Inclusion of insoluble fiber sources in mash or pellet diets for young broilers. 1. Effects on growth performance and water intake.

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.

Inclusion of fiber in diets for brown-egg laying pullets: Effects on growth performance and digestive tract traits from hatching to 17 weeks of age.

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.

Feed form and energy concentration of the diet affect growth performance and digestive tract traits of brown-egg laying pullets from hatching to 17 weeks of age.

The influence of feed form and energy concentration of the diet on growth performance and the development of the gastrointestinal tract (GIT) was studied in brown-egg laying pullets. Diets formed a 2 x 5 factorial with 2 feed forms (mash vs. crumbles) and 5 levels of energy differing in 50 kcal AMEn/kg. For the entire study (0 to 17 wk of age) feeding crumbles increased ADFI (52.9 vs. 49.7 g; P < 0.001) and ADG (12.7 vs. 11.6 g; P < 0.001) and improved feed conversion ratio (FCR; 4.18 vs. 4.27; P < 0.001). An increase in the energy content of the diet decreased ADFI linearly (P < 0.001) and improved FCR quadratically (P < 0.01) but energy intake (kcal AMEn/d) was not affected. BW uniformity was higher (P < 0.05) in pullets fed crumbles than in those fed mash but was not affected (P > 0.05) by energy content of the diet. At 5, 10, and 17 wk of age, the relative weight (RW, % BW) of the GIT and the gizzard, and gizzard digesta content were lower (P < 0.05 to P < 0.001) and gizzard pH was higher (P < 0.05 to P < 0.001) in pullets fed crumbles than in pullets fed mash. Energy concentration of the diet did not affect any of the GIT variables studied. In summary, feeding crumbles improved pullet performance and reduced the RW of the GIT and gizzard, and increased gizzard pH at all ages. An increase in the energy content of the diet improved FCR from 0 to 17 wk of age. The use of crumbles and the increase in the AMEn content of the diet might be used adventageously when the objetive is to increase the BW of the pullets. However, crumbles affected the development and weight of the organs of the GIT, which might have negative effects on feed intake and egg production at the beginning of the egg laying cycle.

Influence of the main cereal and feed form of the rearing phase diets on performance, digestive tract, and body traits of brown-egg laying pullets from hatch to 17 weeks of age.

The effects of the main cereal and feed form of the rearing phase diets on growth performance, gastrointestinal tract characteristics, and body traits were studied in brown-egg pullets from hatch to 17 wk of age. Eight dietary treatments that were a combination of 2 main cereals (corn vs. wheat) and 4 feeding programs were used. The feeding program consisted in feeding crumbles from 0 to 5, 0 to 10, or 0 to 17 wk of age followed by mash until 17 wk, or feeding mash continuously from 0 to 17 wk. Each treatment was replicated 9 times. From hatch to 17 wk of age, pullets fed corn had similar ADG but poorer feed conversion ratio (FCR; P < 0.001) than pullets fed wheat. Also, pullets fed crumbles continuously (0 to 17 wk) had greater ADG (12.3 vs. 11.5 g; P < 0.001) and better FCR (4.21 vs. 4.36; P < 0.001) than pullets feed mash continuously, with pullets that were changed at any age of the rearing period from crumbles to mash feeding showing intermediate results. At 17 wk of age, the relative weights (% BW) of the gastrointestinal tract and gizzard were greater in pullets fed corn than in pullets fed wheat (P < 0.01) but the relative length (cm/kg full BW) of the small intestine, body, and tarsus was not affected. Pullets fed crumbles continuously had lighter gizzards (P < 0.001), higher gizzard pH (P < 0.001), and were shorter (P < 0.01) than pullets fed mash continuously, with pullets fed the other 2 treatments being intermediate. In summary, wheat can be used in substitution of corn in pullet diets without any adverse effect on growth performance. Feeding crumbles improves pullet performance but hinders gizzard and gastrointestinal tract development. Growth performance, gastrointestinal tract, and body traits of the pullets re-adapt quickly to changes in feed form of the rearing diets.

Productive performance of brown-egg laying pullets from hatching to 5 weeks of age as affected by fiber inclusion, feed form, and energy concentration of the diet.

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.

Hydrolyzed porcine mucosa in broiler diets: effects on growth performance, nutrient retention, and histomorphology of the small intestine.

