bluuebunny/crossref_metadata_2025 huggingface dataset:
Feeding straw to small ruminants: effect of amount offered on intake and selection of barley straw by goats and sheep
Authors: Wahed R. A. , Owen E. , Naate M. , Hosking B. J.
Published: September 2010

The hypothesis that increasing the amount of straw offered and allowing animals to refuse proportionately more than 0·1 to 0·2 would increase intake and quality of the straw consumed was tested in two experiments with castrated goats (aged 6 to 31 months) and one with wether sheep (aged 6 to 18 months). Each trial (over 21 to 42 days following 14 to 35 days preliminary feeding) involved individually feeding long barley straw and concentrate supplement (15 g dry matter (DM) per kg live weight (M075) daily) and monitoring the quantity and quality of straw offered and straw refused. The results supported the hypothesis. In experiment 1, with 18 goats per treatment, those allowed to refuse 500 rather than 200 g straw per kg DM offered consumed more (18·9 and 14·4 g DM per kg M75 per day, s.e.d. 0·70) and their straw refusals contained more digestible organic matter (DOM) in vitro (347 and 320 g/kg DM, s.e.d. 7·7). For both treatments, refusals were less digestible in vitro than the straw offered (412 g DOM per kg DM). Thirty-six goats in experiment 2 (over 42 days) offered increasing amounts of straw (18, 54 and 90 g DM per kg M075 per day) consumed more (15·5, 22·8 and 26·2 g DM per kg M per day, s.e.d. 0·74), refused more (125, 566 and 703 g/kg DM offered) and the refusals were of increasing digestibility in vitro (354, 370 and 403 g DOM per kg DM, s.e.d. 14·5). All refused straw was inferior to that offered (443 g DOM per kg DM). The estimated intake of straw DOM was markedly improved by offering more straw (7·2, 12·8 and 14·5 g per kg M75 per day). Experiment 3, using 30 wethers over 21 days fed as in experiment 2, showed similar treatment responses, although absolute intakes of straw were lower. The responses observed are comparable to improvements in intake following treatment of straw with alkali. Further research is required to determine optimum feeding rates as affected by straw quality and animal productivity level. Practical feeding strategies will also need to consider utilizing refused straw.
The effect of amount of protein in the concentrates on hay intake and rate of passage, diet digestibility and milk production in British Saanen goats
Authors: Badamana M. S. , Sutton J. D. , Oldham J. D. , Mowlem A.
Published: September 2010

During the first 2 weeks after kidding, 27 multiparous British Saanen goats were offered 1·5 kg hay (98 g crude protein (CP) per kg dry matter (DM)) and from 0·45 increasing to 0·70 kg concentrates (152 g CP per kg DM) daily. Week 2 was used as a covariance period. At week 3 of lactation all the goats were allocated to one of three groups and were offered hay ad libitum and 1 kg concentrates containing 117 (LP), 152 (MP) or 185 (HP) g CP per kg DM daily to week 15. During weeks 4 to 15, hay intake and milk yield were highest in the HP group. With increasing protein in the concentrates, hay DM intake was 1·20, 1·19 and 1·37 (s.e. 0·060) kg/day respectively and milk yield was 3·04, 3·21 and 3·36 (s.e. 0·080) kg/day respectively (linear response P < 001). There was no significant effect on the concentration of solids-not-fat, fat, total nitrogen or casein in milk. The digestibility of dietary organic matter, acid-detergent fibre and total nitrogen measured after week 15 was significantly greater with HP than with LP (P < 0·05), with MP values being intermediate (linear response P < 005). The rate of passage of ytterbium-labelled hay was unaffected by the treatments. The results indicate that, with lactating goats given hay and concentrates, beneficial responses may be expected to increasing concentrate CP to at least 185 g CP per kg DM.
Enzyme supplementation of low or high crude protein concentration diets for broiler chickens
Authors: Pettersson D. , Graham H. , Åman P.
Published: September 2010

Previous investigations have established that supplementing broiler chicken diets with appropriate endosperm cell wall degrading enzymes can improve nutrient digestion, and indicated that this could allow lower protein diets to be used. In this study the effect of enzyme supplementation on the productive value of low (192 g/kg dry matter (DM)) and high (227 g/kg DM) protein diets was studied. The diets employed were based on barley, wheat and rye, and the two enzyme preparations used, Glucanase GP 5000® and Novozym-343®, contained β3-glucanase and arabinoxylanase activities.

The high protein diet gave a higher incidence of sticky droppings, but resulted in a higher growth rate and improved food conversion ratio than the low protein diet. Enzyme supplementation reduced the incidence of sticky droppings and also improved growth rate, food intake and food conversion efficiency for both diets, with the Glucanase GP 5000 preparation generally being more effective. Enzyme supplementation improved growth rate on the low protein diet to a level equal to or better than that on the high protein diet, although this was achieved by a better food intake and an inferior food conversion ratio. This study demonstrated that supplementation with appropriate enzymes could allow a reduction in dietary protein level without affecting broiler growth rate.
A note on the effect of Aspergillus oryzae fermentation extract on the rumen fermentation of sheep given straw
Authors: Fondevila M. , Newbold C. J. , Hotten P. M. , Ørskov E. R.
Published: September 2010

