bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of energy and protein concentration in the diet on the performance of growing pigs 3. Response to differences in levels of both energy and protein
Authors: Cooke R. , Lodge G. A. , Lewis D.
Published: September 2010

One hundred and twenty eight gilts by Landrace sires out of Large White × Landrace females were allocated on the basis of litter relation-ship and initial weight to 16 treatments involving the individual feeding of four dietary protein levels (approximately 15%, 18%, 21% and 24% CP) at each of four energy levels (2830, 3100, 3375 and 3585 kcal DE/kg air-dry feed). Amino acid balance (as% of total CP) was maintained relatively constant, using synthetic lysine and methionine where necessary. Growth performance was measured over a live-weight range of 23 kg to 59 kg, at which latter weight the pigs were slaughtered for carcass evaluation by dissection of the middle ‘joint’ from a half carcass. Linear carcass measure-ments were also taken. There was a significant energy × protein interaction only for killing-out percentage; for all other measures the main effects could be assessed independently. Increase in dietary energy value gave linear increase in growth rate (GR) and improve-ment in efficiency of feed conversion (EFC), accompanied by linear decrease in lean percentage and increase in fat percentage. Increase in dietary protein level gave an increase in GR and improvement in EFC with the first increment (from 15% to 18% CP), but depressions in both these characteristics with the final increment (from 21% to 24% CP). Lean percentage increased and fat percentage decreased with the first protein increment, with no further significant changes. Calculation of daily rates of tissue deposition indicated that maximum rate and efficiency of fat-free carcass gain could be attained with the second lowest energy and protein levels tested (i.e. 3106 kcal DE/kg and 18·2% CP).
Genetic and non-genetic factors affecting body weights in Sahiwal × Friesian crosses
Authors: Taneja V. K. , Bhat P. N.
Published: September 2010

The data were collected from seven dairy farms in India on Sahiwal × Friesian crosses over a period of 30 years (1937–1966). There were nine distinct genetic groups (grades); Sahiwal, 1/8, 1/4, 3/8, 1/2, 5/8, 3/4 and 7/8 Friesian and Indian Friesians (animals having 15/16 or more Friesian blood).

Least-square analysis of variance was run to examine the effects of grades, farms, periods, seasons, and breed of sire on body weights at birth, 19 weeks, 12 months and 3 years. The effects due to grades, farms and periods were significant for all the traits. The effects due to season and breed of sire were significant for all traits except for weight at 3 years.

The least-square constants showed that, with increase in Friesian inheritance, birth weight increased considerably, while the increase in body weights at 19 weeks, 12 months and 3 years was only marked up to the 1/2-Friesian group.
A Comparative study of some carcass characteristics of Sudan Desert sheep and goats
Authors: Gaili E. S. E. , Ghanem Y. S. , Mukhtar A. M. S.
Published: September 2010

Male Sudan desert sheep and goats of three age-groups, young, yearling and mature, were used to compare some of their carcass characteristics when reared under range conditions and in feedlot. Carcass traits studied were the dressing percentage, the percentage of bone in the carcass and wholesale cuts, chemical composition of meat, and muscle fibre thickness. An organoleptic test was carried out on meat from the fattened animals.

The dressing percentage, percentage of edible meat, chemical fat and muscle fibre thickness were increased by fattening in the feedlot. Increases were also observed with advancing age, but the effect was more marked in fattened than unfattened animals. Goats yielded a higher carcass weight per unit live weight than sheep, the stomach content and skin weight relative to live weight being greater in the sheep than in the goats. Goats were shown to possess less chemical fat and thicker fibres than sheep. Taste panel scores revealed a highly significant (P < 0·005) treatment effect on tenderness and a significant (P = 0·5) treatment effect on juiciness in relation to age and species. Taste panel flavour scores were not associated with animal age or species.
A note on the need for supplementary nitrogen in diets for fattening beef cattle
Authors: Kay M. , Macdearmid A.
Published: September 2010

Thirty British Friesian steers were given either a pelleted diet of bruised barley and ground barley straw (70:30) containing 9·4% crude protein (N × 6·25) or a similar diet with urea or soya bean meal added to raise the crude protein content to 15·0%. Up to a live weight of 200 kg, the growth rate and feed conversion of steers were improved by supplementary nitrogen and urea provided this as effectively as soya bean meal. Beyond 200 kg there were no differences in growth rate or feed conversion between any of the experimental treatments.
Studies on Belgian Pietrain pigs 2. A comparison of growth and carcass characteristics of Pietrain used in three breed crosses with Landrace, Large White and Hampshire breeds
Authors: Curran M. K. , Lean I. J. , Duckworth J. E. , Holmes W.
Published: September 2010

1. The growth, feed consumption per unit weight gain, carcass characteristics and some aspects of meat quality were studied in two trials with crosses derived from Landrace (L), Pietrain (P), Hampshire (H) and Large White (LW) breeds.

2. In Trial 1, 96 pigs of both pure Landrace and LW(× (L♀ × P♂)♂ origin were studied up to slaughter weights of 64 and 91 kg live weight. In Trial 2, Landrace, LW♀ × (L♀ × P♂)♂ and LW ♂x (P♀x L♂)♂, (H♀ × P♂ × L♂ and (H♀ × P♂)♀ × LW♂ pigs were compared up to 91 kg live weight using 48 pigs of each type.

