The effect of feeder type and change of feeder type on growing and finishing pig performance and behaviour

Reduced feed intake and hence lower growth rates commonly occur when the environment of the pig changes, e.g. at weaning and when pigs are moved from growing accommodation to finishing accommodation. It is hypothesised that if environmental factors, such as feeder type, remain the same in the weaning and finishing accommodation this ‘growth check’ may be reduced. A total of 640 pigs in 32 pens of 20 pigs per pen were used to investigate the effects of two feeder types and changing or not changing the feeder type at 10 weeks of age on growth performance and behaviour in the periods from 4 to 10, 10 to finish (22) and from 4 to finish (22) weeks of age, respectively. The two feeder types tested were a ‘wet and dry’ single-space (S) feeder and a ‘dry’ multi-space feeder (M).In the period 4–10 weeks of age feeder type had no significant effect on growth performance though pigs on the ‘dry’ multi-space feeder tended to exhibit significantly better feed efficiency from 4 to 7 weeks of age. In the first week after changing accommodation the growth rate of pigs on all treatments was depressed (compared to the last 3 weeks of the grower period) and was reduced a further 60 g/day when the feeder type was changed. However, the “feeder” effect was transitory and had no effect on overall finisher performance except for pigs changed from a ‘dry’ multi-space feeder to ‘wet and dry’ single-spaced feeder. These animals had significantly faster growth rate over the finisher phase (P<0.05, 886 g/day) and between 4 weeks of age and finish (P<0.05, 730 g/day) than pigs on all other treatments. Feeder treatment had no significant effect on feed intake or feed efficiency in the finisher period or overall from wean to finish. Similarly, the treatments had no effect on the variation in growth rate. Behavioural observations showed that the average number of pigs at the feeder during the finishing period was significantly higher when feed was offered from treatment M–S (1.19 (freq/30 s), P<0.001). In conclusion, the present results suggest that, a change in feeder type, from a ‘dry’ multi-space feeder in growing accommodation to a ‘wet and dry’ single-space feeder in finishing accommodation appears to stimulate improved growth performance in the early finishing period and overall from weaning to finish.     

The effect of age at introduction and number of milk-portions on the behaviour of group housed dairy calves fed by a computer controlled milk feeder

This study is an investigation of the effect of age at introduction (6 days versus 14 days) and number of milk-portions (four milk-portions a day versus eight milk-portions a day) on integration into a large dynamic group of calves, fed by a computer controlled milk feeder. Forty calves (Jerseys, Danish Reds and Holstein-Friesians) were allocated equally to the two age conditions (A6 and A14) and the two milk-portion conditions (M4 and M8) in a 2 × 2 factorial design, according to sex and breed, and introduced into the group in pairs (one A6 and one A14). The behaviour of each pair was video-recorded for 8 h from 8 a.m. to 4 p.m. and 1 h from 1 to 2 a.m. on days 1, 8 and 15 after introduction.

The A6 calves performed less licking and sniffing, changed posture more often and tended to spend less time standing than the A14 calves. In the course of time A14 calves lay closer to other calves than the A6 calves.

The M8 calves, which were offered the same daily milk allowance as the M4 calves stood for a longer time in the milk feeding station and the M8 calves also sucked the empty teat more frequently than the M4 calves. Finally, the M8 calves initiated more social play behaviour than the M4 calves. On the first day after introduction the M8 calves lay closer to other calves than the M4 calves.

The results suggest that calves integrate better into a group when introduced at the age of 14 days than at the age of 6 days. Distributing the milk into eight daily milk-portions, rather than four milk-portions in the first period after introduction, increased milk feeder occupancy, which may facilitate learning to use the milk feeder. Surprisingly, more milk-portions also stimulated play behaviour, which is suggested to be due to M8 calves encountering more calves in the milk feeder area.     

