bluuebunny/crossref_metadata_2025 huggingface dataset:
The effect of silage fermentation characteristics on dry-matter intake of steers
Authors: Dawson L. E. R. , Mayne C. S.
Published: September 2010

Juke was expressed from two silages of contrasting fermentation type with either high (H) or low (L) levels of lactic acid and reconstituted either with the silage from which it had been expressed or the other silage. This procedure produced four dietary treatments (HH, HL, LL, LH) each differing in fermentation characteristics. The dietary treatments HH, HL, LL, and LH contained 81, 71, 59, and 49 g lactic acid per kg dry matter (DM) and 101, 133, 193 and 159 g ammonia-N per kg total nitrogen (TN) respectively. The four diets were offered to four steers (mean live weight 679 (s.e. 49) kg) in a four-period change-over design experiment. Each period was of 17 days duration. DM intakes were recorded daily, with intakes on days 8 to 17 used in the statistical analysis of data. On day 12 of each experimental period, rumen fluid samples were taken throughout a 24-h period. The rates of disappearance of DM, nitrogen (N), modified acid-detergent fibre (MADF) and neutral-detergent fibre (NDF) in the rumen were determined on days 14 to 17 using the polyester bag technique. DM intakes were 7·2, 6·9, 6·0 and 6·0 (s.e. 0·50) kg/day (P = 0·08) for HH, HL, LL and LH dietary treatments respectively. Diet had no significant effect on eating behaviour, rumen fermentation parameters or degradability of DM, N, MADF and NDF fractions (P > 0·05). Silage L increased rumen fluid pH (P < 0·05), reduced buffering capacity (P < 0·05) and increased the molar proportion of propionic acid and n-butyric acid (P < 0·05 and P < 0·01) compared with silage H. Silage L also had a lower DM apparent digestibility, D-value and DM, (P < 0·001), N and MADF (P < 0·05) degradabilities than silage H. The higher DM intake of dietary treatment HH compared with dietary treatments LL and LH could not be explained by any single constituent of the silages although it was apparent that physical characteristics of the silage were more important in determining intake than the chemical characteristics.
The prediction of rumen fermentation characteristics in sheep given grass silage diets
Authors: Offer N. W. , Percival D. S.
Published: September 2010

Eight change-over design experiments (each a duplicated 3 × 3 Latin square design using six rumen-fistulated wether sheep, live weight 50 to 60 kg) measured rumen fermentation patterns for 24 perennial ryegrass silages. Sheep were offered 800 g dry matter (DM) per day of each silage in two equal meals at 09.00 and 17.00 h. Samples of rumen liquor were taken on days 19 and 21 of each 21-day period, at 08.50 h and at 1·5-h intervals until 16.30 h. Rumen samples were analysed by gas chromatography; silages by high-performance liquid chromatography and by near infra-red reflectance spectroscopy (NIRS) using samples scanned after drying at 100°C (NIRSdry) or in the fresh state (NIRSwet).

Mean intake of DM was 737 g/day. The range of silage composition was as follows (mean, range, s.d., g/kg DM unless specified): metabolizable energy (ME MJ/kg DM) 11·1, 8·8 to 12·6, 0·81; pH 4·0, 3·6 to 5·0, 0·34; lactic acid 86, 4 to 139, 42·6; butyric acid 4·7, 0·1 to 46·7,10·2. Rumen measurements varied substantially both diurnally and between silages. Mean diurnal rumen values for the 24 silages (mean, range, s.d.) were: pH 6·76, 6·55 to 7·09, 0·155; ammonia (mg/l) 132, 70 to 247, 47·7; total volatile fatty acids (TVFA mmol/l) 58·2, 45·8 to 72·0, 8·97; (acetate+butyrate)/propionate (ABP) 3·2, 2·2 to 4·8, 0·56.

Partial least-square models were developed to predict rumen fermentation (means for six sampling times) using either the silage chemical composition (CHEM g/kg DM unless specified: DM, ME (MJ/kg DM), crude protein (CP), ammonia (NH3, g N per kg total N), neutralizingvalue (meq per kg DM), sugar, lactic, formic, acetic, propionic and butyric acids and ethanol) or silage NIRSdry or NIRSwet. Prediction performance was assessed comparing values for R2, standard error of cross validation (SECV) and SD/SECV (s.d. of reference population! SECV) obtained by the ‘leave one out’ cross validation method. NIRSwet gave slightly better prediction accuracy overall than NIRSdry but both were superior to prediction from chemical composition. Values for R2, SECV and SD/SECV for pH were 0·23, 0·14, 1·09; 0·76, 0·08, 2·01 and 0·72, 0·08, 1·89 for CHEM, NIRSdry and NIRSwet respectively. Corresponding values for rumen ammonia (mg/l) were 0·48, 35·2, 1·35; 0·69, 27·1, 1·76 and 0·70, 26·3, 1·81; for TVFA 0·52, 6·73, 1·33; 0·80, 4·06, 2·21 and 0·93, 2·47, 3·63; for rumen ABP ratio 0·69, 0·32, 1·78; 0·76, 0·30,1·88; 0·72, 0·30,1·85. The silage predictors with greatest influence in the CHEM model for rumen ABP ratio were sugar, CP and lactic acid (negative) and butyrate and ethanol (positive). NIRS shows considerable promise as a means of predicting rumen fermentation of animals given grass silage diets.
The effect of virginiamycin supplementation in sow diets on the reproductive performance of the gilt/sow
Authors: Monetti P. G. , Tassinari M. , Vignola G. , Maculan L. , Read M. P.
Published: September 2010

