Influence of the nature of dietary fibre on digestive utilization, some metabolite and hormone profiles and the behaviour of pregnant sows

Wheat bran inclusion level impacts its net energy by shaping gut microbiota and regulating heat production in gestating sows

An accurate estimation of net energy (NE) of wheat bran is essential for precision feeding of sows. However, the effects of inclusion level on NE of wheat bran have not been reported. Inclusion level was hypothesized to impact NE of wheat bran by regulating gut microbiota and partitioning of heat production. Therefore, twelve multiparous sows (Yorkshire × Landrace; 2 to 4 parity) were assigned to a replicated 3 × 6 Youden square with 3 successive periods and 6 diets in each square. The experiment included a corn-soybean meal diet (WB0) and five diets including 9.8% (WB10), 19.5% (WB20), 29.2% (WB30), 39.0% (WB40) and 48.7% wheat bran (WB50), respectively. Each period included 6 d of adaptation to diets followed by 6 d for heat production measurement using open-circuit respiration chambers. Compared with other groups, WB30, WB40, and WB50 enriched different fiber-degrading bacteria genera (P < 0.05). Apparent total tract digestibility of neutral detergent fiber and acid detergent fiber of wheat bran were greater in WB30 and WB40 (P < 0.05). Physical activity (standing and sitting) decreased as inclusion level increased (P = 0.04), which tended to decrease related heat production (P = 0.07). Thermic effect of feeding (TEF) was higher in WB50 than other treatments (P < 0.01). Metabolizable energy of wheat bran was similar among treatment groups (except for WB10). NE of wheat bran conformed to a quadratic regression equation with inclusion level (R2 = 0.99, P < 0.01) and peaked at an inclusion level of 35.3%. In conclusion, increasing inclusion level decreased energy expenditure of sows on physical activity and promoted growth of fiber-degrading bacteria, which improved energy utilization of fiber. Fermentation of wheat bran fiber by Prevotellaceae_UCG-003 and norank_f__Paludibacteraceae might increase TEF. Consequently, sows utilized energy in wheat bran most efficiently at an inclusion level of 35.3%.

Effects of Fermented Radix puerariae Residue on Nutrient Digestibility and Reproductive Performance of Sows

This study was conducted to investigate the effect of fermented Radix puerariae residue (FRPR) on reproductive performance, apparent total tract digestibility (ATTD) of nutrients, and fecal short-chain fatty acid (SCFA) contents of sows. A total of 36 landrace × large white multiparous sows were randomly arranged into three treatments, representing supplementation with 0, 2, and 4% FRPR to a corn-soybean meal and wheat bran-based diet during the whole gestation period. The results showed that dietary FRPR had no effects on litter size and the number of total alive piglets (P > 0.05), and that the number of weaned piglets and weaning weight of litter were increased in sows with 4% FRPR treatment compared with control treatment (P < 0.05). Dietary 4% FRPR significantly decreased constipation rate, improved the ATTD of dry matter and organics, and fecal contents of acetate, propionate, and total SCFAs (P < 0.05). In the offspring piglets, serum concentrations of total protein, alkaline phosphatase, IgG, IL-10, and TGF-β were increased, but blood urea nitrogen content was decreased with 4% FRPR treatment (P < 0.05). There were no significant differences in all determined indexes except for fecal acetic acid and total SCFAs between control and 2% FRPR treatment (P > 0.05). These findings indicated that FRPR used in the diets of sows showed positive effects on fecal characteristics, utilization of nutrients, and reproductive performance. Maternal supplementation with 4% FRPR is recommended for improving immune responses, weaning litter size, and litter weight of offspring piglets, which provide useful information for the application of residues of R. puerariae.

