Creep Feed Research Articles

Effects of Weaning Age, Creep Feeding, and Type of Creep on Steer Performance, Carcass Traits, and Economics

<h3>ABSTRACT</h3> Spring-born, Angus × Simmental steers (n = 168) were randomly assigned to 1 of 4 treatments: early wean with program-fed high concentrate (EWP), normal wean with creep (NWC), normal wean with fiber creep (NWF), and normal wean with no creep (CON). Steers were weaned at 63 ± 1.3 d or 189 ± 1.3 d of age. The EWP steers were program-fed a high-concentrate diet to gain the same as steers on the 2 creep-fed treatments from the time of early weaning un-til normal weaning. The NWC had greater (P < 0.05) ADG during creep period and greater (P < 0.05) supplemental G:F than NWF steers. During the combined finishing period there were no differences in ADG, DMI, or G:F between the EWP and the NWC and NWF. For the overall duration of the trial, CON steers had lesser (P < 0.05) ADG and required more (P < 0.05) days to harvest than other treatments. The EWP steers had a greater (P < 0.05) marbling score, percentage of steers grading Average Choice or greater, and percentage of steers grading Low Prime or greater than NWC and NWF steers. The CON steers had lesser (P < 0.05) carcass values than the other treatments. Program-feeding early-weaned steers high-concentrate diets improved carcass quality compared with creep feeding, but it also resulted in greater costs per steer. Type of creep did not influence overall performance, carcass quality, or carcass value. Early weaning and creep feeding resulted in greater overall ADG, greater hot carcass weight, greater costs, and improved value of carcasses than normal weaning with no creep feed.

Addition of chromic oxide to creep feed as a fecal marker for selection of creep feed–eating suckling pigs

To determine whether the addition of chromic oxide (Cr(2)O(3)) to creep feed could be used as a visual marker in feces for selection of creep feed-eating suckling pigs. 20 suckling pigs. Via syringe, 5 pigs (2 to 3 days old on day 0; 1 pig/treatment) from each of 4 litters received oral administrations of 10, 20, 30, or 40 g of creep feed containing 10 g of Cr(2)O(3)*kg(1) on each of 2 consecutive days (days 20 and 21) or 30 g of creep feed containing 10 g of Cr(2)O(3)*kg(1) on day 20 and 30 g of Cr(2)O(3)-free creep feed on day 21. On days 21 through 24, 6 fecal samples were collected from each pig at regular intervals between 8:00 AM and 6:00 PM. Green-colored feces were considered indicative of creep feed consumption (eaters). Data analyses were based on single and multiple fecal samples. On day 22, evaluation of 1 fecal sample/pig and multiple fecal samples per pig resulted in identification of as many as 40% and only 15% of the feed-treated pigs wrongly as noneaters, respectively. Repeated sampling over multiple days would identify 99% of eaters accurately. Pigs erroneously identified as noneaters were those administered either low amounts of Cr(2)O(3)-supplemented creep feed for 2 days or Cr(2)O(3)-supplemented creep feed on only 1 day. Data suggest that addition of Cr(2)O(3) to creep feed enables selection of individual creep feed-eating suckling pigs via examination of feces, provided that repeated fecal samples are evaluated.

Parenteral long-acting amoxicillin reduces intestinal bacterial community diversity in piglets even 5 weeks after the administration

We investigated the long-term effects of a single intramuscular administration of amoxicillin (15 mg kg(-1)) 1 day after birth, on piglet intestinal microbiota. Animals received no creep feed before weaning on day 28 of age. For the next 11 days, the piglets received a wheat-barley-based diet. Colon digesta samples were collected on day 39 and subjected to denaturing gradient gel electrophoresis (DGGE) of PCR-amplified 16S rRNA gene fragments. DGGE fingerprint diversity indices differed between the group treated with amoxicillin and the untreated group (0.8+/-0.19 and 1.03+/-0.17, respectively, P=0.012). Reamplification and sequencing of two bands present in all samples revealed that a Roseburia faecalis-related population was strongly reduced in relative abundance (98% identity) in the treated group, while an enterobacterial population with 100% identity to Shigella spp., Escherichia coli and Salmonella enterica serovar Typhi was enriched. A band corresponding to Lactobacillus sobrius was present only in the control group. The protective effect of prophylactic antibiotic administration may be outweighed by the long-lasting disturbance of the gut ecosystem.

