bluuebunny/crossref_metadata_2025 huggingface dataset:
Growth, food consumption and litter production of female pigs mated at puberty and at low body weights
Authors: Pay M. G. , Davies T. E.
Published: September 2010

Gilts were allocated at 55 kg live weight to one of three treatments: 1. 1·4 kg of food daily to service, served at puberty, and 1·4 kg of food daily throughout pregnancy.

2. 1·4 kg of food daily to service, served at the third heat, and 1·4 kg of food daily during pregnancy.

3. 2·3 kg of food daily to service, served at the third heat, and 1·4 kg of food daily during pregnancy.

An attempt was made to encourage early puberty by stimulation using the presence of a boar. Natural service with boars was used on all gilts.

There were no significant differences between the treatments in time taken to reach puberty and the gilts were mated at 77, 97 and 116 kg live weight on Treatments 1, 2, and 3 respectively. The gilts on Treatment 1 had a significantly lower conception rate and a significantly smaller litter size than those on Treatments 2 and 3. However, the average birth weight did not vary significantly among treatments.
A note on the social behaviour of a flock of Merino and Wiltshire Horn sheep
Authors: Winfield C. G. , Mullaney P. D.
Published: September 2010

The behaviour of 12 Merino and 12 Wiltshire Horn ewes was observed on the day they werefirstintroduced together into a 0·85 ha paddock and over the following 9 days. Neither breed group had associated with sheep of the other group previously. Both groups formed and maintained their own strong social groupings, and despite the small area of pasture and enforced close association each day, no significant integration of the groups was observed.
The nutritive value of cooked potato in liquid and creep diets for early-weaned calves
Authors: Hinks C. E. , Armishaw Alison M.
Published: September 2010

1. In three experiments, 112 7-day-old British Friesian male calves were used in performance and digestibility trials to evaluate dried cooked potato in liquid and creep diets.

2. A 15% depression in growth rate for each 10% inclusion of cooked potato flour in liquid diets was recorded from 4 to 21 days and the faeces of potato-fed calves also tended to be less solid. Over the whole feeding period, liquid diets containing up to 20% potato did not significantly depress performance to weaning at 35 days.

3. Only when a liquid diet containing potato starch was introduced prior to 4 weeks of age was daily live-weight gain markedly depressed.

4. Incorporating potato starch in milk diets did not influence creep intake.

5. Calves offered a creep diet containing 40% cooked potato flake ate less, but grew faster than calves given a diet containing 40% flakedmaize. At constant intakes of creep, daily gains were 14 to 18% greater on the diet containing potato flake.

6. The apparent digestibility of gross energy and nitrogen was 0·67 and 0·66 for the flaked maize creep and 0·71 and 0·69 for the potato creep. Digestible energy and digestible nitrogen values were 12·7 MJ and 18·2 g/kg dry matter for the maize diet and 13·0 MJ and 19·0 g/kg dry matter for the flaked potato diet.

7. The incidence of bloat was higher for calves fed on potato than for those fed on maize.
A note on performance traits of crossbred beef × dairy steers finished on fast- and slow-gaining feeding regimes
Authors: Lalande Gaspard , Fahmy M. H.
Published: September 2010

A total of 178 castrated male cattle (steers), the progeny of Charolais, Hereford and Limousin bulls mated to Holstein-Friesian and Ayrshire cows, were raised from 8 months of age to 545 kg (slaughter weight) on fast- or slow-gaining regimes. The steers on the fast gaining regime were fed a grain mixture with little hay, while those on the slow-gaining regime grazed all summer and were wintered on hay supplemented with a little grain.

The steers on the fast-gaining regime were more efficient in feed conversion ratio, had 0·42 kg per day higher live-weight gain, reached slaughter weight 306 days earlier, and had 2% higher dressing-out percentage, 5·7 mm thicker fat and 5 mm2 larger area of m.longissimus thoracis than those on the slow-gaining regime.

Charolais-sired steers on both regimes had the fastest gain and were the first to reach slaughter weight. Limousin-sired steers raised on the fast-gaining regime had the highest dressing-out percentage, and the largest area of m. longissimus thoracis on both regimes. Hereford-sired steers had the thickest fat cover and the smallest area of m. longissimus thoracis. Little difference was found between the steers from Holstein and Ayrshire cows.
A note on the effect of rearing experience upon the development of sexual behaviour in ram lambs
Authors: Bryant M. J.
Published: September 2010

Sixteen cross-bred male lambs were assigned to either a group- or a single-rearing treatment up to 150 days of age. After this time the single-housed rams were penned together and all rams were tested weekly for their abilities to successfully mate with ewes for a further 10 weeks. There were no marked differences in the development of sexual behaviour between the two treatments.
Soaking of complete fattening rations high in poor roughage 1. The effect of moisture content and spontaneous fermentation on nutritional value
Authors: Holzer Z. , Levy D. , Tagari H. , Volcani R.
Published: September 2010

The effect of three moisture concentrations (10, 50 and 75%) and of four fermentation conditions (none, 24 hr aerobic, and 24 and 48 hr anaerobic) on the nutritive value of two complete fattening diets containing 25 and 45% poor roughage, was examined in three digestion and nitrogen balance trials, each of Latin square design, in cattle.

