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The effects of feed form and dietary fiber on the development of the gastrointestinal tract (GIT) and nutrient digestibility were studied in broilers at 8 and 21 d of age. The experiment included 14 treatments arranged as a 2 × 7 factorial with 2 feed forms (mash vs. pellet) and 7 diets that consisted in a low fiber diet and 6 extra diets resulting from the combination of 3 insoluble fiber sources [oat hulls (OH), rice hulls, and sunflower hulls] and 2 levels of inclusion (2.5 and 5.0%). Pelleting decreased the relative weight (% BW) of the full GIT, and empty gizzard (P < 0.001) and the relative length (cm/kg empty BW) of the small intestine and ceca (P < 0.001) and increased full crop (P < 0.001) and liver (P < 0.05) weights. Fiber inclusion increased the empty weight and the fresh digesta content of the gizzard (P < 0.001) but had limited and inconsistent effects on the weight of the full GIT or the length of the small intestine and ceca. Gizzard pH decreased with mash feeding and fiber inclusion (P < 0.001). Pelleting decreased ether extract retention (P < 0.05) but did not affect N retention or AMEn of the diets. Fiber inclusion improved nutrient retention (P < 0.05 to P < 0.001) with more pronounced effects with OH than with sunflower hulls or rice hulls inclusion. The AMEn of the diets increased (P < 0.05) with 2.5% of fiber inclusion but no extra benefits were obtained with a further increase to 5.0%. Starch ileal digestibility increased with mash feeding (P < 0.001) and fiber supplementation (P < 0.05). In summary, pelleting increases full crop weight and gizzard pH and decreased full gizzard weight and starch ileal digestibility. Moderate amounts of insoluble fiber, especially OH, increases gizzard weight, reduces gizzard pH, and improves nutrient digestibility in young broilers., (© 2019 Poultry Science Association Inc.)

This research studied the effects of additional fiber in the rearing phase diets on egg production, gastrointestinal tract (GIT) traits, and body measurements of brown egg-laying hens fed diets varying in energy concentration from 17 to 46 wk of age. The experiment was completely randomized with 10 treatments arranged as a 5 × 2 factorial with 5 rearing phase diets and 2 laying phase diets. During the rearing phase, treatments consisted of a control diet based on cereals and soybean meal and 4 additional diets with a combination of 2 fiber sources (cereal straw and sugar beet pulp, SBP) at 2 levels (2 and 4%). During the laying phase, diets differed in energy content (2,650 vs. 2,750 kcal AMEn/kg) but had the same amino acid content per unit of energy. The rearing diet did not affect any production trait except egg production that was lower in birds fed SBP than in birds fed straw (91.6 and 94.1%, respectively; P < 0.05). Laying hens fed the high energy diet had lower feed intake (P < 0.001), better feed conversion (P < 0.01), and greater BW gain (P < 0.05) than hens fed the low energy diet but egg production and egg weight were not affected. At 46 wk of age, none of the GIT traits was affected by previous dietary treatment. At this age, hen BW was positively related with body length (r = 0.500; P < 0.01), tarsus length (r = 0.758; P < 0.001), and body mass index (r = 0.762; P < 0.001) but no effects of type of diet on these traits were detected. In summary, the inclusion of up to 4% of a fiber source in the rearing diets did not affect GIT development of the hens but SBP reduced egg production. An increase in the energy content of the laying phase diet reduced ADFI and improved feed efficiency but did not affect any of the other traits studied., (© 2016 Poultry Science Association Inc.)

