.
Published: September 2010

1. Thirty-six Large White fattening pigs, eight to nine weeks old at the beginning of the trial, were used to study the effects of cubing pig rations.

2. There were three treatments, meal, cubes and cubes reground to meal.

3. Pigs fed on cubes had significantly higher growth rates (by 0·09 ± 0·03 lb. per day or 7·1%) than those fed on meal.

4. Food conversion was significantly lower, by 0·18 ± 0·05 lb. feed per pound gain, for cube-fed pigs. The saving in feed was 5·1% for the complete fattening period, this difference being statistically significant (P < 0·001).

5. No significant differences between treatments were recorded for any of the carcass measurements.

6. Meal-fed pigs had significantly lower dressing-out percentages than those fed cubes.

7. There were no significant differences in performance between pigs fed on cubes and ground cubes.
Further studies on the water requirements of the growing pig
Authors: Barber R. S. , Braude R. , Mitchell K. G.
Published: September 2010

1. Results of an experiment involving 48 individually-fed pigs, covering the growing period between about 40 and 208 lb. live-weight, indicated that reduction in the amount of water allowed per lb. of meal from 3 lb. to 2 lb. or 1½ lb. had no significant effects on either the performance or the carcass quality of the pigs.

2. Provision of an unrestricted supply of water, in addition to the allowance of 1½ lb. added to each lb. of meal, resulted in a significant improvement in the rate of weight gain which was caused almost entirely by an increase in daily meal consumption by these pigs.

3. Under the conditions of the experiment, the provision of water ad lib. was not accompanied by any adverse effects on carcass quality, although conditions under which it might do so are discussed.

4. The data on water consumption of the pigs indicated that the observed effects on performance of providing water ad lib. did not arise as a result of a deficiency in the total water intake of the pigs given a restricted supply. The possibility is discussed that the length of time that water was available to the animals might be of importance.
A genotype-environment interaction experiment with bacon pigs
Authors: King J. W. B.
Published: September 2010

A genotype-environment interaction experiment was carried out on a total of 140 pigs. Three genotypes, produced by mating an inbred boar of each of the Large White, Landrace and Wessex Saddleback breeds to Large White sows, were fattened on conventional rations and on a high growth ration with 10% fat and growth promoting additives.

The high growth ration increased growth rate by 34% and improved food conversion ratio by 26% and gave a higher dressing-out percentage, but produced shorter and fatter carcasses. No significant genotype-environment interactions were found for growth rate or food conversion. A significant interaction was found for streak thickness but not for other carcass measurements.
Intensive beef production 4. The effect on nitrogen retention of all-concentrate diets containing different levels of fish meal
Authors: Bowers H. B. , Preston T. R. , McDonald I. , MacLeod N. A. , Philip Euphemia B.
Published: September 2010

1. All-concentrate diets given ad libitum and containing different levels of fish meal, and varying in crude protein content from 16 to 22% in dry matter were given to eight Friesian steers at 150 kg. and at 240 kg. live-weight.

2. At a mean live-weight of 150 kg., the retention of nitrogen increased significantly to a maximum of 41.5 g. per day on the diet having 22% crude protein in dry matter. At 240 kg. live-weight, the maximum retention of 37 g. per day was achieved at 20% crude protein in dry matter.

3. Faecal nitrogen excretion per unit of metabolic body weight was approximately constant at all protein levels and at both live-weights.

4. Urinary nitrogen excretion per unit of metabolic body weight increased with increasing crude protein level in the diet and for any crude protein level was higher at 240 kg. than at 150 kg. live-weight.
The interaction between dietary lipids and fibre in the sheep 2. Digestibility studies
Authors: Devendra C. , Lewis D.
Published: September 2010

Digestibility studies were carried out to establish the inter-relationship between crude fibre and total lipid digestibility in the presence of added calcium or non-ionic detergents. Three levels of calcium, corresponding to daily intakes of 2·3, 4·8 and 22·9 g per sheep, were used in a predominantly ground barley diet (65 to 73%) to which was added 8% beef tallow or maize oil. Two non-ionic detergents were used at 0·1% of the diet: nonyl phenol ethylene oxide and fatty alcohol combined with 3 molecules of ethylene oxide.

With a daily intake of 2·3 or 4·8 g calcium per sheep, supplementation with fat resulted in a reduced fibre digestibility. When the intake was increased to 22·9 g, there was a significant improvement (P<0·05) only for the maize-oil-supplemented diet. Increasing calcium intake, associated with increased calcium digestibility, significantly (P<0·05) depressed total lipid digestibility. Intake of 4·8 g calcium per day was associated with the highest calcium digestibility of 33% digestibility units and the total lipid digestibility of 94%. Maize oil was better digested than beef tallow with the lower level of calcium; the position was reversed with the higher level of calcium supplementation. No advantages were found for crude fibre and total lipid digestibility when detergents were added.