Systemic and intraovarian effects of corpus luteum on follicular dynamics during estrous cycle in hair breed sheep

The present study aimed to determine systemic and local effects of corpora lutea (CL), on follicular dynamics throughout the estrous cycle. All follicles >or=2 mm and CL were assessed by daily transrectal ultrasonography in 12 West African ewes. Blood samples were collected to determine plasma concentration of progesterone. Fifteen estrous cycles were evaluated with a mean interovulatory interval of 16.8+/-0.2 days. Two (13.3%), 10 (66.7%) and 3 (20%) of the estrous cycles had 2, 3 and 4 waves of follicular development, respectively. In sheep with three waves of follicular development, both the length of growing phase and the growth rate of dominant follicles from midluteal wave II were diminished (3.4+/-0.3 days, P<0.0001, and 0.4+/-0.1 mm/day, P<0.01, respectively) when compared to follicles from early luteal phase (wave I, 4.1+/-0.2 days, and 0.7+/-0.1 mm/day) or late luteal phase (wave III, 6.3+/-0.4 mm and 0.6+/-0.1 mm/day). The diameter of the dominant follicle was smaller during the midluteal phase (3.9+/-0.1 mm, P<0.0001) than in the early and late luteal phase (5.0+/-0.2 and 5.7+/-0.2 mm; respectively). The effect of the dominant follicle was less during midluteal phase, because number of accompanying smaller follicles was fewer (P<0.01) in waves I and III (6.3+/-0.9 compared with 3.4+/-0.8 and 2.3+/-0.7). The number of follicles was also different between ovaries that had CL and those that did not. The total number of large follicles during the luteal phase was less in ovaries with CL (0.9+/-0.5 compared with 2.7+/-0.3; P<0.01), as was the mean daily number of both large (0.1+/-0.02 compared with 0.2+/-0.02; P<0.001) and total number of follicles >or=2 mm (2.5+/-0.1 compared with 3.3+/-0.1; P<0.01). Current results indicate that the presence of a functional CL may exert both systemic and local effects on the population of follicles, affecting the dominance exerted by large follicles.     

Evaluation of lamb performance and costs in motherless rearing of German Grey Heath sheep under field conditions using automatic feeding systems

Performance and costs were evaluated for 205 German Grey Heath lambs reared artificially under field conditions using three feeding and three weaning regimes. In phase 1 (pre-weaning), ad libitum feeding of milk replacer (MR) on an automatic lamb feeder was compared to restricted MR feeding on the modified calf feeder “Stand alone II^®” or with buckets. In phase 2 (after weaning at 12 kg body weight), abrupt weaning was compared to gradual weaning systems with reduction of the amount or the concentration of MR over 2 weeks. In phase 1, average daily gains (ADG) were highest in the Ad libitum group (0.262 ± 0.032 kg/d), followed by Bucket and Stand alone with 0.227 ± 0.036 kg/d and 0.209 ± 0.023 kg/d, respectively (P < 0.05). In contrast, feed conversion rate was best for group Stand alone (1.17:1), compared to 1.20:1 in group Bucket and 1.23:1 in group Ad libitum. In phase 2, abrupt weaning caused weight loss in lambs from the Ad libitum and Bucket groups, but not in group Stand alone. No post-weaning growth check was seen in lambs weaned gradually. In general, differences in body weight (BW) between groups were low, and on d 70, no significant difference was seen between feeding groups, whereas lambs weaned abruptly still had lower BW than lambs weaned by reducing the amount of MR (P < 0.05). Total lamb mortality was 3.9%, with no accumulation of infectious disease in any of the feeding or weaning groups. Economic analysis revealed that total costs in phase 1 were highest for group Stand alone (57–70 € per lamb), followed by the Bucket group (63 € per lamb). Although MR consumption was higher in the Ad libitum group, this method was the most cost-efficient (50–54 € per lamb), because purchase price of the feeder and labor costs were relatively low. In phase 2, gradual weaning systems added costs of 4.70–9.50 € per lamb. Our findings indicate that the most efficient way to rear 60–120 lambs artificially under field conditions is by using an automatic ad libitum lamb feeder followed by abrupt weaning.     

