Supplemental biotin for swine. II. Influence of supplementation to corn- and wheat-based diets on reproductive performance and various biochemical criteria of sows during four parities

Data from 116 females previously fed a corn-soybean basal diet with 0 or 220 micrograms supplemental biotin/kg during growth and development were used to study the influence of 0 (NB) or 440 (SB) micrograms of supplemental biotin/kg to corn-(C) or wheat-(W) based diets for gilts and sows housed in total confinement. Reproductive performance through four parities (total of 245 litters) and various sow and pig biochemical criteria were evaluated. Females fed W diets were older (P less than .07) at first estrus, farrowed litters that were lighter weight (P less than .01) at birth and that contained fewer (P less than .05) total and live pigs compared with females fed C diets. Biotin supplementation did not significantly influence (P greater than .10) farrowing and lactation performance; however, after the first parity, total and live pigs/litter at farrowing tended to be larger for SB females. Conception rate at first estrus postpartum was increased (P less than .07) by 9% and the average weaning to estrus interval was reduced (P less than .05) from 14.5 to 10.2 d with SB. Biotin supplementation increased (P less than .001) the biotin content of sow plasma, milk and liver, while sow liver pyruvate carboxylase activity was not altered (P greater than .10). Pigs farrowed by SB females had three- and fivefold higher (P less than .001) levels of plasma biotin at birth and 14 d of age, respectively; however, liver biotin levels at birth were not different (P greater than .10) for pigs from NB and SB females.(ABSTRACT TRUNCATED AT 250 WORDS)     

Performance of gestating sows in bedded hoop barns and confinement stalls

The effects of gestation housing systems on sow and litter performance were evaluated for 2.5 yr in southwest Iowa. Gestation housing system treatments were as follows: 1) individual gestation stalls in a mechanically ventilated confinement building with a partially slatted floor and a manure flush system and 2) group pens with individual feed stalls in deep-bedded, naturally ventilated hoop barns. In all, 957 litters from 353 sows were evaluated. Number of pigs born alive per litter differed for the 2 housing treatments (P = 0.002). Sows gestated in hoop barns gave birth to more live pigs per litter (10.0 +/- 0.2 pigs) than sows gestated in stalls (9.3 +/- 0.2 pigs). Preweaning mortality was not different for the 2 housing treatments (P = 0.70). Cross-fostering was done to equalize litter size within 24 h of birth, which resulted in an equal number of weaned pigs per sow (P = 0.50) regardless of gestation housing treatment. The weaning-to-breeding interval was different (P = 0.01), with sows kept in stalls (4.3 +/- 0.6 d) returning to estrus sooner than sows gestated in hoop barns (6.0 +/- 0.6 d). These results indicate that gestating sows can be housed as groups in deep-bedded hoop barns equipped with individual feeding stalls and will perform comparably to gestating sows housed in confinement systems with individual gestation stalls.     

Effects of dietary additions of 1,3-butanediol or lard for sows on survival of neonatal pigs

In nine trials, 278 late-term gravid sows were fed isocaloric amounts (8,500 kcal metabolizable energy (ME)/d) of a fortified, corn-soybean meal based diet in which 20% of their daily ME intake was supplied by corn starch, 1,3-butanediol or lard from about d 106 of gestation to parturition. After parturition, the sow's daily ME intake was increased to 18,000 kcal. Sows fed starch and lard remained on their respective diets for the duration of a 28-d lactation; whereas, those initially fed butanediol were switched to the starch diet after parturition. Number of pigs born per litter, average pig birth weight and incidence of stillbirths were not influenced (P greater than .30) by the prepartum diet of the sow. However, the inclusion of isocaloric levels of butanediol for starch in the preparatum diet and lard for starch in the pre- and postpartum diets increased the number of pigs weaned per litter by .45 (P less than .13) and .16 pigs (8.25, 7.96 vs 7.80) and improved the survival rate of pigs from birth to weaning by 4.3 (P less than .13) and 2.7 percentage units (84.5, 82.8 vs 80.1%), respectively. Average pig weights at 28 d of age for litters of sows fed butanediol prepartally were similar to those of sows fed starch, but were less (P less than .01) than those of sows fed lard throughout lactation.     

