bluuebunny/crossref_metadata_2025 huggingface dataset:
The effect of diet and housing on the development of sole haemorrhages, white line haemorrhages and heel erosions in Holstein heifers
Authors: Livesey C. T. , Harrington T. , Johnston A. M. , May S. A. , Metcalf J. A.
Published: September 2010

Haemorrhagic lesions, heel erosions and changes in foot conformation have been associated with husbandry, underfoot conditions and nutrition of dairy cows.

These characteristics were monitored in 40 heifers in a 2 × 2 factorial design starting in the last trimester of pregnancy and continuing until 12 weeks post partum. Primary treatments were housing in straw yards or cubicles and secondary treatments were alternative complete diets given during lactation which differed in concentrate: forage ratio. A scoring system was developed for each of the foot lesions to allow statistical analysis of results. Locomotion scoring was carried out weekly.

White line haemorrhages, sole haemorrhages and heel erosions were all present before calving. White line haemorrhages were exacerbated by housing in cubicle yards and alleviated by housing in straw yards (P < 0·001) with an interaction between diet and housing around calving (P < 0·05). Sole haemorrhages were exacerbated both by housing in cubicle yards (P < 0·01) and the high concentrate diet (P < 0·01) with an interaction between diet and housing around calving (P < 0·05). Heel erosions were exacerbated (P < 0·05) by housing in straw yards but not affected by diet. Sole haemorrhage and heel erosion scores generally increased during early lactation (P < 0·001) independent of the treatments. There was evidence that these foot lesions were not caused by laminitis. There was a higher incidence of lameness for heifers given the high concentrate diet but no correlation between locomotion score and the type of lesion or lesion score.
The effect of dietary energy concentration and lysine/digestible energy ratio on growth performance and nitrogen deposition of young hybrid pigs
Authors: Van Lunen T. A. , Cole D. J. A.
Published: September 2010

An experiment was conducted to examine the effects of dietary lysine/digestible energy (DE) ratio (g/MJ) and dietary energy concentration on growth performance and body composition of young hybrid gilts from 9·1 to 25·4 kg live weight. Seven pigs were assigned to each of 10 dietary treatments consisting of lysine/DE ratios from 0·6 to 1·4 in 0·2 g/MJ increments and two DE concentrations (14·25 and 16·40 MJ/kg). Food was provided ad libitum and at 25·4 kg all pigs were slaughtered and body composition was determined. Responses to lysine/DE ratios were different for each DE concentration. The pigs given the 16·40 MJ/kg DE diets had a higher daily live-weight gain (DLWG) and nitrogen deposition rate (NDR) than those given the 14·25 MJ/kg diets up to the 1·2 g/MJ lysine/DE ratio. Beyond this point no DE effects were evident. Lipid deposition rate (LDR) was higher for all 16·40 MJ/kg diets as compared with the 14·25 MJ/kg diets and decreased with increasing lysine/DE ratio. The 14·25 MJ/kg diets resulted in increasing efficiency of nitrogen and gross energy utilization with increasing lysinel DE ratio up to the 1·0 g/MJ ratio after which it declined. Efficiency of lipid utilization decreased with increasing lysine/DE ratio for all 14·25 MJ/kg diets. The 16·40 MJ/kg diets resulted in a decrease in nitrogen and gross energy utilization efficiency with increasing lysine/DE ratio while lipid efficiency decreased up to the 1·0 g/MJ lysine/DE ratio after which it increased. Young hybrid pigs given high energy diets appear to be less sensitive to dietary lysine/DE ratio than those given lower energy diets. The optimum lysine/DE ratio for the genotype tested from 9 to 25 kg live weight was of the order of 1·2 g/MJ for both DE concentrations. The maximum DLWG and NDR of the genotype tested over the live-weight range of 9 to 25 kg appears to be of the order of 620 and 17 g/day (106 g/day protein deposition rate) respectively.
Differential effects of feeding fermentable carbohydrate to growing pigs on performance, gut size and slaughter characteristics
Authors: Pluske J. R. , Pethick D. W. , Mullan B. P.
Published: September 2010

Thirty-five gilts grown between 18 and 55 kg live weight were used to examine the effects of feeding fermentable carbohydrate on voluntary food intake, performance, carcass characteristics, and large intestinal growth. Five diets were used. The first diet contained steam-flaked sorghum and a supplement based on animal protein sources and 40 g/kg soya-bean meal (diet SAP). Using this diet as a base, three other diets contained either (i) guar gum, a source of soluble non-starch polysaccharide (NSP) (diet SAP + S-NSP), (ii) Novelose™, a source of resistant starch (RS) (diet SAP + RS), and (Hi) a combination of both S-NSP and RS (diet SAP + S-NSP + RS). The final diet (diet WBL) was based on wheat, barley and Australian sweet lupins. Diets (i), (ii) and (Hi) were formulated such that the concentrations of soluble NSP, oligosaccharide and RS were similar to those contained in diet WBL. There was no relationship (F > 0·05) between voluntary food intake and indices of hind-gut fermentation, although pigs given diets SAP + S-NSP and SAP + S-NSP + RS took longer to reach the slaughter weight of 55 kg (F < 0·001) and converted food less efficiently than pigs given other diets (F < 0·001). An increased intake of S-NSP (R2= 0·842,P< 0·05) and S-NSP + RS (R2 = 0·805, F < 0·05) was positively correlated to an increased (empty) weight of the large intestine. A significant negative relationship (R2= 0·78, F < 0·05) existed between the daily intake of S-NSP + RS and dressing proportion, such that each gram increase caused a 0·25 g/kg decrease in the dressing proportion of pigs. No such relationships existed between the daily intake of soluble NSP, insoluble NSP, or RS (P > 0·05) with dressing proportion. These data suggest that the sources of fermentable carbohydrate used in this study, i.e. soluble NSP and RS, may not significantly depress voluntary food intake but can affect performance and have a significant effect on large intestinal growth and dressing proportion.
Genetic variability of populations and similarity of subpopulations in Austrian cattle breeds determined by analysis of pedigrees
Authors: Sölkner J. , Filipcic L. , Hampshire N.
Published: September 2010