Effects of supplementing processed straw during late gestation on sow physiology, lactation feed intake, and offspring body weight and carcass quality1

This study investigated the effects of supplementing late gestation sow diets with processed or unprocessed oat or wheat straw on physiology, early lactation feed intake, and offspring performance. One hundred fifty gestating sows were randomly assigned to 1 of 5 dietary treatments (30 sows per diet) from day 86 of gestation until farrowing. Treatments, arranged as a 2 × 2 factorial plus a control, were a standard gestation diet (control) or control supplemented with 10% wheat or oat straw, processed or unprocessed. Sows were fed a standard lactation diet postfarrowing. The processed straws were produced by high-pressure compaction at 80 °C. On day 101 of gestation (day 15 of the trial), blood samples were collected from a subset of sows (n = 8 per treatment) through ear vein catheters and analyzed for insulin, insulin-like growth factor 1 (IGF-1), prolactin, glucose, and urea concentrations. Fecal samples were collected on days 103 to 104 of gestation to determine nutrient digestibility, and feeding motivation was investigated on day 104. Litter characteristics and sow feed intake were recorded for 7 d postfarrowing. Three piglets per litter were selected at weaning, fed standard diets, and followed to market. Treatment had no effect on feeding motivation, piglet characteristics at birth, estimated milk production, and offspring BW at market or carcass quality. Processed straw improved DM digestibility and energy content and the effect was greater with oat straw (straw × processing effect, P < 0.05). Pre- and postprandial glucose concentrations tended to decrease (P < 0.10) with processing of wheat, but not oat straw, and this effect was more apparent in the preprandial samples. Preprandial prolactin concentration increased with oat but decreased with wheat straw, whereas postprandial IGF-1 and prolactin concentration increased with processing of wheat, but not oat straw (straw × processing, P < 0.05). Sow lactation feed intake improved (P < 0.05) with oat straw supplementation relative to wheat straw. Piglet weaning weight increased (P < 0.05) with oat straw supplementation and processing improved (P < 0.05) nursery exit BW. However, straw supplementation, regardless of processing, had no effect on offspring BW at market or carcass quality. Overall, oat straw supplementation had a greater impact on sow physiology and provided benefits for sows in late gestation, and there was some indication that further benefits could be obtained through mild processing.

Influence of dietary fibre on digestive utilization and rate of passage in growing pigs, finishing pigs and adult sows

Four experimental diets differing in the level and the origin of dietary fibre (DF) were studied: a control, low DF diet (diet C, 100 g total dietary fibre (TDF) per kg dry matter (DM)) and three fibre-rich diets (200 g TDF per kg DM) which corresponded to a combination of diet C and maize bran (diet MB), or wheat bran (diet WB), or sugar-beet pulp (diet SBP). During two successive experimental periods, each diet was offered to five pigs at a growing stage (35 kg body weight (BW)) and at a finishing stage (75 kg BW). In addition, four adult ovariectomized sows received successively one of the four diets according to a 4 ✕ 4 Latin-square design. Digestive utilization of energy and nutrients of diets and rate of passage parameters were determined using a pulse dose of ytterbium oxide followed by total faecal collection. Faecal marker excretion was quantified using an age-dependent, one-compartment model, from which the mean retention time in the gastrointestinal tract of pigs (MRT) was obtained. The digestibility of dietary energy and nutrients, especially the DF fraction, increased with the increase in BW from growing to finishing pigs (P < 0.01) and was still higher in adult sows; the difference between pig stages was more pronounced for diet MB. At each stage, the digestibility of energy or nutrients was lower (P < 0.01) for diets MB or WB than for diet SBP. Accordingly, the energy and DF digestibility of sugar-beet pulp was higher and increased much less with BW. The MRT was shorter for diets MB and WB in growing pigs and in sows. Sows had a longer MRT (81 h) than finishing pigs (37 h) and growing pigs (33 h); however, MRT was highly variable between sows. It is concluded that the degree to which different types of DF are digested depends, in part, on the botanical origin, and it may be improved by a longer MRT in the gastrointestinal tract of pigs. Some fibrous foodstuffs (such as maize-by products) will benefit more from a longer MRT than others.

The Impacts of Climate Change Mitigation Strategies on Animal Welfare

The objective of this review is to point out that the global dialog on reducing greenhouse gas emissions in animal agriculture has, thus far, not adequately considered animal welfare in proposed climate change mitigation strategies. Many suggested approaches for reducing emissions, most of which could generally be described as calls for the intensification of production, can have substantial effects on the animals. Given the growing world-wide awareness and concern for animal welfare, many of these approaches are not socially sustainable. This review identifies the main emission abatement strategies in the climate change literature that would negatively affect animal welfare and details the associated problems. Alternative strategies are also identified as possible solutions for animal welfare and climate change, and it is suggested that more attention be focused on these types of options when allocating resources, researching mitigation strategies, and making policy decisions on reducing emissions from animal agriculture.