Effect of different creep feeding treatments and group composition on the initiation of piglet feeding behaviour immediately post-weaning

The post-weaning growth check of the piglet can be attributed to the inability of the animal to eat sufficient food in the initial post weaning period and hence grow at a maximum rate (Pluske et al., 1996). It is essential therefore to identify determinants of individual feed intake characteristics post weaning to improve piglet performance. A palatable creep-diet is often fed to piglets pre-weaning to increase performance and to allow piglets to become familiarised with solid feed sourced from a feeder. Bruininx (2002) et al., demonstrated using single spaced Feed Intake Recording Equipment (FIRE), that creep feed stimulates post-weaning feed intake and gain. In addition, Morgan et al. (2001) investigated feeding behaviour of piglets paired from creep or no creep backgrounds and concluded a learning effect which increased the feeding behaviour of the naïve piglet. The purpose of this experiment, therefore, was to investigate the effect of offering selected litters either creep feed or zero creep (naïve) pre-weaning on their latency to initiate feeding post weaning. It was hypothesised that learning behaviour between piglets may influence feeding initiation and so this experiment would also look at the effect of mixing piglets from the two lactation backgrounds.

Effects of Distillers Dried Grains with Solubles as a Protein Source in Creep Feed. 2. Subsequent Feedlot Performance, Carcass Measurements, and Plasma Parameters

<h2>ABSTRACT</h2> A 2-yr study was conducted to evaluate the effects of protein source in a creep ration as well as creep vs. no creep treatments on subsequent feedlot performance and carcass characteristics of steers. During each year, 36 steer calves were assigned to treatments: corn distillers dried grains with solubles (DDGS) or soybeanmeal (SBM) as the protein sources compared with a noncreep dietary treatment. After the creep feeding phase, they were placed in the feedlot. During the receiving period in both years, creep-fed steers tended to have greater DMI (P < 0.10) than noncreep-fed steers, resulting in different (P < 0.01) ADG between creep-fed and noncreep-fed steers in yr 1, but not yr 2. During both years, cost of gain tended to be lower (P ≤ 0.11) for creep vs. noncreep-fed steers. During the grow-ing period in yr 1, noncreep-fed steers were more efficient (P < 0.01) than creep-fed steers, and SBM steers tended to be more efficient (P < 0.10) than DDGS steers. During the growing period in both years, noncreep-fed steers tended to have greater (P < 0.10) ADG than creep-fed steers. In yr 1, creep-fed steers had greater (P < 0.05) final live weights and hot carcass weights, and tended to have greater (P ≤ 0.10) dressing percent, fat thickness, yield grade, and carcass value as compared with noncreep-fed steers. In yr 2, there were no differences in subsequent feedlot performance and carcass characteristics attributed to previous creep feeding treatment. In yr 2, DDGS had lower (P < 0.05) longissimus muscle area than SBM steers. In conclusion, protein source had no effect on ADG or final weight; however, DDGS tended to reduce the cost of gain.

Effects of Distillers Dried Grains with Solubles as a Protein Source in a Creep Feed. 1. Suckling Calf and Dam Performance

ABSTRACT A 2- yr study was performed to evaluate the effect of corn distillers dried grains with solubles (DDGS) vs. soybean meal (SBM) as the protein source in a creep feed. Thirty-six steer calves were used in each of the 2 yr to compare the performance of traditionally noncreep-fed, control weaned calves with those offered creep feed with either DDGS or SBM beginning 68 d prior to weaning. The creep supplements consisted of a 2:1 ratio of soy hulls and cracked corn with the protein source. In yr 1 and 2, creepfed steers had greater (P 0.10) on ADG, supplemental DMI, and supplemental feed efficiency. In yr 1, cost per kilogram of supplemental gain for DDGS tended to be less (P

Creep feed composition did not affect feed intake, growth rate or gut microflora in weaned pigs