Parameters based on probabilities of gene origin were used to evaluate the genetic variability of four Austrian cattle breeds. Effective numbers of founders, ancestors and remaining founder genomes showed that all four populations investigated are rather small genetically. Effective numbers of remaining founder genomes were 94 for Simmental, 41 for Braunvieh (Brown Swiss), 32 for Pinzgauer and 21 for Grauvieh (Grey cattle, a small mountain breed). As the value of 94 for Simmental was rather large in comparison with estimates from other populations in previous studies, the effect of population structure was investigated. A cosine measure of similarity based on differences in individual founder contributions to different subpopulations was defined and used for analysis. Subpopulations defined by regions were clearly more distinct for Simmental than for Braunvieh. The size of the cosine values depended on the method of calculating founder contributions and was overestimated when choosing the method not accounting for drift and bottlenecks (effective number of founders).
An evaluation of the use of synchrony technology in beef breeding herds
Authors: Pleasants A. B. , Macmillan K. L.
Published: September 2010

A model which was originally developed to derive the probability density of a calving distribution for beef cows under natural breeding has been modified to incorporate the effects of using oestrous synchronization at the beginning of the breeding period.

The model has been used to investigate five oestrous synchronization strategies over four herds, each with differing calving patterns: no synchronization; every cow in the herd is synchronized; every anoestrous cow is synchronized; every cow calving more than 20 days after the date of the planned start of calving is synchronized; every cow calving 30 days after the date of the planned start of calving is synchronized. Two of the herds previously had long calving periods and two previously had short, compact calving periods.

Model results showed that synchronization improved average herd calf live weight by 21 kg in the two herds with long prior calving periods but showed little effect in the two herds with compact prior calving periods. Synchronizing cows which calved more than 20 days after the start of calving in the herd showed similar results to synchronizing every cow in the herd and thus would be more cost effective. Synchronizing cows which calved more than 30 days after the start of calving in the herd showed a smaller advantage but only in the herds with long prior calving periods. The optimal strategy for oestrous synchronization in a herd will depend on the prior calving distribution and the average duration ofanoestrus in that herd as well as the relative costs of the treatment.
Identification of early predictors of carriers of the Booroola gene in sheep using a mixed inheritance model
Authors: Nieuwhof G. J. , Visscher A. H. , Engel B. , Werf J. H. J. van der , Jong F. H. de , Dijkstra M.
Published: September 2010

A study was conducted to find early predictors of the Booroola gene in several generations of a crossbred sheep population. Merino carriers of the Booroola gene were mated with Texel sheep to improve prolificacy of the latter. Ovulation rate at 8 months of age, litter size at 1 and 2 years of age and FSH and inhibin levels at 3, 4, 5 and 6 weeks of age were determined in about 700 females.

Gibbs sampling was applied for inference in a mixed inheritance model. Estimates for the gene effect in heterozygous females were +1·5 corpora lutea and +1·3 lambs at 2 years of age. The gene effect on litter size at 1 year was small. The only significant major gene effect for hormone levels found was for lnINH4 (–0·66).

A number of hormone levels and combinations of hormone levels appeared to be useful predictors of carrier status of individual animals. In comparison with a situation where only parents' genotype is known, posterior probabilities for non-carriers were on average increased from 50 to over 95% when FSH levels were used. However, the combined posterior probabilities of carriers and non-carriers increased only up to 67%. So in general, classification with Gibbs sampling resulted in too few animals being identified as carrier. The sum of FSH levels at 3, 4, 5 and 6 weeks of age is proposed as a predictor of presence of the Booroola gene in an animal. Multivariate analysis of mixed inheritance models could help to find more effective combinations.
The influence of litter size on milk production of sows
Authors: Auldist D. E. , Morrish L. , Eason P. , King R. H.
Published: September 2010

Thirty sows were allocated at their first farrowing to five litter size treatments. Litter sizes of six, eight, 10,12 and 14 were established by cross-fostering within 48 h post partum. Milk yield (Y, kg/day) of sows was linearly related to litter size (L) and was described by the equations; Y = 5·98 (s.e. 0·48) + 0·689 (s.e. 0·046)L, R2= 0·99; residual s.d. = 0·29;P< 0·001 and Y = 8·20 (s.e. 0·46) + 0·324 (s.e. 0·044)1, R2= 0·95; residual s.d. = 0·28;P< 0·002 for early (day 10 to day 14) and late (day 24 to day 28) lactation, respectively. The composition of milk from sows suckling various litter sizes remained relatively stable but suckling frequency in early lactation increased linearly in response to increased litter size. Litter size significantly affected the average growth rate of individual piglets; piglet growth rate from birth to weaning at 28 days of age decreased from 283 g/day to 202 giday in response to increasing litter size from six to 14. The relationships between milk yield, average piglet growth rate and litter size indicate that the number of functional glands is the major factor influencing milk yield of sows. Increasing the number of functional glands by increasing litter size more than compensates for any decrease in milk output from individual glands.
Effect of draught work on performance and metabolism of crossbred cows 1. Effect of work and diet on body-weight change, body condition, lactation and productivity
Authors: Gemeda T. , Zerbini E. , Wold A. G. , Demissie D.
Published: September 2010

