bluuebunny/crossref_metadata_2025 huggingface dataset:
Feeding value of three categories of pea (Pisum sativum, L.) for poultry
Authors: Grosjean F. , Barrier-Guillot B. , Bastianelli D. , Rudeaux F. , Bourdillon A. , Peyronnet C.
Published: August 2016

The nutritional value of different categories of peas was measured in mash or pelleted diets using adult cockerels. Twenty-five round and white-flowered peas (feed peas), 12 round and coloured-flowered peas and five wrinkled and white-flowered peas were used in mash diets. From the same batches, 11 feed peas, five coloured peas and four wrinkled peas were tested in pelleted diets.

Mean apparent metabolizable energy (AME) values were 12·02, 11·35 and 10·50 MJ/kg dry matter (DM) for feed peas, coloured peas and wrinkled peas respectively in mash diets and 13·18, 12·72 and 11·63 MJ/kg DM for the same categories in pelleted diets.

Mean starch digestibility was 0·905, 0·887 and 0·802 for feed peas, coloured peas and wrinkled peas respectively in mash diets and 0·985, 0·984 and 0·840 for these categories in pelleted diets.

Mean protein digestibility was 0·788, 0·643 and 0·798 for feed peas, coloured peas and wrinkled peas respectively in mash diets and corresponding values for peas in pelleted diets were 0·855, 0·743 and 0·853.

Pelleting thus had a positive effect on the nutritional value of peas and this improvement was all the more important because the AME and protein digestibility of the pea in mash diets was low.

The nutritional value of feed peas for cockerels was not strongly correlated with chemical composition or to digestibility data obtained in the pig.
Effects of oral and injected vitamin A (retinol) supplements on liver vitamin A and plasma carotenoid and cholesterol concentrations in cattle
Authors: Knight T. W. , Death A. F.
Published: August 2016

Two experiments determined the effects of daily oral supplements of vitamin A (retinol) and injected preparations of vitamin A on liver vitamin A concentration and plasma carotenoid (PC) concentration. Vetade is an oily injectable vitamin A preparation, while Nov-a-Vit is an aqueous injectable vitamin A preparation. Angus crossbred heifers were used in experiment 1 and Angus and Simmental crossbred steers were used in experiment 2. All cattle grazed pasture but were given also 1 kg per head of pellets daily and vitamin A supplements were included in the pellets when required. In experiment 1, one group of heifers was given 1 × 106i.u. vitamin A per head daily for 31 days, while a second group in another part of the paddock was not supplemented with vitamin A. A third group of heifers grazed with this latter group and was injected with 2·5 × 106i.u. vitamin A (Vetade) three times weekly. The oral vitamin A supplement proportionately reduced plasma and liver carotenoid concentrations by 0·49 and 0·41 respectively, while increasing liver vitamin A concentration three-fold. By contrast, the Vetade failed to increase liver vitamin A concentration or to reduce liver and plasma carotenoid concentrations. In experiment 2, two groups of steers were injected twice weekly for 7 weeks with 2 × 106i.u. vitamin A as Nov-A-Vit or as Vetade. A third treatment group, grazing with these steers, received no vitamin A injection, while a fourth group grazing in a separate area of the paddock was supplemented daily with 1 × 106i.u. vitamin A per head in their diet. The injection of Nov-A-Vit and the oral vitamin A supplement decreased PC concentration by a similar amount but the increase in liver vitamin A concentration was larger for steers injected with Nov-A-Vit. Vetade injections failed to increase liver vitamin A concentration and there was no decrease in PC concentration. The plasma cholesterol concentration for the treatment groups varied over the duration of the experiment but could not be related to the vitamin A treatment or to the changes in PC concentration. These results indicate that vitamin A injections can be used to reduce PC concentration provided they increase liver vitamin A concentration.
Limb injuries, immune response and growth performance of early-weaned pigs in different housing systems
Authors: Kelly H. R. C. , Bruce J. M. , Edwards S. A. , English P. R. , Fowler V. R.
Published: August 2016

The welfare of early-weaned pigs in different housing systems was examined using a range of indicators. Three replicates of 20 pigs were weaned at 6·4 kg live weight into either: (a) deep-straw; (b) Straw-Flow®; (c) large flatdeck; (d) small flatdeck. A kenneled lying area was provided in (a) and (b). The floor in (c) and (d) was expanded metal. Stocking densities were 0·23 m2 per pig in (a), (b) and (c) and 0·17 m2 per pig in (d). After 4 to 5 weeks (19·6 kg live weight), 16 pigs from each pen were moved into Straw-Flow grower pens (0·68 m2 per pig) and observed until slaughter at 90·6 kg. The remaining pigs were grouped together to examine the effects of mixing. At weaning, 24·1% of pigs had foot injuries. Pigs with foot injuries recovered quickly on deep-straw but the injuries increased in flatdecks immediately after weaning (Straw-Flow was intermediate). Injuries were more persistent in the small flatdeck. Deep-straw prevented adventitious bursitis of the hock. After 1 month in the grower pens, there was no residual treatment effect. Antibody response was examined by immune challenge with keyhole limpet haemocyanin (KLH). Immunoglobulin (Ig) response was greater in straw pens. Pigs mixed at 20 kg showed a decreased immune response to KLH challenge. Growth and food intake showed no treatment effects; food conversion ratio was poorer in (c) than in (b) or (d).
Conditioned feeding responses of sheep towards flavoured foods associated with casein administration: the rôle of long delay learning
Authors: Arsenos G. , Hills J. , Kyriazakis I.
Published: August 2016