The effects of feed form and the inclusion of insoluble fiber in the diet on growth performance and water intake were studied in female broilers from 0 to 21 d of age. The experimental design was completely randomized with 14 treatments arranged as a 2 × 7 factorial with 2 feed forms (mash vs. pelleted) and 7 diets that consisted of a control diet low in fiber (1.6% crude fiber) based on broken rice, fermented soybean meal, and fish meal and 6 extra diets that resulted from the inclusion of 3 insoluble fiber sources (oat hulls; OH, rice hulls; RH, and sunflower hulls; SFH) at 2 levels (2.5 vs. 5%). Each treatment was replicated 6 times. Broilers fed pellets had 32% greater ADG and 3% better feed to gain ratio (F:G) than those fed mash (P ≤ 0.001). The inclusion of the fiber sources improved ADG (P ≤ 0.05) and F:G (P ≤ 0.05). Pelleting increased (P ≤ 0.001) water intake from 6 to 8 d, water-to-feed intake ratio from 18 to 20 d, and moisture content of the excreta at 20 d of age. The inclusion of the insoluble fiber sources increased water intake (P ≤ 0.05) from d 18 to 20 but not from d 6 to 8. Increasing the level of fiber inclusion from 2.5 to 5.0% tended to increase (P = 0.086) moisture content in the excreta at d 20. Pelleting and the inclusion of insoluble fiber sources improved ADG and F:G in broilers fed low-fiber diets, and the improvements observed were more pronounced with pellets than with mash. Growth performance of young broilers improves with the addition of moderate amounts of structural insoluble fiber in the diet, regardless of feed form. The inclusion of OH or SFH into low fiber diets was more beneficial for improving broiler performance than the inclusion of RH., (© 2015 Poultry Science Association Inc.)

We investigated the effects of fiber inclusion in the diet on growth performance and digestive traits in pullets from hatching to 17 wk of age. The control diets of the 3 feeding periods (0 to 5 wk, 5 to 10 wk, and 10 to 17 wk) were based on corn and soybean meal and did not include any additional fiber source. The experimental diets included 2 or 4% of cereal straw or sugar beet pulp (SBP) at the expense (wt:wt) of the control diet. From 0 to 5 wk of age, fiber inclusion did not affect pullet performance. From hatch to 17 wk of age, the inclusion of straw had little effect on pullet performance but the inclusion of 4% SBP reduced (ADG) (P < 0.05) and reduced feed conversion ratio (FCR; P < 0.001). Pullets fed straw had greater ADG (P < 0.05) and better energy conversion ratio (P < 0.01) than pullets fed SBP. An increase in fiber from 2 to 4% reduced FCR (P < 0.05). Body weight uniformity was not affected by diet. Fiber inclusion increased the relative weight (% BW) of the gizzard at 5 wk (P = 0.056) and 10 wk (P < 0.01) of age, but no differences were detected between fiber sources. At same ages, the relative length (cm/kg BW) of the pullets (P = 0.058 and P < 0.01, respectively) and tarsus (P = 0.079 and P < 0.05, respectively) was higher in pullets fed SBP than in pullets fed straw. Fiber inclusion, however, did not affect any of these traits at 17 wk of age. In summary, the inclusion of 2% straw at the expense (wt:wt) of the whole diet did not affect pullet performance at 17 wk of age. An increase in the level of straw from 2 to 4% reduced FCR but did not affect ADG. The inclusion of SBP, however, reduced pullet growth, with effects being more pronounced at the higher level., (© 2015 Poultry Science Association Inc.)

Two experiments were conducted to study the effects of inclusion of additional fiber in the Phase I diet on growth performance and nutrient digestibility in piglets reared under "optimal" or "poor" hygienic conditions. In both experiments, the design was completely randomized with a control diet that contained 2.2% crude fiber and 8 additional isonutritive diets that included 2.5 or 5.0% of sugar beet pulp (SBP), straw, oat hulls (OH), or wheat middlings (WHM). Preplanned polynomial contrasts were used to study the effects of 1) fiber inclusion (control diet vs. average of the 8 fiber-containing diets), 2) source of fiber, 3) level of fiber, and 4) interaction between source and level of fiber. In Exp. 1 (clean barn), fiber inclusion increased ( < 0.01) the incidence of postweaning diarrhea (PWD) and reduced ( < 0.05) feed efficiency and apparent total tract digestibility (ATTD) of all nutrients except that of CP, which was not affected. Piglet performance was not affected by source or level of dietary fiber. The ATTD of all nutrients decreased ( < 0.05) as the level of fiber increased and was lower in pigs fed straw or OH than in pigs fed SBP or WHM. The apparent ileal digestibility of GE and DM decreased ( < 0.05) with fiber inclusion, a reduction that was more pronounced ( < 0.05) with straw or SBP than with OH inclusion, with WHM inclusion being intermediate. Fiber inclusion did not affect villous height to crypt depth ratio of the ileum mucosa. The inclusion of 5% of a fiber source increased and counts in the cecum ( < 0.001) but the to ratio was not affected. In Exp. 2 (dirty barn), fiber inclusion did not affect piglet performance but tended to increase PWD ( = 0.07). Also, fiber inclusion reduced ( < 0.05) the ATTD of all dietary components except that of CP, which was not affected. Source and level of fiber did not affect ATTD of nutrients except for DM, which was greater for pigs fed SBP than for pigs fed straw ( < 0.05). In conclusion, in the current research, pigs reared under optimal hygienic conditions had lower incidence of PWD, better growth performance, and greater DM and GE digestibility than pigs reared under poor hygienic conditions. An excess of dietary fiber was more detrimental for all these traits in piglets reared under optimal hygienic conditions. The effects of the source and level of fiber on piglet performance was limited in the 2 experiments.