Eight mature Dorset-cross sheep, each fitted with a permanent rumen cannula, were given a diet of chopped barley straw (plus urea and minerals) either with or without an Aspergillus oryzae (AO) fermentation extract (2 glday). The addition of AO fermentation extract to the diet increased the initial rate of straw degradation (P < 0·05) but did not alter the final extent of degradation. Total culturable bacteria increased with AO treatment but numbers of cellulolytic bacteria, ciliate protozoa, and aerobic fungi, were not significantly altered. Rumen pH, liquid clearance rate, total volatile fatty acids, acetate, propionate, butyrate, L-lactate and ammonia concentrations were also unaffected.
Evaluation of a slow-release form of recombinantly derived bovine somatotropin in dairy cattle
Authors: Kim J. , Campling R. C. , Wilkinson J. I. D.
Published: September 2010

Dairy cattle were injected at intervals of 4 weeks with recombinantly derived bovine somatotropin (bST) i n a slow-release form (somidobove, Lilly Research Centre Ltd, Windlesham, Surrey), to examine the effect on milk production. In the first experiment with 38 autumn-calving animals in a randomized-block design, treatment lasted for 28 weeks and a control and three doses of bST: 320 (low), 640 (medium) and 960 (high) mg were compared. Over the 28 weeks the mean daily milk yields were: control 23·4, low 23·4, medium 25·4 and high 25·4 (s.e.d. 1·17) kg. Milk composition was not affected by bST. In experiment 2 with 40 autumn-calving animals, the medium dose of bST was used for 24 weeks in animals given two levels of concentrate in a factorial design. On average there was a non-significant increase in daily milk yield of 1·3 kg in the bST-treated cattle; there was no interaction between bST and level of concentrate. There were no effects of bST on milk composition. Changes in live weight and body condition of the cattle and their food intake were measured. It was concluded that the trends toward higher milk yields were supported initially at the expense of live weignt and possibly later by increased food intake. In a third experiment 10 grazing cows were given three consecutive doses of 640 mg bST and 10 similar cows acted as controls. There were no significant effects of bST on milk production and food intake. Reasons for the low responses in milk production compared with several recent American and European experiments may possibly be the pattern of use of the slow-release form of bST and the low content of dry matter in the maize silages which restricted forage intake and response in milk production.
The use of the rumen degradation characteristics of hay as predictors of its voluntary intake by sheep
Authors: Carro M. D. , Lopez S. , Gonzalez J. S. , Ovejero F. J.
Published: September 2010

Eleven sun-cured hays with crude protein (CP) and neutral-detergent fibre (NDF) concentrations ranging from 57 to 207 and 428 to 744 g/kg dry matter (DM) respectively, were used to study the relationship between the DM and NDF degradation characteristics and the voluntary DM intake (VDMI) by sheep.

The VDMI was measured in the last 10 days of a 21-day period using 50 mature ewes in five groups of 10 ewes per group, with a mean live weight (LAY) of 55 kg and ranged from 41·2 to 69·8 g/day per kg LW075. Disappearanc e rates of DM and NDF were measured by incubating samples in nylon bags in the rumens of three hay-fed rumen-cannulated ewes for 3, 6, 9, 15, 24, 48 and 72 h and by fitting the exponential model Y = a + b (1 — e-ct) to the results. Potential degradabilities (defined as a + b) for DM and NDF ranged from 679 to 868 and from 445 to 808 g/kg respectively.

The VDMI was significantly correlated with the soluble fraction of DM (aDM; P < 0·05) and the rate of degradation of DM (cDM; P < 0·01) and NDF (cNDF; P < 0·01). The inclusion of aDM and cDM ni a multiple regression model resulted in the equation: VDMI = 21·3 + 0·0733 (s.e. 0·01577) aDM + 138 (s.e. 26·0) cDM (R2 = 0·897; residual s.d. = 2·79), with a significant increase of the variance explained by one single degradation characteristic (P < 0·05). The prediction was not improved by adding the constant cNDF to the equation (P > 0·05). These results indicate the possibility of predicting the VDMI of hays by sheep from the rumen soluble fraction (aDM) and the rate of degradation (cDM) of DM.
Pre-mating herbage intake and the reproductive performance of north Country Cheviot ewes in different levels of body condition
Authors: Gunn R. G. , Smith W. F. , Senior A. J. , Barthram E. , Sim D. A. , Hunter E. A.
Published: September 2010

Over 4 years, a flock of mature North Country Cheviot ewes was grazed on different swards between weaning in August and mid October to achieve a range of condition scores at 5 weeks before mating (post-weaning period). During the subsequent 5 weeks before a synchronized mating (pre-mating period), all ewes were grazed on a perennial ryegrass/white clover sward, provided at high (H) or low (L) herbage masses (1600 to 2100 or 1200 to 1400 kg dry matter (DM) per ha, respectively). Ovulation rate was derived from the number of corpora lutea in 101 ewes slaughtered after first mating. Conception and lambing rates were derived from the number of lambs born to first mating of 406 ewes. In 2 out of the 4 years, 79 ewes were used to estimate herbage intake.