The objective of two experiments was to investigate whether a delayed type of learning could account for the conditioned feeding responses of sheep towards novel food flavours associated with post-ingestive consequences (PIC) created from the administration at different points in time of a nutritive stimulus (casein). The doses of casein were low (15 g) and high (75 g) for experiments 1 and 2, previously known to result in positive and negative PIC respectively. Each experiment consisted of three conditioning periods, during which sheep were trained to associate one of two novel flavours with either casein or water (placebo) administration. During each conditioning, a novel flavoured food low in protein and relatively high in energy, was offered for 3 h (08:00 to 11:00 h) and was followed by an unflavoured, nutritionally similar food for the rest of the feeding time (11:00 to 17:00 h). Sheep were randomly assigned to one of three treatments that were defined by the time when casein or water doses were administered, in relation to the presence of the flavoured food (A= 08:30 and 10:00, B= 11:30 and 13:00 and С = 14:30 and 16:00 h respectively). At the end of each conditioning period preference tests were performed, where sheep were offered a choice between the two flavoured foods. There was no effect of time of casein administration on the conditioned responses towards flavoured foods in either experiment. In both experiments, the proportion of the flavoured food selected was significantly affected by the interaction between preference tests and casein association. For experiment 1 this was due to an increasing preference for the casein associated food accompanied by a decreasing preference for the water associated flavoured food as a result of repeated conditioning. The degree of such preference was different between flavours used for association with casein or water. For experiment 2 avoidance of the casein and preference for the water associated food were established after the completion of the second and reinforced by the third conditioning period. Flavours used had a lesser effect on the conditioned responses of this experiment. The results support the view that sheep develop conditioned responses towards novel food flavours associated with the administration of a nutritive stimulus, even when the PIC resulting from its administration are significantly disassociated in time from the presence of the flavoured food.
Genetic parameters of functional and fertility determined length of productive life in Swedish dairy cattle
Authors: Strandberg E. , Roxström A.
Published: August 2016

The objective of this study was to estimate genetic parameters and breeding values of sires for different definitions of length of productive life in Swedish Red and White dairy cattle. The data consisted of 534 016 daughters with initial calvings between 1988 and 1996. These cows were daughters of 1266 sires (55 of which were considered proven bulls, and treated as fixed effects). The model for the hazard included: a random time-dependent effect of herd-year-season (hys), a fixed time-dependent effect of year-season, a fixed time-dependent effect of parity by stage of lactation, a fixed time-dependent effect of the cow’s peak yield as deviation from her herdmates in that herd-year, a fixed time-independent effect of age at first calving, and random and fixed effects of sire. The hys effect was assumed to follow a gamma distribution and the random sire effect a normal distribution with mean zero and variance Aσ2s, where σ2s is the variance among sires and A the relationship matrix. Length of productive life was defined as the number of days from first calving to culling or end of data. Two types of length of productive life were studied: (1) functional productive life (PL), all cows that were culled before the end of data were considered as uncensored; (2) fertility determined productive life (FPL), only cows that were culled for fertility problems were considered as uncensored. Heritability estimates were 6·9% and 6·1% for PL and FPL, respectively. The approximated genetic correlation estimates between fertility measures in first lactation and FPL was higher than the corresponding estimates with PL. In conclusion, it was feasible to use the trait fertility-determined length of productive life, its heritability was almost as large as for PL, and the genetic correlation with fertility was higher than for PL. However, the expected selection response in fertility from indirect selection on FPL was lower than from direct selection.
Influence of environmental enrichment on welfare-related behavioural and physiological parameters in growing pigs
Authors: Beattie V. E. , O’Connell N. E. , Kilpatrick D. J. , Moss B. W.
Published: August 2016

Three hundred and twenty pigs were reared from birth to slaughter at 21 weeks in either barren or enriched environments. The barren environments were defined as intensive housing (slatted floors and minimum recommended space allowances) and the enriched environments incorporated extra space including an area which contained peat and straw in a rack. Behavioural observations showed that environmental enrichment reduced time spent inactive and time spent involved in harmful social and aggressive behaviour (P< 0·001). Each pig was individually exposed to a novel object during a novel pen test at 18 weeks of age and behavioural, heart rate and plasma cortisol responses were recorded. At slaughter plasma cortisol levels were measured, adrenal glands were weighed and hearts were examined for endothelial haemorrhages. Pigs from enriched environments appeared less fearful during the novel pen test by showing a shorter latency to contact the novel object (P< 0·001) and spending more time in contact with it (P< 0·05). Plasma cortisol responses to the novel pen test tended to be higher in pigs from enriched environments (P> 0·05) and pigs from enriched environments had significantly higher cortisol levels at slaughter (P< 0·05). Adrenal weights were greater in pigs from barren environments (P< 0·05) and it is suggested that chronic activation of the pituitary-adrenal axis in barren environments led to a suppression of cortisol responses to acute stress. The higher cortisol responses to the novel pen test in pigs from enriched environments may also have resulted from greater levels of behavioural activity. This could also explain the higher maximum heart rates in pigs from enriched environments during the 1st min of the test (P< 0-05) and during the period prior to the test when they were being driven towards the test arena (P< 0-05). However, the fact that enriched pigs also showed a greater number of lesions to the endothelium of the heart (P< 0-05) may mean they had a more reactive sympathetic nervous system.
Roughage as additional rooting substrates for pigs
Authors: Olsen A. W. , Vestergaard E.-M. , Dybkjær L.
Published: August 2016