A possible mechanism by which the physical wetting of dietary lipids causes decreased digestibility of the fibre component is discussed.
A note on the effect of once, twice or three times a day feeding with concentrate on the efficiency of utilization of a diet given to beef cattle
Authors: Renton A. R. , Forbes T. J.
Published: September 2010

An experiment was carried out in which equal amounts of concentrate were given to beef cattle once, twice or three times per day, with a basal hay diet. There were no significant differences between treatments in food and water intake, digestibility coefficients, nitrogen balance data or live-weight gain.
The effect of supplementary protein on the performance of dairy cows offered grass silage ad libitum
Authors: Laird R. , Leggate A. T. , Castle M. E.
Published: September 2010

Sixty-four lactating dairy cows (Ayrshire, British Friesian and Shorthorn × Ayrshire) were offered grass silage with a dry-matter content of 258 g/kg, and containing 75 g/kg digestible crude protein and 64·6% digestible organic matter in the dry matter for an average period of 16·7 weeks. The control and supplemented groups, each of 32 cows, received concentrates containing on a fresh basis 14% and 18% crude protein respectively which were offered at the rate of 0·4 kg/kg milk for yields above 2·3 kg/day. The mean daily yields of milk were 17·4 and 19·5 kg/cow, silage dry-matter intake 8·16 and 9·00 kg/cow per day and concentrate dry-matter intake 5·36 and 5·94 kg/cow per day on the control and supplemented treatments respectively and these differences were highly significant. The treatments had no significant effects on milk yield and composition in the post-experimental grazing period.
Production in mature corriedale ewes first mated at 7 to 11 or 18 months of age
Authors: Ponzoni R. W. , Azzarini M. , Walker S. K.
Published: September 2010

Production in 210 mature Corriedale ewes first mated between 7 and 11 or at 18 months of age was studied at Paysandu, Uruguay. Ewes were classified into one of the following five classes according to their oestrous and lambing performance in 1968: (1) reared a lamb; (2) lambed but lamb died; (3) mated but did not lamb; (4) oestrus detected by vasectomized ram, true mating deferred for 12 months; and (4) no oestrus, mating deferred for 12 months. Records on flock performance and mortality were kept from all ewes from 1969 to 1973, when the dental status of all ewes present was assessed.

There were no significant differences between classes in number of ewes lambing per ewe exposed to the ram, number of lambs born per ewe exposed to the ram, number of lambs weaned per ewe exposed to the ram, weight of lamb weaned per ewe exposed to the ram, and pre-mating body weight.

Greasy fleece weight varied significantly (P < 0·01) with class of ewe. The least squares means for ewe classes 1 to 5 were 3·93, 3·99, 4·06,4·12 and 3·92 kg respectively. Class 4 ewes differed significantly (P < 0·01) from class 1 ewes and from class, 3 and 5 ewes (P < 0·05). Class 3 ewes differed significantly (P < 0·05) from class 1 ewes. Other differences were not significant.

Ewe mortality between 1969 and 1973 was independent of class of ewe. The dental status of ewes appeared to vary with class of ewe. Early mating of Corriedale ewes apparently had no adverse effects on mature reproductive performance, but somewhat reduced wool production. If mating is to take place for the first time at 18 months of age, ewes that have shown oestrus previously are likely to exhibit greater overall productivity (wool plus lambs).
A seriatim study, using ultrasonic measurements, of fat depth and m. longissimus area in Hereford bulls, steers and heifers under grazing conditions
Authors: Truscott T. G. , Tulloh N. M. , Whitfield D. E.
Published: September 2010

Abastract

Measurements of live weight and of ultrasonic (Scanogram) fat depth and m. longissimus cross-sectional area at the 12th/13th rib were taken at 4— to 6-week intervals from 10 to 35 months of age (23 occasions) on 15 Hereford males (bulls), 15 castrate males (steers) and 15 females (heifers) managed under grazing conditions.

Mean rates of live-weight change throughout the measurement period (0·51, 0·47 and 0·39 kg/day for bulls, steers and heifers, respectively) were significantly different. When compared at the same ages, fat depth was similar in the steers and heifers, beginning at about 3 mm and increasing to 11 mm. Fat depth changed little in the bulls, beginning at 1·7 mm and increasing to 3 mm. At the same age, bulls had larger m. longissimus cross-sectional areas than steers and steers had larger muscle cross-sectional areas than heifers.

