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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 (P< 0.01) the incidence of postweaning diarrhea (PWD) and reduced (P< 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 (P< 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 (P< 0.05) with fiber inclusion, a reduction that was more pronounced (P< 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 Escherichia coliand Lactobacilluscounts in the cecum (P< 0.001) but the E. colito Lactobacillusratio was not affected. In Exp. 2 (dirty barn), fiber inclusion did not affect piglet performance but tended to increase PWD (P= 0.07). Also, fiber inclusion reduced (P< 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 (P< 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.

In total, 240 pigs were used to compare growth performance and carcass quality traits of immunocastrated males (ICM), surgically castrated males (SCM), and intact females (IF) of crossbreds from Large White × Landrace females and Duroc (DU) or Pietrain (PI) sires destined to the dry-cured industry. Between the 2 Improvac injections (87 and 137 d of age), ICM and IF had less ADG than SCM (P < 0.01). Also, ICM ate less feed than IF and both less than SCM (2.33, 2.55, and 2.77 kg/d; respectively; P < 0.001) and consequently, ICM had better G:F than SCM and IF (P < 0.001). From second Improvac injection to slaughter (137 to 164 d of age), ICM were more efficient than IF and both more efficient than SCM (0.346, 0.323, and 0.300 g/g; respectively; P < 0.001). The differences in growth performance among genders observed in this period were more pronounced for the PI than for the DU crossbreds (P < 0.05 for the interaction). For the entire experimental period (87 to 164 d of age), gender did not affect ADG for DU crossbreds but for PI crossbreds ICM and SCM had greater ADG than IF (P < 0.05 for the interaction). The ICM pigs had better feed efficiency (0.406, 0.364, and 0.380; g/g; P < 0.001) and lower carcass yield (76.6, 78.1, and 78.8%; P < 0.001) than SCM or IF. Carcasses from IF were leaner than carcasses from SCM with carcasses from ICM being intermediate (P < 0.01). Ham and loin (P < 0.001) yields were greater for IF than for ICM or SCM. Intramuscular fat content was lower for IF than for SCM with that of ICM being intermediate (3.5 vs. 3.9 and 3.7%; P < 0.05). Cumulatively, crossbreds from DU sires had greater ADG (1.167 vs. 0.986 kg/d; P < 0.001) and ADFI (3.07 vs. 2.56 kg/d; P < 0.001) and more intramuscular fat (P < 0.001) but less ham and loin yields (P < 0.01) than crossbreds from PI sires. It is concluded that growth performance was better but carcass yield less for ICM than for SCM and IF. Intramuscular fat content in LM was less for IF than for SCM with ICM intermediate. Crossbreds from Duroc sires grew faster and had more intramuscular fat but less ham yield than crossbreds from Pietrain sires. Therefore, ICM should be preferred to SCM and Duroc crossbreds should be preferred to Pietrain crossbreds to produce carcasses destined to the production of primal cuts for the dry-cured industry.