Effects of sow-crate design on sow and piglet behavior

The effects of sow-crate design on certain behaviors of sows and piglets at farrowing and again approximately 3 wk later were evaluated with a 2 x 2 x 4 factorial arrangement of crate width (narrow [N = 55 cm] or wide [W = 64] between lowest horizontal pipes), length (short [S = 183 cm] or long [L = 198] from rump stop to front gate) and side type (lower side of sow crate "fingered" [F], "bowed" bottom bar 20 cm above the floor [B], or straight bottom bar 20 cm [S20] or 25 cm above the floor [S25]). Farrowing-crate design influenced both sow and piglet behaviors both during and immediately after parturition and during nursing-suckling bouts approximately 3 wk later. Activities of 51 sows and their piglets were videorecorded during and immediately following parturition. Sow-crate design affected neither the interval between births of successive piglets in a litter nor the frequency of standing by the sow during parturition. Latency from birth to first mammary contact (LMC) was greater with S25-sided and S sow crates, and especially with S, W crates. A significant interaction occurred between sow-crate side type and dimensions; LMC was longer when S25 sides were combined with S or W crates. Data on suckling behavior were collected from 113 litters over three successive sucklings approximately 3 wk after farrowing. Sow-crate design had no effect either on the consistency with which a piglet suckled a particular teat or teat pair or on the frequency of multiple-teat use. Piglets maintained fewer functional teats with S, S20 crates. The distribution of functional teats between rows was less symmetric with S crates. Piglets nursed with their bodies over a side bar more frequently with B- and S20-sided crates. The sow permitted her piglets to suckle while she was in a vertical stance more frequently with S and N crates, and especially with S, N crates. Sow-crate design affected important behaviors of sows and piglets both during and immediately after parturition as well as during nursing-suckling bouts about 3 wk later.     

Effects of additional feed during late gestation on reproductive performance of sows: a cooperative study

A cooperative research study involving 1,080 litters was conducted at eight stations to determine the effects of additional feed during the last 23 d of gestation on reproductive performance of sows and on preweaning performance of their pigs. Primiparous and multiparous sows were fed fortified corn- or sorghum-soybean meal diets (14% crude protein). Control sows received 1.82 kg/d from March through November and 2.27 kg/d from December through February. Treated sows were fed an additional 1.36 kg of feed/d from d 90 of gestation to farrowing. Sows were allowed to consume the same diet ad libitum during a 21-d lactation. Additional feed in late gestation resulted in greater (P less than .001) sow weight gain from d 90 to d 110 of gestation (16.8 vs 9.0 kg) and greater (P less than .001) parturition-lactation weight loss (21.3 vs 16.4 kg). Total weight gain from breeding to 21 d of lactation favored sows that received extra feed (27.5 vs 22.7 kg; P less than .001). Sows receiving extra feed had more live pigs at farrowing (10.05 vs 9.71, P = .06) and at 21 d postpartum (8.35 vs 8.06, P = .09), and the pigs were heavier at birth (1.48 vs 1.44 kg, P = .003) and at 21 d (5.37 vs 5.20 kg, P = .006). Lactation feed intake and number of days from weaning to estrus were not affected by treatment. The results indicate that additional feed in late gestation improves reproductive performance in sows. In this study, the cost of an additional 31 kg of feed/sow was more than offset by the value of the additional sow weight gain (approximately 5 kg), the additional .3 of a pig/litter at weaning and the additional 2.6 kg of total litter weaning weight.     

Effects of dietary additions of fat and triamcinolone for sows during late gestation on subsequent pig performance

Three trials involving 118 sows were conducted to evaluate the effects of fat and triamcinolone additions in the diets of late-term gravid sows on pre- and postweaning performance of pigs. Beginning an average of 9 d prepartum, sows were fed daily 1.8 kg of a fortified, corn-soybean meal diet [6 Mcal of metabolizable energy (ME) and 290 g of protein/sow] that was supplemented with 4 Mcal of ME/sow in the form of starch, soybean oil or soybean oil plus 70 mg/sow of triamcinolone, a synthetic glucocorticoid. During a 28-d lactation, sows were self-fed a standard 14% protein, corn-soybean meal diet. The addition of soybean oil to the diet of sows during late gestation did not (P greater than .10) influence the weights of survivability of pigs at birth, 14 or 28 d of age, but increased (P less than .05) the carcass fat content of the pigs at birth. The dietary addition of triamcinolone to the sow's prepartum diet increased (P less than .10) pig weights at birth and 14 d, and tended to increase pig weights at 28 d compared with those of pigs from sows fed soybean oil only. Prepartal administration of triamcinolone depressed (P less than .05) carcass protein content and adrenal weights in pigs at birth or 28 d of age. From weaning (d 28) to 56 d of age, pigs from sows fed soybean oil before parturition, particularly those from sows fed triamcinolone, tended to consume less feed and gained slower and less efficiently than pigs from sows fed starch, although the differences were not significant.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effect of birth and fraternal litter size and cross-fostering on growth and reproduction in swine