The effects of fiber inclusion, feed form, and energy concentration of the diet on the growth performance of pullets from hatching to 5 wk age were studied in 2 experiments. In Experiment 1, there was a control diet based on cereals and soybean meal, and 6 extra diets that included 2 or 4% of cereal straw, sugar beet pulp (SBP), or sunflower hulls (SFHs) at the expense (wt/wt) of the whole control diet. From hatching to 5 wk age fiber inclusion increased (P<0.05) ADG and ADFI, and improved (P<0.05) energy efficiency (EnE; kcal AMEn/g ADG), but body weight (BW) uniformity was not affected. Pullets fed SFH tended to have higher ADG than pullets fed SBP (P=0.072) with pullets fed straw being intermediate. The feed conversion ratio (FCR) was better (P<0.05) with 2% than with 4% fiber inclusion. In Experiment 2, 10 diets were arranged as a 2×5 factorial with 2 feed forms (mash vs. crumbles) and 5 levels of AMEn (2,850, 2,900, 2,950, 3,000, and 3,050 kcal/kg). Pullets fed crumbles were heavier and had better FCR than pullets fed mash (P<0.001). An increase in the energy content of the crumble diets reduced ADFI and improved FCR linearly, but no effects were detected with the mash diets (P<0.01 and P<0.05 for the interactions). Feeding crumbles tended to improve BW uniformity at 5 wk age (P=0.077) but no effects were detected with increases in energy concentration of the diet. In summary, the inclusion of moderate amounts of fiber in the diet improves pullet performance from hatching to 5 wk age. The response of pullets to increases in energy content of the diet depends on feed form with a decrease in feed intake when fed crumbles but no changes when fed mash. Feeding crumbles might be preferred to feeding mash in pullets from hatching to 5 wk age., (© 2015 Poultry Science Association Inc.)

The effects of inclusion of cellulose or inulin as a source of dietary fiber and CP content of the diet on hepatic fat deposition were investigated in hens fed restricted or close to ad libitum consumption. There were 12 dietary treatments forming a 2 × 3 × 2 factorial with 2 feeding regimens [restricted and liberal (close to ad libitum consumption; LIB)], 3 fiber sources (control, 3% inulin, and 3% cellulose), and 2 levels of CP (14.5 and 17.4%). Hens were assigned in groups of 6 to 60 floor pens. From 43 to 55 wk of age, hens fed LIB showed increased activity of the hepatic malic enzyme (MalE; P < 0.01), which led to an increase (P < 0.001) in liver weight and hepatic lipid deposition and was associated with enhancements (P < 0.05) in plasma levels of glucose, triglyceride, total cholesterol, and low-density lipoprotein cholesterol. Abdominal fat deposition and BW of the hens increased (P < 0.001) with liberal feeding. Inclusion of inulin in the diet reduced (P < 0.05) liver and abdominal fat weight, whereas cellulose inclusion decreased (P < 0.05) feed intake, abdominal fat, and BW. An increase in CP content of the diet from 14.5 to 17.4% reduced MalE activity (P < 0.001), liver weight (P < 0.001), and the accumulation of lipids and cholesterol in the liver, as well as plasma triglyceride concentration and abdominal fat pad weight (P < 0.05). It is concluded that fiber inclusion reduced abdominal fat and liver weight, with effects being more pronounced with cellulose than with inulin. An increase in dietary CP reduced MalE activity and alleviated hepatic and plasma lipid concentration; therefore, it might be a practical approach to reduce the incidence of obesity-linked problems in broiler breeder hens. The combination of high-CP diets and the inclusion of a fiber source did not suppress liver lipid content over that observed with the high-CP diet, exclusively.