The influence of CP content and ingredient complexity, feed form, and duration of feeding of the Phase I diets on growth performance and total tract apparent digestibility (TTAD) of energy and nutrients was studied in Iberian pigs weaned at 28 d of age. There were 12 dietary treatments with 2 type of feeds (high-quality, HQ; and low-quality, LQ), 2 feed forms (pellets vs. mash), and 3 durations (7, 14, and 21 d) of supply of the Phase I diets. From d 7, 14, or 21 (depending on treatment) to d 35, all pigs received a common diet in mash form. Each treatment was replicated 3 times (6 pigs/pen). For the entire experiment, ADG (P < 0.05) and ADFI (P < 0.01) were less with the HQ than the LQ Phase I diets, but G:F was not affected. Pelleting of the Phase I diets did not affect ADG but improved G:F (P < 0.01). Feeding the Phase I diets from d 0 to 21 improved G:F (P < 0.05) but decreased ADG (P < 0.01) as compared with 7 or 14 d of feeding. Postweaning diarrhea (PWD) tended to be greater (P = 0.06) for pigs fed the HQ diets than pigs fed the LQ diets and pigs fed pellets than those fed mash (P < 0.001). Also, PWD was greater for pigs fed the Phase I diet for 14 or 21 d than those fed the diet for 7 d (P < 0.01). From d 0 to 21, ADG and G:F were not affected (P > 0.10) by feed quality, but feeding pellets or increasing the duration of feeding the Phase I diets improved G:F (P < 0.01). Also, in this period, PWD was greater with pellets than with mash and for pigs fed the Phase I diets for 14 or 21 d than for pigs fed the diet for only 7 d (P < 0.01). From d 21 to 35, pigs previously fed the LQ diet had greater ADG than pigs fed the HQ Phase I diets (P < 0.001). Also, pigs fed the Phase I diets for 21 d had decreased ADG (P < 0.05) and ADFI (P < 0.001) and reduced G:F (P < 0.05) than pigs fed these diets for 7 or 14 d. Organic matter digestibility was greater for pigs fed the HQ Phase I diets than pigs fed the LQ Phase I diets (P < 0.05). Pelleting improved TTAD of all nutrients (P < 0.01). It is concluded that HQ Phase I diets increased TTAD of nutrients but not feed efficiency of Iberian pigs from d 0 to 35. Also, pelleting improved energy and nutrient digestibility and feed efficiency. Increasing the duration of supply of the Phase I diets from 7 to 21 d improved feed efficiency but reduced ADG. Therefore, the use of LQ Phase I diets in pellet form for no more than 7 d after weaning is recommended in Iberian pigs.

An experiment was conducted to compare different dietary vegetable sources of starch and protein on the coefficient of apparent total tract digestibility (CATTD) of energy and nutrients and performance of piglets from 29 to 60 d of age. The experiment was completely randomized with 6 treatments arranged factorially with 3 sources of starch (cooked-flaked corn, cooked-flaked rice, and pea starch) and 2 sources of protein [soy protein concentrate (SPC) and pea protein concentrate (PPC)]. The pea starch and the PPC used were obtained by dehulling and grinding pea seeds to a mean particle size of 30 μm. Each treatment was replicated 6 times (6 pigs per pen). For the entire experiment, piglets fed cooked rice had greater ADG than piglets fed pea starch with piglets fed cooked corn being intermediate (471, 403, and 430 g/d, respectively; P< 0.05). Protein source did not have any effect on piglet performance. The CATTD of DM, OM, and GE were greater (P< 0.05) for diets based on cooked rice than diets based on cooked corn with diets based on pea starch being intermediate. Crude protein digestibility was not affected by source of starch but was greater for the diets based on SPC than for diets based on PPC (0.836 vs. 0.821; P< 0.01). Protein source did not affect the digestibility of any of the other dietary components. It is concluded that cooked rice is an energy source of choice in diets for young pigs. The inclusion of PPC in the diet reduced protein digestibility but had no effects on energy digestibility or piglet performance. Therefore, the finely ground starch and protein fractions of peas can be used in substitution of cooked corn or SPC, respectively, in diets for young pigs.