Straw is frequently supplied as a rooting material to improve the welfare of pigs. In Denmark, organically raised slaughter pigs must have access to both straw and roughage. In order to evaluate whether roughage can he used as an appropriate rooting substrate for pigs, the effects of six different roughage types on pigs’ behaviour was examined. Pairs of 11-week-old pigs were placed in specially designed 4 m2pens. Each pen contained a self-feeder for cereal, a water bowl, a box for roughage, a straw- bedded area and a dunging area. Four replicates were carried out, each consisting of seven pairs of pigs. In each replicate, each pair of pigs was supplied with either whole-crop silage of oats, vetch and lupin (Avena sativa, Vicia sativa, and Lupinus luteus(OVL), whole-crop silage of barley and peas (Hordeum vulgare and Pisum sativum ssp. arvense) (BP), whole-crop silage of clover and grass (Trifolium repens and Lolium perenne(CG), green grass meal (Poassp.) (GM), hay of clover and grass (Trifolium repens and Lolium perenne(H), fodder beets (Beta vulgarisssp. vulgaris) (B), or no roughage (the control treatment) (CON). The pigs manipulated OVL for longer than the other roughage products (P< 0·01). When OVL was omitted from the analysis, B was manipulated for longer than CON (P< 0·05). The pigs that were offered CON manipulated equipment for a longer time than pigs offered B (P< 0·05) and tended to manipulate equipment for longer than pigs offered OVL (P= 0·065). Interestingly, OVL and B were the two products with the lowest dry-matter content. It may suggest that the amount of time spent manipulating roughage will depend considerably on the specific characteristics of the roughage offered, for instance dry matter content and complexity but probably also texture, smell and taste. In addition, the time spent manipulating other elements in the pen will depend on the type of roughage offered. In conclusion, the present study shows that some, but not all, types of roughage are suited as an enrichment of the pig’s environment.
Growth and development of testes in domesticated and hybrid (wild x domesticated) yak bulls
Authors: Ping Yan , Heping Pan , Dejuan Zhi
Published: August 2016

Testicular tissue was studied in domesticated yak and in wild yak x domesticated yak (F1 and F2) bulls at 6, 12, 18 and 24 months of age by stereology for quantitative histology and by comparative studies on the lactate dehydrogenase (LDH) isoenzyme spectrum, LDH activity and the percentage content of LDH isoenzymes in testes. The results indicated that all three types of yak were similar in both the characteristics of ultrastructure of testicular tissue and the degree of germ cell development. The process of spermatоgenesis was initiated and sperm were produced for the first time at the age of 12 months in all three yak types. All yak types exhibited similar age-related increases in weight of testes, volume density of both the seminiferous tubules and seminiferous epithelium and height of seminiferous epithelium but all these indexes were slightly affected by season. The number of LDH isoenzyme bands after electrophoresis varied with age as follows: four bands were present at 6 months of age, five bands at 12 and 18 months and six bands at 24 months of age. The sixth band was LDH-x, which appeared between the LDH4 and LDH5 band. These results indicated that yak bulls reach sexual maturity at 24 months of age and that puberty is not affected by infusion of wild strains.
Effect of organic matter digestibility on obligatory faecal phosphorus loss in lactating goats, determined from balance data
Authors: Rodehutscord M. , Heuvers H. , Pfeffer E.
Published: August 2016

Obligatory faecal phosphorus (P) losses in ruminants are commonly regarded as depending on dry-matter (DM) intake. This study was designed to investigate whether it is the digestible or the indigestible fraction of the diet which causes the obligatory faecal P loss. Three groups of six lactating goats each were given a diet consisting of maize silage, chaffed barley straw and a low P concentrate achieving a DM intake of 1·76 kg/day. Goats of two groups were given approximately 0·4 kg/day supplementary DM either in the form of sawdust or in the form of potato starch. Organic matter digestibility, determined by difference, was 0·15 for sawdust and 0·79 for potato starch. Goats were kept in balance crates and milk as well as faeces and urine were quantitatively collected. P intake was 2·9 g/day in unsupplemented goats and slightly higher (3·2 and 3·0 g/day, respectively) when sawdust or starch were supplemented. Urinary P output was very low (23 mg/day) and not affected by treatment. Milk yield and milk P output were 2·5 kg/day and 2·4 g/day, respectively, and not affected by treatment either. Compared with the goats without supplementary DM, faecal P output was higher in goats given supplementary starch but not in goats given supplementary sawdust. Increase in faecal P output due to starch supplementation exceeded the increase in P intake from starch by more than a factor of 4. When related to DM intake, faecal P excretion was significantly different between treatments (P = 0·058). The variation between treatments became even greater when faecal P output was related to indigestible organic matter intake (P < 0·001). When related to organic matter intake, however, differences in faecal P output between treatments were not significant (P = 0·445). It is concluded, that obligatory faecal P losses depend on the digestible fraction of the diet rather than on the indigestible fraction.
Effects of dietary vegetable oil inclusion and composition on the susceptibility of pig meat to oxidation
Authors: Rey A. I. , López-Bote C. J. , Kerry J. P. , Lynch P. B. , Buckley D. J. , Morrissey P.
Published: August 2016