This trial investigated the effects of virginiamycin on sow and litter performance. Virginiamycin was added to the sow diet during the period of gestation and lactation at the levels of0, 40 and 60 mg/kg, throughout two breeding cycles. Virginiamycin did not significantly affect sow weight change during gestation or lactation, or litter size and weight; there were no significant effects on food consumption (P > 0·05). However, when added at a level of 40 mgl kg virginiamycin tended to produce a better condition of sows which resulted in a significant reduction of replacement rate (P < 0·05), even though the proportion of gilts culled in the treated and untreated groups was high. The most evident result was a significantly shorter weaning-to-conception interval for the virginiamycin group at the end of the second reproductive cycle (first period, 5·9 days less than the control group, 2·5 days less than the 60 mg/kg group; second period, -9·5 days v. control group, P < 0·05, and -7·1 days v. 60 mg/kg group, P < 0·05), allowing a numerical improvement in productivity. Piglet performance was not significantly improved by the use of virginiamycin even though there was an evident trend in favour of the 40 mg/kg group which presented a higher proportion of heavier piglets (P < 0·05) and a reduction of pre-weaning mortality. A significant quadratic regression was found for weaning-to-conception interval and numeric productivity, indicating that the dosage more efficient to improve these parameters was 32 mg/kg. The results obtained in the virginiamycin 60 group were generally inferior to those of the 40 mg/kg group and also to the control group and seem to demonstrate that the 60 mg/kg dosage was too high.
Factors associated with average pig weight at weaning on farms using early weaning
Authors: Koketsu Y. , Dial G. D.
Published: September 2010

The objective of this study was to investigate the effect of various factors on average pig weight at weaning on farms using early weaning. Farms were selected based on average weaning age and whether they recorded lactation food intake and litter weights at weaning. The database contained 9834 litter weights and 8903 food intake records. Average pig weight at weaning, litter size at weaning, weaning age, and average daily food intake during lactation (ADFl) were 4·9 (s.d. 1·0) kg, 9·3 (s.d. 1·6) pigs, 16·8 (s.d. 2·8) days, and 4·9 (s.d. 1·1) kg, respectively. Litter size, weaning age, parity, farrowing season, and ADFl groups influenced average pig weight at weaning (P < 0·01). Three two-way interactions between parity and season, weaning age and farrowing season, and weaning age and ADFl groups were found fP < 0·01). Average pig weights for litter sizes between six and 10 were higher than those between litter sizes one and four, and 11 and 22. Parity 1 sows produced lighter pig weights than any other parity group during any other season (P < 0·01). Average weights of weaned pigs farrowed during the summer in all parities groups were lighter (P < 0·01) than those during the autumn. Pig weights for weaning ages between 22 and 21 days during the summer tended to be lighter than those during the autumn. Pigs weaned between days 16 and 22 of age in the high ADFI group (>5·6 kg) were heavier (P < 0·01) than those in the low ADFl (> 4·2 kg) group.
Effects of pre-mating energy intake on reproductive performance of rabbit does
Authors: Fortun-Lamothe L.
Published: September 2010

The aim of this experiment was to study the effect of stimulation of pre-mating energy intake on reproductive performance at the subsequent mating or parturition of rabbit does during four successive cycles. In the C (control, no. = 59) and R (restricted, no. = 67) groups, females had free access to the M diet (9·92 MJ/kg dry matter (DM)), except from 18 to 31 days of gestation when R females were given 150 glday. In the E group (high energy diet, no. = 64), females were given ad libitum the H diet (12·19 MJ/kg DM) from 1 to 14 days of lactation, with the M diet for the rest of the time. Females were presented to the male 10 toll days after parturition during four cycles. For primiparous does, the experimental design had no effect on pre-mating energy intake, acceptance or conception rate and litter size or weight. However, for multiparous does, pre-mating energy intake was higher for the E and the R group females than for the C group females (+0·08 and +0·04; P < 0·01). Acceptance rate of the male (47·1% v. 69·0%) and weight of the young rabbits at birth (-0·09) were lower in the R group than in the other groups (P < 0·001). The mortality of sucking rabbits was lower (6·5% v. 24·7%) and conception rate for the fourth litter was higher (97·1% v. 78·4%) in the E group than in the other groups (P < 0·05).

These results suggested that increased pre-mating energy intake could have a positive effect on conception rate. However, inadequate pre-partum energy intake (food restriction) has a detrimental effect on receptivity and litter weight.
Possible causes of differences in glucose metabolism between Angora goats of two different phenotypes
Authors: Cronjé P. B.
Published: September 2010

Previous results have shown that certain phenotypes of Angora goat differ in respect of glucose metabolism and it has been proposed that this is linked to the high incidence of abortions in this breed. The aim of this experiment was to investigate adrenal function, food digestion and nutrient partitioning as possible causes of differences in glucose metabolism between a phenotype which produces a relatively large amount of mohair of a large fibre diameter (high producers) and a phenotype which produces less mohair of a smaller fibre diameter (low producers). Two groups consisting of 15 3-year-old Angora bucks each and representing two different phenotypes were given a maintenance diet for the duration of the trial. Plasma glucose concentrations during a 4-day fast were lower (P < 0·01) in high producers than in low producers and plasma glucose concentrations following insulin injection also fell to a greater extent in high producers than in low producers (P < 0·05), indicating that high producers were less able to mantain plasma glucose concentrations during periods of increased demand than low producers. The decrease in glucose concentration following insulin injection was accompanied by a rise in plasma cortisol concentrations until 60 min after the insulin injection but there were no differences between phenotypes (P > 0·05). Similarly, cortisol concentrations rose to a peak 60 min after ACTH injection and there were no differences between phenotypes (P > 0·05). In both instances, the pattern of cortisol concentrations was consistent with normal adrenal function and there were no indications of adrenal insufficiency. Although differences in digestion were observed between phenotypes (P < 0·01), these were small. There were no differences in nitrogen (N) intake or retention (P > 0·05). High producers deposited substantially more (proportionately 0·56) N as fleece than low producers (P < 0·01), and partitioned a greater proportion of N intake to fleece production (P < 0·01). It was concluded that adrenal insufficiency was not implicated in the observed differences in glucose metabolism between phenotypes but differences in digestibility and nutrient partitioning may play a role.
The prediction of the voluntary food intake of pigs on poor quality foods
Authors: Tsaras L. N. , Kyriazakis I. , Emmans G. C.
Published: September 2010