Twelve hundred fifty-one pigs from six farrowings (FGRP) were classified within a FGRP by their birth litter size (BL- = below average and BL+ = above average), randomly allotted to nursing litter sizes of 6 or 12+ pigs/sow (NL- vs NL+) and reared by their own or foster dams (XF- vs XF+). Pigs were weighed at birth, 21 d and when near 105 kg. A random sample of 40 gilts per FGRP was retained for observation of pubertal age and primipara conception. Twenty-four gilts per FGRP were farrowed and rebred for a second parity. Pigs born in large litters were younger at 105 kg than those born in small litters (189 vs 196 d +/- 1.4); no other differences (P greater than .05) were observed for BL. Pigs reared in larger litters had lower survival rate from birth to weaning (79 vs 86% +/- 1), had slower weight gains to 21 d of age (5.3 vs 6.6 kg +/- .17) and were older at 105 kg (195 vs 190 d +/- 1.4) than those reared in small litters (P less than .04). Cross-fostered pigs were slower gaining to 21 d (5.9 vs 6.1 kg +/- .14) and were older at 105 kg (195 vs 191 d +/- 1.4) than pigs not cross-fostered pigs (P less than .02). Growth beyond 105 kg and pubertal age were unaffected by any factor studied (P greater than .05). Although size of birth litter did not affect (P greater than .05) any reproductive trait, an interaction between litter size and farrowing group was detected.(ABSTRACT TRUNCATED AT 250 WORDS)     

The effects of crossfostering pigs on survival and growth

Data from 254 crossfostered pigs and 753 noncrossfostered pigs of Duroc and Landrace first-parity litters were used to assess the phenotypic effects of crossfostering on baby pigs. Differences between crossfostered and noncrossfostered pigs in the recipient litter were analyzed. Phenotypic correlations were calculated for selected individual pig traits (n = 1007, combined foster and nonfoster data). Birth weight was correlated positively with improved birth vigor (r = .40; P less than .01), survival to 21 d (r = .34; P less than .01) and weight at 21 d (r = .37; P less than .01). Improved birth vigor was correlated positively with pig survival to 21 d (r = .70; P less than .01) and to weaning (r = .66; P less than .01). These correlations indicate that baby pig size and strength are related and that these two characteristics influence survival and performance. Pigs that were not crossfostered (adjusted for birth vigor) had a 4.8% (P less than .10) higher rate of survival to 21 d and a 6.8% (P less than .05) higher rate of survival to weaning (42 d). However, crossfostered pigs had greater birth vigor (P less than .01). Unadjusted for vigor, crossfostered pigs had an 11.3% (P less than .01) higher rate of survival to 21 d and an 8.6% (P less than .05) higher rate of survival to weaning than noncrossfostered pigs. These results indicate that when average-strength pigs were crossfostered, livability was reduced. However, crossfostered pigs that were stronger than average had greater livability than pigs that were not crossfostered.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effect of vitamin E and fat source in sows' diets on immune response of suckling and weaned piglets

Thirty-six 7-mo-old gilts were used to study the effects of dietary vitamin E and fat source (5% sunflower oil or animal fat) in pregnant and lactating sow diets on serum vitamin E concentration and on cell-mediated and humoral immune response in suckling and weaned piglets. Six gilts each received one of six diets throughout pregnancy and lactation. The basal diets (13 mg alpha-tocopherol/kg diet) were supplemented with dl-alpha-tocopheryl acetate to 48 and 136 mg alpha-tocopherol/kg of feed (average analyzed values). After weaning (at 4 wk of age) all pigs received identical diets (20 mg of alpha-tocopherol/kg feed). One week after weaning, pigs were immunized (i.m. with ovalbumin and tetanus toxoid) and antibody production was measured. Blood samples were taken immediately after birth, at 1 wk after birth, at weaning, and at four weekly intervals after weaning. Samples were analyzed for alpha-tocopherol concentration, total number of leukocytes, T- and B-lymphocytes, lymphocyte stimulation with concanavalin A, lysozyme activity, and immunoglobulin concentrations. It was concluded that a high vitamin E level in the sow's diet increased serum vitamin E concentration of 1-wk-old pigs (P less than .05). Immune response against ovalbumin was increased (P less than .05) at 1 wk of age after immunization for weaned pigs from sows fed the high level of vitamin E. Also, the phagocytic measures of pigs at 1 wk of age were increased by the medium vitamin E level (P less than .05). Fat sources in the sow's diet had no consistent effect on the immunological measures of pigs.     