In vitro and in vivo digestion of octenyl succinic starch

This study aimed to understand effects of octenyl succinic anhydride (OSA) modification of normal corn (NCS) and high-amylose corn (HA7) starch on their enzymatic hydrolysis rates. After modification with 3% and 10% OSA, resistant starch (RS) contents of the cooked OS-NCS increased from 0.8% of the control starch to 6.8% and 13.2% (Englyst Method), respectively, whereas that of the cooked OS-HA7 decreased from 24.1% to 23.7% and 20.9%, respectively. When the cooked NCS, HA7 and OS (10%)-HA7 were used to prepare diets for rats at 55% (w/w) starch, RS contents of the diets were 1.1%, 13.2% and 14.6%, respectively. After feeding to the rats, 20.2-31.1% of the starch in the OS (10%)-HA7-diet was not utilized in vivo and was found in rat feces, which was substantially larger than that of the HA7-diet (≤4.9%) and NCS-diet (≤0.2%). The body weights of the rats, however, remained similar between different groups.

Effect of dietary fiber and crude protein content in feed on nitrogen retention in pigs

Eight gilts (29.9 ± 1.7 kg initial BW) were used to evaluate effects of dietary (crude) fiber on N excretion via feces and urine at 2 levels of dietary CP. Pigs were fed 4 dietary treatments according to a double 4 × 4 Latin square. Treatments were low (14%) CP and low (3.25%) (crude) fiber (LPAA), low CP and high (4.46%) fiber (LPAABP), high (18.8%) CP and low fiber (HP), and high CP and high fiber (HPBP). Diets were based on soybean (Glycine max) meal, wheat (Triticum aestivum), and maize (Zea mays) and were supplemented with crystalline AA. High fiber diets contained 15% dried beet (Beta vulgaris) pulp. Pigs were housed in metabolic cages and fed 2 equal meals at 0700 and 1700 h at a daily rate of 90 g/kg BW(0.75). Water was offered ad libitum. Each experimental period consisted of a 6-d adaptation followed by a 4-d collection of feces and urine (bladder catheters). Data were analyzed using ANOVA. Differences between means (P < 0.05) were assessed using Fisher's LSD procedure. The N intake, fecal N excretion and absorption, and N retention increased (P < 0.05) in pigs fed high-CP diets with added fiber (HP vs. HPBR). With added fiber, urinary N excretion (g/d) was reduced (P < 0.02) only for the low-CP diet. Urinary N as a percentage of N intake was reduced (P < 0.01) in both groups fed high-fiber diets irrespective of dietary CP content. Dietary fiber level did not affect DMI. Fecal DM excretion (g/d) was higher (P < 0.02) in pigs fed diets with high CP and high fiber content than in pigs fed diets with high CP and low fiber content. In conclusion, beet pulp fiber added to diets increased fecal N and reduced urinary N and in diets with higher CP content increased overall N retention.

The effect of increasing dietary fibre and the provision of straw racks on the welfare of sows housed in small static groups

This study assessed the effects of increasing dietary fibre levels in concentrate rations and providing access to straw in racks on the welfare of pregnant sows housed in small static groups. In a 2 × 2 factorial design experiment, 128 Large White × Landrace pregnant sows were offered one of two diets: (i) High fibre diet with 9% crude fibre, or (ii) Control diet with 4.5% CF, and one of two levels of access to a foraging substrate: (i) access to straw in racks or (ii) no straw. The study was replicated eight times using groups of four sows, and treatment periods lasted four weeks. Sows were housed in pens with voluntary cubicles and a slatted exercise area and were offered a wet diet twice a day. Back-fat levels were measured before sows were mixed into groups at 28 days post partum, and four weeks later. Aggressive interactions were recorded on the day of mixing, and injury scores were recorded one week post mixing. Scan sampling was used to collect data on general activity, posture and location of the sows, and on sham-chewing and bar-biting behaviours across the treatment period. In addition, detailed focal observations were carried out on all sows across the treatment period. Straw usage was also recorded. There were no treatment effects on changes in back-fat levels over the treatment period. Treatments had no effect on post-mixing aggression or on injury scores. However, focal observations showed that sows with access to straw were involved in fewer bouts of head-thrusting over the treatment period. Control diet sows spent more time inactive than sows on the high fibre diet, however high fibre diet sows spent more time lying with eyes closed than sows on the control diet. Sows on the high fibre diet with access to straw showed less sham-chewing and bar-biting behaviour than sows in other treatments. These results show that although a diet containing 9% crude fibre promoted resting behaviour, it was necessary to combine it with access to straw to reduce stereotypic behaviour of sows in small static groups.