Forty pregnant F1 crossbred dairy cows (20 Friesian × Boran and 20 Simmental × Boran) were stratified in a 2 × 2 diet × work factorial experiment (not working-not supplemented, NWNS; not working-supplemented, NWS; working-not supplemented, WNS; and working-supplemented, WS). Working cows pulled sledges 100 days/year (pull = 350 to 450 N, 4 h/day, 4 days/week). Work output of supplemented and non-supplemented cows was similar over 1 and 2 years. Over all 3 years, dry-matter intake relative to metabolic body size (g/kg M0.75 was greater for working, compared with non-working cows. Body-weight changes and body condition score were similar for working and non-working cows. Non-supplemented cows lost weight throughout the first 2-year period, while supplemented cows tended to maintain or gain body weight over 1 and 3 years. Over 2 years, supplementation of working cows proportionately reduced live-weight loss by 0.73 and doubled the number of conceptions and parturitions. Days in milk, milk, milk fat and protein yields were similar for working and non-working cows, but were greater for supplemented, compared with non-supplemented, cows. Total conceptions and calves born in all 3 years tended to be greater for supplemented and non-working compared with non-supplemented and working cows. A productivity index (PI) that took into account food intake was calculated. The PI for supplemented cows over 2 years was greater than that for non-supplemented cows. Meanwhile the PI was similar for working and non-working cows over all periods considered. A similar PI for working and non-working cows under supplementation indicates potential of on-farm adoption of a cow traction technology that includes improved food production and ng strategies.
The performance and changes in body composition of steers offered cut grass or grazing following three patterns of nutrition in winter
Authors: Baker R. D. , Gibb M. J.
Published: September 2010

Friesian steer cahes were reared over winter on a silage (S) or on a silage plus concentrate (SC) diet to provide cattle of the same live weight, but of different ages for a comparison of grazing and feeding cut herbage indoors during the summer. A further group received fish meal (SF) as a supplement in an attempt to provide cattle of the same age as the S group, but of different body composition. Although supplementation improved the daily deposition of fat and protein, it did not lead to differences in body composition at the end of the winter period. The ratio of protein to fat deposition and the efficiencies of conversion were low for all groups, but they did improve as the level of supplementation increased.

There was no carry-over effect of winter treatment on summer performance. However, housed cattle deposited significantly more fat.

The trial demonstrated the inefficient use of nitrogen from silage with poor fermentation characteristics and the predisposition of cattle on such diets to low protein to energy retention. Whilst supplementation altered this balance, higher levels than given would be needed to have a marked effect. It was also concluded that the performance of housed cattle as an indicator of that of grazing cattle, is likely to be misleading because lower activity reduces maintenance requirement and leads to greater fat deposition.
Resistance to cold stress in sheep shorn by cover comb or standard comb
Authors: Dabiri N. , Holmes C. W. , McCutcheon S. N. , Parker W. J. , Morris S. T.
Published: September 2010

The cover comb has been developed in New Zealand as a means of increasing residual fleece depth after shearing and so increasing the resistance of shorn sheep to cold stress.

The effects of shearing by cover comb and standard comb were studied over 2 days pre-shearing and 10 days post-shearing in eight pairs of non-pregnant, non-lactating 2-year-old ewes. Animals were housed and given a maintenance level of chaffed lucerne hay. One member of each pair was shorn with a cover comb, the other with a standard comb. Each pair was exposed to ‘cold plus wind’ (7°C ambient temperature, 7 km/h air movement) followed by ‘cold plus wind plus rain’ (10°C ambient temperature, 7km/h air movement, wetting at a rate equivalent to 25 mm/h rain from overhead sprinklers) in a calorimetry chamber on days S –3, S –2, SO (day of shearing), S2, S6 and S10. Heat production immediately after shearing (SO) was proportionately 0·22 greater in ewes shorn by the standard comb under conditions of ‘cold plus wind’ and 0·38 greater under conditions of ‘cold plus wind plus rain’ than in their cover comb-shorn cohorts. Circulating concentrations of non-esterifiedfatty acids were substantially elevated on the day of shearing and 2 days thereafter in ewes shorn by the standard comb, indicating increased rates of body fat mobilization to support heat production in these ewes compared with those shorn by the cover comb. This was reflected in a 1·4 kg weight loss in the standard comb-shorn ewes compared with a 0·4 kg live-weight gain in the cover comb-shorn group over the 10 days of the experiment. It was concluded that use of a cover comb will significantly reduce the risk of death from hypothermia in sheep shorn during winter and spring, and should facilitate an increase in the productivity of animals by allowing a greater proportion of food energy to be used for productive purposes.
Effects of pre-partum oestradiol injection on parturition in sows and piglet survival
Authors: Kirkwood R. N. , Thacker P. A.
Published: September 2010