There was no effect of post-weaning management on reproductive performance. Herbage intake and reproductive performance were examined in relation to the body condition of the ewes at 5 weeks before mating. On an H herbage mass pre-mating, herbage intake in the period immediately prior to mating was greatest in ewes in low body condition and declined significantly with increasing condition. On an L herbage mass pre-mating, herbage intake did not vary significantly with condition. Ovulation rate was low in ewes in low body condition (scores =≤·25) at 5 weeks before mating, increased significantly with increasing condition up to scores 2·50/2·75 but did not change significantly above such intermediate scores. Conception and lambing rates increased significantly with increasing body condition up to scores 2·50/2·75 and then decreased significantly as condition increased above these levels. These effects of body condition were greater on an L herbage mass pre-mating than they were on an H herbage mass. Ewes in the intermediate body condition scores of 2·50 and 2·75 at 5 weeks before mating had a low sensitivity to contemporary nutrition pre-mating. Such condition levels are therefore considered to be above the range of condition in the North Country Cheviot breed within which reproductive response is affected by contemporary nutrition pre-mating.

The lower reproductive performance of ewes in high body condition (scores 3=3·00) at 5 weeks before mating was related to an increase in estimated ova and embryo loss and may be associated with a reduced herbage intake.
The response of growing pigs to a choice of diets differing in protein content
Authors: Bradford M. M. V. , Gous R. M.
Published: September 2010

An experiment was designed to test whether pigs can differentiate between two foods differing in their protein content. A control food (160 g protein per kg food) and six choice-feeding treatments, in which the diets differed only in their protein concentrations, were used in the experiment. Pigs were given the following choices of protein: 220v.180; 220v.140; 220v.100; 180v.140; 180v.100 and 140v.100 g protein per kg food. Group data were collected on 240 Landrace × Large White pigs during the growing phase (30 to 90 kg), all pigs used being of similar genetic background. A 2 × 7 factorial design was replicated twice, with 10 pigs per pen, and with barrows and gilts being penned separately. Food bins for the choice-feeding treatments were placed side-by-side and an 8-day training period, in which the pigs were allowed access to only one of the two foods on alternate days, was used at the beginning of the trial to allow them to learn the position, taste and physiological effect of each of the two foods. All pigs were weighed weekly, as was the amount of food consumed in each pen. The conclusion reached was that growing pigs were able to differentiate successfully between two foods on the basis of their protein content and to change the selected diet to match their changing requirement for dietary protein. As a result, there was a significant reduction in food intake (P< 0·001) and in the P2 backfat thickness (P< 0·01) and the food conversion ratio was significantly improved (P< 0·001) compared with the control treatment.
Effect of type of basal diet and rate of inclusion on the evaluation of protein concentrates with rabbits
Authors: Villamide Maria J. , Fraga Maria J. , de Blas C.
Published: September 2010

One hundred and eight New Zealand × Californian growing rabbits (nine per diet) were used to determine the nutritive value (digestible energy (DE), digestible protein (DCP) and digestible acid-detergent fibre (DADF)) of five protein concentrates. In assay 1, the effect of the type of basal diet (BD) (7·6 or 10·0 MJ DE per kg dry matter (DM) for BD1 and BD2 respectively) and the substitution level (150, 300 and 450 g/kg) on nutritive value of soya-bean meal was studied. According to the results of assay 1, one basal diet (BD2) and one substitution level (300 g/kg for sunflower 380, gluten meal and extruded soya-bean meal or 500 g/kg for sunflower 320) were selected in assay 2 to determine their nutritive value.

The effect of the basal diet and the substitution level on the nutritive value of soya-bean meal was evident only for the values calculated from BD1 and the lowest level of inclusion. The data obtained by difference at the highest level of inclusion and by extrapolating the linear equations were very similar (16·32 v. 16·35 MJ DE and 387·62 v. 388.58 g DCP per kg DM for BD2), but the standard errors were lower (0·52 v. 0·72 for DE and 6.76 v. 8.95 for DCP) in the former. The DE values obtained for sunflower meal 320 and 380, extruded soya-bean and gluten meal were 10·29, 14·37, 18·58 and 20·57 MJ/kg DM respectively; protein digestibilities were high (with coefficients from 0·80 to 0·90) except in the case of sunflower-320 (0·73). A stepwise regression analysis was made to predict the nutritive value from chemical composition including values from literature. For prediction of DE, the variables selected were: crude fibre, ether extract and ash, obtaining a determination coefficient of 0·935. The protein digestibility was independent of variables employed.
Effect of feeding level, breed and milking potential on body tissues and organs of mature, non-lactating cows
Authors: Taylor St C. S. , Murray J. I.
Published: September 2010

Body composition was studied in 20 mature, non-pregnant, non-lactating cows from five breeds (Hereford, Aberdeen Angus, Dexter, British Friesian and Jersey) kept on four feeding levels until they attained equilibrium body weights that were proportionately 0·7,0·9,1·1 or 1·3 of their normal adult body weight.

Significant breed differences were found in the proportions of body tissues and organs and these were associated with breed differences in lactability (i.e. genetic milking potential adjusted for body size). As a proportion of body weight, intra-abdominal fat, liver, spleen and uterus increased significantly with lactability and hide decreased significantly. Empty gut and gut fill also increased with lactability but not significantly. Liver proportion in dairy breeds was 1·26 times the proportion in beef breeds. Corresponding values for intra-abdominal fat and hide were 1·43 and 0·83.

The most dramatic increases with feeding level were in the proportions of subcutaneous fat, both intra-abdominal fat depots, and the udder. All fat depots were completely depleted when body weight decreased to about 0·6 of its normal adult value. Strong decreases occurred in the proportion of muscle, carcass bone and offal. The proportion of empty gut decreased significantly with increased feeding level. Liver, tail, thymus and possibly gut fill were the only traits entirely unaffected by feeding level.