Absolute variation within sex groups increased throughout the experiment in live weight and fat depth, but not in m. longissimus crosssectional area. Simple correlation coefficients, pooled within sex groups, of relationships between the same measurements at various measuring occasions, indicated that measurements of fat depth and of muscle cross-sectional area at 10 to 12 months of age are poor indicators of these measurements at periods of 6 months or more later in life.

When compared at the same live weights, heifers had the greatest and bulls had the smallest fat depth and, within animals, fat depth was closely related to live weight. At any live weight, m. longissimus cross-sectional area was less in heifers than in steers and bulls, which were not significantly different from each other in this trait. Equations relating fat depth and muscle area to live weight are presented and, under the conditions of this study, indicate that there is no basis for adjustment of fat depth for live weight in bulls subjected to contemporaneous selection.
Genetic and environmental influences on beef cattle production in Zambia 3. Carcass characteristics of purebred and reciprocally crossbred castrated males
Authors: Thorpe W. , Cruickshank D. K. R. , Thompson R.
Published: September 2010

Carcass characters for 365 male castrate cattle of the Africander, Angoni, Barotse and Boran breeds, and the reciprocal crossbreds of the latter three breeds, are reported. In each of the two year-of-birth groups, different slaughter-age/management regimes were used. For all carcass characters, except those related to size, the two sanga breeds, Africander and Barotse, were very similar, as were the two zebu breeds, Angoni and Boran. The introduced breeds, Africander and Boran, which had similar carcass weights, had heavier carcasses (+18 kg, +10%) than the indigenous Barotse and Angoni breeds.

The sanga breed carcasses had less fat cover than those of the zebu breeds. Maternal effects were not important for carcass characters and the Angoni/Barotse and Angoni/Boran crosses showed no heterosis. In the Barotse/Boran crosses, slaughter and carcass weights and eyemuscle area gave between 8% and 9·5% heterosis, and the linear carcass measurements between 2% and 3%.

It was concluded from the management comparisons that there was no economic advantage in delaying slaughter to the later of the two ages compared in the two year-of-birth groups.
Biometric properties of lactations in ewes raising single or twin lambs
Authors: Torres-Hernandez G. , Hohenboken W. D.
Published: September 2010

The lactation curves of 21 single- (SR) and 28 twin-rearing (TR)ewes were fitted and milk production was estimated by the model Y = axb e−cx, developed in England for dairy cattle. In addition, persistency of lactation of SR and TR ewes was compared using five procedures reported in the literature. Results indicated that the coefficients that characterize the shape of the lactation curve (b and c values) were of similar magnitude to those reported in dairy cattle, thus denning a curve of similar shape. Lactation curves of SR and TR ewes were essentially parallel throughout lactation, with more milk production from TR ewes. The correlation between total milk production estimated by this model and that based on the sum of partial lactations was 0·98, but variability of milk production as estimated by the latter method was slightly less. Lactations of SR ewes had similar persistency to those of TR ewes.
A note on the influence of ‘boar effect’ component stimuli on puberty attainment in the gilt
Authors: Kirkwood R. N. , Hughes P. E.
Published: September 2010

Forty Large White × (Landrace × Large White) gilts were allocated by litter to one of four treatments, such that one gilt from each of 10 litters was on each treatment. The treatments were: (i) 30-min daily boar exposure; (ii) 30-min daily pen change; (iii) 30-min daily pen change, plus exposure to boar urinary pheromone; and (iv) a control, subject to no stimulation.

The treatments commenced at a gilt age of 165 days and continued either until puberty was detected or a cutoff age of 250 days was reached. Analysis revealed no significant differences between any groups for age at puberty or ovulation rate (determined at slaughter following the second oestrus).
Beef production from silage 2. The performance of beef cattle given silages of either perennial ryegrass or red clover
Authors: Thomas C. , Gibbs B. G. , Tayler J. C.
Published: September 2010

1. A primary growth of perennial ryegrass was cut on 8 to 11 May (early) or on 12 June (late) for comparison with the primary growth of a tetraploid red clover, which was cut either on 1 or 2 June (early) or on 28 June (late). The crops were ensiled, after wilting for about 4h, with the addition of formic acid at 2·21/t fresh crop. The silages were given ad libitum alone or with rolled barley at 11·5 g dry matter per kg live weight to 40 British Friesian steers initially 3 months old and 108 kg live weight.

2. On average there was no significant difference in digestibility between perennial ryegrass and red clover. However, the rate of decline in digestibility with time was greater with perennial ryegrass than with red clover.