An experiment was carried out to investigate the proposal that the voluntary food intake of pigs, when given foods based on bulky materials, can be accurately predicted from the water-holding capacity (WHC, g water per g dry food) values of the foods. A basal food (B), with 12·9 MJ digestible energy and 249 g crude protein per kg dry matter, was diluted to two extents by either sugar-beet pulp (S), grass meal (G) or soya hulls (H). The contents of the bulky materials in the total diets were either 320 g/kg (foods BS, BG and BH) or 800 g/kg (foods S, G and H). Each of these six foods was givenad libitumto six pigs in period I, which lasted for 21 days, with a further four given B. In period II, which lasted for 14 days and followed period I immediately, the pigs were also given their food ad libitum. Only the 36 pigs from the six ‘bulky“treatments (i.e. on treatments other than B) continued in a change-over design. Two pigs from each of the six ‘bulky’ treatments were allocated to the three foods of the same level of dilution (e.g. the six pigs from BS were changed to BS, BG and BH). Of the ‘bulk’ characteristics measured (crude fibre, acid-detergent fibre, neutral-detergent fibre, apparent digestibility of the organic matter, density and WHC) only WHC accounted sufficiently for the effects of the foods on the voluntary food intake of the pigs. The two methods of centrifugation and filtration that were used for the WHC determination were very highly correlated (r = 0·978), with food B having the lowest value, 3·86 g water per g dry food, and food S having the highest value, 8·48 g water per g dry food, when measured by centrifugation. In both periods the rate of intake was calculated as g/kg live weight per day, scaled intake (SFI). Live-weight gain and food conversion efficiency both decreased significantly (P< 0·001) as B was diluted with S, G and H. For the six ‘bulky’ feeding treatments SFI in the last 14 days of period I was proportional to the reciprocal of the WHC of the foods: SFI (g/kg per day) = 235 (s.e. 6·3). No effects of previous feeding treatment on site were observed in period II as a whole; however, intake initially increased when the food had lower WHC than the one previously offered and decreased when it had higher WHC. It was concluded that: (a) the WHC of a food is a sufficient descriptor of its ‘bulk’ and that it accounts for the effects on the voluntary food intake of pigs; (b) the detailed methods used for measuring WHC need to be standardized; (c) pigs can adapt more rapidly to bulky foods when they have had prior experience of such foods; (d) the length of time needed to observe an intake, which will be characteristic of the bulky food on offer, depends on the prior experience of the pig.
Changes in adipose tissue accumulation in Rasa Aragonesa breed lambs during growth and fattening
Authors: Arana A. , Soret B. , Mendizabal J. A. , Corroza M. , Eguinoa P. , Purroy A.
Published: September 2010

Changes during growth and fattening in the number and size of adipocytes and in the activity of the lipogenic enzymes glycerol 3-phosphate dehydrogenase (G3PDH), fatty acid synthetase (FAS) and lipoprotein lipase (LPL) were studied in perirenal (PR) and subcutaneous (SO adipose depots of 28 male lambs of Rasa Aragonesa Spanish breed. Three groups of animals were slaughtered at: 32 (s.d. 6) (no. = 10), 89 (s.d. 8) (no. = 10) and 120 (s.d. 8) (no. = 8) days of age. A significant increase in the quantity of fat was observed as the age of the lambs increased (P< 0·001). Fat deposition was higher between 89 and 120 days of age. The number of adipocytes in the PR depot did not change but hypertrophy in this depot continued during the whole period studied (P< 0·001). In the SC depot a significant increase in adipocyte volume was only found between 89 and 120 days of age (P< 0·001). The increase in G3PDH activity (which estimates fatty acid esterification) and FAS activity (which estimates fatty acid synthesis) was greater in the final phase of the study. Besides, LPL enzyme activity (which estimates the uptake of plasma fatty acids) increased between 32 and 89 days of age in both depots and between 89 and 120 days in PR depot (P< 0·001).
Evaluation of the influence of maternal and piglet breed differences on behaviour and production of Meishan synthetic and European White breeds during lactation
Authors: Sinclair A. G. , Edwards S. A. , Hoste S. , McCartney A.
Published: September 2010