The near-constancy of liver proportion at equilibrium implies that the rapid response of the liver to a change in feeding level is eventually matched in magnitude by the slower responses in other tissues and organs, so that the original proportionality of about 1 kg body tissue for each 10 g liver is eventually restored.
The effects of hormones, other pharmacological agents and nutrition on plasma triglycerides and carcass composition in lambs and steers
Authors: Payne E. , Cope B. C.
Published: September 2010

The effects of recombinantly derived growth hormone (GH), oestradiol-17β plus trenbolone acetate, clofibrate, melatonin and fasting on basal plasma triglycerides (TG) and TG entry rate were determined in wether lambs given lucerene/barley pellets ad libitum. Clofibrate was administered at 2 × 0·5 g capsules orally, GH (0·25 mg/kg live weight) was injected subcutaneously daily whilst oestradiol-17β, oestradiol-17β plus trenbolone acetate and melatonin were slow release implants (either 4 or 4·8 mg, 4 nig and 20 nig and 18 mg respectively) placed subcutaneously in the ear. Both fasting and oestradiol treatments raised basal TG levels without influencing TG entry rates, defined as the maximum rate of change of plasma TG 3 to 6h following a dose of Triton WR1339 of at least 0·2 g/kg live weight. Entry rates were similar to those previously reported for goats but were higher than those reported for sheep. Triton WR1339 used to determine entry rates was found to reduce food intake at all levels in some sheep despite reports to the contrary. Among the various treatments, only oestradiol-17β and trenbolone acetate influenced body composition as determined by chemical analysis of minced carcasses, resulting in an increased gain of carcass protein and decreased gain of carcass fat. Clofibrate, melatonin and Triton, if allowance is made for Triton-induced loss in food intake, had no clear effects on body fatness. Overall the effects of hormones on plasma TG appeared to be small and it seems improbable that plasma TG are involved in effects of hormones on fatness.
The effect of formic acid, sulphuric acid and a bacterial inoculant on silage fermentation and the food intake and milk production of lactating dairy cows
Authors: Mayne C. S.
Published: September 2010

Herbage from first and second regrowths of perennial ryegrass based swards was directly ensiled following treatment with formic acid (850 g/kg) at 2·53 and 2·58 l/t, sulphuric acid (45% w/w) at 3·09 and 3·04 l/t, an inoculant of Lactobacillus plantarum (Kickstart, United Distillers Ltd) at 2/24 and 2/14 l/t, or no additive (control). First regrowth herbage had mean dry matter (DM) and water-soluble carbohydrate concentrations of 168 and 27·0 g/kg fresh weight with comparable values for second regrowth herbage of 164 and 16·9 g/kg respectively. All silages preserved well, although both the rate and extent of fermentation, as indicated by pH and lactic acid levels, were greater in control and inoculant-treated silages. Additive treatment had little effect on nutrient recovery following ensilage with the exception of a slightly greater recovery of both DM and energy with inoculant treated, second regrowth material. The silages were evaluated in two experiments, with 9 and 4 week periods for first and second regrowths respectively, using 48 British Friesian dairy cows. Animals were housed in individual stalls and, in addition to the treatment silages, received 5 kg/day fresh weight of a supplement containing 197 g crude protein per kg DM. Treatment of first regrowth material with formic acid significantly increased silage DM intake (P < 0·02) with a smaller, though positive effect being obtained with inoculant treatment. Treatment with either formic acid or inoculant had no significant effect on DM intake with second regrowth material. In contrast sulphuric acid tended to depress intake of first regrowth material whereas a marginal increase in intake was obtained with second regrowth material. Inoculant treatment had no significant effect on milk yield with either first or second regrowth material, although there was a tendency for small, though consistent, increases in milk fat and protein concentrations. Formic acid treatment resulted in marginal increases in fat plus protein yield whereas effects of sulphuric acid were less consistent with animal performance being decreased with first regrowth material and little effect observed with second regrowth material.
A comparison of wheat and barley as supplements to grass silage for finishing beef cattle
Authors: Steen R. W. J.
Published: September 2010

Two randomized-block experiments were carried out to examine the relative value of wheat and barley as supplements to grass silage for finishing beef cattle. In each experiment unwilted, formic acid-treated silage was offered ad libitum and supplemented with 500 g soya-bean meal and 50 g minerals and vitamins to 44 12-month-old bulls for 157 and 172 days in experiments 1 and 2 respectively. Twelve of the animals also received 2·5 kg rolled spring barley (LB), 12 received 4·0 kg barley (HB) and 20 received 3·25 kg rolled wheat (W). For experiments 1 and 2 respectively the barley contained 796 and 787 g dry matter (DM) per kg; 118 and 105 g crude protein (CP) per kg DM; 47 and 57 g crude fibre per kg DM; the wheat contained 845 and 800 g DM per kg; 112 and 116 g CP per kg DM; 23 and 25 g crude fibre per kg DM; and the silages contained 190 and 177 g DM per kg; 153 and 176 g CP per kg DM; 80 and 104 g ammonia-nitrogen per kg total nitrogen. On average over the two experiments, for treatments LB, HB and W respectively, silage DM intakes were 5·4, 4·7 (s.e. 0·14) and 4·9 (s.e. 0·11) kg/day; total DM intakes 7·9, 8·3 (s.e. 0·14) and 8·1 (s.e. 0·11) kg/day; metabolizable energy intakes 91·4, 97·8 and 94·2 MJ/day; live-weight gains 1·04,1·19 (s.e. 0·029) and 1·10 (s.e. 0·023) kg/day and carcass gams 0·65, 0·77 (s.e. 0·017) and 0·70 (s.e. 0·013) kg/day. It is concluded that the feeding value of wheat was proportionately 0·98 of that of barley for finishing beef cattle when given as a supplement to grass silage, and that the type of cereal offered did not affect silage intake or carcass composition.
The effect of breed (Large White × Landrace ν. purebred Meishan) on the diets selected by pigs given a choice between two foods that differ in their crude protein contents
Authors: Kyriazakis I. , Leus K. , Emmans G. C. , Haley C. S. , Oldham J. D.
Published: September 2010