Fermentation increased the lactic acid and volatile fatty acid concentrations of the feed, decreased its pH and the crude fibre content, and caused losses of dry matter.

There were non-significant differences in voluntary intake between the dry and soaked diets. The apparent digestibility of dry and organic matter, crude protein, nitrogen-free extract and crude fibre was non-significantly improved by added moisture. There were no consistent differences in nitrogen retention.

The average metabolizable energy values (ME) observed for both diets were 6% higher than those calculated. There were no significant differences in the apparent digestibility of gross energy or in ME value between treatments of different moisture content.

The fluctuations in pH of rumen liquor during the day differed markedly when the animals received different levels of roughage. These differences were greater when the feed was allowed to ferment. Soaking of feed resulted in a significant increase in the concentration of propionic acid in the rumen liquor, and a non-significant decrease in that of acetic acid. Consequently the C2/C3ratio was significantly lower on the moist feed treatments.

There were no consistent differences in concentration of ammonia in the rumen liquor, or of urea in the blood.
Effects of stage of gestation and litter size on prenatal growth in the mouse
Authors: Koong Ling-Jung , Bradford G. E.
Published: September 2010

A theoretical equation is proposed which describes the dynamics of foetal growth in mice. The equation is basically of exponential form and takes into account the effects of stage of gestation (T) and number of foetuses (N) on the instantaneous relative growth rate. The model was tested against experimental data by using a stepwise regression technique. Both stage of gestation and number of foetuses had significant effects (P< 0·01) on the instantaneous growth rate. When the model was tested against another set of data 44 out of a total of 52 comparisons had a prediction error less than 15 %. As a result, the following equation is proposed to describe the foetal growth of mice

W = e-14·34Ne(1·302–0·0276T–0·00059)T

An equation of this form could be useful in interpreting prenatal growth data for other species. Other factors which may influence the dynamics of foetal growth, such as maternal age or weight, could also be incorporated into the equation.
Economic evaluation of selecting sheep for wool production
Authors: Thatcher L. P. , Napier K. M.
Published: September 2010

A technique is described for assessing the profitability of selecting sheep for wool production. A model of the breeding system incorporating three submodels is developed: one to represent the flock from which the selection intensities for rams andewes are calculated; a second to determine gains made in wool production and the year in which they accrue; and the third uses discounting procedures to examine the economics of selecting for wool production.

Flock and genetic parameters were set at ‘average’ values for an Australian Merino wool producer and gains were determined for a range of lambing percentages. Three measures were used to evaluate profitability; the net present value of the programme which shows overall profits, the internal rate of return, which gives the earning rate of the programme, and the payback period, which identifies the number of years before early costs are repaid.

sensitivity analysis was used to examine changes in the three measures of profitability resulting from changes in interest rate, wool price, costs for labour and computer analysis, wool testing costs and lambing percentage. Profitability was sensitive to changes in all parameters except wool testing charges, and of the remainder the producer has a degree of control only over labour costs. A programme can be profitable, however, if wool price and lambing percentage are adequate and costs can be kept at reasonably low levels. Simple breeding programmes should be studied in which labour inputs are kept to a minimum or where costs are confined to studs (nuclei) and genetic gain disseminated by the sale (migration) of rams.
A note on ensiled ear maize and barley in finishing rations for beef cattle
Authors: Umoh J. E. , Holmes W.
Published: September 2010

Ensiled ear maize was compared with rolled barley as the cereal in a finishing diet for cattle weighing about 400 kg. The diets resulted in similar gains of about 1·2 kg/day.
Effects of post-weaning stress and feeding management on return to oestrus and reproductive traits during early pregnancy in swine
Authors: Fahmy M. H. , Dufour J. J.
Published: September 2010

A total of 177 sows representing five two-breed crosses were used in a 2×2 factorial experiment to study the effects of post-weaning stress (changing environment and group housing) and feeding regime (flushing by feeding ad libitum until mating) on the weaning-oestrus interval and other reproductive traits up to 30 days of pregnancy.

The group which was stressed had about 10% (P<0·05) fewer reproductive failures than those not stressed, while little difference was found between the two feeding regimes. About 61% of the flushed sows returned to oestrus within 7 days after weaning, 9% higher than for those not flushed. The stress treatment had little effect on the weaning-oestrus interval. Neither treatment affected ovarian and follicular-fluid weights, percentage of follicles of different sizes, ovulation rate nor number of viable embryos. The flushed group, however, had 9% lower embryo survival than the group not flushed. A positive relation was found between the number of days on ad libitum feeding and ovulation rate and embryonic mortality.