This investigation was designed to evaluate the effects of the dietary inclusion of vegetable oil and its composition on fatty acid composition and lipid oxidation in pig muscle. Pigs were given the following diets from 50 kg to slaughter (90 kg): a control diet with no added fat (NF) or diets containing 20 g/kg of sunflower (SUN), olive (OL) or sunflower + linseed (SUN + LIN) oils. Meat from pigs given the SUN + LIN diet showed the highest thiobarbituric acid reactive substances (TBARS) from day 3 of refrigerated storage to the end of the experiment (P< 0·05). The OL group showed the lowest TBARS after 9 days of storage (P< 0·05). Pigs on NF showed intermediate values that were generally closer to those recorded for pigs given the SUN + LIN than the OL diet. By day 9, there was no statistical difference between the NF and the SUN + LIN group. The SUN group also showed intermediate TBARS throughout storage, with no statistical differences compared with the NF group. After 9 days of storage the lowest CIELAB a* value, corresponded to the SUN + LIN group and the highest to the OL group. These results indicate similar behaviour to that of lipid oxidation. Meat samples from pigs given the diet not enriched with fat showed greater drip loss than those given the remaining diets (P< 0·05) while there was no significant effect of dietary fat source on water-holding capacity. The inclusion of oils rich in linoleic fatty acids in pig diets modifies muscle fatty acid composition but susceptibility to lipid oxidation does not appear to be increased with respect to that occurring in pigs given diets with no added fat.
Impact of allosucking on growth of farmed red deer calves (Cervus elaphus)
Authors: Bartoš L. , Vaňkovà D. , Hyànek J. , Šiler J.
Published: August 2016

It is generally presumed that allosucking brings benefits to the allosucking infants. Nevertheless, the data supporting such a presumption are rare. The aim of the study was to determine whether allosucking has any impact on growth rates of the allosucking calves. Fifty pregnant hinds were observed between 28 May (1st day of calving) and 2 September (abrupt weaning of all calves) on a red deer farm at Vimperk, South Bohemia, the Czech Republic. Of the 50 calves born the growth curve was calculated for 39 calves. During their 1st month of life these calves were observed in 1015 sucking bouts. In 690 cases the calves sucked from maternal hinds and in 325 cases non-maternal hinds. Only 25·64% of calves sucked exclusively from maternal hinds. The prevailing type of sucking behaviour was a combination of sucking from maternal hinds and allosucking (74·36%). Calves sucking from maternal and non-maternal hinds showed 1·6-fold higher sucking frequency than did calves feeding from maternal hinds only. Our results indicate that to some extend allonursing behaviour of the hind may affect their calves’ feeding behaviour. The more non-filial calves the maternal hind nursed, the higher frequency of the sucking by their calves occurred. The groups of calves did not differ in birth weight. With increasing age, the relative body weight increased faster in calves sucking maternal hinds only than in calves sucking maternal and non-maternal hinds. This gain in body weight was not essentially influenced by the fact whether or not the calf’s maternal hind nursed non-filial or exclusively filial calves. However, at weaning (99 days), the lowest body weight occurred in allosucking calves whose maternal hinds were allonursing. The results suggest that allosucking does not mean an extra profit to the allosucker. Instead, in our subjects, allosucking was rather attributed to compensation of nutritional requirements based on a combination of various factors, such as discrete differences in body weight at birth and also later and allonursing of the maternal hind.
Modelling the effect of high, constant temperature on food intake in young growing pigs
Authors: Collin A. , Milgent J. van , Dividich J. Le
Published: August 2016

Performance in pigs is greatly reduced during periods of heat stress through a reduction in voluntary food intake (VFI). However, little information is available as to what extent growth in piglets is affected by high temperature. The objective of this study was therefore to quantify the change in VFI as affected by environmental temperature. Piglets, initially 15·5 (s.e. 1·9) kg body weight (BW), were individually housed and exposed over a period of 17 days to either 19, 21, 23, 25, 27, 29, 31, 33, or 35ºC. Animals had ad libitum access to a starter diet and water. VFI was measured daily whereas BW was determined twice weekly. Over the 17 days, daily VFI and BW gain were proportionately 0·48 and 0·51 lower at 35ºC than at 19ºC. Due to the reduced VFI at high temperatures, the average BW during the experiment was greater at low temperatures than at high temperatures. Consequently, part of the difference in VFI is directly due to temperature and part may be explained by cascading, indirect effects (i.e. the increased BW). To account for this, VFI was expressed as a power function of BW (VFI = aBWb). It was assumed that environmental temperature affected the scalar (a) through a quadratic or a ‘plateau-linear decline’ function of temperature. The VFI appeared relatively constant between 19 and 25ºC (0·096 (kg/day)/(kg BW0·83)) and decreased thereafter. Between 25 and 35ºC, VFI decreased on average by proportionately 0·28 in a 20-kg pig.
Relationship between litter size and perinatal and pre-weaning survival in pigs
Authors: Lund M. S. , Puonti M. , Rydhmer L. , Jensen J.
Published: August 2016