Two pig breeds, one improved (Cotswold Fl hybrid Large White × Landrace pigs = LWX) and the other unimproved (Chinese Meishan pigs = CM) were used to test the proposition that the genotype of the pig has an effect on the selection of a diet from two foods that differ in their crude protein content. From 21 to 34 kg live weight, the pigs were given access to either one of three foods or a choice of two foods with similar digestible energy concentration (16 MJ digestible energy per kg) but a different crude protein (CP) concentration. This resulted in four dietary treatments: (i) free and continuous access to low (L) crude protein food alone (130 g CP per kg, no. = 4 of each breed); (ii) free and continous access to high (H) crude protein food alone (252 g CP per kg, no. - 4 of each breed); (Hi) free and continuous access to moderate (M) crude protein food alone (206 g CP per kg, no. = 4 of each breed) and (iv) free and continuous access to both foods L and H as a choice (no. = 6 of each breed). On all treatments the LWX performed significantly better than the CM pigs in terms of live-weight gain and food conversion efficiency (P< 0·001). The LWX and CM pigs given access to a single food contained the same amounts of protein in their bodies at 34 kg live weight, but the CM pigs had a considerably higher lipid (P< 0·001) and a lower water content (P< 0·001). When given a choice, the LWX pigs selected a significantly higher proportion of foodH(521v.226 (s.e.d. 49) g food H per kg for LWX and CM respectively) and therefore, a higher CP content in their diet (194v.144 (s.e.d. 5·4) g CP per kg respectively) than the CM pigs. The performance of pigs given a choice between two foods, in terms of live weight and rate of protein gain, was comparable with the best performance achieved on a single food (M) for the LWX, and better than the best performance on a single food (L) for the CM pigs. Thus, when given a choice between an appropriate pair of foods that differ in their crude protein content, pigs are able to select a diet that meets their requirements and allows them to express the growth characteristics typical for their breed (genotype).
Responses of multi-trait selection in open nucleus schemes for dairy cattle breeding
Authors: Meuwissen T. H. E. , Woolliams J. A.
Published: September 2010

Responses of selection for milk production and secondary traits were predicted in open nucleus schemes using a deterministic model. Secondary traits considered were: traits recorded during lactation (e.g. mastitis resistance; calving ease); traits recorded in the nucleus only (e.g. food intake); traits recorded early in life (e.g. growth rate); and traits recorded late in life (e.g. longevity). Also, genotype × environment interactions between nucleus and commercial herds and predictors of merit in juveniles were considered.

Extension of the breeding goal to include an uncorrelated secondary trait, which was recorded at each lactation, had the same heritability as milk production (assumed throughout to be 0·25) and half its economic value, increased total economic gain by a factor of 0·12. This increase was only 0·04, if the heritability of the secondary trait was 0·1. The situation for traits of low heritability was not improved by progeny testing of young bulls due to the short optimized generation intervals. Gain increased only by a factor of 0·04, if the economic value was 0·25.

Including a secondary trait of heritability 0·25 and a genetic correlation with yield of 0·5 in the index, only increased economic response rates by a factor of 0·04. However, when the genetic correlation was –0·5 the benefits were greater with increases of 0·09, 0·10 and 0·22 for heritabilities of 0·05, 0·10 and 0·25, respectively. Hence, including traits with low heritability but with strong negative correlations with yield, which might apply to fertility and disease resistance, increased rates of gain moderately.

If an uncorrelated secondary trait was recorded in the nucleus only, e.g. food intake, and had half the economic value of milk production, total gains increased by a factor of 0·10. Hence, recording of secondary traits can be restricted to the nucleus with only minor loss of gain. The extra economic benefit was greatest from secondary traits measured early in life compared with late in life, e.g. longevity, with benefits increased by factors of 0·24 and 0·06, respectively.

Open nucleus schemes are robust in the presence of genotype × environment interactions between nucleus and commercial herds, if the breeding value estimation method accounts for these interactions, juvenile indicator traits of milk production may increase rates of gain by a factor of 0·11, if the heritability of the indicator trait is 0·25 and the correlation with milk production is 0·5.
Protein, acetate and propionate for roughage-fed lambs. 2. Nutrient kinetics
Authors: van Houtert M. F. J. , Nolan J. V. , Leng R. A.
Published: September 2010

Thirty-six wether lambs were given food hourly consisting of mature chopped oaten hay, sprayed with 10 g urea per kg hay. A pelleted supplement was given containing 0 or 75 g/day fish meal and 0 or ca. 1·5 MJ/day gross energy as acetate or propionate in a 2 × 3 factorial design. Dry matter (DM) digestibility, nitrogen retention and urinary allantoin excretion were determined over 7 days. Tissue protein kinetics were estimated using15N-glycine. Net fluxes of acetate, bicarbonate and glucose were estimated with continuous infusion of14C-acetate,14C-bicarbonate and3H-glucose respectively.