Although dietary composition for weaned pigs can be altered to promote a beneficial microflora which resists proliferation of pathogenic bacteria, this concept has yet to be applied to the pre-weaning phase. Commercial creep feeds typically are highly digestible and based on milk products and cooked cereals which, in the presence of lactase enzyme activity in the suckling piglet, promote relatively limited microbial fermentation in the gut. The gut flora therefore remains relatively immature and less able to deal with the challenges of weaning and transition to a non-milk diet. Recent studies in weaned piglets have shown how dietary ingredients such as inulin can enhance the proportion of beneficial bacteria in the gut (Wellock et al., 2006), and thus may provide a more stable gut pH and microflora over the weaning transition. Similarly, addition of sodium butyrate to the diet can enhance gut architecture (Miller and Slade, 2006), which could promote development of a more mature gut at weaning if fed prior to this time. The aim of this experiment was to test whether manipulations which have had beneficial effects on enteric conditions in weaned pigs can be used prior to weaning, to promote more favourable gut conditions and thereby reduce the feed intake deficit and growth check associated with the weaning process.

Creep feed grinding of a gamma titanium aluminide intermetallic alloy using SiC abrasives

Abstract Experimental results are detailed when creep feed grinding (CFG) a gamma titanium aluminide intermetallic alloy (γ-TiAl) Ti–45Al–8Nb–0.2C with SiC abrasives. When using low porosity wheels at a low wheel speed of 15 m/s and a material removal rate of 62.5 mm/s, G-ratios of ∼15 were produced with workpiece surfaces free of burn. At higher wheel speeds ≥25 m/s, cracks up to 1 mm deep were evident with extreme workpiece surface burn. By increasing the wheel porosity, specific power, cutting forces, workpiece surface burn and cracking were all reduced however, G-ratio was also reduced to ∼4 with heavy profile wear. Operation at 15 m/s with increasing feed rate and depth of cut reduced G-ratio still further to

The influence of nutritional and management factors on piglet weight gain to weaning in a commercial herd in Denmark

The effects of weaning age, type of creep diet and the classification of piglets as 'eaters' or 'non eaters' of creep feed on weight gain to weaning were examined. Four antimicrobial-free diets were offered from day 14 of lactation: (i) wheat-soy based diet with animal and vegetable ('mixed') protein sources (COMM), (ii) heat-processed rice (HPR) with barley hulls and potato starch and mixed protein sources (RBPS), (iii) HPR with sugar-beet pulp and mixed protein sources (RSBP), and (iv) HPR with mixed protein sources (R). Pigs were weaned at an average of either 27 (early) or 33 (late) days of age. A dye (indigo carmine) was added to each diet at day 24 of lactation in both groups to classify piglets as 'eaters' or 'non eaters' of creep feed, based on appearance or non-appearance, respectively, of dye in faeces. Pigs weaned late weighed 1.4 kg more (P 0.05).

Creep feed intake during lactation enhances net absorption in the small intestine after weaning

The aim of the study was to measure the effect of creep feeding during lactation on net absorption in the small intestine at 4 days after weaning. Intermittent suckling was used to increase creep feed intake during lactation. Creep feed containing chromic oxide was provided. Based on the colour of the faeces, piglets were classified as ‘eaters’ or ‘non-eaters’, respectively. At day 4 after weaning, an in vivo small intestine segment perfusion test was performed at 5 sites along the small intestine in 24 piglets (12 eaters and 12 non-eaters). At both sides of each intestinal segment a tube was fitted to perfuse and drain fluid in order to assess net absorption. Net absorption was higher in eaters than in non-eaters (P < 0.001). Net absorption varied greatly between and within piglets and was highest in the caudal segments of the small intestine (P < 0.001). These data suggest that creep feeding could be a useful tool in the prevention of post-weaning diarrhoea.