The objective of this study was to analyse the relationship between direct and maternal genetic effects on litter size and piglet survival. The analyses were performed on records from 26 564 Landrace litters and 15 103 Yorkshire litters from first parity dams in Finnish herds. The trivariate model fitted total number of piglets born, proportion alive at birth and proportion survived from birth until 3 weeks as traits of the litter. The model included direct genetic and maternal genetic effects for all traits. In Landrace pigs, maternal heritabilities were estimated to be 0·11 for total number born, 0·06 for proportion alive at birth, and 0·08 for proportion survived from birth until 3 weeks. The corresponding estimates for the Yorkshire breed were 0·14, 0·06 and 0·01. All heritability estimates of direct effects were below 0·05. In the Landrace breed, there was a negative correlation of -0·39 between maternal genetic effects on total number born and maternal genetic effects on proportion survived from birth until 3 weeks and a negative correlation of -0·41 between direct and maternal genetic effects on proportion survived from birth until 3 weeks. These correlations were not significant in the Yorkshire breed. The results show that selection for number born in total alone will lead to a deterioration in the maternal ability of sows. Selection for pre-weaning survival could be achieved by selecting on direct and maternal components jointly.
Effects of high fat rapeseed press cake on growth, carcass, meat quality and body fat composition of leaner and fatter pig crossbreeds
Authors: Schönet F. , Tischendorf F. , Kirchheim U. , Reichardt W. , Bargholz J.
Published: August 2016

A 3 ✕ 2 factorial experiment with a total of 60 male castrated pigs, live-weight range 24 to 104 kg, was carried out to test three dietary levels of high fat rapeseed press cake in two crossbreeds differing in carcass lean. The six groups with 10 pigs each representing either crossbreeds of Landrace (LR) ✕ (LR ✕ Large White (LW)) (groups 1, 3 and 5) or Pietrain (Pi) ✕ (LR ✕ LW) (groups 2, 4 and 6) were each offered, ad libitum, diets without rapeseed press cake (groups 1 and 2), or with rapeseed press cake: 75 g/kg diet (groups 3 and 4) or 150 g/kg diet (groups 5 and 6). The press cake produced in a small oil press contained 341 g crude protein per kg dry matter (DM), 181 g ether extract per kg DM and 23·3 mmol glucosinolates per kg DM. Rapeseed press cake, particularly at 150 g (3·2 mmol glucosinolates) per kg diet, lowered food intake and weight gain, though only significantly in the Pi-sired hybrids. There were no effects of the diets on leanness, whereas the 550 g/kg of carcass lean of Pi-sired pigs was significantly higher than the 510 g/kg of LR-sired hybrids. Meat of the Pi-sired crossbreeds showed a lower pH (tendency), higher conductivity, lower impedance and higher drip loss. At 150 g/kg diet rapeseed press cake LR-sired crossbreeds showed the darkest meat and the Pi ✕ LR, LW hybrids the lowest sensory evaluation score. In LR-sired hybrids the rapeseed press cake diets increased the backfat polyunsaturated fatty acids (PUFA) to a lower degree (1·3% per 10 g rape oil increase in 1 kg diet) than in Pi-sired hybrids (2·6% per 10 g rapeseed increase in 1 kg diet). Using simple correlation coefficients, the sensory evaluation results were negatively correlated with carcass lean and tended to be so with meat fat PUFA content. Pigs should receive less than 2 mmol glucosinolates per kg diet corresponding to 50 to 100 g double zero rapeseed products per kg diet. Rape oil should be recommended according to the animals lean and fat status, respectively. Fatter pigs may receive a maximum of 40 g, leaner pigs a maximum of 20 g rape oil per kg diet.
Effects of level of concentrate supplementation on grazing behaviour and performance by lactating dairy cows grazing continuously stocked grass swards
Authors: Gibb M. J. , Huckle C. A. , Nuthall R.
Published: August 2016

The effect of level of concentrate supplementation on the grazing behaviour of lactating Holstein-Friesian cows was examined over three periods on continuously stocked grass swards maintained between 7 and 8 cm sward surface height (SSH). A dairy concentrate containing 180 g crude protein per kg fresh weight was offered at 0, 1·2, 2·4, 3·6, 4·8 or 6·0 kg fresh weight per day in two equal feeds during milking. Grazing and ruminating behaviour was recorded automatically over 24 h using sensors to measure jaw movements. Intake rates were calculated by weighing cows before and after approximately 1 h of grazing, retaining the faeces and urine excreted and applying a correction for insensible weight loss. Details of jaw movements were also recorded during these grazing periods. Level of supplementation did not significantly affect short-term intake rate of herbage or total eating time during grazing over the day, which varied between 15 and 21 g organic matter per min and between 530 and 600 min/day respectively. Supplementation had no effect on ruminating behaviour. Increasing the level of supplementation produced a significant linear increase in milk yield. The results show that at the level of grass intake achieved on continuously stocked swards maintained at 7 to 8 cm SSH, daily intake of up to 6 kg concentrates does not significantly affect grazing behaviour or lead to substitution of the grazed herbage.
Estimates of (co)variances due to direct and maternal effects for body weights in Timahdite sheep
Authors: Boujenane I. , Kansari J.
Published: August 2016