Differences among breeds were significant for all the traits, except weaning-oestrus interval, weight of follicular fluids, percentage of large follicles, ovulation and survival rates. The weaning-oestrus interval was not significantly correlated with any of the reproductive traits studied.
A note on the properties of the cumulative difference method for sire evaluation
Authors: Dempfle L.
Published: September 2010

Several of the various dairy sire evaluation methods now in use account for the genetic level of contemporary herdmates. In the cumulative difference method of Bar-Anan and Sacks the contemporary comparison estimate is first calculated and then adjusted by taking into account the genetic level of the contemporaries. These estimates depend on the genetic level of the herdmates. A modification of the procedure in which account is taken of the herdmates' genotype before regressing for small numbers would remedy this deficiency without increasing computing costs.
A note on the use of kale as a replacement for cereal-based concentrates for milk production
Authors: Gordon F. J.
Published: September 2010

Twenty-four lactating cows were used in a 6-week randomized block experiment to assess the effect of replacing 2·4 kg of cereal-based concentrate dry matter by either 2·6 or 3·2 kg of kale dry matter for cows with ad libitum access to grass silage. Milk yield, milk composition and live-weight change were not affected by the inclusion of kale. Silage dry-matter intake was significantly lower on the kale treatments than with concentrate, being 8·51, 7·89 and 7·95 kg per day for the concentrate, low-kale and high-kale supplements respectively. Energy digestibilities were 68·1, 74·4 and 76·4% and nitrogen digestibilities 67·1, 74·9 and 78·8% for the three treatments respectively.
The potential toxicity of copper-rich animal excreta to sheep
Authors: Suttle N. F. , Price J.
Published: September 2010

1. The true availability of Cu in animal excreta and pasture dressed with excreta was assessed in three experiments from the responses in plasma Cu concentration of initially hypocupraemic ewes repleted with diets containing different Cu sources.

2. Herbage from a sward treated with Cu-rich pig slurry contained a larger proportion of available Cu than untreated herbage (0·058 v. 0·047; P<0·05, Experiment 1). Herbage Cu content was also increased from 7·3 to a maximum of 10·2 mg Cu/kg DM by slurry application.

3. Availability of Cu in dried pig slurry (DPS) and Cu sulphate was similar and lowered from 0·068 to 0·040 in both sources by increasing the sulphur content of the diet from 1 g/kg in Experiment 3 to 3 g/kg in Experiment 2. Availability of Cu in dried poultry waste (DPW) was greater than that in DPS (P < 0·05).

4. Treatment with ethylene diamine tetra-acetic acid extracted 64·3 % and 78·3% of the Cu in DPW and DPS, respectively.

5. The Cu toxicity hazard associated with the recycling of animal excreta of high Cu content is discussed.
A note on growth and food conversion in pigs at different air temperatures and ventilation rates
Authors: Morrison S. R. , Givens R. L. , Heitman H.
Published: September 2010

Ventilation rates of 0·14, 0·42 and 0·71 m3/min per pig (2·3, 6·9 and 11·5 air changes per hour) were compared at weight ranges from 42 to 65 kg and from 69 to 88 kg and at optimum ambient temperature and at 8°C above optimal. A total of 96 pigs was used, housed so that gases from manure decomposition were present. Growth rate and food conversion were not affected by ventilation rates, but food intake was significantly lower at the lowest ventilation rate compared with the other two rates at the hotter temperature only. The odours and gases at the lowest ventilation rate were such that attendants strongly objected to them.
Autoradiographic studies of wool growth rate in Wensleydale crossbred lambs: absence of a marked circadian rhythm
Authors: Priestley G. C. , Ryder M. L.
Published: September 2010

The linear growth rate of wool on three sites on each of six Wenslcydale × Blackface lambs was measured by wool fibre autoradiography following 11 injections of 35S-cystine. The first injection was given at 09.00 h, so that alternate 36h intervals between injections represented predominantly day (09.00 to 21.00h) or night (21.00 to 09.00 h). The overall mean growth rates on shoulder, mid-side and breech were 0·83, 0·96 and 0·95 mm/day. Differences between day and night growth rates were very small (proportionally<0·05) and inconsistent in 16 of the 18 samples; although breech samples from two sheep showed up to 0·14 faster growth in daytime, a circadian rhythm of wool growth seems unlikely on this evidence. Both linear wool growth rate and food intake increased steadily throughout the experiment.

Mid-side wool growth rates in a second group of three crossbred longwool lambs averaged 0·79, 100 and 1·14 mm/day and were relatively stable over a period of several months.
Amino acid requirements of growing pigs. 6. Isoleucine
Authors: Taylor S. J. , Cole D. J. A. , Lewis D.
Published: September 2010

The response of the growing female pig (25 to 55 kg live weight) to increasing dietary isoleucine supplies at two levels of dietary leucine was assessed by measurement of growth rate, food utilization, tissue deposition as indicated by ham dissection and changes in plasma urea concentration. A range of isoleucine concentrations from 3·7 g/kg to 5T g/kg of the diet was derived from a basal diet and seven increments of L-isoleucine. Synthetic L-leucine was added to the basal diet to increase the concentration from 12 g/kg to 15 g/kg to achieve the two levels. The basal diet was formulated using barley, maize, blood meal, yeast protein, fat and tapioca with synthetic amino acids included to maintain at least 9·5 g/kg lysine and adequate concentrations of other essential amino acids and non-essential nitrogen. The 16 diets were replicated four times and fed to 64 female growing pigs once daily according to a restricted feeding scale. Blood samples were taken from each pig at 40 kg live weight for the determination of plasma urea nitrogen.