3. Calves given silage of red clover as the sole feed ate more dry matter and grew faster than calves given grass silage (P <0·001) but supplementation with barley reduced the intake of red clover silage to a greater extent than that of perennial ryegrass silage. Barley supplementation increased live-weight gain of calves given perennial ryegrass from 0·32 to 0·83 kg/day and that of calves given red clover from 0·63 to 0·99 kg/day (interaction P <0·05). The results did not indicate a higher net efficiency of utilization of the legume. Date of cut had no significant effect on dry-matter intake but earlier cutting resulted in an increase in live-weight gain from a mean of 0·61 to 0·77 kg/day (P <0·001).

4. The results show that high rates of live-weight gain (0·74 kg/day) can be achieved by calves given silage of red clover and that earlier cutting of herbage for silage does not always result in higher intakes of dry matter. Supplementation of silages with barley can reduce markedly the difference in intake and live-weight gain apparent when the silages are given as sole feeds.
Copper supplementation of isonitrogenous diets for growing pigs containing white-fish meal or soya bean meal as the protein supplement
Authors: Barber R. S. , Braude R. , Mitchell K. G.
Published: September 2010

1. Two trials were carried out to investigate the effects of high-copper supplementation of isonitrogenous diets containing either white-fish meal or soya bean meal as the sole protein supplement.

2. There was no difference in performance between the two diets when they were fed unsupplemented with copper in trial 1. The addition of 250 mg copper per kg diet significantly and similarly improved performance on both diets.

3. Liver-copper stores, but not kidney-copper stores, were significantly increased when the copper-supplemented diets were fed. The level of the liver-copper stores on the soya bean meal supplemented diet was, however, some 400g/kg less than that on the white-fish meal supplemented diet. The significance of this clearly established finding is discussed.
A note on the diurnal activity of early-weaned piglets in flat-deck cages at 3 and 6 weeks of age
Authors: Wood-Gush D. G. M. , Csermely D.
Published: September 2010

The behaviour of eight litters of Large White × Landrace piglets aged 3 weeks was scored in flat-deck cages every 2min for 12 h during the day, noting the frequences of 11 behaviour patterns. Similar observations were made at 6 weeks of age, and five main activities at the two ages were compared. There was a significant decrease in the frequency of aggressive encounters between the two ages, while the other activities remained at the same frequencies. The proportion of scores devoted to the main activities is given.
A function for live-weight change between two calvings in dairy cattle
Authors: Korver S. , van Arendonk J. A. M. , Koops W. J.
Published: September 2010

A function to describe live-weight changes of dairy cows between two calvings is constructed. The following measurements were used: live-weight level (scale), pregnancy parameter, maximum decrease of live weight during the lactation and the time during lactation at which minimum live weight occurred.

An analysis was carried out for each of 71 dairy cows of two genotypes, Dutch Friesian and Holstein Friesian crossbreds, given a high or a low concentrate diet. Data set 1 contained data of 40 weeks lactation and data set 2 data from calving to calving.

The mean residual standard deviation per genotype-diet group ranged from 11 to 14 kg. The mean R2 ranged over the subgroups in data set 1 from 0·715 to 0·792 and in data set 2 from 0·857 to 0·906. Diet had a significant influence on the magnitude of the decrease in live weight during the lactation (71 v. 46 kg) and the mean time during the lactation at which minimum live weight occurred. The latter time ranged from day 58 to 100 over the four groups and a diet effect existed. The pregnancy parameter could not be estimated accurately based on measurements during the first 40 weeks of lactation. The correlation coefficient between the pregnancy parameter in data sets 1 and 2 ranged from +0·13 to +0·78. The other parameters showed coefficients from +0·82 to +0·99.
The effect of fish meal and sucrose supplementation on the voluntary intake of grass silage and live-weight gain of young cattle
Authors: England P. , Gill Margaret
Published: September 2010

In an experiment designed to investigate the effects on the growth and voluntary food intake of grass silage by calves, the silage was supplemented with varying levels of fish meal and sucrose. The grass silage had a pH of 3·6, a lactic acid content of 90·0 g/kg dry matter (DM) and total nitrogen content of 15·5 g/kg DM. Supplements of 50, 75 and 100 g fish meal per kg silage DM and 50, 75, 100 and 150 g sucrose per kg silage DM were mixed with the silage just prior to feeding. The eight diets were offered to 32, 4-month-old British Friesian steers for 12, 7-day periods. Intake was recorded daily and live weight weekly.

Digestibility of organic matter (P < 0·05) and N (P < 0·001) were increased by fish-meal supplementation but the effect of level of fish meal was not significant. Sucrose supplementation significantly decreased both N (P < 0·01) and cellulose (P < 0·05) digestibility. The effect on cellulose digestibility increased with level of sucrose (P < 0·01).