Meishan synthetic sows and gilts have been shown to produce higher litter weights at weaning than White breed type sows and gilts. To investigate the factors contributing to this, 64 multiparous sows were used in a 2 × 2 × 2 factorial experiment to assess the influence of maternal breed type (0·50 Meishan synthetic (M) or purebred European Landrace and Large White (W)), litter size (eight (L) or 12 (H) piglets) and breed of piglet (0·25 Meishan hybrid (m) or white hybrid (w)) on sow and litter production and behaviour over a 28-day lactation. All litters were formed by cross-fostering to standardized litter rearing size 24 h after farrowing. Sows were given food twice daily to appetite. When there were no treatment interactions, main effects are presented. M sows were lighter (M = 215, W = 241 (s.e. 3·61) kg, P < 0·001) and fatter (M = 31·5, W = 21·7 (s.e. 0·72) mm, P < 0·001) at farrowing than W and had higher maternal weight loss (M = 24·7, W = 5·9 (s.e. 0·85) kg, P < 0·001) and higher back fat loss (M = 5·6, W = 2·0 (s.e. 0.28) mm, P < 0·001) in lactation. High litter size resulted in higher maternal weight loss (L = 7·4, H = 13·2 (s.e. 0·85) kg, P < 0·001) and fat loss (L = 2·9, H = 4·7 (s.e. 0·28) mm, P < 0·002) than low litter size. Litter growth rate was higher for M than for W (M = 27·0, W = 14·5 (s.e. 0·42) kg/week, P < 0·002) and for high litter size than for low litter size (L = 24·3, H = 17·3 (s.e. 0·42 kg/week, P < 0·001). The m piglets had lower litter growth rates than w piglets (m = 15·1, w – 16·5 (s.e. 0·42) kg/week, P < 0·001). There were no breed differences in the length of suckling periods but M had shorter suckling intervals than W (M = 38·1, W = 48·7 (s.e. 1·08) min, P < 0·001). It is concluded that the higher litter weights produced by M sows are due solely to maternal effects and not litter size or piglet genotype.
Modification of body composition by altering the dietary lysine to energy ratio during rearing and the effect on reproductive performance of gilts
Authors: Cia M. C. , Edwards S. A. , Glasgow V. L. , Shanks M. , Fraser H.
Published: September 2010

Fifty-four lean genotype crossbred gilts were allocated at 118 days of age among three diets with different protein concentrations to give lysine: energy (g/MJ digestible energy) ratios: high (0·9), medium (0·6) and low (0·3) given twice daily at 2·9 × maintenance energy. At 160 days of age, gilts were treated with exogenous gonadotropin (PG600™) and animals were examined daily for signs of oestrus. Animals were slaughtered after the second oestrus, if they had shown behavioural oestrus, or at the age of 212 days. Reproductive tracts were recovered for counting of corpora lutea and albicantia. L gilts were lighter than M or H gilts at puberty induction (80, 95, 97 (s.e. 0·73) kg for L, M, H respectively, P < 0·001), with greater backfat thickness (10·8,10·0, 9·2 (s.e. 0·21) mm P2,P < 0·001), lesser longissimus muscle depth (57·4, 65·9, 64·3 (s.e. 0·77) mm, P < 0·001) and poorer food conversion ratio during rearing (3·87, 2·48, 2·42 (s.e. 0·098) kg food per kg gain, P < 0·001). There was no statistically significant difference in the total number of animals that responded to the puberty induction, although L had a greater latency to oestrus than H. Ovulation rate at this induced oestrus was significantly lower in L gilts than in M or H gilts (12·5, 17·3, 21·5 (s.e. 1·32), P < 0·02). A lower proportion ofL, compared with M or H gilts showed spontaneous ovulation in a subsequent cycle (0·15, 0·75, 0·77, %2 = 12·72, P < 0·005). It proved possible, by means of low protein (lysine) diets, to increase body fat reserves in breeding gilts but protein restriction in the rearing phase negatively affected aspects of reproductive performance.
The activity of some digestive enzymes in domestic rabbits before and after weaning
Authors: Dojană N. , Costache M. , Dinischiotu A.
Published: September 2010

The activity ofamylase, maitase, lipase, pepsin, trypsin and chymotrypsin in suckling (15 days of age) and in 1-day weaned (43 days of age) domestic rabbits was assayed and compared with older (90 and 180 days) rabbits. It was found that amylase was active in the pancreas at 15 days (11 580 amylase units (AU) per mg protein) and increased during growth, reaching a maximum level (58 960 AU per mg protein) at 90 days of age. Specific activity (SA) of maitase from the small intestine mucosa varied depending on the intestinal segment and the age of the rabbits: activity in the duodenal mucosa decreased, while in the jejunal and Heal mucosa activity increased, during growth. Lipase SA reached a maximum level in suckling rabbits at the age of 15 days (in gastric mucosa 242 and in pancreas 608 mequiv. liberated oleic acid per mg protein per h, 37°C) and decreased sharply at weaning: in gastric mucosa down to 86 and in pancreas down to 89 mequiv. oleic acid per mg protein per h, 37°C. SA of pepsin remained relatively constant for all the studied categories of rabbits: 38 to 39 nmol tyrosine per mg protein per min, 25°C. Trypsin and chymotrypsin SA reached a peak at about weaning: 1·83 nmol benzoyl-arginyl-ethyl-ester per mg protein per min, 25°C and 40·1 nmol benzoyl-phenyl-naphtyl-ester per mg protein per min, 35·5°C respectively.
The effect of dietary fat and metabolizable energy supply on milk protein concentration of dairy cows
Authors: Moorby J. M. , Dewhurst R. J. , Thomas C. , Marsden S.
Published: September 2010