The addition of synthetic leucine to the basal diet had no consistent effect on growth performance or carcass quality, although it did result in elevated levels of plasma urea nitrogen. The response of growth performance and the composition of the ham joint to increasing dietary isoleucine concentration was interpreted by broken line functions which indicated an isoleucine requirement of 4·4 to 4·5 g/kg of the diet.
Influence of anabolic treatments on luteinizing hormone and testosterone secretion in bulls
Authors: Fabry J. , Renaville R. , Burny A.
Published: September 2010

Fourteen growing Belgian White Blue bulls were assigned to three groups: five controls (C); five bulls implanted with 140 mg trenbolone acetate and 36 mg Zeranol (TBA-Z); and four bulls implanted with 140 mg trenbolone acetate and 20 mg oestradiol-17β (TBA-E2). Testosterone (T) and luteinizing hormone (LH) levels in blood plasma were determined at day 0, 30 and 60. Mean plasma LH concentrations measured by repeated sampling over a 10-h period were similar at day 0, 30 and 60 in the three groups. At days 30 and 60, T levels were significantly lowered in treated bulls: namely 2·0 (s.d. 0·7) μg/1 v. 2·7 (s.d. 0·5) μg/1; 0·7 (s.d. 0·1) μg/1 v. 1·0 (s.d. 0·3) μg/1; 0·5 (s.d. 0·1) μg/l v. 0·4 (s.d. 0·2) μg/1 in the C, TBA-Z and TBA-E2 groups respectively. Moreover, anabolic compounds completely abolished pulsatile liberation of LH and T.

In control bulls intravenous injection of 0·5 ng/kg body weight of LH releasing hormone (LHRH) caused the release of a large quantity of LH (10 to 13 times the basal level after 10 min) followed by an increase in plasma T levels. On the other hand, LH and T responses to LHRH were reduced by TBA-E2 and TBA-Z treatments. A delay in LH response to LHRH was apparent 6 days after anabolic treatment. However, the total amount of LH liberated during the test was increased. The second effect was a quantitative reduction at days 20, 30 and 60 in LH and T secretion after LHRH. The modification of the hormonal pattern was quicker and more pronounced in TBA-E2 than in TBA-Z animals. Correlation was negative (r = −0·68; P < 0·05) between the mean daily gain during the experimental period and the total quantity of T liberated by the testis after LHRH stimulation at day 60. It was concluded that administration of trenbolone acetate plus Zeranol or trenbolone acetate plus oestradiol-17β in pubertal bulls reduced the LH and T responses to LHRH and abolished the pulsatile LH and T secretions.
The behaviour of calves at market
Authors: Carson Katherine , Wood-Gush D. G. M.
Published: September 2010

A study was made of the behaviour of young calves at two Scottish auction markets, Lanark and Stirling, and an experiment was conducted to assess the effect of an auction market on the behaviour of calves less than 1 week old.

Several features of the marketing procedure were identified as causing the calves distress, mainly because the calves were unable to lie down and rest. Crowding of calves in the pens, movement to different pens, and penning of very young calves with older calves were the three main reasons why calves could not rest. The older calves (approx. > 10 weeks) were more active, running and jumping around the pens and disturbing the very young animals which stood up in response to being trodden on.

Crowding was severe in some pens although there was no clear evidence to show that small groups of calves (6 to 10 calves) in small pens rested more than calves in large groups (20 to 50 calves) in larger pens.

Calves showed their distress initially by calling loudly, looking wildly around their new environment and sometimes by running around the pen and calling. As time passed behavioural signs of distress were less prominent and calves assumed a ‘depressed’ posture with their heads low, ears held back, tails clamped down and with their weight distributed more on their hindlegs than on their forelegs.

Calves subjected to an experimental market showed similar signs of distress to those calves in the real markets, whereas control calves rested for more than 0·74 of the same time. Experimental calves which were subjected to a journey of 2.5 h were less easily disturbed from the lying posture at the experimental market than calves which had undergone a journey of 15 min only.
Heritability estimates of wool follicle traits in sheep skin
Authors: Abouheif M. A. , Johnson C. LeRoy , Botkin M. P.
Published: September 2010

Data were collected from 600 newborn lambs, offspring of 354 Western crossbred ewes and 26 rams, to determine heritability estimates as well as phenotypic and genetic correlations between wool follicle variables using histological techniques. Breed of sire and sire within breed were significant sources of variation in total and secondary wool follicle populations and secondary:primary (S:P) ratio. Heritability estimates calculated by regression of offspring on dam were slightly higher than by paternal half-sib correlation or regression of offspring on sire. Expressed as an average of the three methods of calculation, the heritability estimate for S:P ratio was highest (0·69), followed by estimates for secondary, total and primary wool follicles (0·52, 0·46 and 0·36, respectively). These estimates are similar to the heritabilities of fleece weight, staple length and fibre diameter. Selection for increased density, provided an accurate measure is used, is suggested as an effective means for increasing fleece weight within grade.
On selection among groups with heterogeneous variance
Authors: Hill W. G.
Published: September 2010

Problems of making selection decisions among animals from several environmental groups with heterogeneous variance are discussed. Unless correction for heterogeneity of variance is made, animals will tend to be selected from the more variable groups, especially if selection is intense. This is an accurate and fair procedure only when the heterogeneity reflects real differences in heritability. It is shown that, if observations are expressed as deviations relative to the estimate of standard deviation from the group, the accuracy is high unless groups are very small.
A comparison of silage-based and dried forage-based diets, and the effect of protein supplementation of a silage-based diet for finishing beef cattle
Authors: Steen R. W. J. , Moore Charlotte A
Published: September 2010