A total of 288 piglets weaned at 28 d and weighing 7.6 ± 0.2 kg were used in a 35-d experiment to evaluate the effect of CP content (44% vs. 49% CP) of soybean meal (SBM), micronization (fine grinding) of the 49% CP SBM (HP-SBM), and soy protein concentrate (SPC; 65% CP) on total tract apparent digestibility (TTAD) and growth performance. In phase I (d 0 to 21 of experiment), there was a positive control diet that included 6.5% of CP from a SPC with 65% CP and a negative control diet that supplied the same amount of CP as regular SBM (R-SBM) with 44% CP. The other 4 diets included the same amount of dietary CP from 2 different sources of HP-SBM that were either ground (990 μm) or micronized (60 μm). All diets were isonutritive, and the main difference was the source of SBM used. Each treatment was replicated 8 times (6 pigs per pen). In phase II (d 21 to 35), all pigs were fed a common commercial starter diet. For the entire phase I, the type of soy product did not affect growth performance of the pigs. However, from 0 to 7 d of experiment, pigs fed the micronized HP-SBM had better G:F (1.11 vs. 0.98; P <0.05) than piglets fed the ground HP-SBM. Also, from 7 to 14 d of experiment, ADFI tended to be greater (P =0.08) for pigs fed the micronized HP-SBM than for piglets fed the ground HP-SBM. During phase II (all the pigs received the same diet), no differences among treatments were observed. In general, TTAD of nutrients at 7 d of experiment was greater for the SPC than the R-SBM diet, with the HP-SBM diets being intermediate. The TTAD of CP was greater (83.8% vs. 81.9%; P≤ 0.01) for the SPC diet than the average of the SBM diets. Also, the digestibility of OM and DM was greater (P <0.01) for the HP-SBM either ground or micronized than the R-SBM diet. Micronization of the HP-SBM did not affect nutrient digestibility. It is concluded that when the R-SBM is substituted by SPC, CP digestibility is improved, but no effects are observed on growth performance. The use of the HP-SBM in substitution of the R-SBM in the diet improved nutrient digestibility but did not affect piglet performance. The inclusion of micronized HP-SBM in the diet improved G:F during the first week postweaning but did not affect TTAD of nutrients. In general, the inclusion of added-value soy products (SPC or micronized SBM) in the diet presents little advantage in terms of growth performance over the use of HP-SBM in pigs weaned at 28 d of age.

In total, 360 pigs slaughtered at 125 kg of BW and destined for the dry-cured industry were used to study the influence of sex and castration [immunocastrated males (IMC), surgically castrated males (CM), and intact females (IF)] in 2 terminal Large White sire lines [Top York (TY) and Tempo (TE)] on growth performance and carcass and meat quality. The female line was Large White × Landrace. The IMC pigs were immunized against gonadotropin-releasing factor (GnRF) with Improvac at 78 (experimental d 16) and 126 (experimental d 64, 48 d before slaughter) d of age. Each of the 6 treatments was replicated 6 times (10 pigs/pen). Through the day of the first Improvac injection (62 to 78 d of age), IMC and IF grew at a slower rate (P< 0.001) than CM with no differences (P= 0.95) in feed intake. The CM had greater G:F than IF, with IMC being intermediate (P< 0.01). From 78 to 126 d of age (between Improvac injections), the IMC pigs ate less feed (P< 0.001) and grew at a slower rate than CM, with IF being intermediate. The IMC pigs were more feed efficient than IF, and both were more efficient than CM (P< 0.001). However, from 126 to 174 d of age (from the second Improvac injection to slaughter), IMC pigs grew at a faster rate (P< 0.001) and were more efficient (P< 0.001) than IF and CM. Overall, IMC and CM pigs grew at a faster rate (P< 0.01) than IF, and IMC were more efficient than the other sexes (P< 0.001), but had reduced (P< 0.001) carcass yield compared with CM and IF. The IMC and IF pigs also had less (P< 0.001) backfat depth than CM. Intact females had greater (P< 0.01) loin yield but less intramuscular fat than IMC and CM and greater (P< 0.05) fresh and trimmed ham yields than CM, with IMC being intermediate. Crossbreds from TE sires grew at a faster rate (P< 0.001) than crossbreds from TY sires, but no differences (P= 0.23 and 0.14, respectively) were found for feed intake or efficiency. Crossbreds from TY produced greater (P< 0.05) fresh and trimmed ham yield, but less (P< 0.01) loin yield and intramuscular fat content than crossbreds from TE. In conclusion, IMC pigs are more efficient, but have less carcass yield than CM and IF. The intramuscular fat content is least for IF and similar for IMC and CM. Crossbreds from TE sires were larger and had greater intramuscular fat content, but slightly less trimmed ham yield compared with crossbreds from TY sires. Immunocastrated pigs can replace CM for the production of heavy pigs destined for the dry-cured industry. Because of increased carcass weight, crossbreds from TE sires may have an advantage over crossbreds from TY sires.