Effect of split nursing on variation in pig growth from birth to weaning

OBJECTIVE: To determine the effect of split nursing (i.e., removal of the larger pigs in a litter from the dam for a short period within 24 hours after birth to allow the smaller pigs in the litter uninhibited access to the dam) on variation in growth from birth to weaning among pigs. DESIGN: Clinical trial. ANIMALS: 1,193 pigs in 118 litters. PROCEDURE: Litters were randomly assigned to 1 of 3 treatment groups: control group (pigs were not split nursed), group 1 (heaviest 50% of pigs in the litter were removed from the sow for 2 hours), or group 2 (heaviest 50% of pigs were removed from the sow for 2 hours and, after the heaviest pigs were returned to the sow, the lightest 50% of pigs were removed for 2 hours). Birth weights and weaning weights were measured. RESULTS: Significant differences in average daily gain (ADG), weaning weight, or serum IgG concentration among groups were not detected. However, significant linear improvements in the SD and coefficient of variation of the ADG were detected, but only for litters with > or = 9 pigs born alive. Percentages of pigs from split-nursed litters that weighed < 3.6 kg (8 lb) at weaning (1.3 and 1.6% for groups 1 and 2, respectively) were lower than percentage of control pigs that did (3%). CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that split nursing will decrease variation in ADG of pigs from birth to weaning but only for pigs from litters with > or = 9 pigs born alive.     

Management program for improving sow and gilt performance by feeding dichlorvos

Treated sows were on a special management program which consisted of feeding 1,000 mg of dichlorvos to the sow each day for the last 30 days of gestation. The dichlorvos was delivered as a slow-release formulation. The late gestation treatment signigicantly (P less than 0.01) improved the productivity of the sows by improving the performance of their litters. The litters from treated sows were superior in 4 ways: (1) increased number of pigs born alive per litter (2.3%); (2) increased pig birth weights (9.6%); (3) improved survival of pigs born alive; and (4) improved growth rate to market weight. The litters from treated sows were 11.6%, 16.5%, and 12.4% heavier than control litters at birth, weaning (35 days), and market (160 days), respectively.     

Attraction of newborn piglets to auditory, visual, olfactory and tactile stimuli

Newborn piglets were removed from their dam and their responses to a variety of sensory stimuli were tested in four experiments. Test stimuli were presented simultaneously in multiple-choice arenas. Piglets allowed to choose among recordings of sow vocalizations, piglet vocalizations or white noise in a 5-min test spent more time in proximity to vocalizations of sows and piglets than near white noise. This was significant for males (P less than .01) but not for females. Piglets choosing among illumination levels (bright, dim or dark) in a 5-min test showed a strong preference for either dim or dark areas over bright light (P less than .01), with no difference between attractivity of dim and dark areas. Piglets choosing among birth fluids, sow's milk or tap water during a 5-min test spent more time with maternal odors than with water (P less than .05). No difference in attractivity between birth fluids and sow's milk was apparent. Preferences of piglets to move either with or against the direction of hair growth were tested using the mid-back area of the sow as a test surface. Piglets moved with the direction of hair growth twice as often as against the growth of hair (P less than .01). Results of these experiments indicate that piglets can discriminate among auditory, olfactory, visual and tactile stimuli immediately after birth.     