Intake of oaten hay (g DM per kg live weight per day) was reduced by supplementation. Live-weight gain was lower in lambs supplemented with propionate than in lambs given the basal diet only. Supplementation with fish meal increased DM digestibility, live-weight gain and wool growth. Daily excretion of urinary allantoin did not differ between groups of lambs. Nitrogen retention and protein flux were reduced in lambs supplemented with acetate or propionate and were increased in lambs given fish meal. Plasma acetate concentrations were higher for lambs supplemented with acetate. However, net flux of acetate did not differ between groups of lambs. The net flux of glucose was increased by supplementation with propionate and with fish meal. Plasma levels of β-hydroxybutyrate were reduced in lambs supplemented with propionate.

Availability of propionate and glucose were not limiting live-weight gain in these lambs. Also, a high ratio of acetate to propionate did not reduce the apparent efficiency of nutrient use.
Prediction of asymptotic rates of response from selection on multiple traits using univariate and multivariate best linear unbiased predictors
Authors: Villanueva B. , Wray N. R. , Thompson R.
Published: September 2010

Predicted rate of genetic response for multiple trait breeding objectives from multivariate analyses is compared with that from univariate analyses for a range of breeding schemes, A selection index that approximates a multipl trait best linear unbiased prediction (BLUP) animal model is utilized. Changes in genetic parameters due to linkage disequilibrium generated by selection are accounted for. This study shows that asymptotic response in the aggregate breeding value, and its component traits, to selection on multivariate predictions, can easily be calculated from first generation responses, which use ancestral information. For two-path breeding schemes with equal accuracy for males and females, proportional reductions in responses depend only on selection intensity. In general, benefit from multivariate over univariate analyses is slightly smaller at the asymptote than in the first generation. Multivariate analyses give substantially more response than univariate analyses on untransformed data, when correlations between traits are high and when genetic and phenotypic correlations have opposite signs. The advantage of multivariate analyses decreases with increasing family size. When three random factors (additive genetic, common and individual environmental effects) are included in the model, the benefit of multivariate analysis is negligible if univariate analyses are performed on canonical traits. In this case, the advantage of multivariate analyses is never higher than 1% for all cases studied. These results are of particular relevance to the design of genetic evaluation programmes.
A comparison of growth, food efficiency and carcass characteristics of single and twin beef calves derived by embryo transfer
Authors: Patterson D. C. , Steen R. W. J. , Kilpatrick D. J.
Published: September 2010

An experiment was designed to examine the interaction between birth status and plane of nutrition of calves in relation to postnatal and lifetime performance. The experiment was a 2 × 2 × 2 factorial arrangement of birth status (single and twin), plane of nutrition from birth to 16 weeks (period 1) and plane of nutrition from 16 weeks to slaughter at a mean live weight of 530·4 (s.e. 0·13) kg (period 2). The planes of nutrition were control and low with metabolizable energy (ME) intakes of 32·1 and 21·4 (s.e. 0·46) MJ/day from birth to 16 weeks, and 73·9 and 64·1 (s.e. 0·95) from 16 weeks until slaughter. The birth weights of the single and twin-born calves were 47·2 and 39·7 (s.e. 0·90) kg respectively. There was no interaction between birth status and plane of nutrition in either main period and by 40 weeks of age the live weights of the twin calves were similar to those of the single-born calves. For period 1 plus period 2 the live-weight gains per unit of ME intake were 12·4 and 13·1 (s.e. 0·28) g/Mf for single and twin-born calves respectively. Although twins had slightly poorer carcass conformation and higher proportion of bone in the carcass, the concentrations of saleable meat and high-priced joints in the carcass were similar. Birth status had no effect on the ultimate pH of muscle. It is concluded that viable twins have similar beef producing potential to single-born calves.

The control and low planes of nutrition imposed during the periods from birth to 16 weeks and 16 weeks to slaughter produced live-weight gains of 822 and 573 (s.e. 31·0) g/day, and 857 and 690 (s.e. 12·6) g/day respectively. Calves which had been on the low plane during the initial period had a compensation index of 0·30 by 64 weeks of age. Carcass measurements were not affected by the plane of nutrition during either period. Steers grew faster than heifers, had lower area o/m. longissimus dorsi but less separable fat and more bone in the forerib joint than heifers at equal carcass weight.
Within-farm estimates of genetic and phenotypic parameters for growth and reproductive traits for red deer
Authors: McManus C.
Published: September 2010

Genetic and phenotypic parameters were estimated for farmed red deer on eight farms distributed throughout the United Kingdom. Genetic parameters were estimated using restricted maximum likelihood (REML) analysis. Heritabilities for date of calving were low on seven of the eight farms (< 0–05), while repeatabilities were low to moderate (0·06 to 0·37). Heritabilities of all weights tended to be moderate to high on most farms (0·31 to 0·49; 0·22 to 0·89; 0·33 to 0·48; 0·37 to 0·45 and 0·37 to 0·90 for birth weight, weaning weight, mid-winter weight, turn-out weight and other weights respectively). The exception was farm 8 for which heritability estimates were very low (<0·08). This is attributed to inbreeding effects on this farm. Phenotypic and genetic correlations between post-weaning traits tended to be high, indicating selection at any stage of growth will be expected to lead to an increased growth at the other stages. Animals whose bloodlines originated in the forests of Eastern Europe (Yugoslavia, Hungary, Germany) were heavier at all stages indicating their usefulness as ‘terminal sire’ breeds. Hinds of mainland ‘European’ parentage also tended to calve earlier.
A note on the comparison of barley-urea, maize gluten and rapeseed meal as supplements to ad libitum winter wheat straw for spring-calving suckler cows
Authors: Pullar D. , Rigby I.
Published: September 2010