The effects of feeding corn or rice, either raw or heat processed (HP), on apparent total tract digestibility (ATTD) and apparent ileal digestibility (AID) of nutrients and on insulin and ghrelin concentrations in the serum were studied in young pigs. Pigs were weaned at approximately 23 ± 3 d of age and weighed 7.4 ± 1.2 kg. Each of the 4 treatments was replicated 9 times, and the experimental unit was a pig individually housed. Pigs (5 males and 4 females/treatment) were fed their respective diets ad libitum from 23 to 47 d of age. At 37 d of age, the effects of dietary treatments on the fasting and postprandial concentrations of insulin and total and acylated ghrelin were studied. The ATTD of OM, GE, and ether extract were, respectively, 4.3, 5.4, and 3.6% greater (P< 0.05) for the rice than for the corn diets, but CP digestibility was not affected. Similar results were observed for AID. Heat processing of the cereal increased (P< 0.05) the ATTD by 2.1% for OM, 3.2% for GE, 7.1% for ether extract, and 2.2% for CP and tended to increase the AID of CP (P= 0.06) and starch (P= 0.09). The postprandial serum insulin response was greater and was more prolonged in pigs fed raw rice than in pigs fed raw corn (P< 0.05). In addition, the effects of HP on serum insulin response were more pronounced with corn than with rice (cereal × HP, P< 0.05). Total ghrelin concentration was not affected by treatment, but acylated ghrelin was greater (P< 0.05) at 6 h postprandially in pigs fed rice than in pigs fed raw corn. Feeding rice and HP corn increased nutrient digestibility and insulin response in the early postprandial period and increased the acylated ghrelin response in the late postprandial period compared with feeding raw corn.

Iberian × Duroc pigs (n = 168), with an average age of 152 d and 42 ± 2 kg, were used to investigate the effect of feeding regimen [ad libitum access to feed (AL) vs. 82% of AL from 152 to 201 d of age and 72% from 202 to 263 d of age (FR)] and sex (intact females, castrated females, and castrated males) on growth performance and carcass and meat quality. For the last 54 d before slaughter at 317 d of age, all pigs had AL access to feed. Between 152 and 263 d of age, pigs consuming AL had greater (P< 0.001) ADFI and ADG than FR pigs; however, when all pigs received AL access to feed (264 to 317 d of age), ADFI (P< 0.05), ADG (P< 0.001), and G:F (P< 0.01) increased in FR pigs compared with AL pigs. During the entire feeding period (152 to 317 d of age), ADG in FR pigs was less (P< 0.01) than in AL pigs. Feed-restricted pigs tended to have greater (P< 0.10) yields of trimmed hams and shoulders and less carcass fat than AL pigs, but feeding regimens did not affect chemical composition and color of meat. Intact females tended (P< 0.10) to have greater G:F and produced carcasses with less (P< 0.05) fat, greater (P< 0.01) proportions of primal cuts, and greater (P< 0.05) CP in the LM than castrated females and castrated males. It was concluded from this experiment that feed restriction applied from 152 to 263 d of age improved primal cut yields without affecting G:F, pork quality, and cured ham production traits. Moreover, intact females were superior to their castrated counterparts (particularly castrated females) in growth performance and primal cut yields. Therefore, feed restriction in intact females can be recommended as an acceptable practice for the production of Iberian pigs under intensive conditions.