The effect of gastric loads of sugars and amino acids on milk intake of suckling pigs

A 3 h fast of suckling pigs less than a week of age decreased plasma glucose (P less than .005), but did not affect plasma protein, osmolality or hematocrit. After fasting, solutions (40 ml/kg body weight) of 5% glucose, 5% fructose, 5% xylose, 5% mannitol, 5% sorbitol, 2.5% leucine, 2.5% phenylalanine (50 ml/kg), .9% NaCl, 5% lactose, 5% sucrose and a 50% egg yolk-distilled water mixture were administered by stomach tube and the piglet then returned to the sow. Weight gain was used as a measure of sow's milk intake. Milk consumption during the first 3 h after fasting was lower (P less than .05) for pigs given glucose than for sham-loaded controls, but no differences were observed between glucose and mannitol or sorbitol for the same period. Mannitol and sorbitol were more effective than NaCl (P less than .01) in lowering consumption for the 3 h after loading. Also during the first hour after loading, xylose caused lower (P less than .001) food intake than glucose. Egg yolk suppressed intake in comparison to sham-loaded controls (P less than .05). D-phenylalanine suppressed intake more than L-phenylalanine (P less than .05), but no differences were observed between the D and L isomers of leucine.     

Danger to pigs due to crushing can be reduced by the use of a simulated udder.

Sows that lie on their young, pig "crushing", is a significant cause of pig mortality in current production systems. Although mortality rates of pigs in farrowing crates are lower than mortality rates of pigs in pens, loss due to crushing is still estimated to be between 4.8 and 18%. During the first few days after parturition, pigs are highly attracted to the odor of their dam's udder. Thus, our research was designed to move the pigs away from the sow by competing with the sow's udder using a "simulated" udder. Fifteen Yorkshire x Landrace sows and their litters (11.4+/-.78 pigs) were assigned to either a control (C, n = 9) or an experimental group (SU, n = 6). The C pigs had access to a heat lamp, whereas the SU pigs' crate had a simulated udder. Data were collected using time-lapse photography (1 frame/.4 s) for a 3-d duration at the initiation of farrowing. When a sow stood, data were recorded by 1-min scan samples to record the number of pigs using either the heat lamp or the simulated udder. In addition, stillborn pigs, pig crushing, and death by other means also were recorded. Data were analyzed by 12-h periods using generalized estimating equations. Results indicate that from 12 to 72 h postpartum, excluding 24 to 36 h postpartum, the estimated probability that pigs were in a safe area (simulated udder or heat lamp) was .89 for SU pigs, compared with only .72 for C pigs (P = .005). During the 24- to 36-h period, it was more probable to find pigs on a simulated udder (.77) than under only a heat lamp (.61, P = .016). Stillborn pigs, pig crushing, and death by other means were not different between treatments (mean = .87, .60, 1.2; P>.20). The simulated udder drew pigs away from the sow's udder better than heat lamps alone. Considering these findings, mortality of pigs due to crushing may be decreased substantially using a simulated udder. These results are promising, but further refinement should be done, including improved udder design and investigation of the attractiveness of various stimuli.     

Effect of feather meal as a source of valine for lactating sows

An experiment was conducted to evaluate feather meal as a source of Val in lactating sow diets. Sows (five farrowing groups; mean parity = 2.34) were allotted to one of two dietary treatments on the basis of ancestry, parity, and weight and date of d 110 of gestation. The treatment diets included 1) corn-soybean meal lactation diet (n = 40) or 2) corn-soybean meal lactation diet with 2.5% feather meal (n = 39). The diets were formulated on an equal Lys basis. All litters were adjusted to 10 pigs within 24 h after farrowing, and all sows weaned at least nine pigs. Sows were bled at 110 d of gestation and at weaning, and serum urea N was determined. Backfat thickness was determined ultrasonically at 110 d of gestation and at weaning. Serum urea N and backfat thickness at d 110 of gestation were used as covariates for serum urea N and backfat thickness at weaning, respectively. The litter response criteria (weaning weight, litter weight gain, and percentage survival) were not affected (P > .10) by feather meal. The sow response criteria (weaning weight, weight loss per day, weaning backfat thickness, change in backfat thickness, ADFI, and days to estrus) were not affected (P > .10) by feather meal. Sows fed feather meal had increased (P < .01) serum urea N and tended (P = .15) to have decreased sow weaning weight. Following the initial analysis of the data, the data set was split into two groups: 1) sows with litters gaining less than 2.17 kg/d (n = 19 and 20 for control and feather meal diets, respectively) and 2) sows with litters gaining more than 2.17 kg/d (n = 21 and 19 for control and feather meal diets, respectively). These two groups were analyzed separately. In sows with litters gaining less than 2.17 kg/d, the litter and sow criteria were not affected (P > .10) by treatment. In sows with litters gaining more than 2.17 kg/d, sow weaning weight was decreased (P < .04) and sow weight loss (P < .02) and serum urea N (P < .01) were increased in sows fed feather meal. Feather meal (as a source of Val) did not improve litter weight gain, but it increased serum urea N.     