An experiment was carried out to compare silage-based and dried forage-based diets for finishing beef cattle and to examine the effects of protein supplementation and formaldehyde treatment of silage on performance and carcass composition. The four diets used consisted, on a dry matter basis, of (1) 700 g/kg formic acid-treated grass silage and 300 g/kg low protein cereal-based concentrate (LPC), (2) 720 g/kg formic acid-treated silage and 280 g/kg high protein cereal/fish meal concentrate, (3) 600 g/kg formaldehyde-treated silage and 400 g/kg LPC, and (4) 480 g/kg artificially dried grass and grass hay and 520 g/kg LPC. The silages were well preserved with 33 to 40 g ammonia N per kg total nitrogen. The diets were offered to 40 British Friesian castrated male cattle which were initially 387 (s.e. 2·9) kg live weight. For diets 1 to 4 respectively metabolizable energy intakes were 91·8, 94·7, 94·9 and 91·8 MJ/day; total nitrogen intakes 192, 234, 189 and 191 g/day; live-weight gains 0/89, 0/93, 0/86 and 0/82 (s.e. 0/045) kg/day; carcass gains 0·51, 0·52, 0·52, 0·52 and 0·50 (s.e. 0·33) kg/day; mean subcutaneous fat depths 5·6, 5·4, 5·3 and 6·0 (s.e. 0·41) mm; marbling scores 3·0, 3·3, 3·2 and 2·6 (s.e. 0·19) and areas of m. longissimus dorsi 65·7, 66·4, 64·7 and 64·3 (s.e. 1·66) cm2. It is concluded that performance, efficiency of energy utilization and carcass fatness were similar for a diet containing 700 g/kg well preserved grass silage and a dried forage-based diet with a similar intake of energy and protein. Protein supplementation of a diet based on formic acid-treated silage or formaldehyde treatment of silage did not affect performance or carcass fatness.
A note on the use of a lumbar joint as a predictor of body fat depots in Aragonesa ewes with different body condition scores
Authors: Delfa R. , Teixeira A. , Colomer-Rocher F.
Published: September 2010

The lumbar joint, which is handled to assess body condition scores, was taken from 52 adult Rasa Aragonesa ewes with body condition scores between 1·5 and 4·5 and dissected into muscle, bone, subcutaneous and intermuscular fat. The subcutaneous fat in the lumbar joint was highly correlated with total fat in the body (r=0·97), confirming the value of this region for assessing body condition in Rasa Aragonesa ewes.
A note on the critical temperature of sucking rabbits
Authors: Sanz E. , Ortiz V. , de Blas C. , Fraga M. J.
Published: September 2010

Five hundred and fifty sucking New Zealand rabbits of three ages (1, 10 and 20 days) were used to measure metabolizable energy intake and heat production at five ambient temperatures varying between 12 and 36°C according to age. Critical temperatures and rate of heat production below them, decreased with age (32, 28 and 24°C; 20·8, 10·8 and 9·2 kJ/kg0·07 per day and °C at 1, 10 and 20 days of age respectively) as a result of the increase in thermal insulation. Energy retention also decreased below critical temperature at a similar rate to the increase of heat production, because rabbits could not increase their milk intake to meet their higher energy requirements.
Pulsatile secretion of oestradiol-17β in post-partum dairy cows
Authors: Peters A. R. , Perera B. M. A. O.
Published: September 2010

Thirteen dairy cows between 7 and 20 days post partum were fitted with catheters in both the jugular vein and caudal vena cava, the latter with the tips anterior to the junction with the ovarian veins. Blood samples were taken from nine control cows from both sites at 15-min intervals for periods of between 8 and 16 h. Four more cows were sampled for 13 h and given 4 × 2·5 ug GnRH intravenously at 3-h intervals starting 1 h after sampling began. Plasma oestradiol-17(3 concentrations were significantly higher in the vena cava than in the jugular vein in the two cows in which they were compared. Twenty-eight LH pulses occurred in the nine control cows during the sampling periods. These were followed within 1 h by increases in caval oestradiol-17β concentrations in 26 cases. LH pulses occurred after 14 of the 16 GnRH injections and with one exception were associated with oestradiol pulses in the vena cava. Oestradiol concentrations generally peaked 15 to 45 min after each LH peak. It is concluded that ovarian follicles are responsive to LH pulses by releasing oestradiol pulses early in the post-partum period.
Growth and carcass performance of British Landrace pigs heterozygous at the halothane locus
Authors: Simpson S. P. , Webb A. J.
Published: September 2010

The effects of the halothane gene on growth and performance were estimated from British Landrace positive and negative selection lines and crosses between the lines. A total of 214 full-sib pairs were performance tested from 25 to 85 kg live weight on either ad libitum or scale (0·69 g/g ad libitum food intake) feeding. Half-sides of 45 carcasses were fully dissected.