3. All crossbred types showed better economy of production than Landrace when assessed by live-weight gain and feed consumption per unit weight gain. Their carcasses contained greater quantities of lean meat and similar quantities of rind, bone and fat than Landrace at comparable weights, but they exhibited a variable tendency to poorer meat quality. LW × (L × P) and LW × (P × L) carcasses at 91 kg live weight were shorter than Landrace; 4% and 14% of pigs in trials 1 and 2 respectively were less than the currently acceptable length of bacon pigs (775 mm). (H × P) × LW and (H×P)×L carcasses at this weight were much shorter; 34% and 38% respectively were less than 775 mm.
Energy supplementation of silage for ewes in late pregnancy
Authors: Sheehan W. , Lawlor M. J.
Published: September 2010

1. Four groups of 20 ewes were individually fed in late pregnancy on: (1) silage ad libitum, (2) silage ad libitum and 12 kg rolled barley, (3) silage ad libitum and 23 kg rolled barley, (4) pelleted milled dried grass ad libitum. The concentrate was offered on a rising plane over the last 6 weeks of pregnancy. After parturition the ewes and lambs were put on spring pasture.

2. The intake of silage by twin-bearing ewes fell slightly but nonsignificantly during week 16 of pregnancy but thereafter remained steady up to lambing. There was no other decline in intake on any of the treatments. Barley, however, significantly depressed silage intake when the quantity was increased above 282 g per day.

3. Single-bearing ewes, except those on treatment 1, gained in net body weight during late pregnancy. Twin-bearing ewes on treatment 4 gained in net body weight while those on the other treatments lost weight.

4. Birth weights of single lambs from ewes on treatment 1 were significantly lower than those from treatment 3. This was the only significant difference in birth weight or subsequent growth rates of single lambs. Birth weights of twin lambs on treatment 1 were significantly lower than those on the other treatments.

5. The birth weight of twin lambs appeared to be an important determinant of subsequent performance, and may thus be a valuable criterion of the adequacy of the ewe's diet in late pregnancy.

6. With medium-quality autumn silages, 12 kg of barley given during late pregnancy is sufficient to ensure good reproductive performance in ewes.
Fleece characteristics and postnatal fleece development in Finnish Landrace × Merino sheep
Authors: Ryder M. L. , Wilson D. T.
Published: September 2010

1. Fleece characteristics in Finnish Landrace × Merino and Merino × Finnish Landrace sheep were compared with those of the parental breeds, and although most characters in the crossbreds showed no significant departure from the parental mean, they had similarities to the Merino which imparted commercial value.

2. The wool was mostly of 60s quality compared with 58s in the Finnish Landrace, and 64s and over in the Merino parents. Crimp number showed heterosis, being 5 to 6 per cm in the crossbreds compared with 2 in the Finnish sheep and 7 in the Merino.

3. The mean fleece weight was 3-5 kg, compared with 2-2 kg in the Finnish sheep and 4-2 kg in the Merino.

4. The mean staple length was 13 cm compared with a very variable length around a mean of 16 cm in the Finnish Landrace, and 10 cm in the Merino.

5. The fibre diameter was nearer to that of the Merino, but not significantly so (primary mean 29·2 μ, secondary mean 26·6 μ).

6. The greater fleece weight of the crossbreds would be expected to be associated with a greater skin follicle density, but they had a secondary/primary follicle ratio of about 10 (compared with 5 in the Finnish Landrace and 20 in the Merino), which did not differ significantly from the parental mean.

7. There was some evidence that fibre development was initially more rapid in the crossbred lambs.
The effects of continuous sire selection on the structure and age composition of dairy cattle populations
Authors: Hinks C. J. M.
Published: September 2010

A numerical model of male and female replacement processes is developed and used to construct a matrix which specifies the numbers of lactations of different parities expressed in a given time period by daughters of bulls used in artificial insemination (AI).

Populations resulting from newly established AI breeding programmes contain an unduly high proportion of offspring by young bulls. Subsequently an equilibrium is reached in which offspring of young and tested bulls are present in proportions determined by the relative usage of the two types of sire and by differences in replacement rates amongst their progeny. Once an equilibrium has been reached the numbers of progeny sired by bulls lacking a progeny test proof is extremely small.

The use of the technique to solve a number of specific planning problems is demonstrated.
Responses to variations in dietary energy intakes by growing pigs 1. Estimates of digestible and metabolizable energy requirements for maintenance
Authors: Davies J. L. , Lucas I. A. M.
Published: September 2010

Groups of individually-fed pigs, each of three gilts and three castrates of mean live weights 18, 31, 46, 58, 72 and 80 kg, were given for 20 days feed allowances based on the ARC estimates of energy required for maintenance, assuming an efficiency of utilization of digestible energy (DE) of 77% for maintenance. As the actual diet used had a higher DE value than that calculated before the start of the experiment, DE intakes (260·3 W056) were about 4·0% above the ARC values.

There was no statistically significant change in live weight over the period of study. This supports the validity of the ARC estimates, if maintenance is defined as a lack of change in body weight.

The metabolizable energy (ME) intakes (248·3 W0·56) which maintained weight were also close to other estimates of ME requirements.
Responses to variations in dietary energy intakes by growing pigs 3. Effect of level of intake of diets of differing protein and fat content on the performance of growing pigs
Authors: Davies J. L. , Lucas I. A. M.
Published: September 2010

Three diets were given separately, each at four levels of digestible energy (DE) intake, to gilts, castrates and boars growing from 21 to 92 kg live weight. The energy levels were those suggested by the Agricultural Research Council, compared with a 5% increase or 10% or 20% decreases in daily allowance. One diet (ME 18) had 3·0 Meal DE/kg and 18·2% crude protein; the other two (HE 16 and HE 19) had 3·26 Meal DE/kg and 16·1% or 19·3% crude protein.