Fifty-four multiparous Yorkshire × Landrace sows were allocated equally to receive an intramuscular (i.m.) injection of 3 ing oestradiol-17β (E2) or no injection at 112 days of gestationto determine the effect of E2on the timing and duration offarrowing. All sows received an injection (i.m.) of 10 mg prostaglandin F2x af 113 days of gestation. Of the soivs allocated to treatment, 21 oestrogen-treated and 19 control sows were assigned to be observed for the onset of parturition. A further six oestrogen-treated and eight control sows were included to increase the data base for litter production. The time of piglet delivery was monitored between 08·00 and 18·00 h on day 114 of gestation. Blood samples were obtained from each offour piglets from four E2-treated and five control litters. More E2-treated (8/21) than control sows (1/19) farrowed before 08.00 h of day 114 (P < 0·05) although, for those sows farrowing during the observation period, there was no effect on the time to onset or duration of parturition. Plasma oestradiol concentrations were higher (P < 0·06) in piglets delivered by E2-treated sows. However,this was not associated with any effect on piglet pre-weaning survival. It is concluded that exogenous oestradiol can influence the timing of onset offarrowing in some sows. Although further refinement in terms of timing of E2injections is required, it seems likely that exogenous E2may have a useful role to play in hastening the induction of parturition in sows.
The effect of heat treatment on ileal amino acid digestibility of growing broilers given vetch and bitter vetch meals
Authors: Fernández-Fígares I. , Pérez L. , Nieto R. , Aguilera J. F. , Prieto C.
Published: September 2010

Forty-eight 4-week-old White Rock growing chickens (mean live weight 500 (s.e. 9·3) g) were given, by crop intubation, four isoencrgetic (13·1 M] metabolizable energy (ME) per kg dry matter (DM)) and isonitrogenous (120 g crude protein (CP) per kg DM) semisynthetic diets based on vetch (V) or bitter vetch (B) seeds, untreated or antoclaved at 120°C for 30 ruin (diets V, AV, B and AB, respectively). Autoclaving of the seeds caused some changes in amino acid (AA) composition but did not reduce the availability of A As, especially of lysine.

The average apparent AA digestibility values derived from ileal content were 0·75, 0·85, 0·59 and 0·85 for diets V, AV, B and AB, respectively, corresponding to true absorption values of 0·90, 1·00, 0·74 and 0·97, respectively. Although the apparent digestibility values of several AAs were relatively low (methionine, isoleucine, tyrosine and cystine), most were higher than 0·70. Heat treatment resulted in a significant increase (P < 0·05) in the AA apparent digestibility of both seeds. It is concluded that heat treatment is useful for improvement of vetch and bitter vetch seeds for inclusion in poultry diets.
Effects of dietary maize level on net flux across splanchnic tissues of oxygen and nutrients in wethers consuming ad libitum different forages
Authors: Goetsch A. L. , Ferrell C. L.
Published: September 2010

Crossbred wethers (34 (s.e. 0·9) kg), with catheters in a hepatic vein, the portal vein and a mesenteric vein and artery, were offered ad libitum alfalfa (A), bermudagrass (B) or ryegrass-wheat (RW) hay and approximately 0, 200 or 400 g/kg maize (dry matter) to determine influences of maize level on net flux of oxygen and nutrients across the portal-drained viscera (PDV) and liver with different forage sources. Digestible energy intake (MJ/day) was 8·5, 12·0 and 12·8 (s.e. VIS) for A; 4·5, 5·5 and 9·0 (s.e. 0·93) for B; and 9·4, 8·8 and 12·2 (s.e. 0·93) for RW with 0, 200 and 400 g/kg maize, respectively. Splanchnic bed oxygen consumption (mmol/h) was 301, 304 and 322 (s.e. 27·2) for A; 178, 187 and 217 (s.e. 30·0) for B; and 226, 133 and 233 (s.e. 19·0) for RW with 0, 200 and 400 g/kg maize, respectively. Increasing dietary maize level linearly increased (P < 0·05) PDV release of alpha-amino nitrogen with B (5, 9 and 14 mmol/h) but not with A or RW. Dietary maize level did not consistently alter PDV or hepatic net flux of urea or ammonia nitrogen, suggesting that changes in ruminally fermentable organic matter from diets offered ad libitum, presumably induced by varying dietary concentrate level, may not alter nitrogen recycling when forage is 86 g/kg or greater in crude protein. Propionate release by the PDV and hepatic uptake increased linearly (P < 0·08) as maize level in A and B diets increased, although increasing dietary maize level did not significantly alter PDV, hepatic or splanchnic bed net flux of glucose regardless of forage source. Nevertheless, glucose concentration in arterial blood with A and RW increased linearly fP < 0·05) with increasing maize level, suggesting increased peripheral glucose availability. In conclusion, the potential to decrease energy consumption by splanchnic tissues relative to digestible energy intake by dietary inclusion of maize, thereby increasing the proportion of absorbed energy available to extra-splanchnic tissues, may be greater for low-quality forage than for forage of moderate or high quality and for moderate v. low dietary levels of maize with low-quality forage.
Steroid production and LH receptor concentrations of ovarian follicles and corpora lutea and associated rates of ova wastage in ewes given high and low levels of food intake before and after mating
Authors: Abecia J. A. , Rhind S. M. , Bramley T. A. , McMillen S. R.
Published: September 2010