The intake of silage DM increased in response to increasing level of fish-meal inclusion when intake was expressed in terms of kg/day (P < 0·01) but not when expressed in g/kg live weight. Total DM intake showed a significant (P < 0·001) linear response when expressed both in terms of kg/day and g/kg live weight. The intake of silage DM declined in response to increased level of sucrose supplementation both in absolute (P < 0·05) and live-weight terms (P < 0·001) but sucrose supplementation had no significant effect on total intake.

Live-weight gain was significantly increased with increasing level of fish-meal supplementation (P < 0·001), but sucrose supplementation had a significant effect on live-weight gain relative to the control treatment at only the 75 g/kg level, where live-weight gain was increased.
An evaluation of the Hennessy Grading Probe and the SFK Fat-O-Meater for use in pig carcass classification and grading
Authors: Kempster A. J. , Chadwick J. P. , Jones D. W.
Published: September 2010

The Hennessy Grading Probe (GP) and the SFK Fat-O-Meater (FOM) are instruments capable of automatically measuring fat and muscle thicknesses from the differential light reflectance of tissues. They may offer advantages in the precision and cost of measurement over the simpler optical probe (OP). The GP and FOM were used on the slaughterline at nine abattoirs to measure fat thickness over the m. longissimus dorsi (MLD) and MLD depth at the last rib (LR) and third to fourth from last rib (3/4 LR) positions. The probes were used alternatively on runs of 100 carcasses which were also measured for LR fat thickness by OP in the normal course of carcass classification. In all 4642 (GP) and 5760 (FOM) carcasses were measured. A further 130 carcasses sampled from six of the abattoirs were measured by all three probes and their left sides were dissected into component tissues. The performance of the automatic probes relative to the OP was found to differ between abattoirs. The FOM worked more effectively on the slaughterline, requiring fewer repeat readings to obtain a satisfactory measurement than the GP. Both automatic probes gave more precise results when used at the 3/4 LR position. In the overall sample, residual s.d. for the prediction of OP-measured fat thickness were 2·33 mm (GP) and 2·07 (FOM). Residual s.d.'s for the prediction of carcass lean content from 3/4 LR fat thickness were 30·8 g/kg (OP), 36·6 (GP) and 31·4 (FOM). Addition of MLD depth provided a significant improvement in precision; residual s.d. were 35·9 g/kg (GP) (P < 0·05) and 29 1 g/kg (FOM) (P < 0·001). These results rate the FOM as superior but the differences are not large enough to discount the GP.
A note on the effect of feeding frequency on nitrogen use in growing boars given diets with varying levels of free lysine
Authors: Partridge I. G. , Low A. G. , Keal H. D.
Published: September 2010

The effect of frequency of feeding on the efficiency of utilization of L-lysine hydrochloride supplements was studied in 30- to 60-kg pigs. The feeding regimes were: (A) once daily, (B) twice daily, (C) four times daily between 08.30 and 20.30 h, (D) four times daily at 6-h intervals. The response criterion was urinary-nitrogen (N) excretion during 5-day periods. Linear improvements in N utilization were seen in response to lysine supplementation: (a) of a mineralized barley diet (4·0 g lysine per kg to levels of 5·0 and 6·0 g/kg (trial 1)), and (b) of a barley-soya diet (5·5 g lysine per kg to levels of 6·8 and 8·1 g/kg (trial 2)). In both trials the efficiency of N use averaged over the three diets was significantly poorer with once-daily feeding than for the other three treatments, which did not differ significantly from each other.
A study of water allowances for the bacon pig
Authors: Holme D. W. , Robinson K. L.
Published: September 2010

The results of two experiments, involving 72 individually fed pigs during a growing period between about 40 and 200 lb. live-weight, indicated that a water allowance of 1½ lb. per 1 lb. meal in place of 2½ lb. water had little effect on the performance of the pigs or on carcass measurements. With unrestricted water there were considerable differences in intakes between experiments but these were without significant effects on the criteria studied, when compared with the respective fixed water to feed ratios.

In the first experiment, but not in the second, a dietary supplement of penicillin was associated with a reduced voluntary intake of water. The penicillin was without overall effect on performance or carcass composition, but was associated with a significant growth response up to 100 lb. live-weight in the first experiment.

In both experiments females were less fat than castrates, as indicated by significantly different carcass densities and by some linear measurements.
The use of station and field tests for the improvement of milking performance in dairy cattle. II. Milking rate and time as indicators of a cow's milking ability
Authors: Hinks C. J. M. , Nielsen E. O. , Neimann-Sørensen A.
Published: September 2010

An investigation of milking ability in three dairy breeds has shown that selection for superior productive performance would contribute little to the improvement of milking time. The heritability of both average rate of flow and milking time was reasonably high in all three breeds, however, and direct selection should result in effective improvements.