The effects of weaning age, diet composition, and categorisation of creep feed intake by piglets on diarrhoea and performance after weaning

This study investigated the effects of weaning age, diet, and classification of piglets as ‘eaters’ or ‘non eaters’ of creep feed in lactation, on production and diarrhoea after weaning. Four antimicrobial-free diets were offered in lactation and for 14 days after weaning: (i) wheat–soy based diet with animal and vegetable (‘mixed’) protein sources (COMM), (ii) heat-processed rice (HPR) with barley hulls and potato starch and mixed protein sources (RBHPS), (iii) HPR with sugar-beet pulp and mixed protein sources (RSBP), and (iv) HPR with mixed protein sources (R). Piglets were individually examined for diarrhoea daily for 14 days after weaning, and antibiotic treatments were individually recorded. Faecal swabs were taken on day 10 after weaning and scored for β-haemolytic Escherichia coli . There were significant main effects of weaning age and diet (both P < 0.001) on daily gain between weaning and 14 days after weaning. Pigs weaned later grew 50 g/day more than pigs weaned earlier, and pigs fed the COMM diet grew slower than pigs fed the rice-based diets. The number of antibiotic treatments was influenced by diet ( P < 0.001), with most treatments (2.1) given to pigs fed the diet RBHPS. Faecal score was influenced by a weaning age and diet interaction ( P < 0.01). There was no correlation ( P > 0.05) between the number of antibiotics treatments and the E. coli score.

Pre-weaning eating activity and morphological parameters in the small and large intestine of piglets

Abstract The effect of pre-weaning eating activity on the intestinal morphology in piglets was investigated on the day of weaning and 5 days post-weaning. The eating activity of each piglet was recorded by means of direct observations. On day 5 post-weaning the villous heights were reduced and the crypt depths were increased irrespective of the pre-weaning eating activity. In the caecum and colon the crypt depth was increased post-weaning and no effect of pre-weaning eating activity was observed. The muscle thickness in the small intestine did not change during the immediate post-weaning period whereas the muscle thickness in the large intestine was doubled in the same period. In conclusion, pre-weaning eating activity did not affect the structural alterations of the small and large intestine. However, the actual number of piglets consuming creep feed prior to weaning was low and the eating activity was highly variable. Therefore, more or later weaned piglets may be needed to show effects of pre-weaning eating activity.

Effects of pre- and postnatal exposure to garlic and aniseed flavour on pre- and postweaning feed intake in pigs

Abstract The low nutrient intake shortly after weaning is a major cause of post-weaning problems. Feed intake after weaning is strongly related to feed intake during lactation. Feed intake during lactation, however, varies considerably between litters. We hypothesised that prenatal and postnatal exposure to certain flavours would increase the intake of feed containing the same flavours pre- and postweaning. Multiparous sows did (n = 17) or did not (n = 14) receive 50 g garlic granulate/powder and 25 g aniseed as daily additive to their diet during the last month of gestation and during lactation. From day 14 of lactation, litters were submitted to intermittent suckling: 12 h separation form the sow each day. During lactation, all litters had 40 g garlic and 20 g aniseed per kg added to their creep feed. After weaning, half of the litters had no additive in their diet. Piglets were weaned at 4 weeks (13 litters) or at 6 weeks (18 litters). At 6 weeks of lactation, litters of which the dam received the flavour in her diet, had a higher feed intake (309 ± 43 vs 233 ± 35 g/p/d) than litters of dams without the flavour, although the difference was not significant. Sow diet had no effect on postweaning feed intake, but postweaning piglet diet did. Late (week 6) weaned litters receiving the flavoured feed had a higher feed intake from 3 to 10 days after weaning (833 ± 38 vs 687 ± 58 g/p/d). Weight gain during the first 10 days after weaning was not affected by sow or pig diets. Feed intake and weight gain shortly after weaning were strongly related to feed intake during lactation (overall R = 0.64, P

Changes in the fermentation end-product profile in the GIT of piglets during post-colostrum suckling period