The effect of feeding a high fibre diet on the welfare of sows housed in large dynamic groups

This study assessed the effect of increasing fibre levels in the concentrate ration on the welfare of sows housed in a large dynamic group. One hundred and twelve Large White * Landrace sows were allocated to one of two treatments over six replicates. Treatments were as follows: (i) High Fibre diet (~15% CF [Crude Fibre]), and (ii) Control diet (~5% CF). Treatments were applied to two separate dynamic groups each containing 33 (±3) sows in a cross-over design, after three replicates the treatments were switched between the groups. Approximately nine sows were replaced in each of these groups at 3-week intervals (each replacement constituting a replicate of the study). Sows on the high fibre diet spent a greater percentage of time lying (High Fibre: 43.8, Control: 28.0, SEM 3.25%), while sows on the control diet spent more time sham chewing (High Fibre: 7.2, Control: 28.8, SEM 1.55%). Sows newly introduced to the group on the high fibre treatment spent proportionally more time in the kennel areas compared to newly introduced sows in the control treatment (High Fibre: 0.893, Control: 0.788, SEM 5.10). In general, aggression occurred at a very low frequency and overall levels did not differ between treatments (High Fibre: 0.005, Control: 0.003, SEM 0.0007 [occurrences per min]). However, sows in the control treatment performed head thrusting (High Fibre: 0.02, Control: 0.00, SEM 0.001 [occurrences per min]), and biting behaviour (High Fibre: 0.02, Control: 0.01, SEM 0.002 [occurrences per min]) more frequently than sows on the high fibre diet. There was no effect of treatment on physiological parameters such as plasma cortisol (High Fibre: 1.34, Control: 1.44, SEM 0.114 ng ml−1) or haptoglobin levels (High Fibre: 0.73, Control: 0.64, SEM 0.080 mg ml−1). In summary, provision of a high fibre diet had a positive effect on the welfare of group-housed dry sows. Sows on the high fibre treatment spent more time resting in the kennel areas, less time performing stereotypic behaviours and showed a reduction in some aggressive behaviours relative to sows fed the control diet.

Influence of benzoic acid in high fibre diets on nutrient digestibility and VFA production in growing/finishing pigs

In a feeding trial with 32 crossbred gilts (13-108 kg bodyweight) the effect of benzoic acid (5 g/kg diet) in low (NDF: 150 g/kg DM) and high (NDF: 202 g/kg DM) fibre diets on performance and apparent nutrient digestibility was examined. The animals were restrictively fed one of four grower and finisher diets: low fibre diet without and with benzoic acid (LF- and LF+), and a high fibre diet without and with benzoic acid (HF- and HF+). At 56 kg bodyweight, four animals per diet were slaughtered to obtain data on volatile fatty acid (VFA) production in the gut. In the grower period, digestibility of nitrogen, energy and neutral detergent fibre was positively influenced by benzoic acid (p < 0.01) and reduced by fibre addition (p < 0.01). The concentration of butyric acid in caecum and colon was increased by benzoic acid (p < 0.05). Dietary fibre content did not influence VFA concentrations. It is concluded that the addition of benzoic acid helped animals to utilise high fibre diets better.