Crossbred pigs (n = 240) from Pietrain × Large White sires mated to Landrace × Large White dams, with an average age of 100 d (60.5 ± 2.3 kg of BW), were used to investigate the effects of sex and slaughter weight (SW) on growth performance and on carcass and meat quality characteristics. There were 6 treatments arranged factorially, with 3 classes (intact females, IF; castrated females, CF; and castrated males, CM) and 2 slaughter weights (114 and 122 kg of BW). Each of the 6 combinations of treatments was replicated 4 times, and the experimental unit was a pen with 10 pigs. Castrated males and CF ate more feed, grew faster, and had more carcass backfat depth and fat thickness at the gluteus medius muscle but lower loin yield than IF (P< 0.05). In addition, CF and CM had more intramuscular fat (P< 0.05) and less linoleic acid content in the subcutaneous fat (P< 0.01) than IF. Pigs slaughtered at 122 kg of BW had lower ADG (P< 0.05), decreased G:F (P< 0.05), and more gluteus medius fat than pigs slaughtered at 114 kg of BW (P< 0.05). It was concluded that CF and CM had similar productive performance and meat quality characteristics when slaughtered at the same age, and that castration of females improved ADG and increased weight and fat content of primal cuts with respect to IF. Therefore, castration of females is recommended in pigs destined for the dry-cured industry because of the beneficial effects on quality of the primal cuts.

A 28-d trial was conducted to evaluate the effect of the main cereal of the diet (corn or rice), heat processing (HP) of rice, and the degree of starch gelatinization (SG) of rice on apparent total tract digestibility (ATTD) of dietary components and productive performance of pigs weaned at 25 d of age. The experimental design was a completely randomized, with 4 treatments and 8 replicates per treatment (5 pigs penned together). Control pigs were fed a complex diet without growth promoters and based on milk products, fish meal, and 50% cooked and flaked corn, with a degree of SG of 84%. Experimental groups received the same complex diet as the control group, but the corn was substituted by rice with 3 different degrees of SG; 11% that corresponded to raw rice and 52 or 76% that corresponded to cooked rice processed under 2 different conditions. Pig growth was measured at 25, 39, and 53 d of age, and ATTD was determined at 29, 39, and 53 d of age. The ATTD of all dietary components except for N increased with age (P<0.01) and were greater for the rice than for the corn diet. Heat processing of rice improved ATTD of all dietary components at 29 d of age, but no beneficial effects were observed at 39 or 53 d of age. Modifying the conditions of HP to increase the degree of SG of rice from 52 to 76% and to reduce mean particle size from 480 to 405 μm did not result in further improvement of nutrient digestibility. From 25 to 53 d of age, pigs fed rice consumed more feed (678 vs. 618 g/d; P<0.05), grew faster (466 vs. 407 g/d; P<0.01), and tended to have greater G:F (0.685 vs. 0.662; P<0.10) than pigs fed corn. In fact, from 25 to 39 d of age, pigs fed rice consumed 23% more feed (P<0.01), grew 29% faster (P<0.01), and had 5% greater G:F (P<0.05) than pigs fed corn. Feeding rice improved performance of weanling pigs, and HP of rice under mild conditions enhanced diet digestibility and productive performance of pigs. Severe processing of rice increased the degree of SG but did not further improve diet digestibility or growth performance.