In the crosses, growth and performance did not depend on whether the sire or the dam was from the positive line. Carcass length, conformation score, eye muscle area and incidence of pale, soft, exudative meat (PSE) were all intermediate in the crosses. Given food ad libitum, the crosses had increased appetite and growth rates which resulted in increased backfat depths. However, in the fully dissected carcasses, the crosses were intermediate for lean proportion. Although the crosses gave a net economic advantage, the incidence of PSE may be unacceptably high for commercial exploitation.
An investigation of the repeatability of eight measurements of beef carcasses
Authors: Bodwell C. E. , Everitt G. C. , Harrington G. , Pomeroy R. W.
Published: September 2010

1. Three measurements on both sides of 15 carcasses and 5 additional measurements on bot h sides of 6 carcasses were taken in duplicate by 3 observers working independently. The carcasses, which ranged in weight from 520 to 884 lb., were measured from 2 to 6 hr. after slaughter while on the hook in the chill-room of a slaughter-house.

2. Length of body and loin were the measurements which could be taken the most consistently, whereas the 2 depth measurements and the length of tibia were the least repeatable.

3. For 2 measurements, there were marked differences between observers i n the average differences between sides. In all carcass investigations, measurements should be taken on both sides and averaged.

4. For all measurements, except the length of body and loin, there were differences in the average values found by the 3 observers.

5. It is suggested that to achieve a satisfactory degree of repeatability, slight redefinition and clarification of the points of reference is required for some measurements, whereas others may have to be discarded.
The effects of inbreeding on carcass traits in the bacon pig
Authors: King J. W. B. , Roberts R. C.
Published: September 2010

Carcass measurements made on 1,463 Large White pigs from 88 inbred lines, at various degrees of inbreeding, have been analysed.

Partial regression coefficients calculated within lines showed that each 10% increase in inbreeding coefficient significantly increased carcass weight by 0·46 lb., decreased mid-back fat thickness by 0·37 mm. and streak thickness by 0·36 mm.

Partial regression coefficients calculated on all the material, or on line means showed, however, that the most highly inbred pigs tended to be shorter and fatter than average. Possible explanations of this finding are discussed and it is suggested that under the selection procedure adopted for litter size and weaning, weight favours the survival of these less desirable lines.
The relative influence of birth weight, milk consumption and supplementary food consumption upon the growth rates of suckling piglets
Authors: Lodge G. A. , McDonald I.
Published: September 2010

1. Data from 208 piglets in 24 litters were examined to evaluate the relationships of weights at 3 and 8 weeks with birth weight and milk consumption within litters, and with these and creep-feed consumption between litters.

2. Of the total variation in 3-week weight within litters, 39% was associated with variation in birth weight, 67% with variation in milk consumption to 3 weeks, and 80% with these two factors combined. Of the total variation in 8-week weight within litters, 30% was associated with variation in birth weight, 25% with variation in milk consumption to 8 weeks, 42% with these two factors combined and 45% with variation in 3-week weight.

3. Of the total variation in 3-week weight between litters, 6% was associated with variation in birth weight, 15% with variation in milk consumption to 3 weeks, and 18% with these two factors together. These values were all too low to be statistically significant, as were the equivalent relationships with 8-week weight. Of the total variation in 8-week weight between litters, 77 % was associated with variation in creep-feed consumption to 8 weeks, 70% with variation in 3-week weight, 85% with consumptions to 8 weeks of milk and creep-feed combined, and 89 % with creep-feed consumption to 8 weeks and 3-week weight combined.

4. The practical significance of these relationships is discussed.
Potassium and hypomagnesaemic tetany in calves
Authors: Blaxter K. L. , Cowlishaw B. , Rook J. A. F.
Published: September 2010

1. Four groups of four calves were given rations containing adequate and inadequate amounts of magnesium, both with or without an excess of potassium, added as potassium chloride.

2. The excess of potassium resulted in the death of three of the eight calves, the clinical signs observed before death being cardiac insufficiency, oedema, severe muscular weakness and muscular atony. The excitability of motor nerves, measured by the method of Kugelberg (1944), was reduced by excess dietary potassium and the serum concentration of potassium was increased. The potassium content of the erythrocytes declined with age, irrespective of dietary treatment.

3. Although this evidence of potassium intoxication was obtained, no concomitant abnormalities were induced in magnesium metabolism by the excess of potassium whether or not the calves received rations containing adequate or inadequate amounts of magnesium.

4. Excess potassium had no effect on the concentration of potassium or magnesium in the muscle or on the Ca : Mg ratio in bone.

5. Magnesium deficiency resulting in tetany was shown to have no statistically significant effect on the intracellular concentration of magnesium i n the muscle. A very small drop in erythrocyte magnesium was noted. No effect on the excitability of motor nerves was observed.

6. The results suggest that the effect of excessive manuring of pastures with potassic fertiliser in increasing the incidence of hypomagnesaemic tetany is not due to a direct effect of potassium on the magnesium metabolism of the animal.
A note on the effect of inbreeding on lamb weights of Sardinian sheep
Authors: Dassat P. , Sartore G.
Published: September 2010

An analysis was made of the effect of inbreeding in Sardinian sheep from the records of 658 single female lambs born in the Monastir flock in the years 1935–42 and 1947–55.