To investigate the effect of dietary fat and metabolizable energy (ME) on milk protein concentration, an experiment was carried out using 12 multiparous early-lactation Holstein-Friesian dairy cows. Three diets were offered in a complete Latin-square change-over design, based on ad libitum access to grass silage. One of three concentrates was offered at a rate of 12 kg/day, each formulated to supply one of two levels of ME (12·1 and 13·6 MJ/kg dry matter (DM)) and one of two levels of fat (31 and a mean of 88 g acid hydrolysis ether extract per kg DM): low energy, high fat (LEHF); low energy, low fat (LELF); and high energy, high fat (HEHF). The concentration of milk protein was significantly higher from animals offered the LELF concentrate (32·5 v. a mean of 31·2 (s.e.d. 0·45) g/kg, P < 0·05), because of lower milk yields (31·0 v. a mean of 33·4 (s.e.d. 0·63) kg/day, P < 0·05). Animals offered the HEHF concentrate produced the highest yields of milk protein but their milk had the lowest concentrations of fat (32·5,34·4 and 31·9 g/kg for LEHF, LELF and HEHF respectively; s.e.d 1·07; P < 0·05 for difference between LELF and HEHF). Silage DM intake was significantly increased by animals offered the LEHF concentrate (9·1, 8·6 and 8·7 (s.e.d. 0·19) kg/day, P < 0·05 for differences between LEHF and the other two concentrates). Urinary purine derivative excretion, used as an index ofmicrobial protein supply, was highest from animals offered the LELF and HEHF concentrates, which both supplied similar amounts of fermentable ME. It is hypothesized that increased de novo synthesis offatty acids on the low fat diet reduced the availability of glucose for lactose synthesis, leading to reduced milk yields and hence increased milk protein concentrations.
Energy and nitrogen balance of lactating dairy cows given mixtures of urea-treated whole-crop wheat and grass silage
Authors: Sutton J. D. , Cammell S. B. , Beever D. E. , Humphries D. J. , Phipps R. H.
Published: September 2010

Energy and nitrogen balances were carried out with four multi-porous Holstein/Friesian cows offered four diets in a Latin-square experiment to evaluate urea-treated whole-crop wheat as a partial grass silage replacement for lactating dairy cows. Grass silage (GS) was produced from the primary growth of a perennial ryegrass sward. Spring wheat (cv. Axona) was harvested at 603 g dry matter (DM) per kg and preserved with 20 (WCW-20) or 40 (WCW-40)kg urea per t DM. The diets were 6 kg DM of a dairy concentrate daily with one of four forage treatments offered ad libitum. The forage treatments were GS alone, a 2:1 DM ratio of GS with WCW-40 (2:1 40), or a 1:2 DM ratio of GS with WCW-20 (1:2 20) or WCW-40 (1:2 40). Each period lasted 4 weeks with energy and nitrogen balances being carried out in respiration chambers over 6 days in the last week. Replacement of GS by diets containing WCW resulted in significant increases in DM intake (P < 0·01). Changes in milk yield and composition were small and non-significant but yields of milk fat and protein were higher on WCW diets than on GS diets (P< 0·05). With increasing proportions of WCW in the diet there were significant linear falls in apparent digestibility of DM (P < 0·001), organic matter (F < 0·001), neutral-detergent fibre (F < 0·01), acid-detergent fibre (F < 0·01), starch (F < 0·001) and nitrogen (P < 0·01). Gross energy intakes (P < 0·01) and faecal (P < 0·001), methane (P < 0·05) and milk (P < 0·05) energy outputs were higher with the WCW diets than with GS but urine energy and heat losses were unaffected. In consequence there were no significant differences among the diets in digestible or metabolizable energy (ME) intakes. However dietary ME concentrations (MJ ME per kg corrected DM) fell with increasing WCW inclusion from 11·54 on GS to a mean of 9·96 on the 1:2 diets (P < 0·001). It was calculated that the ME concentration of the WCW was only 8·1 MJ/kg corrected DM at maintenance intake, considerably lower than values used conventionally. There were no significant diet effects on the partition of ME or on the partial efficiency of ME utilization for milk production (k1). The increasing inclusion of WCW increased N losses in urine (P < 0·05) and faeces (F < 0·01) with no net effect on N digested or retained though there was a small increase in milk N output (P < 0·01). It is concluded that low digestibility is the major cause of the small milk response to the partial substitution of urea-treated WCW for grass silage with no evidence of a reduction in the efficiency of utilization of ME.
Photoperiodic requirements for rapid growth in young male red deer
Authors: Webster J. R. , Corson I. D. , Littlejohn R. P. , Stuart S. K. , Suttie J. M.
Published: September 2010

Winter growth of young male red deer can be increased by exposure to 16 h of light (L) and 8 h of dark (D) per day (16L: 8D). This study tested the duration of photoperiod required for this growth response, determined if the time to reach slaughter weight can be reduced and monitored plasma IGF-1, prolactin and reproductive development. Fifty male calves were allocated to five equal groups. Four groups were housed indoors and for 33 weeks from the winter solstice (22 June, southern hemisphere) until 11 February were placed under either 16L: 8D (16L), 13·25L: 10·75D (13L), 10·751:13·25D (111) or 8L: 16D (8L) photoperiods. The fifth group of deer (OC) remained outside in a gravelled enclosure. All groups were given a pelleted diet ad libitum. Group food intake was recorded daily, individual live weight was measured weekly and testes diameter and blood samples taken at weekly or 2-week intervals.

Plasma prolactin concentrations in 16L increased within 4 weeks of treatment and were different (P < 0·001) between groups from 14 August to 4 September. IGF-1 increased in both 16L and 13L 4 weeks after treatments and then increased further in 16L above that of 13L (P < 0·01). All groups grew at the same rate for the first 7 weeks. 16L then gained more weight (P < 0·001) than the other groups over the next 19 weeks (50·7 kg v. 38·5 for 13L, 35·7 for 11L, 37·0 for 8L and 37·4 for OC; s.e.d. 3·76). Food intake was positively related to growth rate in a similar way among the inside groups (P < 0·001), however there was a higher energy requirement outdoors (P < 0·05). A target live weight for slaughter of 95 kg was reached 7 weeks earlier for 16L than the other groups (P < 0·01). Testes diameter of 16L was larger than in the other groups from 13 November until 24 December (P < 0·001). The growth oflSL slowed from 1 January while that of OC increased and the live weight ofOC was equal to 16L by the end of the experiment. OC also had the largest testes diameter from 5 February onwards (P < 0·01). The live-weight increase in OC was associated with increases in both prolactin and IGF-1 levels.