They were given unchanged throughout the experiment. Responses to change in daily DE intake were not affected by sex or diet, except in shoulder fat thickness. Feed eaten per kg gain did not vary by more than 4% over the intake levels investigated, and no difference was significant. On average, each reduction in daily intake below the ARC+5% allowance led to an increase of 1·2 percentage units of carcass lean and a decrease of 1·3 percentage units of carcass fat.

In comparison with HE 16, the higher protein diet HE 19 gave improved feed conversion efficiency and growth rate, particularly in gilts. It did not cause significant changes in carcass measurements. In comparison with ME 18, HE 19 gave more efficient conversion of DE to weight gain, and faster growth.

Boars required less feed per kg gain and had faster growth rates and leaner carcasses than gilts, which were superior to castrates. There was a high incidence of unpleasant odour in fat from boars, but some was also detected in that from gilts and castrates.
Effects of isolation, confinement and competition for feed on the energy exchanges of growing lambs
Authors: Webster A. J. F. , Smith J. S. , Brockway J. M.
Published: September 2010

1. Calorimetric evaluation of the nutritive value of feeds for ruminants has, of necessity, involved using mature sheep isolated in respiration chambers. This experiment was designed to examine how such information relates to growing lambs reared in different ways.

2. Lambs were either completely isolated, individually fed, or fed in groups. Two lambs in each group were fed to gain 100 g/day (medium) and two to gain 200 g/day (high). Calorimetric measurements were made on individuals or groups at intervals over 20 weeks.

3. All lambs fed to gain 100 g/day consumed their entire ration, isolated lambs gained on average 123 g/day and the others 160 g/day. On the ‘high’ ration isolated lambs ate less than the others and gained 178 as against 228 g/day.

4. Metabolizable energy intake, heat production and thus energy retention were similar in all groups offered the ‘medium’ ration. Differences in energy retention on the ‘high’ ration were related to differences in intake.

5. The net availability for weight gain of the diet (kf) estimated from energy balance trials conducted throughout the growth period (0·61) agreed well with that predicted from its content of metabolizable energy (0·63).

6. Estimates of the caloric density of the weight gain suggested that on the ‘medium’ ration the isolated lambs retained substantially more energy as fat than those reared in groups. These observations are discussed in relation to the design and interpretation of calorimetric experiments to predict the nutritive value of feeds for growing lambs.
An evaluation of beef carcass quality 1. The influence of cereal feeding on the growth and carcass quality of Friesian steers
Authors: Hinks C. E. , Prescott J. H. D.
Published: September 2010

Twenty-four Friesian steers, initially 5 months of age, were involved in a 2 × 2 factorial experiment which spanned grazing and silage feeding periods of 22 weeks' duration. In the first period, cattle were stocked at a uniformly high density, with half of the group being fed 1·25 kg/head per day of supplementary barley. In the second period, the cattle were subdivided into four groups and fed varying levels of barley with silage. Finally all the animals received 3·65 kg/head per day of barley. Replicates of the four treatments were slaughtered at random after 5 to 11 weeks on this treatment. Whilst supplementary cereal feeding significantly increased the live-weight gains of steers at grass by 11%, this live-weight advantage was offset by their slower gains in the final weeks before slaughter. Feeding cereals to grazing cattle had little effect on carcass composition or the proportions of carcass joints, but their beef was considered, by a tasting panel, to be more tender than the meat from the control steers.

Increasing the level of barley fed with silage only increased live-weight gains by 2%, and had little effect on carcass or meat quality.
A note on factors affecting puberty in Clun Forest female lambs
Authors: Dýrmundsson Ó. R. , Lees J. L.
Published: September 2010

In 1971 the attainment of puberty in 30 early-born and 30 late-born Chin Forest female lambs was studied. The early-born lambs showed their first oestrus at a mean age of 265·4 days and a mean body weight of 41·4 kg; the late-born lambs at 222·0 days and 36·8 kg.

Marked individual variation existed in both age and body weight at puberty within the groups, largely because of differences in growth rate during rearing. Early-born singles showed their first oestrus on average 3·4 days earlier than twins while this difference between lateborn singles and twins was 17·9 days. Since early-born lambs attained puberty at a considerably higher mean age and heavier mean body weight than late-born lambs with similar growth rates it is suggested that the daylight environment experienced by the lamb may be a critical factor in regulating the onset of breeding activity.
Development of a model of voluntary food intake and energy balance in lactating cows
Authors: Forbes J. M.
Published: September 2010

Voluntary intake of a range of feeds by cows is predicted on the assumption that the cows will satisfy their energy requirements unless physical limitations intervene. Predicted patterns of intake throughout lactation agree generally with observed changes, including an eventual plateau in body weight due to a predicted physical equilibrium between abdominal fat and gut contents. An attempt to incorporate a depression in milk yield when physical limitations prevented energy requirements being met by food intake was successful only with good quality feeds.
The feeding value for beef cattle of lucerne cobs differing in maturity and date of harvest
Authors: Horton G. M. J. , Holmes W.
Published: September 2010

The feeding value of four batches of dried lucerne cobs was compared in two experiments with beef cattle. The cobs were prepared from primary growths, cut early (LI) and late (L2), and from second-cut (L3) and third-cut (L4) material.