The problem of slow milking was more acute in the Danish Red breed, in which almost one cow in ten needed more than six minutes to milk out, than in the Black Pied or Danish Jersey breeds.

A comparison of the average rate of flow and milking time as criteria of selection for milking ability indicated that both measures were equally effective in the Black Pied and Jersey breeds, but that rate of flow was considerably more (40%) effective than milking time in the Danish Reds. This was largely because the heritability of milking time in this breed was only one-third that of milking rate.

It was concluded that the average rate of flow was to be preferred to milking time as a criterion of selection for milking ability in the Danish station testing programme.
Change in the rate of eating during a meal and the effect of the interval between meals on the rate at which cows eat roughages
Authors: Suzuki Shozo , Fujita Hiroshi , Shinde Yozo
Published: September 2010

1. The rates of eating silages and hay throughout a meal were recorded in eight cows consecutively using a special manger and an automatic recording apparatus. At each meal the rate of eating was highest in the first five or ten minutes and then fell gradually. These characteristics were observed both on silages and on hay and for all the experimental cows. The mean rates of eating hay, but not of silages, agreed with previous reports.

2. The highest rate of eating was slightly faster at the evening meal than at the morning meal, when cows received equal amounts of feeds twice each day. The rate of eating declined at much the same rate throughout each meal when the cows received from 2 to 5 meals daily.

3. When the cows were fed twice daily, the rate of eating throughout a meal was not affected by changing the interval between meals from 12 hr to 6 hr.

4. When cows were given large amounts of feed at any one time, three stages of rate of eating, fast, decreasing and slow, were recognized.

5. The quality of feed, individuality of cow and pregnancy evidently affected the rate of eating throughout a meal.
Albumin polymorphism in British cattle
Authors: Spooner R. L. , Oliver R. A.
Published: September 2010

A survey of albumin polymorphism in the major breeds of cattle in the British Isles is described. Four and probably five alleles have been found.AlbAis the common type in all breeds.AlbBoccurs with less than 1 % frequency in all breeds except Sussex and Charolais, where it has a frequency of 12% and 16% respectively. The possible implications of this finding are discussed. The other allelesAlbC(Ed)andAlbDare extremely rare, and are confined to a few animals each within one breed.AlbGhas been tentatively proposed as the name for a new albumin type.
Thyroid function as measured by131iodine release rate, weight and RNA/DNA in growing lambs, and its relation to growth rate
Authors: Draper S. A. , Haynes N. B. , Falconer I. R. , Lamming G. E.
Published: September 2010

Thyroid activity was assessed in two groups of crossbred lambs and in Dorset Horn lambs fedad libitum, by measuring the rate constant (K4) for the release of131iodine from the gland. The results demonstrated a highly significant curvilinear correlation (P<0·001) between growth rate and the rate constant (K4) in experiments based on individual measurements in animals from three populations.

Separate work carried out on the measurements of both thyroid size and RNA/DNA ratio suggests a need for caution when these are interpreted as parameters of thyroid activity. In the growing animal these may be more reflective of the growth of the thyroid gland itself, differences which may be governed by factors not directly related to variations in hormone secretion rate.

The findings are discussed in terms of an explanation of the contradictory results obtained where attempts have been made to alter the thyroid status of growing animals by the use of thyroid hormone analogues and thyroid depressant drugs.
The effect of birth weight on the estimated milk intake, growth and body composition of sow-reared piglets
Authors: Campbell R. G. , Dunkin A. C.
Published: September 2010

Ten littermate pairs were used to study the effects of light and heavy birth weight on the development of muscle tissue, growth rate, body composition and the estimated milk consumption of piglets reared on the sow to 6·5 kg live weight.

Neither average daily gain to 6·5 kg nor body composition at the latter weight were significantly affected by birth weight. Birth weight also had no effect on the weight or deoxyribonucleic acid content of the semitendinosus musde at 6·5kg. However, pigs of hght birth weight -were lighter at 2\ days of age (P < 0·01) and older at 65 kg (P < 0·01) than those of heavy birth weight.

Pigs of heavy birth weight consumed more milk per suckle than their lighter birth weight littermates (P < 0·01). However, the relative milk consumption (g/kg live weight) of both groups was similar.
A note on the grazing behaviour of young bulls and steers
Authors: Hinch G. N. , Thwaites C. J. , Lynch J. J.
Published: September 2010

The grazing behaviour of bulls and steers was examined by observation and the use of vibra-recorders. Twenty-four-h grazing times were similar for both bulls and steers but grazing patterns differed, with bulls being more sensitive to environmental change and grazing more intermittently than steers.
The effect of type of concentrate and level of concentrate feeding on milk production
Authors: Mayne C. S. , Gordon F. J.
Published: September 2010