The effect of temporal variation in feed quality and quantity on the diurnal feeding behaviour of dairy cows

The diurnal feeding patterns of dairy cows affects the 24 h robot utilisation of pasture-based automatic milking systems (AMS). A decline in robot utilisation between 2400 and 0600 h currently occurs in pasture-based AMS, as cow feeding activity is greatly reduced during this time. Here, we investigate the effect of a temporal variation in feed quality and quantity on cow feeding behaviour between 2400 and 0600 h as a potential tool to increase voluntary cow trafficking in an AMS at night. The day was allocated into four equal feeding periods (0600 to 1200, 1200 to 1800, 1800 to 2400 and 2400 to 0600 h). Lucerne hay cubes (CP = 19.1%, water soluble carbohydrate = 3.8%) and oat, ryegrass and clover hay cubes with 20% molasses (CP = 11.8%, water soluble carbohydrate = 10.7%) were offered as the ‘standard’ and ‘preferred’ (preference determined previously) feed types, respectively. The four treatments were (1) standard feed offered ad libitum (AL) throughout 24 h; (2) as per AL, with preferred feed replacing standard feed between 2400 and 0600 h (AL + P); (3) standard feed offered at a restricted rate, with quantity varying between each feeding period (20:10:30:60%, respectively) as a proportion of the (previously) measured daily ad libitum intake (VA); (4) as per VA, with preferred feed replacing standard feed between 2400 and 0600 h (VA + P). Eight non-lactating dairy cows were used in a 4 × 4 Latin square design. During each experimental period, treatment cows were fed for 7 days, including 3 days habituation and 4 days data collection. Total daily intake was approximately 8% greater (P < 0.001) for the AL and AL + P treatments (23.1 and 22.9 kg DM/cow) as compared with the VA and VA + P treatments (21.6 and 20.9 kg DM/cow). The AL + P and VA treatments had 21% and 90% greater (P < 0.001) dry matter intake (DMI) between 2400 and 0600 h, respectively, compared with the AL treatment. In contrast, the VA + P treatment had similar DMI to the VA treatment. Our experiment shows ability to increase cow feeding activity at night by varying feed type and quantity, though it is possible that a penalty to total DMI may occur using VA. Further research is required to determine if the implementation of variable feed allocation on pasture-based AMS farms is likely to improve milking robot utilisation by increasing cow feeding activity at night.     

Effects of feeder layer and BRL conditioned medium on mouse embryonic stem cells

In vitro growth and maintenance of embryonic stem (ES) cell lines derived from ICM cells of various blastocysts of 129 strain mice,the sustenance of their pluripotency and normal karyotype depend on the feeder layer of mouse embryonic fibroblasts (MEF).Compared with the feeder layer of MEF cells,medium conditioned by Buffalo rat liver cells (BRL-CM) is able to maintain pluripotency and karyotypic normality of ES cells only in short term cell propagation.Besides,ES cells grown in BRL-CM are also capable of aggregation with 8-cell embryos of Swiss strain and develop into germ line chimaeras.Modification to the method of aggregating ES cells with early embryos by making a hole in agar layer on the top of MEF feeder cells was shown to be more converient and efficient than the conventional microdrop method.     

Stomach contents of Latimeria chalumnae and further notes on its feeding habits

Synopsis Stomach contents of three Latimeria chalumnae dissected in Japan support the hypothesis that the coelacanth is a predominantly nocturnal bottom or near-bottom drift feeder. Prey items identified in this study (Ilyophis brunneus, Cephaloscyllium sufflans and Beryx decadactylus) and those reported previously are mostly benthic or epibenthic dwellers. The drifting of the coelacanth in a headstanding posture would account for the easy capture of prey that moves within or just above the bottom strata at night.     

Trophic strategies and functional morphology of feeding appendages, with emphasis on setae, of Upogebia omissa and Pomatogebia operculata (Decapoda: Thalassinidea: Upogebiidae)

Although species of Upogebiidae historically have been considered filter feeders, recent studies show that many species of this group also deposit feed. In this study, the degrees of trophic specialization of two species of this family, Upogebia omissa and Pomatogebia operculata , were analysed. Feeding mechanisms, stomach contents and morphology of the feeding appendages, with emphasis on setae, were examined. U. omissa , found in sandy substrate, is a generalistic feeder while P. operculata inhabits burrows inside corals, being more specialized in filter feeding. Only 21% of the 57 setal types described were common to both species. Setal types were clustered in three main categories: plumed, serrate and plumodenticulate. No simple setae were found. P. operculata has lower setal diversity, with higher ratio of plumodenticulate to serrate setal types than U. omissa. The 1st and 2nd pereiopods have an important role in collecting food. The mouthparts have two main functions: to brush and retain particles so that food can be transported from the pereiopods to the mouth. Generally in these appendages, the dactyli and basal endites are responsible for brushing particles and the meri and coxal endites for particle retention. The diversity of setal types and complexity of their distribution on the appendages may be related to the necessity to select and triturate particles prior to ingestion, reflecting the differences in trophic strategies utilized by U. omissa and P. operculata. Setal characters appear to be indicators of the relative importance of a specific feeding mode for species of this group.     