Two groups of eives were fed to provide 1·5 × (high, H; no. = 13) or 0·5 × (low, L; no. = 12) energy requirements for maintenance of live weight from 12 days before a synchronized mating in November until slaughter at 14 days after mating and the effects on embryo survival and associated patterns of gonadotropin secretion, and ovarian follicle and corpus luteum function were investigated. Proportionately, there were more pregnant ewes in the H group than the L group (0·62v.0·08; %2 = 7·67;P< 0·01) at day 14 of pregnancy but there were no differences in mean LH concentrations, LH pulse frequencies or amplitudes, either before mating and ovulation (follicular phase) or at day 10 after mating (luteal phase). The mean size (mm) of the three largest follicles (H: 5·69; L: 5·65; s.e.d. = 0·21), the proportion of these follicles that were oestrogenic (secreting > 500 pg oestradiol per h; H: 0·29; L: 0·28; y) = 0·01;P> 0·05) and secretion (pg/h) in vitro of oestradiol (H, 294; L, 386; s.e.d. = 146) (pg/h) and testosterone (H: 636; L: 508; s.e.d. = 293) by these follicles were similar for both treatments. There were no treatment differences in LH receptor concentrations (pg hormone bound per mg protein) in granulosa (H: 69·02; L: 67·76; s.e.d. = 0·20) and thecal (H: 46-88; L: 50·82; s.e.d. = 0·19) tissues. However, there was a higher concentration of receptors in the thecal tissue of oestrogenic follicles ofL than H ewes (167v.62; s.e.d. = 18;P< 0·05). Mean weights (g) of corpora lutea (H: 0·72; L: 0·59; s.e.d. = 0·003; P = 0·09), progesterone secretion (ng/mg per h) in vitro by luteal tissue (H: 1·75; L: 1·78; s.e.d. = 0·30) and LH receptor concentrations in corpora lutea (H: 58·16; L: 54·27; s.e.d. = 25·14) were similar for both treatments. It is concluded that the reduction in embryo survival associated with a reduced level of food intake was not attributable to a reduction in LH secretion, inadequacies in follicle growth and development or in the capacity of the corpora lutea to synthesize and release progesterone.
Biological efficiency of meat and wool production of seven sheep genotypes
Authors: Greeff J. C. , Bouwer L. , Hofmeyr J. H.
Published: September 2010

One hundred and thirty-two ewes of the Merino (M), Finn × Merino (FLXM), Border Leicester × Merino (BLXM), Bleu de Maine × Merino (BMXM), Texel × Merino (TXM), Cheviot × Merino (ChXM) and Merino Landsheep × Merino (MLXM) were evaluated for efficiency of lamb production. Individual food intakes of every ewe and also of her lamb(s) were determined over a complete production cycle. Efficiency of lamb production (kg lamb marketed at 35 kg live mass per kg food consumed by the ewe and her lamb(s)) indicated that the FLXM was the most efficient, followed by the TXM, Merino, MLXM, BLXM, ChXM and the BMXM was the least efficient. No significant differences (P < 0·05) were found between genotypes for efficiency of lamb production for ewes producing and rearing singletons until 35 kg live mass with ewe mass included as a covariate. Efficiency of wool production of the Merino was significantly (T < 0·001) higher than that of the other crosses. These results emphasize the importance of reproduction traits in improving efficiency of lamb production.
The effects of frequency of feeding of supplementary concentrates on performance and metabolite and IGF-1 status of ewes given silage in late pregnancy
Authors: Chestnutt D. M. B. , Wylie A. R. G.
Published: September 2010

Eiues on grass silage-based diets were offered, during the last 6 weeks of pregnancy, an increasing allowance of a barley-soya-fish meal concentrate (400 g/day in weeks 15/16; 600 g/day in weeks 17/18; 800 g/day in weeks 19/20) as either one, two or three feeds daily or as a complete mix with silage. Silage dry-matter intake increased with concentrate feeding frequency (P < 0·01) and was greatest with the mixed diet at an average of 1·38 of that with a single daily concentrate meal. The effect on silage intake was evident even at the lowest level of concentrate supplementation during weeks 15/16 and was independent of silage quality. Ewes gained more live weight (P < 0·01), and maintained a higher live weight post partum, as a result of increasing the frequency of feeding of concentrates but mean lamb birth weight was unaffected. Maternal serum metabolites were measured in weeks 17/18 and 19/20 only. Mean [i-hydroxybutyrate was higher, but not significantly so, in weeks 19/20 despite the increased concentrate allowance and was higher overall (P < 0·05) in ewes offered concentrates once daily compared with those receiving concentrates three times daily or mixed with the silage. Insulin-like growth factor 1 (IGF-1) was higher in serum of ewes given frequent concentrate meals compared with those offered concentrate once daily (P < 0·05). Serum albumin and globulin increased as concentrate intake increased between weeks 17/18 and 19/20 (P < 0·05) and also, when concentrates were offered more than once daily (P < 0·05). Serum urea level was higher with more frequent concentrate meals (P < 0·01) and was affected by silage quality (P < 0·001).
Microbial production of skatole in the hind gut of pigs given different diets and its relation to skatole deposition in backfat
Authors: Jensen M. T. , Cox R. P. , Jensen B. B.
Published: September 2010

The intestinal production of skatole and its deposition in backfat was investigated in 35 uncastrated crossbred male pigs. The pigs were fed five purified non-commercial diets containing either casein or brewers yeast slurry as protein source. The yeast slurry diet was used alone or supplemented with either wheat bran (200 g/kg), sugar-beet pulp (200 g/kg), or soya oil (100 g/kg).