Pre-weaning development of microbial activity has an effect on post-weaning establishment of the gastro-intestinal tract (GIT) microbiota. An in vivo study was conducted, to evaluate the effect of age on fermentation end-product profiles during the post-colostrum suckling period, as the variation in composition of mature milk is minimum. Sixteen piglets from two litters (eight per litter) were selected. During the study, piglets had free access to sow's milk, but no creep feed, nor antibiotic treatments. Two piglets from each litter were sacrificed on d 11, 18, 25 and 32 of age. The digesta samples were collected from the beginning and end of the small intestine, caecum and colon. Samples were analyzed for fermentation end-product concentrations. Combining the results from all the GIT sites, it was observed that, total VFA concentration increased with age of the piglets. There was a significant rise in acetic acid concentrations, with a significant decrease in lactic acid concentrations from d11 to d32, while the proportions of SCFA, (acetic acid not, vert, similar 72%, propionic acid not, vert, similar 15% and butyric acid not, vert, similar 6% of total VFA) and ammonia concentrations remained unchanged. These results clearly suggest that, the microbial activity in terms of fermentation end-product profile skewed from lactic acid to acetic acid as a major product during the post-colostrum suckling period. This may be attributed to lower substrate availability due to increased number of microbes or increased diversity in the microbiota in time.

Effects of intermittent suckling and creep feed intake on pig performance from birth to slaughter1

An experiment was conducted to determine if the improved creep feed intake observed during intermittent suckling (IS) is important for postweaning performance. Therefore, creep feed intake of litters was assessed, and within litters, eaters and noneaters were distinguished using chromic oxide as an indigestible marker. Batches of sows were suckled intermittently (IS, 7 batches; n = 31) or continuously (control, 7 batches; n = 31). In the IS group, litters were separated from the sow for a period of 12 h/d (0930 to 2130), beginning 11 d before weaning. Litters were weaned at 4 wk of age. Litters had free access to creep feed from 1 wk of age onward. Five days after weaning, the piglets were moved as a litter to weanling pens. At 8 wk of age, 2 barrows and 2 gilts were randomly chosen from each litter and moved to a finishing facility. Feed intake was improved by IS during the last 11 d of lactation (IS, 284 +/- 27 vs. control, 83 +/- 28 g/piglet; P < 0.001) and after weaning during the first (IS, 201 +/- 24 vs. control, 157 +/- 25 g x piglet(-1) x d(-1); P < 0.05) and second (IS, 667 +/- 33 vs. control, 570 +/- 35 g x piglet(-1) x d(-1); P < 0.05) wk. Thereafter, no differences were found to slaughter. Weaning BW was lower in IS litters (IS, 7.1 +/- 0.01 vs. control, 8.1 +/- 0.01 kg/piglet; P < 0.05), but 7 d after weaning BW was similar (IS, 8.5 +/- 0.2 vs. control, 8.7 +/- 0.2 kg/piglet; P = 0.18), and no differences were found to slaughter. The percentage of eaters within a litter was not increased by IS during lactation (IS, 23 +/- 4.5% vs. control, 19 +/- 4.1%; P = 0.15). Weaning BW did not differ between eaters and noneaters (eater, 7.7 +/- 0.1 vs. noneater, 7.5 +/- 0.08 kg/piglet; P = 0.63). From 1 until 4 wk after weaning, piglets that were eaters during lactation had heavier BW than noneaters (eater, 20.3 +/- 0.3 kg vs. noneater, 18.2 +/- 0.2 kg; P < 0.05). The influence of eating creep feed during lactation on BW and ADG and the influence of suckling treatment never showed an interaction. We conclude that IS increases ADFI during lactation on a litter level and improves ADG in the first week and ADFI in the first and second weeks after weaning. No long-term effects on ADFI or ADG were observed throughout the finishing period. In the current experiment, in which creep feed intake was low, the percentage of eaters within a litter was not increased, suggesting that creep feed intake of piglets that were already eating was stimulated by IS. Further, piglets that were eaters during lactation had heavier BW up to 4 wk after weaning.

Effects of varying creep feeding duration on proportion of pigs consuming creep feed and pre-weaning performance (2007)