Genetic parameters for body weights in Timahdite sheep were estimated using records of 10370 lambs from the ‘Société Nationale de Développement de l’Elevage’ born in 1988-89 to 1998-99. An animal model with derivativefree restricted maximum likelihood procedures was used. Random effects were direct and maternal additive genetic, maternal permanent environmental, and error. Direct and maternal heritability estimates were 0·05 and 0·05 for birth weight, 0·02 and 0·07 for weight at 30 days, 0·07 and 0·08 for weight at 70 days, 0·06 and 0·01 for weight at 90 days. Estimates of fraction of variance due to maternal permanent environmental effects were close to zero, except for weight at 90 days. Genetic correlations between direct and maternal genetic effects were –0·55, –0·51, –0·50 and –0·17 for body weights at birth, 30, 70 and 90 days, respectively. Estimates of direct genetic correlations among body weights were positive and high, ranging from 0·69 to unity. Phenotypic correlations were positive and moderate to high, being lower than their corresponding direct genetic correlations. Estimates of correlations between maternal genetic effects among weights were positive and high, varying from 0·79 to unity. Cross-correlations between direct genetic effects for one weight and maternal genetic effects for another weight were consistently negative, ranging from –0·05 to –0·63. These results indicate that selecting for improved maternal and/or direct effects in Timahdite sheep is expected to generate only slow genetic progress in terms of early growth.
Differences in the somatotropic axis, in blood cortisol, insulin and thyroid hormone concentrations between two pig genotypes with markedly divergent growth rates and the effects of growth hormone treatment
Authors: Elsaesser F. , Pfaffl M. W. , Meyer H. H. D. , Serpek B. , Sauerwein H.
Published: August 2016

The intention of the current study was to gain more insight into the endocrine and molecular control mechanisms of growth in the pig. For this purpose various growth related parameters were determined in 4-month-old barrows of two extreme pig genotyes, the small, obese Göttingen Miniature (GM) and the large and lean German Landrace (DL). Mean growth hormone (GH) concentration, GH pulse frequency and GH pulse amplitude did not differ between breeds. Likewise, plasma IGF-1, thyroxine, tri-iodothyronine (T3) concentrations were similar in both breeds. However the plasma GH response (maximum level and area under curve) to a single i.v. injection of GHRH in DL was higher than in GM (P < 0·05). Furthermore, basal plasma insulin and in particular plasma cortisol concentrations were higher in GM compared with DL pigs (P 0·05 and 0·01 respectively). Analysis of cortisol during 4-h frequent blood sampling indicated higher cortisol amplitudes in GM compared with DL (P ≤ 0·01). Specific bGH-binding to hepatic membrane preparations was not different between breeds and IGF-1 m RNA concentrations determined by reverse transcription-polymerase chain reaction in liver, m. semimenbranosus and m. longissimus dorsi were similar in both breeds. I.m. treatment with recombinant porcine somatotropin (rpST; 70 µg/kg live weight) over an 8-day period in contemporary barrows increased without any breed difference, plasma IGF-1, T3 and insulin concentrations and hepatic specific bGH-binding, but did not affect thyroxine or cortisol concentrations in plasma. IGF-1 gene expression was also elevated in liver and muscle tissues in rpST-treated animals without obvious breed effects. The observations underline the complexity of the hormonal and molecular control of growth and support the notion that differences in growth potential are the consequence of differences at various levels of the somatotropic axis and apparently relate to differences in other control systems of energy metabolism such as the pituitary adrenal axis or the endocrine pancreas as well.
The relationship between adipose tissue skatole levels, rates of hepatic microsomal skatole metabolism and hepatic cytochrome P450IIE1 expression in two breeds of pig
Authors: Doran E. , Whittington F. W. , Wood J. D. , McGivan J. D.
Published: August 2016

The relationships between the level of skatole in backfat, the rate of skatole metabolism in isolated liver microsomes, hepatic cytochrome P450IIE1 content and mRNA levels were investigated in Large White ✕ Landrace (LW) and the Meishan ✕ Landrace (M) breeds. A method based on thin layer chromatography was developed and used for measurement of microsomal skatole metabolism. Skatole metabolism by liver microsomes was inhibited by diallyl sulphide, a specific inhibitor of cytochrome P450IIE1 but not by inhibitors of other P450 isoforms. We have shown that the rate of skatole metabolism by liver microsomes was proportional to the microsomal P450IIE1 content. In LW pigs there was considerable variation in cytochrome P450IIE1 expression and P450IIE1 protein level and there was a significant negative correlation between backfat skatole level and hepatic microsomal cytochrome P450IIE1 content. Pigs exhibiting low P450IIE1 content in general also showed low levels of P450IIE1 mRNA. These results show that the levels of deposition of backfat skatole in LW pigs are inversely related to the rate at which skatole can be metabolized by liver microsomes, and this in turn depends on the level of expression of cytochrome P450IIE1 mRNA in the liver. In the M breed generally the P450IIE1 protein and mRNA levels were very low and backfat skatole level was high. However the skatole level varied over a 10-fold range and there was no significant correlation with P450IIE1 protein or mRNA content. The M breed was shown to express high levels of the multidrug resistance protein in liver, and it is suggested that export of skatole from liver via this transport protein may be an additional factor regulating backfat skatole in M pigs, but not in the LW breed.
Response of beef heifers and non-suckling beef cows to different oestrous synchronization protocols
Authors: Cavestany D. , Negrin N. , Negrin R. , Groth J. F.
Published: August 2016