Improving sow efficiency by management to enhance opportunity for nutritional intake by neonatal piglets

Starvation, primarily during the first week postpartum, is the direct or indirect cause of at least one-half of preweaning mortalities in healthy herds. Causes of starvation originate from characteristics of the dam, of the litter and of individual piglets. A major cause of starvation is congenital weakness associated with birth weights less than 1000 g. Increasing energy during late gestation shows inconsistent effects on birth weight; some dietary component energy sources appear to improve stamina of newborn and(or) energy content of sow's milk with favorable effects on survival. Total or partial supplemental nutrient intake supplied by caretakers, automated feeding devices or transfer of piglets to foster dams are the primary means of providing enhanced nutrient intake opportunity. Nutrient intake from non-dam sources ranges from temporary tube-feeding, administered by caretakers to excessively small or weak pigs, to self-feeding by pigs from simple or sophisticated dispensers of sow milk substitutes. Transfer of piglets to foster dams as a nutrient intake source is most successful when characteristics such as size of dam, size of teats, stage of lactation and temperament are in harmony with characteristics affecting pigs' needs. If other dams are not available, sows 2 to 3 wk into lactation can serve as foster dams for large and strong newborn piglets after resident litters are removed. Planning for availability of appropriate foster dams, based on prior or projected prolificacy and other sow and litter traits, should be done at time of assembling each mating group. Research results show that, on a weight-to-weight basis, pigs requiring artificial or foster dam rearing perform similarly to other pigs and thus justify management to secure their survival.     

The influence of gestational dietary calcium on serum 1, 25-dihydroxycholecalciferol in sows and their pigs

Fifteen multiparous sows (three groups of five) were studied during one gestation-lactation cycle to measure the influence of dietary Ca (.5, .8[control], and 1.1%) on 1,25-dihydroxycholecalciferol (1, 25-(OH)2D3) in serum and colostrum of the sows and serum of their pigs. Concentrations of 1,25-(OH)2D3 and Ca, Mg, P, Cu, and Zn were determined on d 15 and 45 of gestation, at parturition, and at 3 wk postpartum in sow serum and at birth and d 10 and 21 in pig serum. Colostrum was assayed for 1,25-(OH)2D3. Serum 1,25-(OH)2D3 in sows was affected inversely (P less than .05) by dietary Ca within d 15 of gestation and was correlated (r = -.88) with serum Ca during gestation and lactation. Serum Ca was correlated (r = .52) with dietary Ca at d 15 and 45 of gestation and at farrowing. Sow serum Mg was inversely related (r = -.49) to serum Ca during gestation and early lactation. Serum 1,25-(OH)2D3 of the pigs at birth ranged from 38.7 to 44.2 pg/ml was decreased (P less than .05) by 1.1% maternal Ca intake. Sow colostrum 1,25-(OH)2D3 was related (P less than .05) inversely (r = -.40) to sow dietary Ca and directly (r = .90) to sow serum 1,25-(OH)2D3. Serum 1,25-(OH)2D3 of 10- and 21-d-old pigs was inversely related (P less than .05) to their dams' dietary Ca. These results indicate that 1,25-(OH)2D3 production in sows is quickly affected by modest changes in dietary Ca.(ABSTRACT TRUNCATED AT 250 WORDS)     

The addition of ground wheat straw as a fiber source in the gestation diet of sows and the effect on sow and litter performance for three successive parities

A regional experiment was conducted at 8 experiment stations, with a total of 320 sows initially, to evaluate the efficacy of adding 13.35% ground wheat straw to a corn-soybean meal gestation diet for 3 successive gestation-lactation (reproductive) cycles compared with sows fed a control diet without straw. A total of 708 litters were farrowed over 3 reproductive cycles. The basal gestation diet intake averaged 1.95 kg daily for both treatments, plus 0.30 kg of straw daily for sows fed the diet containing ground wheat straw (total intake of 2.25 kg/d). During lactation, all sows on both gestation treatments were fed ad libitum the standard lactation diet used at each station. Response criteria were sow farrowing and rebreeding percentages, culling factors and culling rate, weaning-to-estrus interval, sow BW and backfat measurements at several time points, and litter size and total litter weight at birth and weaning. Averaged over 3 reproductive cycles, sows fed the diet containing wheat straw farrowed and weaned 0.51 more pigs per litter (P 相似文献   