A total of 54 sows (PIC Line 1050) and their litters were used in this study to determine the effects of varying durations of creep feeding on the rate of pigs consuming creep feed (eaters) and pre-weaning performance. Two groups of sows were blocked according to parity and date of farrowing and allotted to three experimental treatments using a randomized complete block design. Creep feeding was initiated at d 7, 14, and 18 from birth for a duration of 13, 6, and 2 d of creep feeding. A creep diet (1,585 kcal ME/lb, 1.56% TID Lys) with 1.0% chromium oxide was offered ad libitum until weaning (d 20) using a rotary creep feeder with hopper. A single lactation diet (1,586 kcal ME/lb, 0.97% TID Lys) was used where sows were allowed free access to feed throughout lactation. Piglets were weighed individually at d 0 (birth), 7, 14, 18, and 20 to calculate total and daily gains. Daily creep feed intake per litter was recorded and calculated. Fecal samples from all piglets were taken twice per sampling day using sterile swabs at d 14, 18, and 20 for Treatment 1; at d 18 and 20 for Treatment 2; and d 20 for Treatment 3. Piglets were categorized as ‘eaters’ when fecal sample was colored green at least once on any of the sampling days. Overall, there were no differences in weaning weights (P<0.61), total gain (P<0.38), and daily gain (P<0.38) among pigs and litters fed creep for different durations. Total creep feed intake of litters fed creep for 13 and 6 d were greater (P<0.0001) than those litters provided creep feed for 2 d. There were no differences (P<0.69) in overall creep intake between litters fed for 13 and 6 d. Litters provided with creep feed for 13 d produced 10% more (80 vs. 70%; P<0.03) eaters than litters fed creep for both 6 and 2 d. There were no differences (P<0.98) in the percentage of eaters between litters fed creep for 6 and 2 d. In conclusion, longer durations of creep feeding did not affect pre-weaning gain and weaning weights but did increase the proportion of eaters in whole litters; however, a relatively high percentage of pigs (70%) were classified as eaters by providing creep feed for only 2 d prior to weaning.; Swine Day, 2007, Kansas State University, Manhattan, KS, 2007

Postweaning growth check in pigs is markedly reduced by intermittent suckling and extended lactation1

The objective of this study was to determine whether intermittent suckling (IS) combined with an extended lactation can reduce postweaning growth check in pigs. Three weaning regimens [conventional weaning (CW), IS with 6-h separation intervals (IS6), and IS with 12-h separation intervals (IS12)] were compared. In CW (n = 17 litters), litters had continuous access to the sow until weaning (d 21, d 0 = farrowing). In IS6 and IS12, litters were separated from the sow for 12 h/d, beginning at d 14 and lasting until weaning (d 41 to 45). Litters were with the sow from 1400 to 2000 and from 0200 to 0800 (IS6, n = 14) or between 2000 and 0800 (IS12, n = 14). Litter size was standardized within 2 d after farrowing by crossfostering, resulting in an average litter size of 10.9 +/- 1.8 piglets. Piglets had ad libitum access to creep feed from d 7 onward. One week after the onset of IS (d 20), creep feed intake was increased in litters from both IS groups compared with CW litters (P < 0.05). Both IS groups consumed considerable amounts of creep feed before weaning (d 41 to 45). Total feed intake before weaning was greater (P = 0.004) in IS12 (3,808 +/- 469 g/piglet) than in IS6 (2,717 +/- 404 g/piglet). In comparison, CW litters consumed 18 +/- 9 g/piglet before weaning (d 21). Irrespective of weaning regimen, total feed intake of litters before weaning was highly correlated with post-weaning feed intake (P < 0.001). Furthermore, in all treatment groups, total preweaning feed intake was correlated with postweaning growth (P < 0.10). Irrespective of treatment, piglets suckling anterior teats grew faster than piglets suckling middle or posterior teats during the first 2 wk of lactation. Body weights at the end of the experiment (d 55) were similar among weaning regimens. Onset of IS induced a growth check in both IS groups (34% for IS12 and 22% for IS6). Only a mild growth check was observed after weaning of IS litters (14% for both IS groups). However, a serious growth check (98%) was observed after weaning of CW litters. Results of the current study indicate that IS stimulated feed intake during lactation, providing a more gradual transition to weaning. Because the IS6 regimen did not prevent the growth check after the onset of IS and is rather laborious, we suggest that IS12 might be preferable for a practical implementation of IS.