Economic weights of fertility, prolificacy, milk yield and longevity in dairy sheep

Economic weights have been estimated in two breeds (Latxa and Manchega) using economic and technical data collected in 41 Latxa and 12 Manchega dairy sheep flocks. The traits considered were fertility (lambing per year), prolificacy (number of lambs), milk yield (litres) and longevity (as productive life, in years). A linear function was used, relating these traits to the different costs in the flock. The variable costs involved in the profit function were feed and labour. From this function, economic weights were obtained. Labour is considered in the Latxa breed to be a constraint. Moreover, farm profits are unusually high, which probably means that some costs were not included according to the economic theory. For that reason, a rescaling procedure was applied constraining total labour time at the farm. Genetic gains were estimated with the resulting economic weights to test if they give any practical difference. Milk yield only as selection criterion was also considered. The medians of the estimated economic weights for fertility, prolificacy, milk yield and longevity were 138.60 € per lambing, 40.00 € per lamb, 1.18 € per l, 1.66 € per year, and 137.66 € per lambing, 34.17 € per lamb, 0.73 € per l, 2.16 € per year under the linear approach in the Latxa and Manchega breeds respectively. Most differences between breeds can be related to differences in production systems. As for the genetic gains, they were very similar for all economic weights, except when only milk yield was considered, where a correlated decrease in fertility led to a strong decrease in profit. It is concluded that the estimates are robust for practical purposes and that breeding programmes should consider inclusion of fertility. More research is needed to include other traits such as somatic cell score, milk composition and udder traits.     

Ovarian and endocrine responses in tropical sheep treated with reduced doses of cloprostenol

The present study aimed to assess the efficacy of reduced doses of cloprostenol for synchronizing estrus and ovulation in hair sheep. With the aim to evaluate the luteolytic activity of reduced cloprostenol doses, a first experiment was performed using a relatively large (group H: 126 μg; n = 8), medium (group M: 68.25 μg; n = 6) and small (group L: 38.5 μg; n = 6) cloprostenol dose. Luteolysis was assessed at Days 3 and 6 after injection (Day 0) by progesterone concentrations (P₄) and transrectal ultrasonography (US). In Experiment 2, sheep were randomly assigned to the same three doses to evaluate a protocol for estrous synchronization using two injections administered 9 days apart. A third trial was performed with ewes treated (9 days apart) with the large dose (H = 126 μg; n = 12) and with a small dose adjusted for facilitating volume management (LA = 43.75 μg; n = 12). Presence of estrous cycling was determined in all the ewes by US and P₄ assay, at Days −9, −6, −2, 0 (Day of second cloprostenol injection), 8 and 11. Bleeding and US were done every 4 h from 16 h of the beginning of the estrus during the third trial to assess the preovulatory LH surge and timing of ovulation. Additionally, blood samples were drawn at Days 0, 1, 2 and 3 to assess estradiol (Experiments 2 and 3) and P₄ (Experiment 2) concentrations during the ovarian follicular phase. In all experiments, percentage of animals showing luteolysis, preovulatory follicular dynamics and function and percentage of ewes showing behavioral estrus in response to treatment was similar among groups. Timing of estrus for group H was earlier than group L (28.6 ± 1.8 h compared with 37.1 ± 2.4 h; P < 0.05). In the third trial, the preovulatory LH peak was higher in the LA group than group H, in terms of maximum mean concentration during the surge (27.7 ± 1.8 ng/mL compared with 21.3 ± 2.2 ng/mL; P < 0.05) and area under the curve (AUC; 183.4 ± 12.7 ng/mL compared with 127.7 ± 10.9 ng/mL; P < 0.01). However, timing of ovulation was similar for H and LA groups. Thereafter, ovulation rate and luteal function at Day 11 were similar. Current results demonstrate that reduced doses of cloprostenol may be applied in a practical manner for reproductive management of sheep, with the additional advantage of reducing treatment costs.     