Twenty-four British Friesian dairy cows in early lactation were used in a change-over design experiment with three periods, each of 4 weeks duration. The aim of the experiment was to assess the effects of both the type of concentrate and the level of concentrate supplementation on the utilization of grass silage for milk production. Four treatments consisted of offering 10 kg/day of either a barley (10B) or a sugar beet pulp-based concentrate (10S), each concentrate being offered at two crude protein concentrations of 175 (low) and 245 (high) g/kg dry matter. In a further two treatments the barley-based concentrates containing the low and high protein concentrations were offered at 7 kg/day (7B). All concentrates were offered in addition to the cows having ad libitum access to grass silage containing a dry-matter concentration of 213 g/kg and a digestible organic matter concentration of 668 g/kg dry matter.

Silage dry-matter intakes (kg/day) for cows given the low- and high-protein concentrates respectively were: 9·06 and 9·28 for the 7B treatments; 8·21 and 8·33 for the 10B treatments; and 8·04 and 7·97 for the 10S treatments (pooled s.e. 0·11). Fat-corrected milk yields for cows given the low- and high-protein concentrates respectively were: 24·0 and 24·1 for the 7B treatments; 25·9 and 27·0 for the 10B treatments; and 25·7 and 26·2 for the 10S treatments (pooled s.e. 0·57).

The higher level of concentrate feeding significantly increased milk yield (P < 0·001) whereas neither energy source nor protein concentration in the concentrates had a significant effect on milk yield (P > 0·05). There was a trend towards a greater response to increased protein concentration at the higher level of feeding.
Performance of lambs from three crossbred ewe types
Authors: Cameron N. D. , Smith C. , Deeble F. K.
Published: September 2010

The performance of predominantly Suffolk-sired lambs from Border Leicester (BL), Bluefaced Leicester (BFL) and ABRO Damline (DL) crossbred ewes was compared on 18 commercial and college farms throughout England and Wales. The comparison took place over the 5-year period 1977 to 1981 and was the second stage in a comparative study on the productivity of the crossbred ewes. A total of 1277 crossbred ewes were involved with data on up to 3 years lambings per ewe, giving a total of 3522 mating records and 4864 lamb records.

The BFL lambs were heaviest and the DL lambs were lightest. The DL lambs had the lowest survival rates, and the BFL lambs the highest. The BFL lambs were slaughtered earlier (12 days) and at heavier weights (1·4 kg) than the DL and BL lambs, and had slightly heavier carcasses. The DL and BFL carcasses had better MLC carcass classifications than the BL, resulting in an advantage of 4 p/kg of carcass.

In productivity per ewe, the BFL litters had the highest slaughter and carcass weights and the highest income per litter, with the DL litters intermediate. An attempt was made to express productivity per unit of sheep weight maintained, taking account of ewe weight, litter size and the lamb slaughter date. On this index, the DL were marginally superior to the BFL, and both were superior to the BL.
Some factors influencing the availability of colostrum to piglets
Authors: Fraser D.
Published: September 2010

Five experiments, involving the hand milking of 53 farrowing sows, examined aspects of colostrum yield during and soon after farrowing. The initial and abundant yield of colostrum from a teat (averaging 6 to 10 g/min) declined after several minutes of continuous milking. Thereafter, most colostrum was released in discrete ejections, possibly caused by discrete releases of oxytocin. Colostrum ejections varied greatly in their yield and duration, and were sometimes associated with the birth of a piglet, sounds of other sows nursing, or other factors.

Teats varied greatly in their yield. During the initial minutes of milking, the most anterior teats gave, on average, 3 to 5 times more colostrum than the most posterior teats, with a nearly monotonic decline from front to rear. However, the difference between anterior and posterior teats disappeared after several minutes of continuous milking. Stimulation of the anterior teats appeared to cause the release of more colostrum than did either the stimulation of the posterior teats or no stimulation of the udder at all. A strong sucking stimulus, applied to several teats by a milking machine, elicited a large, prolonged release of colostrum.

The results suggest that (1) much of the colostrum received by newborn piglets is obtained in discrete ejections rather than in a continuous manner; (2) appropriate stimulation of the udder by the piglets may be important to elicit maximum colostrum yield; and (3) a high initial yield from anterior teats, coupled with a higher yield when anterior teats are stimulated, may help to explain the piglets' preference for anterior positions on the udder.
The effects of exogenous bovine growth hormone and bromocriptine on growth, body development, fleece weight and plasma concentrations of growth hormone, insulin and prolactin in female lambs
Authors: Johnsson I. D. , Hart I. C. , Butler-Hogg B. W.
Published: September 2010