In Experiment 1, intakes and digestibilities of the four cuts, offered as the sole feed, were measured using six British Friesian steers in two (3 × 3) Latin squares. The intake of lucerne cobs decreased as the digestibility of organic matter and cellulose increased, to result in similar intakes of digestible organic matter for all treatments.

In Experiment 2, 32 beef cattle were given rolled barley and the lucerne cobs in the ratio of 1: 2 at two levels, plus barley straw ad libitum. The treatments were compared in eight (4 × 4) Latin squares. Similar daily gains were supported by diets containing LI, L3 and L4. Performance on diets containing L2 was significantly poorer at both levels of feeding.
Growth depression and food requirements of fattening pigs at low environmental temperatures when housed either on concrete slats or straw
Authors: Verstegen M. W. A. , van der Hel W. , Willems G. E. J. M.
Published: September 2010

1. Four experiments, each with two groups of eight pigs, were performed in a controlled environment room equipped with two pens. One pen had straw as bedding and the other had slats. The animals were exposed to temperatures of about 17°C at the initial weight (20 to 25 kg). The temperature was lowered by about 1°C per 10 kg body-weight increase, to 8 to 12°C at the end of the fattening period (80 to 100 kg).

Animals on slats were kept 4·7 to 5·3°C below the calculated zone of thermoneutrality and the animals on straw 2·0 to 2·6°C above the lower limit of thermoneutrality. In Experiments 1 and 2 the animals in both pens received the same amount of food per day and in Experiments 3 and 4 animals on slats received more food to give the same body·weight gain as on straw. Feeding level on straw was about 93 g/kg0·75 per day.

2. In Experiments 1 and 2, body-weight gain on slats was reduced due to the lower effective temperature. After adjusting for feeding level, the reduction in daily gain was calculated as 18·5 and 11·8 g per °C below thermoneutrality. In Experiments 3 and 4 the extra food needed to maintain the same rate of gain on slats as on straw was respectively 18·1 and 45·5 g per °C below thermoneutrality.

3. Carcass length of animals on slats was less than on straw.
Evaluation of three- and four-breed cross litters and pigs sired by purebred and crossbred boars
Authors: Fahmy M. H. , Holtmann W. B.
Published: September 2010

Boars from four pure breeds and three two-breed crosses were mated at two stations to sows from six two-breed crosses to produce three- and four-breed cross litters. Two types of three-breed crosses were produced either using purebred boars or by partial backcrossing using crossbred boars. From the 504 litters produced 965 male pigs were slaughtered at 90 kg live weight. The purebred boars produced litters which were 0·4 and 0·2 pigs larger and 0·14 and 1·14 kg heavier at birth and 21 days respectively than the crossbred boars. Differences between pigs sired by purebred and crossbred boars were negligible for growth rate and carcass quality. Little difference was also found between three- and four-breed cross pigs sired by crossbred boars (except for daily gain, P < 0·05). Breed of dam was a significant source of variation on all the traits except dressing-out percentage. Significant breed of sire effect was found on all the traits related to carcass quality but not on those related to growth. Breed of sire × breed of dam interaction was significant on backfat thickness, carcass lean yield percentage and average daily gain. The best crosses in carcass value were those of Duroc boars mated to Hampshire-Landrace and Landrace-Yorkshire sows, while those pigs with the fastest gain were from Landrace boars ×Duroc-Yorkshire sows and Duroc-Yorkshire boars × Large Black-Lacombe sows.
A note on the effect of omitting the cereal supplement from a finishing diet offered to weaned single-suckled calves
Authors: Broadbent P. J.
Published: September 2010

Weaned single-suckled calves (male castrates) were offered a finishing diet which included 2·3 kg/day bruised barley (F) or a similar diet with the cereal supplement omitted (R) during the main winter feeding period. Some diet R steers had a subsequent grazing period and were re-housed for a second winter when the diet included a cereal supplement. The treatments caused differences in growth rate, distribution of slaughterings and grazing requirements. Diet R reduced growth rate and the steers took longer to reach slaughter, which was at a higher live weight, than on diet F at the same degree of finish. Steers on diet R produced 4·5% more carcass weight, 8·2% more lean, 4·1 % less fat and 11·2% more bone than those on diet F. They consumed more wet distillers' grains (21·1 %), swedes (25·5%) and grass silage (32·0%) from housing to slaughter but saved 80·0 % of the cereal consumed on diet F.
Food intake and grazing behaviour of sheep varying in body condition
Authors: Arnold G. W. , Birrell H. A.
Published: September 2010

Herbage intake and grazing times were measured in four experiments in which adult sheep grazed short and long pastures. The digestible organic matter (DOM) intake of adult wooled Merino and Corriedale wethers was higher, both absolutely and per kg live weight, when they were lower in live weight due to prior under-nutrition. The relative differences were similar on both abundant and scant pasture and were proportional to the relative differences in live weight. The higher intakes were achieved by differences in the time spent grazing and in the rate of intake per hour of grazing. DOM intake of shorn sheep was increased by up to 44% per kg live weight within 5 weeks of shearing in two experiments when the mean temperature was 8°C but no increase in DOM intake was observed in four other experiments when the mean temperature was 11°C. Shorn sheep achieved higher intakes on both abundant and scant pastures by increasing intake per hour of grazing.
Artificial rearing as a system for evaluating male lambs
Authors: Davies D. A. R. , Owen J. B. , Read J. L.
Published: September 2010

The use of an artificial rearing system to provide controlled environment conditions for performance testing of male lambs was investigated in two trials. A sample of lambs from 5 fat-lamb sire breeds was included.