Effects of different creep feeder designs and feed accessibility on creep feed consumption and litter performance (2007)

The objective of this experiment was to determine the effects of different creep feeder designs and increased feed accessibility on creep feed consumption and pre-weaning performance. A total of 54 sows (PIC Line 1050) and their litters were used in this study. Two groups of sows were blocked according to parity and date of farrowing using a randomized complete block design and allotted to three experimental treatments: Treatment 1 – rotary feeder with hopper (Control), Treatment 2 – rotary feeder without hopper, and Treatment 3 – pan feeder. A creep diet (1,585 kcal ME/lb, 1.56% TID Lys) with 1.0% chromium oxide was offered ad libitum at d 18 until weaning (d 21). A single lactation diet (1,586 kcal ME/lb, 0.97% TID Lys) was used, where sows were allowed free access to feed throughout lactation. Piglets were weighed individually at d 0 (birth), 18, and 21 (weaning) to calculate total and daily gains. Litter creep feed intake as feed disappearance was also calculated. Fecal samples from all piglets were taken twice using sterile swabs between 3 and 12 h before weaning for all treatments. Piglets were categorized as ‘eaters’ when the fecal sample was colored green at least once on any of the two samplings. Results showed no differences in pig (P<0.18) and litter (P<0.51) weights at weaning among litters using the different types of creep feeder. Total and daily gains of pigs (P<0.20) and litters (P<0.31) were also similar across treatments. Litters using the rotary feeder without the hopper or the pan feeder had 2.7 times greater (P<0.0001) total creep disappearance than those using the rotary feeder with the hopper. The average feeding frequency was 1, 2.3, and 4.2 times per 12 h for the rotary feeder with and without the hopper, and the pan feeder, respectively. Creep feeder design influenced (P<0.0001) the proportion of eaters created among piglets provided with creep feed. There were 69, 47, and 42% eaters in creep-fed litters using the rotary feeder with a hopper, rotary feeder without hopper, and pan feeder, respectively. In conclusion, the proportion of eaters in creep-fed litters can be influenced by nondietary factors, such as creep feeder design.

Mechanical design of high performance grinding wheels

High performance grinding processes require grinding wheels that can be dressed with a variety of different methods and that can rotate at exceptionally high speeds without distorting or failing catastrophically. These wheels are usually reinforced and the grinding medium is usually attached to the periphery of the wheel using a strong bonding agent such as epoxy adhesive. This paper uses a set of procedures that were developed for designing grinding wheels for creep feed grinding processes and the more modern process of high efficiency deep grinding. Procedures for safe practice and good mechanical design safety at very high rotational speeds are discussed.

Effect of milk deprivation during the lactation period on performance and digestive enzyme activities of the piglets following weaning

Post-weaning performance of piglets from systems where lactation is disrupted (e.g. from multisuckling systems) is superior to conventionally reared piglets. The objective of this study was to establish whether restricted growth prior to weaning caused by disruption of suckling was an important factor in post-weaning performance and also whether there were related changes in gastro-intestinal development. Ten litters of eight piglets were used in a split-plot design. Half of each litter (limited suckling, LS) had suckling disrupted by separation from their dam for 7 h/day from day 14 to 28 after farrowing. The remainder of each litter was allowed to suck normally (normal suckling, NS). The same amount of creep feed was offered to LS piglets as consumed by NS littermates on the previous day. There were no differences in weight between LS and NS piglets at 14 days of age, but restricting access to the sow reduced weaning weight at 28 days of age (7.96 v. 9.00 kg; LS v. NS; P < 0.01; s.e.d. 0.23). Feed intakes were greater for LS than NS piglets over the first 28 days post weaning, particularly in the 1st week after weaning when feed efficiency was also improved (0.91 v. 0.62 kg gain per kg feed; P < 0.01; s.e.d. 0.08). As a result, LS piglets grew more rapidly in the first 28 days post weaning, particularly in the first 7 days after weaning. Subsequent performance to 8 weeks was similar for both groups. Digestive organ weights were not different at 2 and 9 days after weaning; nor were small intestine specific enzyme activities significantly different ( P>0.05). Pancreatic trypsin activity was, however, greater ( P < 0.01) for LS pigs on both days 2 and 9 post weaning. In conclusion the restriction of growth as a result of limited suckling itself is an important factor in determining post-weaning performance and may be related to development of pancreatic trypsin activity.