A 12-wk experiment was conducted to study the effects of feeding regimen, inclusion of a fiber source, and CP content of the diet on performance of broiler breeder hens. In total, 360 hens and 60 males, 43 wk of age, were assigned to 60 floor pens (6 hens and 1 male each). There were 12 treatments arranged factorially with 2 feeding regimens [restricted (R) and liberal feeding (close to ad libitum consumption; LIB)], 3 sources of fiber (0, 3% inulin, and 3% cellulose), and 2 levels of CP (14.5 and 17.4%). No interactions among main effects were observed for any of the traits studied, and therefore, only main effects are presented. Body weight, liver weight, and abdominal fat weight were higher (P < 0.001) for the LIB than for the R-fed hens. However, egg production (P < 0.001), fertility index (P < 0.05), and percentage of hatch (P < 0.01) were lower for LIB than for R hens. The weights of ovaries (P < 0.05) and the size of the first preovulatory follicle (P < 0.05) were higher for the LIB than for the R hens. Also, egg yolk, egg weight, and BW of the hatching chicks were higher (P < 0.001) for the LIB hens. The inclusion of a fiber source in the diet decreased (P < 0.05) feed intake, BW gain, absolute liver and abdominal fat weight, and egg yolk weight, with effects being more pronounced (P < 0.05) with cellulose than with inulin. Hens fed additional fiber produced more (P < 0.05) eggs that were more fertile (P < 0.05) than control hens. Crude protein content of the diet did not affect hen performance but reduced (P < 0.01) the relative weight of the liver, ovary, and abdominal fat. It is concluded that the inclusion of inulin or cellulose in the diet improved hen performance and that an increase in dietary CP reduced obesity in broiler breeder hens.

A trial was conducted to study the effects of type and particle size of dietary fiber on growth performance and digestive traits of broilers from 1 to 21 d of age. There was a negative control diet with 1.54% crude fiber, a positive control diet that included 3% cellulose (CEL), and 4 additional diets arranged factorially that included 3% oat hulls (OH) or sugar beet pulp (SBP) ground through a 0.5- or a 2.0-mm screen. For the entire experimental period, fiber inclusion improved BW gain (P≤0.01) and feed conversion ratio (P≤0.001), but particle size of the fiber source did not affect performance. The relative weight of the gizzard was higher (P≤0.001) with OH and SBP than with CEL or the control diet. Also, gizzard weight decreased (P≤0.001) with a reduction in particle size of the fiber source. Fiber inclusion increased HCl concentration and reduced gizzard pH (P≤0.01), and the effects were more noticeable with OH and SBP than with CEL. Fiber inclusion increased total tract apparent retention of nitrogen (P≤0.001) and soluble ash (P≤0.001) as well as the AMEn of the diet (P≤0.001). All of these effects were in general more pronounced with OH than with CEL, with SBP being intermediate. A reduction in particle size of the OH and SBP improved total tract apparent retention of DM (P≤0.001), nitrogen (P≤0.05), and soluble ash (P≤0.01) as well as the AMEn of the diet (P≤0.05). It is concluded that additional OH and SBP improves gizzard weight and growth performance in young chicks fed low-fiber diets and that the effects are more pronounced with OH than with CEL. Particle size of OH and SBP does not affect broiler performance, but coarse grinding increases gizzard development and reduces nutrient digestibility in young birds.

The influence of fiber source and dietary fat level on digestive traits and productive performance was studied in broilers from 1 to 21 d of age. There were 6 treatments arranged factorially with 3 sources of fiber (none; 3% oat hulls, OH; and 3% sugar beet pulp, SBP) and 2 fat sources (5% soybean oil, SO; and 5% yellow grease, YG). Each treatment was replicated 6 times and the experimental unit was a cage with 18 broilers. Fiber inclusion improved BW gain (P < or = 0.05) and feed:gain ratio (P < or = 0.001) and increased total tract apparent retention (TTAR) of all nutrients measured (P < or = 0.001). The increases observed in TTAR of nitrogen and ether extract and on AME(n) of the diet were more pronounced with OH than with SBP. The increases in nutrient digestibility with OH inclusion were higher at excreta than at ileal level and in fact, SBP inclusion reduced the apparent ileal digestibility of most nutrients. The relative weight (%) of the gizzard was increased (P < or = 0.001) and the pH of its contents was reduced (P < or = 0.001) when additional fiber was included in the diet. The TTAR of nutrients was higher for the SO than for the YG diets (P < or = 0.001). Also, the increases in ether extract digestibility (P < or = 0.05) and AME(n) (P < or = 0.05) of the diet with fiber inclusion were more pronounced with the YG than with the SO. Therefore, the inclusion of moderate amounts of fiber in the diet might improve performance and nutrient digestibility in young chicks, especially when saturated fats are used.