The effects on animal performance of barley-urea (BU), maize gluten (MG) and rapeseed meal (RSM) offered with ad libitum winter wheat straw, were examined with 138 pregnant Hereford (♂ × Friesian ♀ cows over two winters (1987/88 and 1988/89). In each year, seven young cows and 16 old cows per treatment were offered respectively 3·0 or 1·5 kg fresh weight per head per day, of BU, MG or RSM for 167 days. There were no treatment effects on live weight, condition score or calf birth weight. In terms of animal performance BU, MG and RSM were equally effective.
Intake and utilization of energy from ammonia-treated and untreated wheat straw by steers and wether sheep given a basal diet of grass pellets and hay
Authors: Oosting S. J. , Boekholt H. A. , Los M. J. N. , Leffering C. P.
Published: September 2010

Two experiments, experiment 1 with six steers in a 3 × 3 Latin-square design and experiment 2 with four wether sheep in a cross-over design, were conducted to study the effect of species and ammonia treatment on intake and utilization of the energy of untreated wheat straw. Treatments were: (1) untreated wheat straw offered ad libitum on top of a basal diet (B) consisting of hay (0·25) and grass pellets (0·75) (UWS), (2) ammoniated wheat straw offered ad libitum plus B (AWS) and (3) ammoniated wheat straw offered at a restricted level plus B (AWS-). B was offered as a maintenance diet for both species and AWS- was only studied in steers. Voluntary intake of AWS zvas higher than that of UWS. No significant differences emerged between whole rations UWS and AWS with regard to energy digestion (ED), energy metabolizability (ρ = metabolizable energy (ME) I gross energy (GE)) and losses of digestible energy (DE) in urine and methane (average 187 J/KJ DE), but the efficiency of utilization of ME for growth (kg) was significantly higher for AWS than for UWS. ED and ρ of the straw part of the ration was significantly higher for AWS than for UWS. AWS- and AWS did not differ significantly with regard to ED, ρ and DE losses in methane and urine. Steers had a higher intake per kg0·75 per day than wether sheep. Across species, digestible energy intake (DEI) of the whole ad libitum fed diets was related to live weight (M)0·946 (s.e. of exponent 0·0152). ED and ρ of the straw part of the rations did not differ significantly between species, but steers had a significantly higher ED and ρ of β than wether sheep. Steers excreted a significantly lower proportion of DE in urine and a significantly higher proportion of DE in methane than did wethers. Total energy losses in urine and methane, however, did not differ between species.
A comparison of plasma prolactin, LH and progesterone concentrations during oestrus and early pregnancy in ewe lambs and ewes
Authors: Davies M. C. G. , Beck N. F. G.
Published: September 2010

An investigation was conducted to compare, the LH, prolactin and progesterone profiles of ewe lambs with ewes during oestrus and early pregnancy. Peak LH concentration was significantly lower (P < 0·05) and duration of release tended to be shorter during oestrus in ewe lambs. Furthermore, this smaller LH peak tended to be associated with a lower ovulation rate. LH pulse rate, amplitude and concentration were similar in both groups during day 13 of pregnancy. However, LH concentration was higher in ewe lambs compared with ewes on day 28 of pregnancy. Peak prolactin concentration was lower during oestrus in ewe lambs (P < 0·05) but there was no difference between the two groups during early pregnancy. Plasma progesterone concentrations were similar in both groups until day 13 of pregnancy. Thereafter, mean progesterone concentration was lower, from day 14 to 30, in the ewe lambs (P < 0·05). These results indicate that in ewe lambs and ewes maintained under identical conditions plasma hormone profiles differ during oestrus and early pregnancy. Moreover, these differences probably contribute towards the lower reproductive performance of ewe lambs.
The effect of dietary protein quality on free amino acids in plasma, muscle and liver of growing chickens
Authors: Fernández-Figares I. , Lachica M. , Pérez L. , Nieto R. , Aguilera J. F. , Prieto C.
Published: September 2010

Free amino acid (AA) levels in plasma, muscle and liver were measured in growing chickens given either high or low protein diets varying in quality. In experiment 1, they were force-fed once a day (09.00 h), for 4 days, at about 1·5 × M level, a nitrogen-free (NF) diet and then, on day 5, they were given either diet NF or isoenergetic (13·1 kj metabolizable energy (ME) per g dry matter (DM)) and isonitrogenous high protein diets (200 g crude protein (CP) per kg) based on casein (C), lupin (L), soya bean (SB), faba bean (FB), field pea (FP), vetch (V) or bitter vetch (B) as the sole source of protein. In experiment 2, chickens were force-fed twice a day (09.00 h and 18.00 h), for 3 days, at about 1·9 × M level, with four isoenergetic (13·1 k) ME per kg DM) and isonitrogenous low protein diets (120 g CP per kg) based on SB, FP, V or B as the sole source of protein. On days 5 (experiment 1) and 4 (experiment 2) samples of plasma, muscle and liver were taken for AA analysis over 3 to 4h after morning meal.