Crossbred pigs (n = 192) from Piétrain × Large White sires mated to Landrace × Large White dams, with a mean BW of 75 ± 1.3 kg, were used to investigate the effects of gender and slaughter weight (SW) on growth performance, carcass characteristics, and meat quality. Pens of pigs (eight pigs/pen) were assigned randomly to one of six treatments arranged in a 2 × 3 factorial design with two genders (barrows or gilts) and three SW (116, 124, or 133 kg). Each treatment was replicated four times. Over the entire trial, barrows had higher (P< 0.001) ADFI (as-fed basis) and ADG than gilts; however, gilts had higher (P< 0.05) gain-to-feed ratios (G:F) than barrows. Barrows had lower (P< 0.01) dressing percents than gilts and produced fatter (P< 0.001) carcasses that had lower trimmed shoulder (P< 0.10) and ham (P< 0.001) yields than gilts. There was a trend for the semimembranosus muscle (SM) from barrows to have a higher (P< 0.10) 45-min pH than that of gilts, but 24-h pH was 0.11 pH unit higher (P< 0.01) in the SM of barrows than gilts. Gender had no (P> 0.10) effect on the moisture and lipid content of the longissimus muscle (LM), nor did gender affect (P> 0.10) LM color, myoglobin content, or thaw loss percentage. However, the LM from barrows had lower (P< 0.05) cooking loss percentages and tended to have lower (P< 0.10) shear force values than the LM from gilts. Pigs slaughtered at 116 kg had higher (P< 0.05) ADG than pigs slaughtered at 124 and 133 kg. Daily feed intake (as-fed basis) was not (P> 0.10) different among SW; however, pigs slaughtered at 116 and 124 kg had higher (P< 0.001) G:F than those slaughtered at 133 kg. Dressing percent, backfat depth, carcass length, and ham and shoulder weights increased (P< 0.001) as SW increased from 116 to 133 kg. The initial (45-min) pH of the SM from pigs slaughtered at 133 kg was higher (P< 0.05) than from pigs slaughtered at 116 or 124 kg; however, 24-h pH was not (P> 0.10) affected by SW. The LM from pigs slaughtered at 133 kg was darker (lower L* values; P< 0.001), redder (higher a* value; P< 0.01), and had more (P< 0.001) myoglobin than the LM of pigs slaughtered at 116 and 124 kg. Barrows and gilts of this particular crossbreed can be used to produce acceptable quality fresh pork when slaughtered at 116 kg; however, increasing SW to 124 kg, or more, decreased live pig performance and carcass leanness without any additional benefits to pork quality attributes.

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)

1. Three trials were conducted to study the influence of diets containing between 40 and 550 g broad bean (Vicia faba, Major) meal/kg on performance, egg quality and pancreas characteristics of White Leghorn hens.2. The effect of broad beans on performance depended on the dietary content. Up to 100 g/kg did not affect productivity. Contents higher than 200 g/kg depressed egg weight (P<0.05). At 550 g/kg, food intake, egg weight and rate of egg production decreased but efficiency of food conversion was not impaired.3. At 550 g/kg broad beans caused an increase in albumen density (P < 0.01). Broad beans did not affect shell thickness.4. The size, weight, moisture content and histology of the pancreas were not affected by broad bean intake.

Two experiments were conducted to determine the influence of duration of storage of soybean meal (SBM) on variables that define the quality of the protein fraction. Urease activity, protein dispersibility index (PDI), KOH protein solubility (KOHsol), and trypsin inhibitor activity were determined. In experiment 1, 8 samples of SBM, ranging in CP content from 55.4 to 56.5% DM, were collected from a US crushing plant at weekly intervals and analyzed at arrival to the laboratory and after 30, 60, 90, and 120 d of storage. In experiment 2, 7 samples of SBM, ranging in CP content from 49.0 to 55.0% DM, were collected from different Argentinean crushers and analyzed at arrival and after 24, 48, 80, and 136 wk of storage. In both experiments, samples were stored in hermetic glass containers in a laboratory room at 12 ± 2°C and a relative humidity of 70 ± 3%. Duration of storage did not affect urease activity or trypsin inhibitor activity values in either of the 2 experiments. However, PDI values decreased linearly with time of storage in both experiments (P < 0.001). Also, KOHsol decreased linearly (P < 0.05) with duration of storage in experiment 2 (long-term storage) but not in experiment 1 (shorter term storage). Therefore, PDI values might not be adequate to compare protein quality of commercial SBM samples that have been stored for different periods of time. The KOHsol values are less affected by length of storage of the meals under current commercial practices.