Performance during the initial restricted milk-feeding period was uniform but large differences in solid food intake gave variable performance in the adjustment period immediately following weaning. Lambs were evaluated from 40 days onwards in terms of growth rate and efficiency of food conversion. Some breed differences were significant and the variation within groups was sufficiently high to suggest that performance might be improved by within-group selection.

Estimates from Trial 2 show that food conversion efficiency was related to growth rate, but early and late performance in the evaluation period were not correlated (r = 0·12, 0·16 and 0·14 for growth rate, food intake and efficiency, respectively). Some refinements of the method are suggested, and it is concluded that the system could provide suitable conditions for testing male lambs at an early age without the variable influence of the dam.
The electrical conductivity inside the bovine vaginal wall
Authors: Feldmann F. , Aizinbud E. , Schindler H. , Broda Hanna
Published: September 2010

Electrical conductivity was measured during the oestrous cycle of cows with electrodes implanted in the vaginal wall. Conductivity was considerably higher during oestrus than during the preceding or following cycle stage. Conductivity was also high in the fresh surgical wound, whereas the healing process was accompanied by a decrease.
A note on bovine colostrum as an alternative source of immunoglobulin for lambs
Authors: Logan E. F. , Foster W. H. , Irwin D.
Published: September 2010

Newborn lambs were separated from their dams before they had an opportunity to suck. They were given bovine colostrum in a single feed and thereafter fed on a milk substitute. Their weight gain compared favourably with that of lambs fed on ovine colostrum followed by milk substitute or suckled naturally. It was concluded that bovine colostrum can be used successfully as an alternative source of immunoglobulin for rearing lambs.
The effect of two concentrations of dietary protein and of formaldehyde-treated soya-bean meal on the performance of high-yielding dairy cows
Authors: Kaim M. , Neumark H. , Folman Y. , Kaufmann W.
Published: September 2010

In two experiments, 165 dairy cows were allotted to groups given post-partum dietsad libitumcontaining either 150 g (LP) or 190 to 200 g (HP) crude protein (CP) per kg dry matter (DM).

In experiment 1, which lasted 21 weeks after calving, cows were given pre-partum two amounts of energy (National Research Council (NRC) recommended amountv.1·4 × NRC recommended amount). Pre-partum amounts of energy did not affect DM intake, milk yield or milk composition. Protein intake, including that for maintenance, was 84 and 116 g CP per kg milk in the LP and HP groups, respectively.

During 2 to 6 weeks after calving the HP concentration in a diet containing 850 g concentrates and 150 g hay per kg, decreased DM intake, whereas in a diet containing 650 g concentrates and 350 g hay per kg, the HP concentration increased DM intake. During weeks 12 to 21 after calving, the HP concentration decreased milk yield from 33·0 to 28·7 kg and increased milk fat concentration from 24·1 to 29·3 g/kg. Rumen fluid ammonia-N concentrations were 135 and 200 mg/1 in cows given the LP and HP diet, respectively. Plasma urea-N concentrations were 114 and 172 mg/1 in the same groups, respectively.

In experiment 2, three groups of cows were given, during 15 weeks after calving, diets LP, HP and HP containing soya-bean meal treated with formaldehyde (HPSP). Protein intake, including that for maintenance, was 71, 82 and 86 g CP per kg milk in the three groups, respectively. Mean daily milk yields during 15 weeks after calving were 37·5, 39·2 and 39·3 kg in groups LP, HP and HPSP, respectively. Cows given the LP and HP diets lost, after parturition, 22·5 kg body weight, whereas cows given the HPSP diet lost only 6·0 kg. Rumen fluid ammonia-N concentrations were 95, 175 and 81 mg/1 and plasma urea-N concentrations were 80, 200 and 143 mg/1 in cows given the LP, HP and HPSP diets, respectively. It is concluded that on certain diets high-yielding dairy cows can be given, in addition to that for maintenance, as little as 60 g CP per kg milk. Formaldehyde-treated soya-bean meal may increase milk yield during the first 3 weeks after calving, and reduce body weight loss.
The effects of dose and method of administration of biosynthetic bovine somatotropin on live-weight gain, carcass composition and wool growth in young lambs
Authors: Johnsson I. D. , Hathorn D. J. , Wilde R. M. , Treacher T. T. , Butler-Hogg B. W.
Published: September 2010