In crossbred female lambs given a concentrate diet ad libitum between 8 and 20 weeks of age, daily subcutaneous injections of 0·1 mg bovine pituitary growth hormone (GH) per kg live weight increased daily live-weight gain (347 v. 284 g/day; P < 0·01; no. = 8), food conversion efficiency (3·94 v. 4·49 kg dry matter per kg gain; P < 0·01) and greasy fleece weight (1·49 v. 0·99 kg; P < 0·001). The increase (4·8 kg) in final live weight was due primarily to an increase in the non-carcass components of the body (3·5 kg), with little effect on carcass weight (1·3 kg). However, bovine GH treatment markedly increased the weights of lean tissue (11·4 v. 9·2 kg; P < 0·001) and bone (2·8 v. 2·4 kg; P < 0·001) and moderately reduced the weight of fat (7·0 v. 8·0 kg; P < 0·10) in the carcass. The bovine GH treatment raised plasma concentrations of immunoreactive GH within the physiological range for about 16 h each day and significantly increased mean plasma concentrations of insulin and prolactin. Daily injection of 1 mg bromocriptine had no effect on daily live-weight gain, food conversion efficiency or carcass composition. This treatment markedly reduced plasma concentrations of prolactin but also significantly reduced insulin concentrations. When given in combination with bovine GH, bromocriptine reduced the GH-induced stimulation of insulin concentration and tended to decrease the effects of GH on food conversion efficiency and growth. This interaction was significant only for the effects on greasy fleece and skin weights (P < 0·01).
Multibreed designs 3. Inter-breed relationships
Authors: Taylor C. S. , Hnizdo Eva
Published: September 2010

Experimental designs with optimal allocation of animals within and between breeds are given for investigating inter-breed relationships between different traits. Optimal designs are given for estimating the following between-breed parameters: the genetic regression with breeds random, the genetic correlation, the ratio of genetic standard deviations for two traits and also the comparison of regressions within and between breeds. As in the case of between-breed variation, these turn out to be multibreed designs with a few animals per breed and usually as many different breeds as possible. Formulae are given for obtaining optimal numbers and estimation errors for traits with intra- and inter-breed correlations lying within restricted ranges.

If an exepriment with a multibreed design is to be effective, the optimum number of animals (or sires) per breed would normally lie between two and 10. If the optimum number per breed is much greater than 10, the experiment is unlikely to be worthwhile unless the total number of animals is large (at least several thousand).
Genetic improvement of litter size in pigs
Authors: Avalos E. , Smith C.
Published: September 2010

Despite the low heritability (0·1) for litter size in pigs, quite high rates of genetic improvement are predicted theoretically using conventional selection methods. The highest rates are predicted from schemes with rapid generation turnover (1 year) and with selection of both males and females at breeding age on a family selection index. This index would combine litter records (two on each relative) of the dam, her full sibs and half sibs, and of the sire's dam and his full sibs and half sibs. Annual rates of genetic change of up to half a pig per litter (a proportion 0-05 of the mean) are predicted. This rate is substantially greater than the proportional rates of genetic change possible for growth and carcass traits. These predictions are fairly insensitive to maternal and rearing environmental effects which may affect litter performance. High response rates are also predicted from two-stage selection of males, first on family index as before and then on progeny test of daughters in a large artificial insemination bred population. Intense screening in a large population for females with high litter records (hyperprolific females) can be an effective way to start an improvement programme for litter size. However, continuous screening of hyperprolific females is less effective because of the long time taken to generate enough descendants needed for the next round of intense selection. Despite the high rate of genetic change possible for litter size, omission of the trait from an index which includes growth and carcass traits would result in only small losses (proportionally less than 0·05) in economic improvement of general purpose stocks under United Kingdom market conditions. However, the losses would be higher (proportionally 0·10 to 0·18) in specialized dam stocks and inclusion of litter size in an index when selecting such stocks would be worthwhile.
Transferrins and milk production in dairy cattle
Authors: Ashton G. C. , Hewetson R. W.
Published: September 2010

Milk and butterfat production data from eight herds of dairy cows in Australia for the years 1963 and 1964 were analyzed for relationship with serum transferrin type. In the 932 lactations considered D2/D2 cows produced 521 ± 152 lb of milk more than A/A cows and lactated 15·3 ± 7·8 days longer after correction for season. There was no difference in fat percentage of the milk. The production of A/D2 cows was also significantly higher than A/A cows, but less than D2/D2 cows. Allowing for differences in lactation length still left a significant difference between D2/D2 and A/A cows in milk yield.

The best estimate of the effect of replacing aTfAby aTfD2gene, allowing for season, was 170 lb more milk (P<0·01) and 6·5 days longer lactation (P<0·05), whileTfD1did not differ fromTfAin either yield or lactation length.