The objective was to evaluate different oestrous synchronization schemes in beef cattle under range conditions. In experiment 1, 202 heifers averaging 26 months of age were assigned randomly to three treatments: (a) GnRH-PG. (no. = 44) day 0 (D0): injection of GnRH; D7: injection of PGF2α; D0 to D25 oestrous detection (OD) and artificial insemination (AI); (b) OD-PG. (no. = 45) D0 to D4; OD + AI; D5: injection of PGF2α; D5 to D25 OD + AI; and (c)Ovsynch. (no. = 113) D0: injection of GnRH; D7: injection of PGF2α; D9: injection of GnRH and 16 h later AI at fixed time. In experiment 2, 318 non-suckling cows were assigned randomly to three treatments: (a) GnRH-PG. (no. = 106) D0: injection of GnRH; D7: injection of PGF2α; D0 to D25 OD + AI; (b) GnRH-MAP-PG. (no. = 106) D0: injection of a GnRH analogue and insertion of an intravaginal sponge impregnated with 250 mg of medroxyprogesterone acetate; D7: injection of PGF2α and sponge withdrawal; D0 to D25 OD + AI; (c) controls. (no. = 106) OD and AI. The experimental period lasted 25 days and, with exception of the Ovsynch treatment, oestrous detection was carried out twice a day (a.m./p.m.) and inseminations performed 12 h later. The pregnancy rates assessed by ultrasonography 30 days after AI were: experiment 1: (a) 30·0%; (b) 28·6% and (c) 62·3% (P < 0·05); experiment 2: (a) 60·2%; (b) 57·8% and (c) 45·5% (P < 0·05). It is concluded that in heifers and non-suckling cows, oestrous synchronization treatments result in higher pregnancy rates. In non-suckling cows, the addition of a progestagen did not improve the response.
Single and multitrait estimates of breeding values for survival using sire and animal models
Authors: Meuwissen T. H. E. , Veerkamp R. F. , Engel B. , Brotherstone S.
Published: August 2016

Survival data were simulated under the Weibull model in a half-sib family design, and about 50% of the records were censored. The data were analysed using the proportional hazard model (PHM) and, after transformation to survival scores, using a linear and a binary (logit) model (LIN and BIN, respectively), where the survival scores are indicators of survival during time period t given survival up to period t – 1. Correlations between estimated and true breeding values of sires (accuracies of selection) were very similar for all three models (differences were smaller than 0·3%). Daughter effects were however less accurately predicted by the LIN model, i.e.taking proper account of the distribution of the survival data yields more accurate predictions of daughter effects. The estimated variance components and regressions of true on estimated breeding values were difficult to compare for the LIN models, because estimated breeding values were expressed as additive effects on survival scores while the simulated true breeding values were expressed on the underlying scale. Also the differences in accuracy of selection between sire and animal model breeding value estimates were small, probably due to the half-sib family design of the data. To estimate breeding values for functional survival, i.e. the component of survival that is genetically independent of production (here milk yield), two methods were compared: (i) breeding values were predicted by a single-trait linear model with a phenotypic regression on milk yield; and (ii) breeding values were predicted by a two-trait linear model for survival and milk yield, and breeding values for survival corrected for milk yield were obtained by a genetic regression on the milk yield breeding value estimates. Both methods yielded very similar accuracies of selection for functional survival, and are expected to be equivalent.
The effects of intradermal injections of spermidine on the growth rate of fibres and mitosis of wool follicles in Merino lambs
Authors: Liu S. M. , Murray A. , Schlink A. C. , Mata G. , Masters D. G.
Published: August 2016

Polyamines (putrescine, spermidine and spermine) are required for optimal growth in all cells, and are essential for cell proliferation and growth of cultured wool follicles, with an optimal concentration of spermidine required for the fibre elongation. The effects of a local supply of exogenous spermidine on the rate of cell division in the wool follicles, the length growth rate and diameter of fibres were therefore examined in Merino lambs. Three groups of eight lambs (40 kg) were given food at 1·2 ✕ maintenance. Spermidine was injected intradermally into a small patch (3 ✕ 3 cm) on the left flank three times per day for 7 days at one of three concentrations: 1·38, 2·75 or 4·58 џmol in 0·8 ml volume. The same volume of saline was injected into the contralateral side as a control. The concentration of spermidine in the skin patch 3 h after injection on day 7 increased by proportionately 018, 0·33 or 0·41 (P < 0001) respectively. The rates of cell division in the follicle bulb 3 h after the spermidine injection were proportionately 0104, 0184 and 0·283 higher compared with the contralateral side (P = 0078 overall) for the low, medium and high doses of spermidine respectively and differed between the three doses (P < 005). The fibre length growth rate, as measured using autoradiography, was proportionately 0099, 0117 and 0156 higher than that of the contralateral side (P < 0001 overall) for the low, medium and high doses of spermidine respectively, but differences between doses were not significant (P > 005). Spermidine injection did not result in a significant change in fibre diameter during the treatment period. The ratio of fibre length growth rate to fibre diameter was increased by the injection of spermidine (P < 0001). The results suggest that injecting extra spermidine into the skin altered spermidine homeostasis in the skin, stimulated cell proliferation and resulted in increased fibre growth.
Sow behaviour and welfare in voluntary cubicle pens (small static groups) and split-yard systems (large dynamic groups)
Authors: Durrell J.L. , Sneddon I.A. , Beattie V.E. , Kilpatrick D.J.
Published: August 2016