Exogenous bovine pituitary somatotropin (GH) can influence markedly body composition in fattening lambs. However, neither the effects of biosynthetic somatotropin nor the effects of dose and method of administration have been reported. Fifty Dorset-cross lambs (female and castrated male) were given concentrate ad libitum and treated between 10 and 22 weeks of age with biosynthetic bovine somatotropin either dissolved in buffer and injected subcutaneously (s.c.) in proportion to body weight (0·025, 0·1 or 0·25 mg/kg per day), dissolved in buffer and continuously infused s.c. (0·1 mg/kg per day) or suspended in olive oil and injected s.c. (0·1 mg/kg per day), and compared with 10 untreated control lambs. Somatotropin had little effect on live-weight gain (controls = 228 g/day; final live weight 37 kg), food intake and food conversion efficiency, and only marginally increased the weight of muscle and bone dissected from the shoulder joint. The weights of the major fat depots in the abdominal cavity and of fat dissected from the shoulder joint were linearly related to dose of somatotropin (P < 0·001). Lambs given the highest dose had less visceral fat (1·18 v. 2·84 kg; P < 0·001) and proportionately less fat (285 v. 374 g/kg; P < 0·001) and more muscle (542 v. 447 g/kg) and bone (172 v. 149 g/kg; P < 0·001) in the shoulder joint than control lambs. There was a positive curvilinear relationship (P < 0·01) between clean wool growth (mid-side patch sample) and dose; lambs injected daily with 0·1 mg somatotropin per kg grew one-third more wool than control lambs. Method of administration affected plasma somatotropin profiles but had no significant influence on any of the responses measured. The anabolic actions of somatotropin may have been limited in this experiment by a low sodium concentration in the diet. It is concluded that the lipolytic/anti-lipogenic effect of somatotropin can occur in the absence of conditions conducive to the stimulation of muscle protein deposition and that the response is dose dependent but not influenced by method of administration of the hormone.
Effects of dam and sire group on the propensity for twin calving in cattle
Authors: Morris C. A. , Day A. M.
Published: September 2010

The incidence of twin calvings and double ovulations was studied in two Milking Shorthorn herds and one Friesian herd, each with above-average annual twin calving rates (average 0·031, compared with a national rate of 0·01). The proportions of double ovulations were calculated from records comprising 1237 cow × years (cows over 2·0 years of age); means were 0·08, 0·27 and 0·50, for three groups which had previously produced 0, 1 or >1 sets of twins, respectively. All cows (whether still present or no longer in the herd) were then allocated a twin production status, to indicate the number of twin sets (0, 1 or >1) produced, or produced so far, in their lifetime. There were records from 1559 cows, with sire and dam also known. Twin production status was significantly influenced by dam group (P < 0·01), i.e. the twin production status of the cow's dam. Sires were classified into two groups, according to whether any daughters had produced two or more sets of twins. After allowing for ascertainment, sires in the two groups were found to differ (P < 0·01) by 0·06 in the probability of their daughters producing at least one set of twins in their lifetime (i.e. 0·08 to 0·14). One sire and dam combination in particular had prolific daughters with a probability of 0·39 of producing at least one set of twins in their lifetime (compared with a probability of 0-07 for the other extreme combination). The possibility of these observations being explained by the segregation of a single recessive gene was considered, but the necessary interaction between sire group and dam group was not significant.
Development of a dynamic, mechanistic model of lamb metabolism and growth
Authors: Sainz R. D. , Wolff J. E.
Published: September 2010

A dynamic, mechanistic model of lamb metabolism and growth was developed for the purpose of evaluating hypotheses regarding the mechanisms of action of growth promotants. The model relates tissue growth to DNA accretion and protein turn-over. State variables include circulating amino acids, glucose, lipids and acetate; four protein pools (carcass, viscera, other tissues and wool) and storage triacylglycerol are also included. Equations are mainly of the Michaelis-Menten form, allowing for nutrient utilization patterns to be determined by relative tissue affinities for substrates (ko.5), enzymatic capacities (Vmax) and substrate concentrations ([S]). Protein degradation rates are defined as first-order with respect to protein. The model adequately simulated growth from 20 to 40 kg empty body weight. Simulated changes in nutrient input yielded reasonable energy balance response patterns, although theoretical growth efficiencies were greater than those observed in practice. Variations in volatile fatty acid absorption patterns were accommodated well, with predicted nitrogen retention closely approximating experimental observations. The model also responded appropriately to changes in dietary protein level, with body fat varying inversely with amino acid absorption. In summary, the model was found to perform adequately for the purpose of examining mechanisms responsible for alteration of growth and body composition.
Effect of forage type on the digestion of whole barley grain by breeding ewes
Authors: Chestnutt D. M.
Published: September 2010

The proportion of whole grain consumed that was voided intact in the faeces of ewes in late pregnancy and early lactation was measured for diets based on a range of forages in two experiments. The proportions of grain voided intact varied widely between ewes and was to some extent a characteristic of the individual ewe. During late pregnancy on hay-based diets the mean proportion of grain recovered was 0·053 with a range from 0·042 to 0·063 while on silage-based diets 0·135 (range 0·082 to 0·209) was recovered. On silage-based diets after lambing 0·196 and 0·235 of grain was voided intact in the faeces. The proportion of intact grain voided was affected by forage intake. The estimated increase in the proportion of grain voided intact was 0·012 measured over a range of forages before lambing and 0·021 on silage after lambing per 100 g increase in dry matter intake. However, when the total digestibility was measured, there were no differences between feeding of whole and processed grain where proportionately 0·06 of whole grain consumed was voided intact.
Artificial insemination of farmed red deer (Cervus elaphus)
Authors: Fennessy P. F. , Mackintosh C. G. , Shackell G. H.
Published: September 2010