In general, within experiments, no significant differences in AA concentrations in plasma, muscle or liver among diets were found. However, there was a qualitative but not a quantitative agreement between the AA abundance in tissues and the AA rank of dietary protein. Moreover, when pooling data from experiments 1 and 2, significant regressions were found between the levels of threonine, aspartic acid, glutamic acid, glycine and proline in plasma, of lysine, alanine, glutamic acid, glycine and proline in muscle or that of proline in liver and the corresponding amounts ingested with the different diets. Under the conditions of these experiments, however, it was not possible to establish conclusively a direct relationship between the level of free amino acids in tissues and dietary protein quality.
A note on the nutritive value ofUlva lactucafor ruminants
Authors: Arieli A. , Sklan D. , Kissil G.
Published: September 2010

An experiment was designed to test the value of Ulva lactuca, produced from an integrated mariculture project, using six Finn-Merino crossbred ram lambs. Diets consisted of concentrate with vetch hay for the control, with additional Ulva for the treatment diet. Measurements of digestibility of energy, volatile fatty acid concentration in the rumen fluid, effective degradability of nitrogen in the rumen, rumen ammonia concentration and excretion of nitrogen in urine all indicated that Ulva could be categorized as a low-energy high-nitrogen foodstuff.
A note on growth curves of rabbit lines selected on growth rate or litter size
Authors: Blasco A. , Gómez E.
Published: September 2010

Two synthetic lines of rabbits were used in the experiment. Line V, selected on litter size, and line R, selected on growth rate. Ninety-six animals were randomly collected from 48 litters, taking a male and a female each time. Richards and Gompertz growth curves were fitted. Sexual dimorphism appeared in the line V but not in the R. Values for b and k were similar in all curves. Maximum growth rate took place in weeks 7 to 8. A break due to weaning could be observed in weeks 4 to 5. Although there is a remarkable similarity of the values of all the parameters using data from the first 20 weeks only, the higher standard errors on adult weight would make 30 weeks the preferable time to take data for live-weight growth curves.
Economic weights from profit equations: appraising their accuracy in the long run
Authors: Amer P. R. , Fox G. C. , Smith C.
Published: September 2010

Methods which estimate the effects on farm profit of a change in a genetic trait (economic weight) are compared. A neoclassical economic model based on a Cobb Douglas type production function, is extended to the long run and compared with a conventional profit equation for two types of trait changes. With this model, an optimal production plan can be derived for the farm which depends on input prices and the production function parameters. In the calculation of economic weights by animal breeders, costs are usually linear with respect to farm output, and so input levels and output are determined arbitrarily. Differences between methods for the estimation of both absolute and relative economic weights are shown to be small for proportional trait changes of 0·01 to 0·05. However, for proportional trait changes of 0·3, proportional differences were from 0·01 to 0·75 and from 0 to 0·6 for absolute and relative economic weights respectively, depending on the production function parameters. This dependence on the size of the trait change is attributed to the non-linearity of the production function. The effects of ‘rescaling’, which implicitly discounts economic weights for output increasing traits, are also evaluated. Absolute and relative ‘rescaled’ economic weights for 0·01 proportional trait changes are shown to differ proportionally from those estimated by the neoclassical economic model by from 0·14 and 0·12 to 0·50 respectively. For 0·3 trait changes, proportional differences were from 0·16 to 0·79 and from 0·8 to 0·43 for absolute and relative trait changes respectively. The results have important implications for conventional breeding programmes, and the economic evaluation of breeds and major genes.
Effects of rapeseed-meal and fish-meal supplementation of maize silage-based diets upon the tissue growth and body composition of store lambs
Authors: Kossaibati M. A. , Bryant M. J.
Published: September 2010

Thirty-six individually penned lambs (mean live weight 32·4 (s.d. 2·27) kg) were offered maize silage ad libitum and one of three concentrate mixes, two of which contained extracted rapeseed meal (control and HR) and the other fish meal (FM). The concentrates were given according to live weight and in sufficient quantities to provide proportionately about 0·4 of the dry matter (DM) intake of the lambs. The dietary concentrations of the nitrogen (N) g/kg DM were 22·4, 27·4 and 27·5 and of the rumen undegradable N 6·6, 7·3 and 11·6 for the control, HR and FM diets, respectively. All lambs were slaughtered at 45 kg live weight and chemical composition of the empty body and some of the component parts determined. A further 12 lambs were slaughtered at the beginning of the experiment to establish body composition before the dietary treatments were imposed.

The HR lambs had lower fleece.free empty body (FFEB) gains than either control or FM lambs (P < 0·05). This reduced gain of HR lambs was particularly associated with a reduction in fat deposition (P < 0·01) such that the FFEBs contained less fat than control and FM lambs (P < 0·01). The efficiency of conversion of metabolizable energy for growth (kg) was worse than both the control (P < 0·01) and the FM (P < 0·001) diets. The FFEBs of HR lambs also contained more ash (P < 0·05) than the lambs receiving the other diets.

The FM diet was associated with greater gains of fat and energy in the guts compared with the control diet (P < 0·05) and FM lambs had a better kg, value than control lambs (P < 0·05). There was no evidence that FM lambs had better N retention than lambs on the other two treatments.