This study confirmed that 16L: 8D stimulates rapid growth of young male red deer during winter for sufficient time to achieve an earlier slaughter date. The live-weight advantage was lost by late summer however. The increased growth rate was mediated by food intake and associated with increases in IGF-1 and prolactin and earlier reproductive development. Photoperiods of 13 h of light per day or less did not stimulate growth and increases in IGF-1 and prolactin were of a lower amplitude than under 16L: 8D.
Effects of ensilage of grass on performance and nutrient utilization by dairy cattle 1. Food intake and milk production
Authors: Cushnahan A. , Mayne C. S.
Published: September 2010

Twelve lactatiug dairy cows were offered either fresh grass (G) or grass silage prepared from the same pasture which had undergone either an extensive (E) or restricted (R) fermentation, in a three-period change-over design experiment. Ensilage resulted in a reduction in forage pH and water-soluble carbohydrate concentration and an increase in ammonia-nitrogen concentration. The ensiling techniques used ensured that both silages were well preserved with pH values for E and R of 3.81 and 4.08 respectively, while the respective lactic acid concentrations were 124.6 and 27.0 g/kg dry matter respectively. Whilst there were no significant differences in dry-matter intake between treatments, when corrected for losses of volatile compounds, animals offered silage with a restricted fermentation consumed their food at a higher rate of intake (P < 0.001) than did animals on the other treatments. It was also found that while there was no significant difference in milk yield between animals offered fresh or ensiled forage, both butterfat and protein concentration and yields of butterfat were significantly higher (P < 0.01 or greater) with grass and restricted fermented silage than with extensively fermented silage. Ensiling of herbage had no significant effect on apparent digestibility. It is concluded that ensiling of herbage per se had little effect on overall animal performance but pattern of silage fermentation resulted in alterations in milk composition.
Effects of ensilage of grass on performance and nutrient utilization by dairy cattle 2. Nutrient metabolism and rumen fermentation
Authors: Cushnahan A. , Mayne C. S. , Unsworth E. F.
Published: September 2010

A study was carried out to examine the effects of ensiling and pattern of silage fermentation on nitrogen and energy utilization, rumen fermentation and rumen degradation characteristics of forage by lactating dairy cows. Six nonfistulated dairy cows and three rumen fistulated dairy cows were offered fresh grass (G) or grass silage produced from the same sward which had undergone either an extensive (E) or restricted (R) fermentation. Animals offered extensively fermented silage had liigher urinary nitrogen (N) outputs (expressed as a proportion of N intake) than those offered fresh grass (P < 0·05). Corresponding values for animals offered restricted fermented silage were intermediate between those offered grass and extensively fermented silage. Animals offered fresh grass and restricted fermented silage also had higher methane energy losses (P < 0·05), than those offered extensively fermented silage. The ensiling of grass had little effect on metabolizable energy (ME) intake or on the efficiency of utilization of ME for lactation (k1). Animals offered extensively fermented silage had higher proportions of propionate and lower proportions of acetate than those offered fresh grass or restricted fermented silage (P < 0·001). Ensiling resulted in an increase in the soluble (a) fraction and a reduction in the potentially degradable (b) fraction of N.
Effects of ardacin supplementation on food intake and growth rate of growing and finishing steers
Authors: Keane M. G. , Read M. P. , Moloney A. P.
Published: September 2010

Ardacin is an antibacterial glycopeptide with ruminal activity. The objective of this study was to measure its effects on food intake and growth rate of growing and finishing steers. Two experiments were carried out simultaneously using the same foods and the same ardacin supplementation levels. In experiment 1, 72 growing steers (8 months old and 240 kg initial weight) in four treatment groups were individually offered a basal diet of grass silage ad libitum. In experiment 2, 44 finishing steers (19 months old and 463 kg initial weight), also in four treatment groups were individually offered a basal diet of grass silage ad libitum plus 3 kg (5 kg for the final 28 days) concentrates per head daily. The four treatments were 0, 50, 125 and 210 mg ardacin per head daily incorporated into 1 kg ground barley. This was offered in addition to the basal diet. The duration of the experimental period was 154 days after which 48 of the growing steers were put to pasture for a 196-day grazing season. The finishing steers were slaughtered following a withdrawal period of 7 days. Mean daily silage dry-matter intakes, and mean daily total metabolizable energy intakes for the treatments as listed above were 4·91, 5·15, 5·10 and 5·03 (s.e. 0·083) kg and 63, 66, 65 and 65 (s.e. 0·7) MJ (experiment 1), and 5·63, 5·62, 5·51 and 5·54 (s.e. 0·059) kg and 108, 108, 107 and 107 (s.e. 0·4) MJ (experiment 2), respectively. In the same order, mean daily live-weight gains during the treatment period were 612, 758, 784 and 798 (s.e. 25·2) g (experiment 1) and 911, 942, 851 and 860 (s.e. 40·0) g (experiment 2). In the growing steers proportionately 0·64 of the weight response to ardacin was retained to the end of the following grazing season. It is concluded that ardacin supplementation increased live-weight gain and improved the efficiency of conversion of food to live weight in growing steers but had no significant effect on finishing steers in this study.
Application of a multiple-trait animal model for genetic evaluation of maternal and lamb traits in Norwegian sheep
Authors: Olesen I. , Svendsen M. , Klemetsdal G. , Steine T. A.
Published: September 2010

A selection index for overall economic merit and five subindexes for maternal and lamb traits were constructed. For estimation of breeding values, two computer programs were developed. A multiple-trait animal model was programmed for the ewe traits including number of lambs born ofl-, 2- and 3-years-old ewes and ewe fleece weight of yearlings. In order to reduce the memory requirement, the lamb data (growth rate, carcass weight, carcass grade, fat% and lamb fleece iveight) were analysed by a reduced multiple-trait animal model including genetic maternal effect. Experiences with the computer programs in genetic evaluation of approximately 619 000 animals are presented. It is concluded that the models and computing strategy may be used for genetic evaluation in the national sheep breeding programme in Norway.