Effects of dietary fibre on behaviour and satiety in pigs

During the past decades there has been considerable interest in the use of dietary fibre in both animal and human nutrition. In human subjects dietary fibre has been studied intensively for possible effects on body-weight management and health. In animal nutrition the interest in dietary fibre has increased because it can be used as a cheap source of energy and because of its potential to improve animal welfare and reduce abnormal (mainly stereotypic) behaviour. Animal welfare is impaired if the diet does not provide sufficient satiety, combined with an environment that does not meet specific behavioural requirements related to natural feeding habits (e.g. rooting in pigs). A considerable proportion of the behavioural effects of dietary fibre are thought to be related to reduced feeding motivation. It has been hypothesized that: (1) bulky fibres increase satiety and thereby decrease physical activity and stereotypic behaviours immediately following a meal in pigs; (2) fermentable fibres prolong postprandial satiety and thereby reduce physical activity and appetitive behaviours for many hours after a meal. The validity of these hypotheses is examined by considering published data. In sows dietary fibres (irrespective of source) reduce stereotypic self-directed behaviours and substrate-directed behaviours, and to a lesser extent overall physical activity, indicating enhanced satiety shortly after a meal. Furthermore, fermentable dietary fibre reduces substrate-directed behaviour in sows and physical activity in sows and growing pigs for many hours after a meal. Evidence of long-term effects of poorly-fermentable fibre sources is inconclusive. The findings suggest that highly-fermentable dietary fibres have a higher potential to prolong postprandial satiety.

Effect of polyethylene glycol on in vitro degradability ofnitrogen and microbial protein synthesis fromtannin-rich browse and herbaceous legumes

A low (L) and high-fibre (H) diet were fed to six multiparous sows during gestation in a 2 × 2 repeated Latin square design. A single meal per day was given that provided 37·2 MJ digestible energy/d. The kinetics of heat production (HP) and its partitioning (fasting HP, activity HP, and thermic effect of feeding (TEF)) were determined. The TEF was partitioned between a dynamic component (TEFst) and a constant component (TEFlt). Digestibility of energy and nutrients was lower for the diet H. In spite of the lower metabolisable energy (ME) intake (33·9 v. 35·4 MJ/d for diets H and L respectively), HP was higher for diet H (30·5 v. 28·9 MJ/d) resulting in a lower energy retention. The estimated fasting HP was 270 kJ/kg body weight0·75 per d at day 0 of gestation and increased with advancement of pregnancy. The TEFlt was not significantly different from zero for diet L, but represented 4·1 % of ME intake for diet H. The TEFst was not affected by the diet but diet H delayed the postprandial peak of HP. Total TEF was higher for diet H than for diet L (11·7 v. 8·2 % of ME intake). The longer duration of eating with diet H was compensated for by less physical activity between meals, so that activity HP was equivalent for both diets. The activity HP represented 20 % of ME intake but was variable between sows. The ME requirements for maintenance averaged 440 kJ/kg body weight0·75per d. Feeding high-fibre diets increases HP, delays the postprandial peak of HP and maintains the basal HP at a higher level.

Dietary fiber stabilizes blood glucose and insulin levels and reduces physical activity in sows (Sus scrofa)

The aim of this study was to test whether a diet with a high level of fermentable dietary fiber can stabilize interprandial blood glucose and insulin levels, prevent declines below basal levels, and reduce physical activity in limited-fed breeding sows. Stable levels of glucose and insulin may prevent interprandial feelings of hunger and, consequently, increased activity. Catheterized sows (n = 10) were fed twice daily (0700 and 1900 h) 900 g of a diet with either a low (L-sows) or a high level of fermentable dietary fiber (H-sows; sugarbeet pulp). Blood samples, taken between feeding times, were analyzed for glucose and insulin levels (basal and area under the curve) and stability of levels (variance and sum of absolute differences between levels in consecutive samples). The main focus was on samples taken after the postprandial peak. Behavior was videotaped for analysis of postures and posture changes. Basal glucose and insulin levels did not differ between treatments. H-sows had more stable levels than L-sows. Interprandial levels of H-sows were higher than or equal to basal levels. L-sows showed a decline in glucose below basal levels at 1400 h (P < 0.05). Before 1400 h, no difference in the frequency of posture changes was observed between treatments. After 1400 h, the frequency of posture changes increased more in L-sows than in H-sows. We concluded that sugarbeet pulp as a source of fermentable dietary fiber stabilizes glucose and insulin levels and reduces physical activity in limited-fed sows several hours after feeding. This may indicate a prolonged feeling of satiety.