Skatole concentrations in backfat, and in digesta in different sections of the gastro-intestinal tract were measured at slaughter (mean weight 112 kg). There were large variations in skatole concentrations in the hind gut of different animals given the same diet. Although there was some correlation between skatole in intestinal contents and deposition in adipose tissue, there were also large variations between individual animals in their response to intestinal skatole. Nevertheless, there was a clear effect of diet on both intestinal skatole production and skatole deposition in backfat. The use of casein as a protein source decreased microbial skatole production, the total amount in the gut, and the concentration in the backfat. Addition of sugar-beet pulp to the yeast slurry diet increased microbial activity in the intestine (measured as ATP content, concentration of short-chain fatty acids, and lowering of digesta pH). There was a decreased rate of skatole production during in vitro incubations of intestinal content, and less skatole in the hind gut and backfat.

In vitro fermentations of freeze-dried Heal effluent inoculated with faecal bacteria, and addition of substrates to in vitro incubations of intestinal contents, demonstrated that tryptophan availability rather than microbial activity was the limiting factor for skatole production.

The results show that skatole production depends on the amount of protein entering the hind gut and the proteolytic activity of the intestinal microbiota. Protein fermentation in the hind gut can be decreased either by using more readily digestible protein sources (for example casein rather than yeast slurry) which reduce the amount of protein passing through to the hind gut, or by adding an alternative energy source which is more readily metabolized by the hind gut microbiota (for example supplementation of the yeast slurry diet with sugar-beet pulp). This provides a basis for the rational design of diets which will decrease skatole concentrations in the carcass.
The digestion of dry matter and non-starch polysaccharides from diets containing plain sugar-beet pulp or wheat straw by pregnant sows
Authors: Yan T. , Longland A. C. , Close W. H. , Sharpe C. E. , Keal H. D.
Published: September 2010

Forty days after mating, 16 pregnant sows were randomly allocated to two diets containing either sugar-beet pulp (SBP) or wheat straw (WS) each offered at two levels (1·0 or 1·5 × maintenance energy requirement (M), where M = 460 kJ digestible energy (DE) per kg0·75 per day). Diets were iso-nitrogenous, and contained similar levels of DE together with 260 g non-starch polysaccharides (NSP) per kg dry matter (DM) largely derived from either the SBP or the WS. A 7-day NSP and DM balance was made between day 60 and 100 of gestation. During lactation sows had ad libitum access to a conventional sow diet which contained neither SBP or WS.

Outputs of both fresh and dry faeces from sows given diet WS were significantly greater than the outputs from sows given the corresponding SBP diets (P <0·05), and outputs were significantly greater at the higher feeding level for both diets (P < 0·05). There was a tendency for higher urinary outputs from sows given diet WS, but these were variable and not significantly different from those from sows given diet SBP. The apparent digestibility and retention of DM was significantly greater for the SBP diet than for diet WS but were not significantly affected by feeding level. The apparent digestibilities of the total NSP and each of the individual constituent monomers were significantly higher for diet SBP than for diet WS (P < 0·001), but were independent of feeding level (P> 0·05). Xylose was the most poorly digested NSP constituent from both diets. Apparent digestibility coefficients for the remaining NSP constituents in diet SBP were > 0·8 and were > 0·52 in diet WS, with the uronic acids and mannose being the most highly digested NSP fractions from diets SBP and WS respectively.
Qualitative requirement for B vitamins in diets for the gilthead seabream (Sparus aurata L.)
Authors: Morris P. C. , Davies S. J. , Lowe D. M.
Published: September 2010

Semi-purified diets incorporating 495·4 g/kg crude protein and 72·0 g/kg oil, were used to identify the qualitative requirement of Spams aurata juveniles for thiamin, riboflavin, pyridoxine, niacin and pantothenic acid. Deficiency of these vitamins was associated with poor performance in terms of growth, food efficiency and apparent net protein utilization. All dietary vitamin deficiencies resulted in elevated moisture and a lowering of the lipid content of the carcass. In addition to increased mortality among the fish fed deficient diets, a small number of externally visible changes were observed including food refusal, anorexia and changes of skin colour. At the haematological level, all cases of vitamin deficiency were associated with significant reductions in haematocrit. In general, histological examination revealed that the pancreas of vitamin-deficient animals became atrophic with an accumulation of pigmented granules around this organ while additionally, the normal homogeneity of the liver parenchyma was lost.
Effects of single-space feeder design on feeding behaviour and performance of growing pigs
Authors: Nielsen B. L. , Lawrence A. B. , Whittemore C. T.
Published: September 2010

Computerized food intake recording systems of various designs are used by research, centres and breeding companies to monitor the individual food intake of pigs kept in groups. In the present experiment, three feeder designs are compared in order to estimate the effect on performance and feeding behaviour. Ninety entire male pigs (34 (s.e. 0·6) kg) were allocated in three replicates to pens of 10 pigs; each pen containing one of three different feeder entrance designs: low (head-guard), medium (full-length standard race), and high (enclosed pneumatic race) protection against disturbance of the feeding pig. No significant differences were found between treatments in daily food intake, daily live-weight gain, food conversion ratio, number of visits per day and daily feeder occupation. Pigs with access to an enclosed race had longer visits than pigs on the two other treatments, and they also ate more per visit (4·8, 4·8 and 6·2 (s.e.d. = 0·37) min per visit; 172, 157, and 202 (s.e.d. = 11·1) g per visit; means of low, medium and high protection, respectively). The enclosed race was not only the most protective, it was also the most difficult to enter, and this decreased accessibility of the food may have given rise to the changed feeding pattern displayed by pigs using this type of race. Access to a feeder with low protection resulted in a faster rate of eating (36·9, 33·2, and 32·8 (s.e.d. = 0·82) g/min; means of low, medium and high protection, respectively) indicative of a more forced feeding behaviour.
Application of Bayesian inference in the comparison of lactation curves of Merino ewes
Authors: Groenewald P. C. N. , Ferreira A. V. , van der Merwe H. J. , Slippers S. C.
Published: September 2010