The calculations of differences between inbreds (both 12·5% and 25%) were done within recording years. The results showed that inbreeding had no significant effect on birth weight or 30-day weight.
The effects of oral and implanted hydroxyzine on growth, endocrine and carcass characteristics of lambs
Authors: Preston T. R. , Charleson Euphemia B. , MacLeod N. A. , Rosen G. D. , Vernon J.
Published: September 2010

1. The results of four experiments on the effects of oral and implanted hydroxyzine on lambs are reported.

2. The effect of hydroxyzine on daily rate of live-weight gain ranged from +7·8% to −6·2% improvement with a mean value of +2·3%.

3. Lambs receiving hydroxyzine in the creep feed manifested significantly higher killing-out percentages and lower thyroid weights than the controls. Pituitary weights were not affected by hydroxyzine.

4. In an experiment on individually-penned, weaned wethers, given a high energy diet, hydroxyzine by either route did not affect live-weight gain but significantly increased killing-out percentage, rate of gain of carcass weight and fat deposition in certain tissues. Hydroxyzine did not affect the fresh weights of the pituitary, thyroid and adrenal glands or the weights of the teats.
The influence of contemporaneity, genetic variation and herd differences on variation in milk yield and butterfat percentage
Authors: Watson J. H.
Published: September 2010

1. Paired lactation records of milk yield and fat percentage from experimental twins and commercial twins, full-sisters and half-sisters are used in a study of the influence of contemporaneity, genetic variation and herd differences.

2. The design of the investigation was such that members of a pair were alike in:

(i) both time of calving and lactation number,

(ii) time of calving only,

(iii) lactation number only, or

(iv) neither time of calving nor lactation number.

3. Intra-class correlations between pair members in respect both of yield and fat percentage were highest for contemporary records. Differences in time of calving and in lactation number produced, in aggregate, a decline in correlation of about 20%. However, the separate estimates varied considerably between the different types of pair.

4. The within-pair and between-pair variance components independently confirm these effects of contemporaneity. As the degree of contemporaneity of pair members declines the within-pair variance increases in size and the between-pair component decreases.
The effect of hexoestrol on the eating quality of beef and lamb
Authors: Preston T. R. , Greenhalgh Isoline , Boyne A. A. , Crichton J. A. , Rolfe E. J. , Brown Agnes , Dodsworth T. L.
Published: September 2010

There were no differences in toughness, juiciness, intensity of flavour and incidence of taints between samples of meat from wether lambs and cattle which had been treated with oestrogens and similar meat samples from untreated controls.

During feeding trials prior to slaughter both the cattle and sheep which had been given oestrogens gained in live-weight significantly faster than their respective controls.
Modification of gestation length in cattle by the type of environment present at the end of pregnancy
Authors: Dickinson A. G.
Published: September 2010

The gestation lengths of cattle are considered in terms of variation due to the month in which calving occurs. The well-known summer decrease in gestation length is re-established but in addition there is a short-term decrease in April which appears to be related to the cattle being put out to grass at a late stage of pregnancy after they have been housed for the winter.
Influence of natural service on length of oestrus in the cow
Authors: de Alba Jorge , Corta Eduardo Villa , Ulloa Gustavo
Published: September 2010

Observations on duration of the period of receptivity in two groups of Milking Criollo, one of Jersey and one of Brahman cows are presented. After one or two oestrus periods measured without service the cows were bred naturally in the case of Jerseys, Brahmans and one group of Milking Criollos. In the other group of Milking Criollos, artificial insemination was used. The period of receptivity was shortened after natural service by 8·7 hours in Milking Criollo and by 4·1 hours in Brahman cows. No shortening of oestrus occurred in the Jerseys and no significant shortening in artificially inseminated Milking Criollos.

Nine of the cows under observation (and seven other cows with some Zebu blood) allowed only one service by the bull.
The requirements of bacon and heavy pigs for certain essential amino acids
Authors: Bellis D. B.
Published: September 2010

The requirements of bacon and heavy pigs for lysine and methionine have been investigated. The trials employed 3rd and 4th cross Large-White × Essex pigs.

In the first trial, which involved 560 pigs during the 40 to 120 lb. growth stage, the amount of herring meal in the standard weaner diet was progressively reduced from 7 to 1%. Total protein was kept constant by including soyabean and groundnut meal.

Growth efficiency worsened progressively as herring meal was reduced but growth was restored by adding lysine and methionine to the levels of the 7% herring diet. The optimum levels of lysine for pigs during the 40 to 120 lb. growth stage appeared to be higher than reported elsewhere (0·85% against 0·76% and 0·65%).

Treatments prior to 120 lb. had no residual effects on growth during the 120 to 200 lb. stage when all pigs were on a normal fattening diet containing no animal protein and there were also no residual effects on the carcass composition of the pigs at 200 lb. live-weight.

The results support the view that the nutritional value of animal proteins to pigs lies solely in the quantity of essential amino acids that they supply. Under the conditions of this trial, the particular essential amino acids were lysine and methionine.

The second trial involved 260 individually and group-fed heavy pigs. Lysine supplementation of the barley-mineral diet during the 140 to 260 lb. growth stage improved food conversion and increased the lean content of the carcasses of heavy pigs fedad lib.; with restricted feeding growth rate was also improved.