The role of sediment type in growth and fecundity of mud snails (Hydrobiidae)

Summary We test the hypothesis that body size and population density of the deposit-feeding gastropod, Hydrobia truncata, are greater in muddy than in sandy habitats as a result of faster growth on fine- compared to coarse-grained sediments. We refute this hypothesis using a combination of field measurements and laboratory experiments. Three out of three populations tested had higher maximal growth rates and two of three populations approached their asymptotic size more quickly on sand than on silt-clay fractions of natural sediment. Growth decreased with increasing snail density and was as high or higher on sand as on silt-clay at all densities. Two populations were more fecund on sand than on silt-clay, and fecundity of the third population was not affected by sediment type. We show that the smaller body sizes observed in snails from the sandiest habitat result from late recruitment of these snails, relative to the other populations.     

Effects of culture density,conditioned medium and feeder cultures on microspore embryogenesis in Brassica napus L. cv. Topas

Summary In microspore cultures of Brassica napus L. cv. Topas, embryo yield increases with culture density up to about 40,000 microspores per ml. A much higher density (100,000 per ml) appears inhibitory to embryogenesis. A relatively high culture density (30,000 or 40,000 per ml) for the first 2–4 days of culture is crucial for embryogenesis, after which cultures may be diluted to allow better embryo growth.Medium conditioned by culturing microspores at 30,000 or 40,000 per ml for 1 day improved microspore-embryo yield in low density cultures (3,000 or 4,000 per ml) more than 3-fold. In contrast, media conditioned with microspores from 1–4 days or 0–4 days of culture were inhibitory.Use of feeder cultures resulted in up to 10-fold increase of embryo yield in low density microspore cultures, depending on the method used. Filter papers and other membranes placed on top of feeders greatly inhibited embryogenesis in the feeder layer as well as microspores cultured on the feeder, possibly due to poorer gaseous exchange.     

The feeding behaviour of Psoroptes spp. mites on rabbits and sheep

A scanning electron microscope (SEM) study of the mouthparts of Psoroptes cuniculi from rabbits and P. ovis from sheep established that they are identical in morphology and are adapted for surface feeding rather than piercing the epidermis. Haemoglobin was found in both P. cuniculi and P. ovis on rabbits but not in P. ovis on sheep and it is concluded that the haemoglobin is derived from small haemorrhages on the surface of inflamed rabbit skin. This inflammation is caused by the deposition of antigenic material on the skin which is abraded by the mite mouthparts. The mites feed on the resulting exudate and on other surface material. An immunofluorescent assay revealed that the 2 mite species are antigenically similar.     

Combined effect of salinomycin and feeding on whole body glucose kinetics in sheep fed a high-concentrate diet

The aim of this study was to investigate the effects of salinomycin (SL) and feeding on whole body glucose kinetics in sheep fed a high-concentrate diet (25% orchardgrass hay and 75% commercial concentrate). Four adult sheep were fed the diet with or without 20 mg x kg(-1) diet of SL once daily for each 3 wk. The rates of glucose entry and utilization were determined before and during 3 h after feeding using a [ (13)C(6)] glucose dilution approach. Ruminal characteristics and concentrations of blood volatile fatty acids (VFA) and plasma glucose and insulin were also measured. Metabolizable energy intake was unaffected (P = 0.22) with SL. Salinomycin decreased (P = 0.06) the ratio of acetate to propionate in rumen fluid. Salinomycin increased (P = 0.01) both rates of entry and utilization of glucose, but did not affect (P > 0.10) concentrations of blood VFA or plasma glucose or insulin. Feeding caused gradual increases in concentrations of blood acetate (P < 0.01) and propionate (P = 0.01), a transient increase in plasma insulin concentration (P = 0.05), a transient decrease in plasma glucose concentration (P < 0.01), and persistent increases in both rates of glucose entry (P < 0.01) and utilization (P < 0.01). No SL x feeding interaction was observed (P > 0.10) on any measurements. We conclude that SL and feeding would have an additive effect on both rates of glucose entry and utilization without modifications with SL to feeding responses of peripheral concentrations of blood VFA, plasma glucose and insulin.     