Six experiments involving the artificial insemination (AI) of a total of 300 female red deer (hinds) with frozen-thawed red deer semen (collected by electro-ejaculation) were conducted over 3 years. Insemination took place at fixed times following various oestrous synchronization procedures using progesterone withdrawal and treatment with pregnant mare's serum gonadotropin (PMSG). In the 1st year, the experiments evaluated basic AI techniques in which pregnancy rates were 45% in 20 hinds receiving two inseminations per vaginam (PV) and 56% in 27 hinds inseminated by the laparoscopic intrauterine method (IU). In the 2nd year, the experiments involved comparisons of the progesterone regime, one or two PV inseminations, and the timing of a single PV insemination. There was no effect of replacement of the progesterone device after 9 days and withdrawal 3 days later compared with the use of one device for the whole period in two experiments. The pregnancy rate for a double PV insemination was significantly higher than for a single PV insemination (58 and 34%;P< 0·05) and there was also a small effect of timing of insemination relative to the synchronization treatment. In the 3rd year all hinds were inseminated by the IU method. The experiments involved a comparison of various times of AI following progesterone withdrawal and a comparison of the progesterone regime. The overall pregnancy rate for 63 hinds inseminated was 56% with no difference between three times of insemination (48, 52 and 55 h). In the second experiment, the difference in pregnancy rate between treatment with progesterone for 15 days and 12 days (44 and 72% for 18 hinds per group) was not significant, but the interaction between the length of progesterone treatment and insemination time was significant (P < 0·05), with the 12-day progesterone/55 h insemination giving a much higher pregnancy rate than the 15-day/55 h insemination (89 and 20% respectively). Although no experiments involved direct comparisons of the routes of insemination, overall pregnancy rates were 56% for IU, 53% for double PV and 35% for single PV inseminations.
Diet selection in pigs: dietary choices made by growing pigs following a period of underfeeding with protein
Authors: Kyriazakis I. , Emmans G. C.
Published: September 2010

Forty pigs (half each of females and entire males) were used in anad libitumfeeding experiment from weaning to 33 kg live weight (LW). In period 1 to 16 kg LW, the pigs had either food L (134 g crude protein (CP) per kg) or food H (278 g CP per kg) alone. The aim was to delay the growth of pigs on L and create two groups of pigs with different body compositions. At 16 kg LW, eight pigs were killed and their empty bodies chemically analysed. The pigs given L had 1·06 (s.e. 0·08) kg more lipid and a lower protein: ash ratio in their empty body than pigs on H; growth rates, from 9 to 16 kg LW, were 386 (L) and 591 (H) (s.e.d. 17)g/day. Both aims were thus achieved.

In period 2 the pigs previously given L (no. = 16) or H (no. = 16) in period 1, were given L alone (no. = 4), H alone (no. = 4) or a choice between L and H (no. = 8) to 33 kg LW when the choice-fed pigs were killed and their empty bodies chemically analysed. The objective of the experiment was to test the idea that pigs previously given a food deficient in CP, when given a choice between foods, one of high and one of low, protein content will select a diet of a composition that allows them to correct the effects of the previous mis-feeding. The pigs given L alone in period 2 grew more slowly, and ate more per day, than those given H alone, with no effect of the food given in period 1. Of those given H alone in period 2, the pigs previously given L grew faster, and were more efficient, than those previously given H.

The protein contents (g CP per kg food) of the diets selected by the choice-fed pigs were significantly affected by both sex (228 for malesv.181 for females; s.e.d. 15) and the food given in period 1 (233 for L and 175 for H; s.e.d. 15) with no significant interaction between these factors. The pigs from L grew faster (1039v.780 (s.e.d. 70) g/day) had a higher daily food intake (1420v.1319 (s.e.d. 71) g/day) and were more efficient (0·736v.0·595 (s.e.d. 0·034) g gain per g food) than those from H. At 33 kg LW lipid weights were similar for the two period 1 treatments (L had 0·40 (s.e. 0·54) kg more lipid than H); females had 1·79 (s.e. 0·54) kg more lipid than males.

It is concluded that, where pigs are given a choice between foods of low and high protein contents, they will select a diet of a composition such that the effects of previous mis-feeding are corrected. Giving pigs a choice between an appropriate pair of foods allows them to select a diet of a composition suitable for their needs.
Effect of α-tocopherol and dietary fat source on some blood and immunological variables in lactating sows
Authors: Babinszky L. , Langhout D. J. , Verstegen M. W. A. , Hartog L. A. den , Joling P. , Nieuwland M.
Published: September 2010

Thirty-six 7-month-old gilts were used to study the effects of different levels of a-tocopherol (13, 48, 136 mg/kg food) and different source of fat (50 g/kg sunflower oil or animal fat) in gestation and lactation diets on α-tocopherol concentration in serum, colostrum and milk and on cell-mediated and humoral immune response of lactating sows.

Blood samples were taken from six sows per treatment after farrowing and at weaning (28 days of lactation) and were analysed for α-tocopherol concentration, total number of leucocytes and T- and B-lymphocyte counts. In blood lymphocyte stimulation with concanavaline, lysozyme activity and immunoglobulin concentration were also measured. In milk samples α-tocopherol and immunoglobulin concentration were determined at farrowing and at weaning. It was concluded that a high α-tocopherol level in the sow's diet including either sunflower oil or animal fat increased as expected the serum α-tocopherol concentration (P< 0·05) just after farrowing and at weaning. In colostrum the combination of high α-tocopherol with animal fat gave the highest (P< 0·05) α-tocopherol concentration. At weaning α-tocopherol in milk fat was highest in both fat groups with extra high α-tocopherol in the diet. The cell-mediated immunity of sows as tested were not systematically affected by α-tocopherol supplementation or fat addition to diet. However, the humoral immune system may be affected by the combinations of α-tocopherol and fat given.
Effect of constant-release melatonin implants on the onset of oestrous activity and on reproductive performance in the ewe
Authors: Durotoye L. A. , Rajkumar R. , Argo C. M. , Nowak R. , Webley G. E. , McNeil M. E. , Graham N. B. , Rodway R. G.
Published: September 2010