Characterization of creep feed consumption and its subsequent effects on immune response, scouring index and performance of weanling pigs

Four trials were conducted to characterize the consumption of creep feed by nursing pigs and the effects of creep feeding (from 10 d to weaning at 28 d) on the immune response, scouring index and subsequent performance of weanling pigs. Pigs were fed a ground 20% CP corn-soybean meal-whey diet with 1.0% chromic oxide (control, 9 litters), this diet with 2.7% ovalbumin added as a dietary antigen (ovalbumin, 14 litters), or no creep feed (unexposed, 11 litters). At weaning, pigs within a litter were fed a 20% CP corn-soybean meal diet either with or without 2.7% ovalbumin. Creep-fed litters began eating at 11 d of age and disappearance of creep feed increased linearly until weaning (P less than .01). However, based on the chronic oxide coloring of the feces, total creep feed consumption was quite variable from pig to pig (13 to 194 g) and from litter to litter (107 to 1,550 g). Preweaning daily gain was similar between creep-fed and noncreep-fed litters; larger litters generally had lower daily gains (P less than .09) and less feed disappearance per pig (P less than .02). Weekly blood sampling showed that pigs fed the antigen diet had a higher (P less than .001) antibody titer to ovalbumin at 14, 21 and 28 d of age than did pigs fed the control diet or pigs unexposed to creep feed. At 56 and 63 d of age, all pigs given an ovalbumin injection at 49 d (1 ml containing 3 mg of ovalbumin) had responded (P less than .001) to injection, with the lowest titers for pigs fed the control creep diet and the highest titers for pigs fed the ovalbumin creep diet; titers were intermediate for pigs not fed creep. Regardless of preweaning or postweaning treatment, most pigs began scouring 4 to 5 d postweaning; scouring peaked at d 10 and returned to normal after d 15. Although the magnitude of difference was small, creep-fed pigs tended to scour more than pigs not fed creep (P less than .01). Postweaning performance was not influenced by preweaning treatments.     

Epidemiological studies of piglet diarrhoea in intensively managed Danish sow herds. I. Pre-weaning diarrhoea

The study comprised 70,796 litters in 104 sow herds, observed from 1976 through 1982. Weaning age decreased from approx. 42 days to approx. 30 days during the observation period. Diseases and symptoms were recorded together with production parameters (feeding, barn construction, economic returns etc.). The mean incidence rate of pre-weaning diarrhoea was 6.8% of litters, with considerable inter-herd differences (incidence rates from 0 to approx. 50%). There was a slight increase in incidence during the autumn (August through October). Incidence rates increased with litter size, with a peak incidence in litters of 11-13 piglets, and decreased with increasing parity of the sow. There was a positive association between occurrence of arthritis and pre-weaning diarrhoea in the litters, and litters from sows with post parturient disease (MMA complex) had 1.8 times higher risk of getting diarrhoea than litters from healthy sows. No important differences among breeds were found. Small herds (less than 200 farrowings per year) had higher incidence rates than large herds (400-499 farrowings per year). Herds with a gilt proportion above 30% had an incidence rate of 12.3%, i.e. nearly twice as high as the overall mean (6.8%). There was a trend towards a higher incidence rate in litters kept in traditional pens (i.e. large pens with solid floor and loose sows) than in intensive pens (i.e. small pens with slatted flooring and tethered sows). The overall pre-weaning mortality rate was 16.2% of pigs born, half of which was due to stillbirths (6.3%) and overlaid piglets (2.2%). In litters with pre-weaning diarrhoea, the mortality rate was 19%, compared to 13% in litters without occurrence of diarrhoea. This difference accounts for an excess loss of 0.6 piglets from birth to weaning in diarrhoeic vs. non-diarrhoeic litters. Piglets from litters with pre-weaning diarrhoea had reduced weight gain. Thus, on the average, they were 2.2 days older at 25 kg bodyweight and weighed 0.4 kg less at 30 days than piglets from non-diarrhoeic litters. Also, litters with pre-weaning diarrhoea had a significantly increased risk of post-weaning diarrhoea. The present information forms a basis for defining acceptable disease thresholds in suckling litters in intensively managed herds.