The effect of roughage to concentrate ratio in the diet on nitrogen and purine metabolism in dairy cows

Four lactating dairy cows were used in two experiments to study the effects of the roughage to concentrate ratio in the diet on nitrogen balance, plasma urea, urinary urea, milk urea and urinary purine derivatives. The use of the allantoin to creatinine ratio in spot samples of urine as an index of the urinary allantoin excretion was also evaluated. Four isoenergetic and isonitrogenous diets were formulated according to a 2 × 2 factorial arrangement. Factor I was concentrate content. The roughage to concentrate ratios were 65:35 and 35:65 for the high roughage and high concentrate diets, respectively. Factor II was fat content, which was 2.8% and 5.8% for the low and high fat diets, respectively. In Experiment 1 cows were fed diets with low fat content, and in Experiment 2 cows were fed diets with high fat content. In both experiments, diets were fed according to a change-over design. Nitrogen balance was not affected by the treatments. In cows fed high concentrate diets the amount and the proportion of nitrogen excreted in milk, as well as milk production was higher than in cows fed the high roughage diets. In both experiments, as an overall effect, the urea levels in plasma, urine and morning milk were higher, although the total urinary excretion of urea was lower, for the high concentrate diets. Urinary allantoin excretion was higher, although not significantly in Experiment 1, for the high concentrate diets. The allantoin to creatinine ratio in spot samples of urine showed the same pattern as the total allantoin excretion. Urinary creatinine excretion appeared to be affected by the diet.     

Effect of increasing the proportion of chicory in forage-based diets on intake and digestion by sheep

There is a lot of evidence that chicory could be a highly palatable and nutritious source of forage for ruminants, well adapted to climate change and dry conditions in summer, thanks to its resistance to drought and high water content. This study aimed to describe the effect of incorporating chicory to ryegrass or to a ryegrass–white clover mixture on feeding behaviour, digestive parameters, nitrogen (N) balance and methane (CH₄) emissions in sheep. In total, three swards of ryegrass, white clover and chicory were established and managed in a manner ensuring the forage use at a constant vegetative stage throughout the experiment. In all, four dietary treatments (pure ryegrass; binary mixture: 50% ryegrass–50% chicory; ternary mixture: 50% ryegrass–25% white clover–25% chicory; and pure chicory) were evaluated in a 4×4 replicated Latin square design with eight young castrated Texel sheep. Each experimental period consisted of an 8-day diet adaptation phase, followed by a 6-day measuring phase during which intake dynamics, chewing activity, digestibility, rumen liquid passage rate, fermentation end-products, N balance and CH₄ emissions were determined. Data were analysed using a mixed model and orthogonal contrasts were used to detect the potential associative effects between ryegrass and chicory. The daily voluntary dry matter intake was lower for pure ryegrass than for diets containing chicory (P<0.001) and increased quadratically from 1.39 to 1.74 kg/day with increasing proportion of chicory. Huge positive quadratic effects (P<0.001) between ryegrass and chicory were detected on eating time and eating rate just after feeding indicating an increase of the motivation to eat with mixtures, whereas rumination activity decreased linearly with the proportion of chicory (P<0.001). The organic matter digestibility was similar among treatments (around 80%), but a strong positive quadratic P<0.001) effect was observed on liquid passage rate suggesting that chicory allowed fast particle breakdown in the rumen. Animals fed with the ryegrass–white clover–chicory mixture had the higher urinary N losses (P<0.001), whereas retained N per day or per g N intake was greater when the proportion of chicory was at least 50% (P<0.001) being ~40% greater than for the other treatments. The CH₄ yield was lower with pure chicory than with the other treatments (P<0.001) for which emissions were similar. In conclusion, mixing ryegrass and chicory in equal proportions produces a synergy on voluntary intake and an improved N use efficiency likely due to complementarity in chemical composition, increased motivation to eat and faster ruminal particle breakdown.