Bayesian theory is applied to compare the characteristics of the estimated lactation curves of two groups of 5-year-old Merino ewes. The diets of the two groups were supplemented respectively by DL-methionine and maleyl-DLmethionine. The purpose is to illustrate the Bayesian approach when analysing for the effect of supplement on the lactation pattern of the sheep. Using Wood's model, the posterior distributions of the model parameters are determined for the two groups. This is achieved by assuming a hierarchical Bayes model and applying the Gibbs sampler, a sampling based computer intensive algorithm that is very efficient in obtaining marginal distributions of functions of parameters. The Gibbs sampler enables us to obtain marginal posterior distribution of characteristics of the lactation curve such as peak yield, time of peak yield, persistency and total milk yield. The results are notable differences in the marginal posterior distributions of mean peak milk yield and mean total yield. The posterior probability that the mean peak milk yield of the group supplemented by maleyl-DL-methionine is higher than that of the group with DL-methionine supplement is 0·98, while the same probability for mean total yield is 0·83.
A comparison of ovulation rate and late embryonic mortality in ewe lambs and ewes and the rôle of late embryo loss in ewe lamb subfertility
Authors: Beck N. F. G. , Davies M. C. G. , Davies B.
Published: September 2010

An investigation was conducted to compare late embryonic losses in ewe lambs and ewes and to determine the effect of inducing embryonic mortality on day 15 of pregnancy on reproductive function in ewe lambs. Ovulation rate and embryo survival were determined, at 15 and 30 days after mating, in a total of 83 ewe lambs and 67 ewes. Ovulation rate was lower, at spontaneous oestrus, in ewe lambs (1·07) than in ewes (1·25; P < 0·05). There was no difference in embryo survival at day 15, as 79% of ewe lambs and 80% of ewes contained expanded conceptuses. However, embryo survival was lower in ewe lambs (69%) than ewes (88%) at day 30 (P < 0·05). Embryonic mortality was induced in an additional 18 ewe lambs with an intrauterine injection of colchicine on day 15 post mating. Four of these animals had normal length oestrous cycles, six had inter-oestrus intervals ranging from 22 to 35 days and eight did not return to oestrus. Overall, the results of this study demonstrate that low ovulation rate and late embryonic losses make a significant contribution to subfertility in ewe lambs. Moreover, conceptus death is associated with luteal persistence, which may reduce reproductive performance by preventing remating.
Oestrus synchronization in ewes: the effect of combining a prostaglandin analogue with a GnRH agonist (buserelin)
Authors: Beck N. F. G. , Jones M. , Davies B. , Peters A. R. , Williams S. P.
Published: September 2010

An experiment was designed to determine whether an injection of 4 μg of the GnRH agonist buserelin (GnRH) followed, 5 days later, by an injection of 100 μg of prostaglandin F2α analogue (PGF), would give a level of oestrus synchronization and fertility comparable with a standard double dose PGF regime. A total of 200 Welsh Halfbred ewes were divided by live weight into two treatment groups using a system of random stratification during the 1994 breeding season. Ninety-one percent of the ewes treated with GnRH combined with PGF were mated by fertile rams within a 3-day period compared with 94% of ewes treated with two injections of PGF, 11-days apart. Returns to service for the two groups were 11·1% and 7·4%, respectively. There was no effect of treatment on lambing performance, as a similar percentage of ewes in the GnRH plus PGF group (88·8%) and the double dose PGF group (92·5%) lambed to synchronized oestrus. Gestation length, litter size and lamb birth weight were similar for both groups. These results demonstrate that GnRH combined with PGF will produce levels of oestrus synchronization and fertility comparable with a double dose PGF regime.
Effect of draught force and diet on dry-matter intake, milk production and live-weight change in non-pregnant and pregnant cows
Authors: Zerbini E. , Wold A. G. , Demissie D.
Published: September 2010