The welfare of sows kept in two different group housing systems, namely voluntary cubicle pens housing small static groups and a split-yard housing system housing a large dynamic group, were examined. Each week, four newly weaned sows were introduced into either a voluntary cubicle pen or the split-yard system, with a total of eight groups of four sows introduced into each system. Behavioural and skin lesion data were recorded during the sows’ first 5 weeks in either system. Agonistic behaviours were performed more frequently during week 1 than in subsequent weeks in both housing systems (P < 0001). Sows in the voluntary cubicle pens spent more time standing inactive (P < 0001) and spent less time in exploratory (P < 005) and locomotory (P < 001) behaviours. However, sows in the split-yard system had higher skin lesion scores (P < 001) and engaged in more social (P < 005) and agonistic interactions (P < 005). These agonistic interactions included attacks (P < 005) and fleeing (P < 0001) throughout the 5-week observation period and fighting (P < 0001) during week 1 only. The split-yard system, therefore, appeared to offer sows a more stimulating social and physical environment than the voluntary cubicle pens, but also led to higher levels of aggression and skin damage. Both housing systems, therefore, appear to compromise sow welfare in different ways.
Effect of social group size and initial live weight on feeder space requirement of growing pigs given food ad libitum
Authors: Turner S.P. , Dahlgren M. , Arey D.S. , Edwards S.A.
Published: August 2016

Feeder space allowance should be sufficient to ensure adequate access to food for all group members, irrespective of competitive ability. However, the influence of social group size on minimum feeder space requirement of pigs given food ad libitum is poorly understood. Performance, aggression and feeding behaviour were assessed over a 6-week period from 29·3 (s.e. 0·19) kg live weight, using four replicates of a 2 ✕ 2 factorial design with two group sizes (20 v. 80) (small and large) and two feeder space allowances (32·5 v. 42·5 mm per pig) (low and high). Food intake was significantly lower in the low feeder space allowance treatments (1·44 v. 1·56 (s.e.d. 0·050) kg per pig per day, P < 0·05) and group mean growth rate was reduced in the later phase between 41 and 56 kg live weight. There was no main effect of group size or interactive effect between group size and feeder space allowance on performance. Mean skin lesion score and the frequency of aggression given or received at the feeders was unaffected by treatment. Heavy weight pigs showed similar feeding behaviour in each treatment, but light pigs visited the feeder more frequently in groups of 20 (23·1 v. 16·0 (s.e.d. 2·04) visits per pig per day, P < 0·05) and spent the greatest time feeding when at a low feeder space allowance (5461 v. 4397 (s.e.d. 288·8) s per pig per day, P < 0·05). To avoid a depression in growth rate, pigs >40 kg should be allocated a minimum feeder space allowance of 42·5 mm per pig. There was little indication of a need to specify differential feeder space allowances according to group size.
The combined effects of animal species (sheepversuscattle) and level of feeding on digestible and metabolizable energy concentrations in grass-based diets of cattle
Authors: Yan T. , Agnew R. E. , Gordon F. J.
Published: August 2016

A total of 317 dairy and beef cattle, offered grass silage-based diets, have been subjected to energy metabolism measurements in calorimetric chambers in 11 feeding experiments at this Institute. In addition the silages (no. = 33) were also given individually to sheep as a sole food at maintenance feeding level for measurement of energy intake and outputs (faeces and urine). The digestible (DE) and metabolizable (ME) energy concentrations of mixed diets for sheep at maintenance were estimated using these measured silage data, predicted silage methane energy output and tabulated energy values of concentrates. The objective of the present study was to use treatment mean data (no. = 59), derived from the cattle (production level) (MEprod or DEprod) and the sheep (maintenance level) (MEmaint or DEmaint), to evaluate the combined effects of animal species and level of feeding on dietary ME or DE concentration. The mean-square prediction error technique and the sensitivity test both indicated that there was little bias derived from the deviation of the slope (line bias) when relating MEprod (DEprod) with cattle to MEmaint (DEmaint) with sheep. Relating feeding level to the decline in ME or DE concentration (from maintenance to production level) revealed that the constant had no significant effect on the relationship, suggesting that there was little difference in dietary ME or DE concentration between sheep and cattle when given food at maintenance. ME d and DE d were significantly related to MEmaint and DEmaint (P < 0001) respectively. These two relationships were however influenced (P < 0001) by level of feeding above maintenance (FL-1). There was little effect of silage DM proportion in the total diets (S/T) on the depression of ME concentration from maintenance to production levels, while this effect on the depression of DE concentration was significant (P < 0001). Therefore, the following two equations are recommended to calculate MEprod and DEprod concentrations respectively for cattle using data obtained with sheep at maintenance. Alternatively, with each unit increase in feeding level above maintenance, dietary ME and DE concentrations respectively were reduced by proportionately 0016 and 0025 for grass silage-based diets, irrespective of the effect of forage proportion on the latter. MEprod = [1 068 - 0019 ✕ (FL-1)] ✕ MEmaint - 0·755 DE d = [0·891 + (-0027 + 0018 ✕ S/T) ✕ (FL-1)] ✕ DEmaint + 1·355
Livestock nutrition and foodstuff research in Africa: when is a nutritional constraint not a priority research problem?
Authors: Sumberg J.
Published: August 2016

This paper examines a paradox at the centre of efforts to improve livestock production in sub-Saharan Africa. For decades livestock nutrition and animal food have been identified as critical constraints, yet producers have shown little interest in improved food technologies. The main argument is that the analyses highlighting nutrition and food as critical constraints have focused primarily on biological productivity, and are thus at odds with livestock producers’ perceptions. The paper concludes by suggesting that livestock research in Africa must taker greater account of different systems, situations and producers, as well as key characteristics of technology such as reliability and management flexibility.