Relative economic values for all traits were derived from a profit equation on a 3-year-old ewe basis. The sensitivity towards changed economic values urns found to be low. Further, the genetic change in the ewe traits of the Norwegian breeds has been estimated, and a significant improvement was found, which was two to four times higher in the ram circles than outside. For breeding rams, the genetic change for number of lambs born was estimated to be approximately 0·01 lambs per ewe and year.
Changes in the secretion rate and production of colostrum by ewes over the first 24 hpost partum
Authors: Pattinson S. E. , Davies D. A. R. , Winter A. C.
Published: September 2010

An experiment was conducted to examine the changes in colostrum secretion rate and colostrum composition in ewes over the first 24 h post partum. Sixteen mature Suffolk × Cambridge ewes, which had produced one to four lambs, were used. Colostrum yield was estimated within 1 h of parturition and colostrum secretion rate measured between 3 and 6 h, 9 and 12 h, 15 and 18 h and 21 and 24 h post partum. Samples of colostrum were taken at each milking and the composition analysed. The mean yield (g) of colostrum at 1 h was 801 (s.d. 568·9) with a range from 35 to 2450 g. Mean secretion rates, in g/h, at 3 to 6 h, 9 to 12 h, 15 to 18 h and 21 to 24 h were 120 (s.d. 67·0), 104 (s.d. 55·2), 112 (s.d. 49·8) and 109 (s.d. 41·1) respectively. At 1 h, mean concentrations, in g/l, of total solids, fat, protein, ash and IgG were 367 (s.d. 76·9), 132 (s.d. 43·7), 203 (s.d. 43·2), 9.6 (s.d. 2·4) and 116 (s.d. 30·2) respectively. Corresponding values at 24 h were 242 (s.d. 38·8), 122 (s.d. 39·5), 71 (s.d. 11·2), 6.8 (s.d. 1·0) and 15 (s.d. 12·5).

Sequential samples were taken throughout the milking process within 1 h of paturition from a further eight Dorset-cross ewes. There were no significant differences in the composition of colostrum due to stage of milking, although there was a suggestion that fat content was higher in the final sample than the first (140·1v.104·1 g/l, P = 0·084). It is clear that there is a large amount of variation in the secretion rate and composition of colostrum produced by ewes over the first 24 h post partum. However, a single sample taken between 3 and 12 h post partum would be a good indicator of 24 h yield (r = 0·88) and composition (total solids, r = 0·90 and IgG, r = 0·93).
The relationship between reflectance (EEL value) and colour (L*) in pork loins
Authors: Warriss P. D. , Brown S. N.
Published: September 2010

The relationships between reflectance values measured with an EEL reflectometer, and C1ELAB L* a* b* coordinates measured with a tristimulus meter, were determined using 572 samples of pork m. longissimus dorsi. These samples covered the muscle colour/condition range from extreme pale, soft, exudative (PSE) to extreme dark, firm, dry (DFD). There was a good (r = 0·91) and slightly curvilinear relationship between L* value and reflectance, the other relationships being significantly poorer. Based on these findings, pork loins with L* values between 49 and 60 would on average have consistently good visual appeal using criteria in the Meat and Livestock Commission blueprint for quality pork.
Genetic contributions of Finnish Ayrshire bulls over four generations
Authors: Woolliams J. A. , Mäntysaari E. A.
Published: September 2010

The long-term genetic contributions were calculated for 219 Finnish Ayrshire bulls born between 1958 and 1964 to 707 Finnish Ayrshire bulls made available for artificial insemination and born between 1986 and 1988. Three strategies were employed:(i) using all known pedigree information; (ii) ignoring information on the dam of females; (iii) only using information on sires. Expected contributions were calculated using gene flow matrices.

The contributions from strategies 1, 2 and 3 were only 0.6 (1 and 2) or 0.7 (strategy 3) of those expected. The causes of this shortfall for strategies 2 and 3 were identified as (i) the use of an imported sire and (ii) generation skipping. For strategy 1, 0.2 of the expected pathways remained unaccounted for and were ascribed to missing pedigree information.

Of the 219 ancestors, only 86 made positive contributions to the descendants. Only 10 ancestors made contributions more than the average, and one bull accounted for 0.3 of all pathways traced on strategy 2. There was general agreement in the relative contributions of individual bulls when assessed using the three strategies.