Under the conditions employed the optimum lysine content of heavy pig diet during the final growth stage is at least 0·67%.
Estimation of genetic change in farm livestock using field records
Authors: Smith Charles
Published: September 2010

This paper describes the estimation of genetic changes in farm livestock using field data. The method proposed depends on a difference in rate of change in performance of the population and of the successive progenies of individual sires. The change in the population with time is taken as t+g, where t represents environmental change and g represents genetic change, while the within-sire change is taken as t+½g. Their difference measures half the genetic change.

This principle can be applied, with certain precautions, tofielddata where there is some spread of sires over time. The method has two advantages over other methods in that past as well as current changes can be measured and no additional facilities are required. However, selection among sires may bias the estimates of genetic change. Approximate sampling errors of the estimates of change can be obtained and hence the rate of genetic change which a certain body of data will demonstrate to be significant can be estimated.

The method was applied to a set of pig records collected over nine years by a private pig breeder. There was considerable change with time in all six traits examined and in at least three of them there appeared to have been a substantial genetic change accounting for the whole of the observed change.
An experiment with a constant environment for the domestic fowl
Authors: Greenwood Alan W.
Published: September 2010

A pilot experiment is described to observe the effect of a constant environment (temperature 65° F., relative humidity, 60%, artificial light for 12 hours daily alternating with 12 hours darkness, and constant diet) on the subsequent reproductive performance of fowls maintained under these conditions from hatching to the end of the 3rd annual cycle of egg laying.

The elimination of normal seasonal moulting of the plumage both at the beginning and at the end of the pullet laying year gave an advantage of 57 eggs for experimental birds over a group of sisters maintained under a more normal system of intensive husbandry.

This advantage in eggs laid was much reduced in succeeding years owing to a persistent and continuing decrease in rate of lay of hens in the constant environment.

All eggs were incubated and, although no differences in fertility, dead germs and hatchability were observed over the first full year of production in the birds in contrasting environments, the deleterious effects of a constant environment became increasingly apparent with age.

It is suggested that control of the environment induces a premature senility in the domestic fowl.
Insemination before and after the onset of heat in sows
Authors: Hancock J. L. , Hovell G. J. R.
Published: September 2010

Counts were made before and after fixation of the numbers of fertilised and unfertilised ova recovered from 3 mated sows, 7 unmated sows and from 34 sows inseminated at varying times before and after the onset of heat.

The percentages of fertilised ova for sows inseminated the day before heat (day — 1) on the first day of heat (day 0) the second day of heat (day 1) and the third day of heat (day 2) are respectively for unfixed and fixed ova: 7·1 and 9·8, day – 1 ; 55·9 and 68·8, day 0; 63·4 and 98·2, day 1; 20·1 and 15·2, day 2. No fertilised ova were recorded from unmated sows; the percentages for mated sows were 94·3 and 95·5.

It is concluded that failure of fertilisation is likely to be the greatest source of loss of fertility in inseminations made before heat and late in heat.

Most ova from sows inseminated on day — 1 and from sows inseminated in day 2 had no spermatozoa on the zona pellucida. A few ova from sows inseminated on day 2 had very large numbers of spermatozoa present.

It is suggested that failure of the spermatozoa to reach the site of fertilisation rather than their loss of fertilising capacity is likely to be the cause of the low fertility of early inseminations.
The measurement of the flow of food to the duodenum of sheep
Authors: Harris L. E. , Phillipson A. T.
Published: September 2010

1. A comparison of the performance of Scottish Blackface ewe hoggets with and without an exteriorised flow to the duodenum was carried out while the animals were fed on hay with a low nitrogen content and added salt. No evidence was found from the food and water consumed, from the weight changes or from a comparison of the organic matter, nitrogen and ash contents of the food and the faeces that the operation caused any permanent disturbance to digestion.

2. Regular measurements of the flow of abomasal contents to the duodenum established a pattern of flow that was influenced by feeding. A relationship between the quantities passed per hour from the abomasum and the time devoted to rumination was found, but the relationship appeared to be dissociated in time so that increased rumination preceded the increased passage of contents.

3. The mean quantity of abomasal contents passed from four animals was 398 ml./hour. According to the quantities of chromium sesquioxide administered by mouth, passed from the abomasum, and excreted in the faeces this value represents not more than 90% and not less than 86% of the flow that can normally be expected.

4. The quantities of organic matter that disappear in the stomach were calculated and represent about half or more of the total disappearance in the alimentary tract.

5. Substantially more nitrogen left the abomasum than was eaten in the food daily. Of the nitrogen passing to the duodenum the greater part disappeared in the intestines.

6. About twice as much ash left the stomach as was present in the food and about two-thirds of the ash entering the duodenum disappeared in the intestines.
The maternal effects on size at birth and weaning in Landrace-Native pig crosses
Authors: Joubert D. M.
Published: September 2010

Reciprocal matings between large, improved Swedish Landrace and small, primitive South African Native pigs produced strong evidence of a maternal effect at birth. However, compared with purebred Landrace piglets, the crossbred offspring out of large dams weighed less; conversely, compared with purebred Native piglets, the crossbred offspring out of small dams were heavier at birth. Differences between the various mean weights were all statistically significant.

At weaning (eight weeks of age), the weights of crossbred pigs out of large Landrace sows equalled those of purebred Landrace pigs. Crossbred pigs out of Native-pig sows occupied an intermediate position between the above-mentioned and purebred Native pigs. The differences between the latter group means remained significant statistically.