Effects of dietary fermentable carbohydrates on behavior and heat production in group-housed sows

The effects of dietary nonstarch polysaccharides (NSP) on behavior and heat production in group-housed sows were studied. Twelve groups of six nonpregnant sows were fed one of four experimental diets that were similar in composition except for starch and NSP contents. Exchanging sugar beet pulp silage (SBPS) for tapioca created the difference in dietary starch and NSP ratio. On a dry matter (DM) basis, diets contained 0, 10, 20, or 30% SBPS. Sows were group-housed. Intake of fermentable NSP (fNSP) for diets containing 0, 10, 20, or 30% SBPS averaged 7.06, 9.18, 11.61, and 13.73 g x kg(-0.75) d(-1), respectively. Sows were fed, once a day at 0800. Dry matter intake for diets containing 0, 10, 20, or 30% SBPS, averaged 38.05, 38.38, 38.53, and 38.35 g x kg(-075) x d(-1), respectively, and ME intake averaged 523, 518, 514, and 493 kJ x kg(-0.75) x d(-1), respectively. On average, sows spent 177 min/d on physical activity, of which 8.8% was spent on eating. Time spent in physical activity was affected by diet (P = 0.005). Sows fed 0 or 10% SBPS spent more time on physical activity than sows fed 20 or 30% SBPS (P = 0.002). Energy cost of physical activity averaged 464 kJ x kg(-0.75) x d(-1) (standard estimated mean of 31) and was similar for diets (P = 0.679). Total heat production (HP) and activity-related heat production (AHP) were affected by diet (P < 0.05). Sows tended to be quieter when fNSP intake increased (P = 0.063). The effect of fNSP intake on HP and AHP was not constant during the day. During the night period, fNSP intake did not affect HP and AHP (P > 0.10). During the day period, increased fNSP intake decreased HP (P = 0.006) and tended to decrease AHP (P = 0.062). During eating, increased fNSP intake increased HP (P = 0.012) and tended to increase AHP (P = 0.074). Despite similar DMI, sows fed 0 or 10% SBPS spent less time eating than sows fed 20 or 30% SBPS (P = 0.009). Feed consumption rate was higher (P = 0.003) in groups fed 0 or 10% SBPS than in groups fed 20 or 30% SBPS. Feed consumption rate decreased by 0.19 g DM x kg(-0.75). min(-1) (P = 0.003) for each gram of fNSP intake. The energy saving effect of physical activity on the NE value of fNSP from SBPS ranged between 2.3 and 3.7 kJ/g of fNSP intake. In conclusion, intake of fNSP from SBPS affected energy expenditure for physical activity (P = 0.063); however, this effect was not constant during the day.

The short-term feeding behavior of growing pigs fed foods differing in bulk content

We investigated the effects of foods of different bulk on the short-term feeding behavior (STFB) of 16 individually housed pigs. The three foods used had different bulk contents [low-control (C), medium-70% wheat bran (WB), and high-70% sugar beet pulp (SBP)]. We expected the different intakes of the foods to be reflected in differences in STFB. Three hypotheses were developed based on ideas about the way in which a physical constraint to intake could arise. H(1): there would be less diurnal variation in feeding on high-bulk foods that limit food intake. H(2): feeding patterns on the bulky foods would be less flexible than those on C. H(3): a change in food type would result in food intake and STFB being rapidly altered to become appropriate to the new food. There were significant differences in food intake and STFB between the foods as intended. Pigs fed WB and SBP spent longer eating and had a slower feeding rate (FR) than pigs fed C. H(1) was rejected, as there was no difference in diurnal variation in intake between the foods. Feeding was not extended into the night on WB and SBP and the proportion of feeding that occurred during the night was the same for all three foods. H(2) was supported, as pigs fed WB and SBP were unable to maintain food intake and performance when time of access to the feeder was reduced. There was no adaptive change in STFB. H(3) was supported as a change from WB or SBP to C, or vice versa, caused a rapid change in STFB so that it became appropriate to the new food. It is concluded that physical constraints to food intake, caused by food bulk, may bring about changes in STFB and that they are important for the regulation of intake of such foods.