We studied the influence of the cereal (corn and rice), heat processing (HP) of the cereal (raw and steam cooking), and fiber inclusion (none; 3% oat hulls, OH; and 3% soy hulls, SH) in low-fiber diets on the development and pH of the digestive tract in broilers. There were 12 treatments arranged factorially and 3 replicates (a cage with 12 chicks) per treatment. Digestive traits were measured at 1, 5, 9, 15, and 22 d of age, and digesta pH was determined at 22 d of age. The relative weight (% BW) of proventriculus and gizzard was greater in chicks fed corn than in chicks fed rice (P < or = 0.01). Heat processing had little effect on relative weight (RW) of the digestive organs. An interaction between cereal and HP of the cereal was detected for the gizzard and the liver; HP of corn reduced RW of the gizzard and increased that of the liver, but no effect was observed with HP of rice. The RW of the proventriculus was increased by SH inclusion (P < or = 0.05), whereas the RW of the gizzard was increased by OH inclusion (P < or = 0.001). Also, SH inclusion increased gizzard digesta (P < or = 0.01) and moisture (P < or = 0.001) content. Dietary treatment did not affect relative length (cm/kg of empty BW) of the intestines. Feeding rice tended to increase gizzard digesta pH (P = 0.081) but reduced that of the intestines (P < or = 0.001). Neither HP of the cereal nor hull inclusion affected pH of the digestive tract. We conclude that the RW of the proventriculus and gizzard is reduced by feeding rice and increased by hull inclusion. Dietary treatment had little effect on the weight and relative length of the intestines. Chicks might require a minimal amount of fiber in the diet to stimulate the development of the upper gastrointestinal tract.

We studied the influence of cereal, heat processing of the cereal, and inclusion of additional fiber in the diet on the productive performance and digestive traits of broilers from 1 to 21 d of age. Twelve treatments were arranged factorially, with 2 cereals (corn and rice), 2 heat-processing treatments of the cereals (raw and cooked), and 3 sources of fiber (none, 3% oat hulls, and 3% soy hulls). Each treatment was replicated 6 (trial 1) or 3 (trial 2) times. Growth traits were recorded in both trials; digestive traits were measured in trial 1, and total tract apparent retention (TTAR) of nutrients was determined in trial 2. Feeding rice improved TTAR of all nutrients and feed conversion from 1 to 21 d of age (P

The optimal level of starch in diets for rabbit does was investigated. Five isoenergetic and isoproteic diets containing 26.6, 24.6, 19.0, 16.8, or 13.0% starch and 31.2, 33.4, 36.0, or 41.2% NDF, respectively (DM basis), were made by substitution of starch for NDF and fat. The effect of diet on nutrient digestibility was determined in fattening and nonlactating and lactating adult does using a total of 105 rabbits. Increasing dietary starch content linearly increased (P < .001) DM, GE, CP (P = .07), and starch digestibilities but decreased (P < .001) NDF digestibility. Nutrient digestibility was higher (P < .05), except for CP, in adult does than in fattening rabbits. Dry matter and GE digestibilities were higher (P = .08) for nonlactating than for lactating does. A lactation trial using 440 rabbit does was conducted over a 6-mo experimental period. Milk production and milk composition were measured in 70 lactations. A decrease in dietary starch content did not improve pup mortality before weaning but impaired (linear, P < .001) dry feed intake and pup growth from 21 d until weaning. Diet did not influence does' feed intake, milk DM, ether extract, and CP contents or prolificacy. However, diet had quadratic effects on milk production (P = .15), milk lactose content (P = .07), parturition interval (P = .02), and feed conversion efficiency (P = .02), expressed both per weight or number of pups weaned. Optimal values were reached for dietary starch and NDF contents at approximately 20 and 35.5% (DM basis), respectively.(ABSTRACT TRUNCATED AT 250 WORDS)