The effect of including hydrolyzed porcine mucosa sprayed into soybean meal (HPM) in the diet was studied in broilers. In experiment 1 (pen study), 1,080 one-day-old chicks were used in a completely randomized design with 8 treatments arranged as a 4 × 2 factorial with 4 levels of HPM (0, 2.5, 5.0, and 7.5%) and 2 levels of Lys (1.23 and 1.38%). From d 1 to 22, HPM inclusion quadratically improved BW gain (BWG, P < 0.01) and feed conversion ratio (FCR, P < 0.01). From d 1 to 8, birds fed 1.38% Lys had higher BWG (P < 0.05) and better FCR (P < 0.05) than birds fed 1.23% Lys but only a trend (P < 0.08) for improved BWG was detected from d 1 to 22. From d 22 to 37, a period in which all birds received a common finisher diet, growth performance was not affected by the previous starter diet. In experiment 2 (battery study), birds were fed for 37 d the same diets used in the starter period of experiment 1. Broilers fed HPM had higher BWG (linear, P < 0.05; Quadratic, P < 0.05) than birds fed control diet, and birds fed 1.38% Lys had higher BWG (P < 0.01) than birds fed 1.23% Lys. From d 1 to 22, BWG (P < 0.05) and ADFI (P < 0.01) increased quadratically and FCR improved linearly (P < 0.05) with HPM inclusion. Also in this period, BWG was higher at the higher Lys level (P < 0.01). Diet did not affect intestinal histomorphology of broilers on d 8 or nutrient retention on d 22. We conclude that the inclusion of 2.5 to 5% HPM in the diet improved growth performance of broilers from d 1 to 22. An increase in Lys from 1.23 to 1.38% improved growth performance up to 15 d of age, but not thereafter. Diet did not affect villus histomorphology or nutrient retention of the small intestine.

Influence of source and level of glycerin in the diet on growth performance, liver characteristics, and nutrient digestibility in broilers from hatching to 21 days of age.

The influence of source and level of inclusion of raw glycerin (GLYC) in the diet on growth performance, digestive traits, total tract apparent retention (TTAR), and apparent ileal digestibility of nutrients was studied in broilers from 1 to 21 d of age. There was a control diet based on corn and soybean meal and 8 additional diets that formed a 2 × 4 factorial with 2 sources of GLYC and 4 levels of inclusion (2.5, 5.0, 7.5, and 10%). The GLYC used were obtained from the same original batch of soy oil that was dried under different processing conditions and contained 87.5 or 81.6% glycerol, respectively. Type of processing of the GLYC did not affect any of the variables studied except DM and organic matter retention (P < 0.05) that was higher for the 87.5% glycerol diet. From d 1 to 21, feed conversion ratio (FCR) improved linearly (L, P ≤ 0.01) as the GLYC content of the diet increased, but ADG was not affected. On d 21, the relative weight (% BW) of the liver and the digestive tract increased (L, P < 0.01) as the level of GLYC in the diet increased, but lipid concentration in the liver was not affected. The TTAR of DM and organic matter increased quadratically (Q, P < 0.05) and the AME(n) content of the diet increased linearly (L, P < 0.01) with increases in dietary GLYC. Also, the apparent ileal digestibility of DM (L, P < 0.05; Q, P = 0.07) and gross energy (L, P < 0.01) increased as the GLYC content of the diet increased. It is concluded that raw GLYC from the biodiesel industry can be used efficiently, up to 10% of the diet, as a source of energy for broilers from 1 to 21 d of age and that the energy content of well-processed raw GLYC depends primarily on its glycerol content.

Apparent metabolizable energy and ileal amino acid digestibility of commercial soybean meals of different origins in broilers.

We studied the chemical composition and the in vivo AMEn content and apparent (AID) and standardized (SID) ileal digestibility of CP and amino acids (AA) of 27 samples of soybean meals (SBM) from Argentina (ARG), Brazil (BRA), and USA, collected in Spain. On 88% DM basis, the BRA meals had more CP (46.9 vs. 46.0 and 45.9%; P < 0.05) and less sucrose (5.21 vs. 6.28 and 6.47%; P < 0.001) and stachyose (4.20 vs. 4.66 and 4.78%; P < 0.05) than the USA and ARG meals. Urease activity, protein dispersibility index, KOH protein solubility, and trypsin inhibitor activity values, were higher for the USA meals than for the South American meals (P < 0.05). In the in vivo trial, broilers received a common crumble diet from 0 to 16 d of age and then, their respective experimental diets (53% of a N-free diet and 47% of each of the 27 SBM tested) in mash form, for 5 d. The AMEn (2,334 vs. 2,282 and 2,277 kcal/kg; P = 0.062) and the AID (87.3 vs. 86.7 and 86.4%; P = 0.054) and SID (91.9 vs. 91.2 and 90.8%; P < 0.05) of the protein, were greater for the USA meals than for the ARG and BRA meals. In fact, the SID of Lys (93.5 vs. 93.0 and 92.1%; P < 0.001) and of the sum of Lys, Met, Thr, Trp, and Cys (91.4 vs. 91.0 and 90.2%; P < 0.05) were greater for the USA meals than for the ARG and BRA meals. In summary, the chemical composition, protein quality indicators, AMEn content, and ileal digestibility of the CP and the AA of the SBM, varied with the country of origin of the soybeans. In order to increase the accuracy of the feed formulation process, the composition and nutrient content of commercial batches of SBM, by country of origin should be controlled and periodically updated.

- Invited Review - Pig meat production in the European Union-27: current status, challenges, and future trends.