Eighteen F1 crossbred dairy cows (Friesian × Boran and Simmental × Boran) were allocated to one of three diet groups (H: natural pasture hay; H+3: natural pasture hay + 3 kg concentrate; and H+5: natural pasture hay + 5 kg concentrate) using a stratified random sampling procedure, with parity, milk production genotype, body weight and body condition score as blocking variables. Cows on each diet were then allocated to three draught forces (7, 11 and 15 kg draught force per 100 kg live weight) in a cross-over design to investigate relationships between work output, live-weight changes, dry-matter intake (DMI) and milk yield. Each cow worked for 36 days in early lactation (from calving to 90 days) and for a further 36 days in late lactation (from 250 to 340 days post partum). Work output was similar for cows on each of the three diets. Cows on the H diet consumed more hay than cows on H+3 and H−5 diets. Hay and total DMI, milk yield and milk fat were similar across draught forces and during working and resting days when the cows were not pregnant. Similar results were obtained when cows were from 82 to 172 days pregnant. Pregnancy did not affect the ability of cows to perform work at different intensities. During working days cows lost live weight both when pregnant and when non-pregnant. During rest days, non-pregnant cows on diets H, H+3 and H+5 compensated proportionately 0·12, 0·59 and 0·59, respectively, of the live weight lost during working days. Pregnant cows on diet H+3 and H+5 compensated proportionately 0·95 and 1·77 live weight, respectively. Lower total live-weight losses during the pregnant period could be attributed partly to relatively greater DMIs and lower milk production, but also to gestation. Prediction of live-weight change from total DMI above maintenance, milk yield and work output during periods of 6 working days was poor (R2 = 0·18). However, the same parameters explained adequately changes in live weight for supplemented and non-supplemented working cows (R2 = 0·38 and 0·79, respectively) during a period of 90 days.
Towards automatic interpretation of sheep ultrasound scans
Authors: Glasbey C. A. , Abdalla I. , Simm G.
Published: September 2010

Ultrasound imaging is widely used in animal breeding to provide in vivo estimates of the carcass composition of candidates for selection. Although the technique is less accurate than more recent medical imaging methods, such as X-ray computed tomography and magnetic resonance imaging, it is relatively cheap and mobile. Therefore large numbers of animals can be measured. Most current ultrasound scanners require some degree of manual interpretation of images, which is time consuming and liable to vary both between and within individuals. Hence, this study investigated the automatic interpretation of ultrasound scans from sheep. A computer algorithm is proposed for identifying tissue boundaries. Estimates of tissue depth are shown to be comparable with those obtained by manual interpretation, for images of 72 sheep scanned twice at the position of the 13th thoracic vertebra. The root-mean-square errors of subcutaneous fat depth and m. longissimus muscle depth ivere 0·7 mm and 1·7 mm, respectively.
Taql growth hormone gene polymorphism and milk production traits in Holstein-Friesian cattle
Authors: Falaki M. , Sneyers M. , Prandi A. , Massart S. , Corradini C. , Formigoni A. , Burny A. , Portetelle D. , Renaville R.
Published: September 2010

The positive effect of administration of growth hormone (GH) on milk production and its presence in selected dairy cattle lines of higher GH concentrations prompted an examination of the presence of restriction fragment length polymorphism (RFLP) in the growth hormone gene using the enzyme Taq/ and to investigate associations between this polymorphism and milk production traits. Blood was sampled from 251 Italian Holstein-Friesian cows. Three fragment bands, arbitrarily denoted A, B and E, of 6·2, 5·2 and 1·9 kilobase (kb), respectively, were observed. Their combinations exhibited six patterns, AA, AB, ABE, AE, BB and BE with frequencies of 64·5, 24·3, 2·4, 6·8, 1·4 and 0·4%, respectively. The statistical analysis was performed using linear mixed animal models. The results indicated an effect of the GHgene polymorphic Taq/restriction fragment on 305-day productions of milk, fat and protein; the low frequency pattern AE showed productions inferior to those for AA or AB patterns. Effect estimates of AA, AB and AE were, respectively, 200 (s.e. 215), 218 (s.e. 267) and -910 (s.e. 380) kg for milk production, 7·75 (s.e. 7·98), 16·10 (s.e. 9·79) and -22·14 (s.e. 14·42) kg for fat production, and 6·78 (s.e. 6·21), 8·57 (s.e. 7·58) and -20·74 (s.e. 11·14) kg for protein production. The average substitution effect estimates of E were -891 (s.e. 278), -26·56 (s.e. 10·16) and -24·50 (s.e. 9·43) kg for milk, fat and protein yields, respectively. In conclusion, these results suggest that the E fragment deserves further designed and specific study.
Milk acetone concentration as an indicator of hyperketonaemia in dairy cows: the critical value revised
Authors: Gustafsson A. H. , Emanuelson U.
Published: September 2010

Acetone concentration in milk is correlated with subclinical and clinical ketosis and also with milk yield and reproductive efficiency. The purpose of this study was to assess a threshold of milk acetone at which cows tend to be adversely affected. The critical values were estimated on data from 11690 lactations where the change in daily milk yield from weeks 1 to 2 to weeks 5 to 6 of lactation was evaluated in relation to different milk acetone concentrations. Daily milk yield tended to be reduced in cows with acetone concentrations between 0·7 and 1·4 mmol/l, but responses were not entirely consistent. At concentrations >l·4 mmol/l, daily milk yield was clearly reduced. Long-term milk yield (day 0 to 100 and day 0 to 200) was about 190 kg of 40 g/kg fat-corrected milk (FCM) less in cows with acetone concentrations >l·4 vis-à-vis <0·7 mmol/l. Reproductive efficiency was also impaired in cows with acetone concentrations >l·4 mmol/l; 4·9 days longer interval from calving to first service (first parity and parity 2+ cows) and 5·7 times a greater risk of cystic ovaries (parity 1), compared with cows with milk acetone <0·7 mmol/l. However, no significant effects on long-term milk yield or on reproductive efficiency were found in cows with acetone concentrations 0·7 to 1·4 vis-à-vis <0·7 mmol/l. The results suggest that 1·4 mmol/l acetone in milk may be used as the most important critical value, as higher concentrations are detrimental to productivity. The interval 0·7 to 1·4 mmol acetone per I milk may be used as a warning class, since early lactation yield may be reduced.