The rate of inbreeding (ΔF) estimated by regression from 1974 to 1988 and using known pedigrees was 0.0018 per year and the average coefficients of additive genetic relationship among cohorts was increasing by 0.0030 per year. AF was estimated using the contributions calculated by strategies 1, 2 and 3 to be 0.0147, 0.0151 and 0.0125 per generation respectively. These were converted into rates per year by assuming a generation interval of 6.5 years taken from both published and new information on generation intervals in the Finnish Ayrshire population. This gave annual rates of 0.0023, 0.0023 and 0.0019. The estimates from strategy 3 were obtained without the use of any pedigree information pertaining to dams.
Selection for longevity and yield in dairy cows using transmitting abilities for type and yield
Authors: Veerkamp R. F. , Hill W. G. , Stott A. W. , Brotherstone S. , Simm G.
Published: September 2010

A dynamic programming model was used to derive economic values for the goal traits milk, fat and protein yield and longevity. The economic values derived were £3.37 per % cows surviving to complete lactation four (conditional on having a milk record in the first lactation) and £-0.03, £0.60 and £4.04 per kg for milk, fat and protein yield respectively. In terms of genetic standard deviations the weight for protein, fat, milk and longevity were 1.0, 0.21, —0.25 and 0.55, respectively. Using economic values and genetic (co) variances, weights were derived for milk fat, protein and four linear type traits (chosen out of fifteen on the basis of the genetic correlation with longevity): angularity (angular), foot angle (steeper), udder depth (shallower) and teat length (shorter). Three additive indices were derived, assuming that the breeding goal was for: (i) yield only (PIN), (ii) longevity only (LIN) or (ii) yield and longevity, hence economic merit (ITEM). Selection on ITEM is expected to give a 2% higher annual rate of genetic progress compared with selection on PIN. Efficiency of using ITEM was larger than 0.97 compared with the optimum index, when the real individual economic values increased or decreased by a factor 1.5 or 2.0. Weights for ITEM were calculated assuming that predicted transmitting abilities (PTAs) from complete multivariate analysis were used as index measurements. In the practical situation that index measurements came from (i) separate univariate best linear unbiased prediction (BLUP) evaluations or (ii) two multivariate BLUP evaluations (one for type and one for yield), efficiency of ITEM (compared with the optimum index) decreased with decreasing accuracy of the PTAs and with increasing ratio between number of records for type and yield, or vice versa, but remained close to 100%. Only in the (not practical) situation where accurate PTAs for type and inaccurate information for yield were combined, did the efficiency of ITEM drop as low as 0.44, due to a change of sign for udder depth in the optimal index.
Enhanced pyridoxine supplementation of diets for gilthead seabream (Sparus aurata L.)
Authors: Morris P. C. , Davies S. J.
Published: September 2010

Using a high protein diet (483 g/kg), two trials were carried out to assess any potential benefit which may result from the supplementation of diets for fingerling and grower class gilthead seabream with pyridoxine at levels which were below, matched and far exceeded the minimum dietary requirement. At the level of supplementation below the minimal requirement (lowest level) the responses from the practical diet almost matched the responses from the diet containing an amount of pyridoxine corresponding to the published minimum requirement for the species and no significant improvement in performance was recorded in response to increasing supplement level. However, despite the absence of a marked effect on overall performance, a small potential for increased activity of alanine aminotransferase was recorded amongst grower class fish given diets containing the lowest supplement. The proximate composition of the grower class fish was unaffected by the level of pyridoxine supplementation though marginal increases in the lipid content of the fingerlings were observed. At the haematological level, haematocrit, total haemoglobin and the plasma concentrations of glucose and protein were also unaffected. However, on the application of an acute stressor (repeated netting), significant alterations in haematocrit and plasma glucose concentration reflecting dietary pyridoxine supplement were recorded.
The performance of dairy cows offered ensiled whole-crop wheat, urea-treated whole-crop wheat or sodium hydroxide-treated wheat grain and wheat straw in a mixture with grass silage
Authors: Leaver J. D. , Hill J.
Published: September 2010

Twenty-four Holstein Friesian cows in experiment 1 and 40 cows in experiment 2 were used over 12 weeks in continuous designs, to evaluate winter wheat as a forage for dairy cows. In experiment 1, whole-crop wheat was ensiled at 350 g dry matter (DM) per kg (EW) or harvested later and stored at 550 g DM per kg following treatment with 40 g urea per kg DM (40W). In addition to these treatments in experiment 2, whole-crop wheat of 550 g DM per kg treated with 20 g urea per kg DM (20W), and combine harvested wheat grain plus wheat straw (40: 60 ratio) treated with sodium hydroxide (SG) were also included. These whole-crop wheat forages were incorporated into the diet at a level of 400 g/kg of the forage DM in experiment 1, and 330 g/kg in experiment 2, with the remainder of the forage being grass silage. A control treatment of grass silage (GS) offered as the sole forage was also included. The forages were mixed in a mixer wagon and offered ad libitum. A fixed level of 8 kg/day of concentrates was offered in experiment 1 and 7 kg/day in experiment 2. Total DM intake was significantly greater for EW and 40W than for GS in experiment 1, but not in experiment 2. Milk yield was not significantly affected by diets (mean 28·8 kg/day in experiment 1 and 29·6 kg/day in experiment 2). Milk fat, protein and lactose contents and yields were also not significantly affected by diets. The additional total metabolizable energy (ME) intake of the whole-crop diets compared with GS was partitioned to live weight. There was no evidence of ME intakes being substantially greater than ME requirements as found in previous studies. A 5 × 5 Latin square digestibility experiment was carried out with Holstein-Friesian heifers offered the individual forages used in experiment 2. Intake was significantly greater for the urea-treated whole-crop wheat forages than for grass silage and for sodium hydroxide-treated grain and straw. The digestible organic matter in the dry matter (DOMD) of grass silage was 692 g/kg and the whole-crop wheat diets ranged from 626 g/kg for ensiled whole-crop wheat to 682 g/kg for the sodium hydroxide-treated grain plus straw (40: 60 ratio), with the DOMD of urea-treated whole-crop being intermediate. The results indicated that whole-crop wheat had higher intake characteristics than grass silage in spite of its lower digestibility.