Various types of constant-release melatonin implants were designed and administered to adult ewes during seasonal anoestrus. Implants were given between May and July in a series of four experiments. Treatment of ewes with melatonin implants resulted in advancement of the onset of oestrous activity. Melatonin treatment also resulted in improved reproductive performance, increased numbers of lambs born per ewe bred and caused more multiple births. Results from this study show, therefore, that constant-release melatonin implants administered during late spring or early summer advance the onset of the breeding season and improve reproductive performance in ewes.
Nutritional evaluation of triple low rapeseed products for growing pigs
Authors: Agunbiade J. A. , Wiseman J. , Cole D. J. A.
Published: September 2010

Ground full-fat rapeseed (FFRS) and the resulting extracted oil (RSO), meal (RSM) and recombined RSO and RSM (ORSM) from a triple-low cultivar containing low levels of erucic acid, glucosinolates and tannins were evaluated. RSO, FFRS and ORSM were included into a basal diet to give levels of added oil of 40, 80 and 120g/kg. RSM was also incorporated into the basal diet at the same rates as in ORSM. The 12 experimental diets together with the basal diet were given to 13 gilts in a metabolism trial conducted over four time periods. A 10-day acclimatization in holding pens preceded a 5-day total collection of faeces and urine in metabolism crates. Rapeseed products, diets, faeces and urine were analysed for gross energy (GE) and all, except urine, for oil content measured by two methods (petroleum ether and acid hydrolysis prior to ether extraction). Apparent digestible energy (DE) and metabolizable energy (ME) of rapeseed products were determined by single-level assay and by regression. Oil DE was also derived indirectly as a product of apparent oil digestibility (AOD) and oil GE. Apparent nitrogen digestibility was estimated for diets and rapeseed products. The response of dietary DE, ME and AOD to rates of test material inclusion was linear (P < 0·001) in all cases except for ORSM and RSM the DE and ME of which, in addition, showed evidence of curvilinearity. Age of pig had no significant effect on dietary AOD and energy values. Linear regression techniques were better than single level assays (particularly at low rates of inclusion) in determining energy values and gave DE values of 42·4, 190, 14·6 and 25·8 MJ/kg dry matter for RSO, FFRS, RSM and ORSM respectively. Oil DE and AOD were not influenced by method of evaluation. The results of this study indicated improved energy values for FFRS and RSM of a triple-low cultivar over published data for high-glucosinolate varieties but not over data for double-low varieties. In addition it appears that AOD is the main factor determining dietary utilization of FFRS and would need to be considered in order to optimize the nutritive value of FFRS in diets for growing pigs.
Sucrose as an energy source for growing pigs: energy utilization for protein deposition
Authors: Beech S. A. , Elliott R. , Batterham E. S.
Published: September 2010

An experiment was conducted to determine the effect of sucrose as an energy source on energy utilization and protein retention by growing pigs. Growing pigs (20 to 50 kg live weight) were restrictively fed (three times maintenance) either a control wheat-based diet (14 MJ digestible energy (DE) per kg), a sucrose-based diet (15 MJ DE per kg) or a wheat-based diet made i so-energetic with the sucrose diet by the addition of oil. Net energy (NE) content of the diet, energy utilization, protein and fat deposition were measured.

Both the sucrose- and the iso-energetic wheat-based diets improved energy utilization and increased NE retention. They also increased fat deposition (P < 0·05) but had no effect on protein deposition (P > 0·05) compared with the wheat-based control. Increased DE utilization in the sucrose-based diet appeared due to (i) lower dietary fibre, (ii) a better balance of amino acids, or possibly due to (iii) increased fat synthesis due to sucrose metabolism. The lack of effect of sucrose on protein deposition appeared due to either (i) an increased amino acid requirement as a result of the higher NE content of the diet or (ii) preferential use of sucrose for fat deposition.
Feed intake in six lines of pigs and its influence on growth and carcass traits 1. Feeding twice daily for 20 min per session
Authors: Cöp W. A. G. , Buiting G. A. J.
Published: September 2010

For a crossbreeding experiment six lines of pigs were developed from six breeds: Belgian Landrace (B), Pietrain (P), Dutch Landrace (N), Dutch Yorkshire (G), Duroc (D) and Hampshire (H). Out of 10 different litters per line, one female and one castrate male were housed and fed individually from 20 to 96 kg. All pigs were offered feed twice daily for 20 min exactly.

Maximum differences in feed intake between the lines increased from 150 g at 25 kg to more than 500 g at 95 kg live weight. Daily intake of Pietrain pigs was lower than that of all other lines. Differences between the N, H and G lines were small. The difference between the feed intake of males and females increased from zero at 27 kg to 230 g at 75 kg. Differences in daily gain were greatest between the P and G lines, and doubled during the growing period from 80 g to 170 g.

Differences in daily gain between the N, H and B lines were small. Pietrain pigs and, to a lesser extent, Belgian Landrace pigs produced more meaty carcasses but both had poorer meat quality than other other lines. It is concluded that differences in feed intake might be the main causal factor for the existence of differences between biological types of pigs.