The ban on the use of antibiotics in feeds as growth promoters in many countries throughout the world has increased the incidence of enteric disorders in poultry. Natural additives, inclusion of whole cereals, feeding coarse mash diets, and increasing the level of fiber in the diets have been explored as nutritional strategies to reduce the incidence of the problem. Traditionally, dietary fiber has been considered a diluent of the diet and, often, an antinutritional factor. However, moderate amounts of fiber might improve the development of organs, enzyme production, and nutrient digestibility in poultry. Some of these effects are a consequence of better gizzard function, with an increase in gastroduodenal refluxes that facilitate the contact between nutrients and digestive enzymes. These effects often result in improved growth and animal health, but the potential benefits depend to a great extent on the physicochemical characteristics of the fiber source. In conclusion, poultry require a minimal amount of fiber in the diet for proper functioning of the digestive organs. The response to fiber inclusion depends on the source and level of dietary fiber and the characteristics of the diet as well as on the physiological status and health of the bird. In particular, the inclusion in the diet of moderate amounts of coarse, insoluble fiber sources, such as oat hulls, at levels between 2 and 3% usually improves the growth performance of broilers fed low-fiber diets.

The restrictions in the use of in-feed antibiotics and proteins of animal origin in many European countries have increased the incidence of enteric disorders in poultry. Management and dietary changes have been suggested to reduce the negative effects of enteritis on broiler performance and carcass quality. Practices used in this respect are enhancement of the development of the gastrointestinal tract, improvement of nutrient digestibility, and modification of the conditions of the intestinal contents to promote a balanced growth of native flora. The most promising areas of research are the use of enzymes and the inclusion of whole grains in the diet. Areas of interest, but needing large amounts of basic information, include studies on the interrelationship between diet composition and the microbiota within the gastrointestinal tract. Also, the influence of processing of diets and ingredients and of the inclusion of natural additives on digestive physiology and microflora growth deserves attention. In conclusion, dietary manipulation of the diet together with management changes will reduce to manageable levels the problems associated with the ban of use of growth promoters in broiler feeds.

This experiment was conducted to test the influence of three dietary sources of yellow (YEW) and two sources of red (RED) oxycarotenoids when combined at two different YEW to RED ratios (a 3x2x2 factorial arrangement of treatments) on egg yolk color. Pigmentation was measured visually by the Roche color fan (RCF) and by reflectance colorimetry using a Minolta CR-300 colorimeter. Source of YEW, RED, and YEW:RED ratio influenced yolk pigmentation. Beta-apo-8’-carotenoic acid ethyl ester pigmented the yolk more efficiently than either of two natural saponified marigold extracts. A natural saponified marigold extract rich in zeaxanthin obtained by isomerization pigmented the yolk better than a standard saponified marigold concentrate. Canthaxanthin pigmented the yolk better than a natural saponified red pepper extract. A YEW:RED ratio of 8:4 improved pigmentation over a ratio of 12:3 (RCF of 13.3 and 12.9, respectively; P<.001). The ratio of redness to yellowness obtained by reflectance colorimetry gave scores similar to those obtained by RCF. Thus, industry use of RCF or reflectance colorimetry to evaluate egg yolk color will yield indistinguishable results in practical application.

A study was conducted to test the effects linolenic acid (LIN) content of the diet on egg production, weight of eggs and egg components, and commercial value of eggs of Isabrown hens 20-32 wk of age. Four diets were formulated using as many ingredients as economically feasible. All the diets had the same energy and nutrient content except for LIN, which was 0.79, 1.03, 2.23, and 2.73%. Diet did not influence hen-day production, feed intake, feed conversion, egg mass output, or body weight (BW) change. From 20-32 wk of age, increasing the LIN content of the diet from 0.79 to 1.03% or more and at the same time increasing the added fat from 0.60 to 3.8% or more increased egg weight (P=.09). Weights of shell, yolk, and albumen were not modified by the experimental treatment, but hens fed the 0.79% LIN diet produced eggs with a greater yolk: albumen ratio (P<.05) than the 1.03% LIN to maximize egg size at the beginning of the laying period when fed practical diets containing 6.2% ether extract.