The main objective of this study was to present data on the current situation and future trends of pig meat production in the European Union-27 (EU). Pig production has played an important social and economic role for centuries in many states of the EU. In 2022, pig meat production in the EU reached 23 M tons, which represented 21% of total production worldwide. The two key reasons that justify such amount of pork produced, are the acceptance and high consumption of the meat by the local population and the high quality of the meat produced which facilitated pork export. However, current data show a reduction in pork production for the last three years, as a consequence of a series of events that include i) problems with the chain of ingredients supply, ii) uncontrolled increase in African Swine Fever (ASF) outbreaks, iii) fast recovery of pig production in China, iv) increasing concerns by the rural population on the high cost to meet future requirements of the EU legislation on farm management, environmental sustainability and animal welfare, v) increased cost of all inputs involved in pig production and vi) limited interest of the new farmer generation to work on the pig sector. Consequently, pork production is expected to decrease in the EU for the next years, although sales will be maintained at a relative high level because pork is the meat preferred by local consumers in most EU countries. In order to maintain the favourable position of the pork industry in the near future, strategies to implement include: i) maintain the quality of the meat destinated to export markets, ii) improve the control of outbreaks of ASF and other swine diseases, iii) implementation of technological innovations to improve working conditions making more attractive to work in the pork sector of the food chain to the new generation of farmers and workers.

Influence of feed form and source of soybean meal on growth performance, nutrient retention, and digestive organ size of broilers. 2. Battery study.

Two experiments were conducted to determine the apparent ileal digestibility (AID) of the amino acids (AA) of 4 commercial soybean meals (SBM) from the United States (USA-1, 48.1% CP and USA-2, 46.2% CP), Brazil (BRA, 47.6% CP), and Argentina (ARG, 46.3% CP) and the effects of the inclusion of these SBM in diets in mash, crumble, or pellet form on growth performance, total tract apparent retention of nutrients, and digestive organ size in broilers reared in cages from 1 to 25 d of age. In experiment 1, the AID of Lys was higher (P < 0.05) for the USA-2 than for the BRA SBM, with the SBM from USA-1 and ARG being intermediate. In experiment 2, 12 diets were arranged as a 3 × 4 factorial with 3 feed forms (mash, crumbles, and pellets) and the 4 sources of SBM used in experiment 1. The feeds were isonutritive and the AID of the AA of the SBM obtained in experiment 1 was used for diet formulation. Broilers fed mash had lower (P < 0.001) ADFI and ADG and poorer (P < 0.001) feed-to-gain ratio than broilers fed crumbles or pellets but source of SBM did not affect growth performance. Nitrogen retention was higher (P < 0.01) in birds fed mash than in birds fed crumbles or pellets at all ages. The total tract apparent retention of nutrients was lower (P < 0.05) for the BRA and ARG SBM diets than for the USA-1 and USA-2 SBM diets. Gizzard empty relative weight (% BW) was higher and gizzard pH lower for broilers fed mash than for broilers fed crumbles or pellets (P < 0.001). The results indicate that crumbling or pelleting of the diets improved growth performance of broilers from 1 to 25 d of age. Diets formulated with analyzed rather than calculated AID of AA of the SBM sources resulted in similar broiler performance.

Ileal digestibility of amino acids of unheated and autoclaved pea protein concentrate in broilers.

The effects of autoclaving 2 varieties of micronized (fine grinding) pea protein concentrate (PPC) on the ileal digestibility (ID) of CP and amino acids (AA) were studied in broilers. There was a control diet based on fermented soybean meal (FSBM) and 4 extra diets in which the FSBM was substituted on a CP basis by PPC from 2 different pea cultivars (PPC-1 and PPC-2), either unheated or autoclaved. Chicks were fed a common diet from 1 to 17 d of age and, then, their respective experimental diets from 18 to 21 d of age. Each treatment was replicated 6 times. Autoclaving reduced trypsin inhibitor activity (TIA) but had little effect on the saponin content of the PPC. The apparent ID (AID) of CP was similar for the FSBM and the unheated PPC and lower for both than for the autoclaved PPC. Autoclaving improved (P < 0.001) the AID of CP (87.6 vs. 82.2%) and most indispensable AA (e.g., 92.1 vs. 88.8% for Lys and 83.6 vs. 76.5% for Thr) of the PPC. The improvement in CP and AA digestibility with autoclaving varied with the PPC used and was consistent with the reduction in TIA observed (9.4 to 2.8 mg/g for PPC-1 vs. 9.1 to 5.3 mg/g for PPC-2). The standardized ID (SID) of most indispensable AA was similar for the FSBM and the PPC-2 and higher for both than for the PPC-1 (P < 0.05). For Lys, the lowest SID value was observed for the FSBM and the highest for the PPC-2 either unheated or autoclaved. It is concluded that the ID of the AA of the PPC improved with heating and was in general higher for the autoclaved PPC than for the FSBM. Consequently, heat processed PPC is a good alternative to FSBM and unheated PPC in starter diets for broilers.

Influence of the calcium and nutrient content of the prelay diet on egg production, egg quality, and tibiae mineralization of brown egg-laying hens from 16 to 63 wk of age.

The influence of the Ca and nutrient content of the diet fed from 16 to 19 wk of age, on egg production, egg quality, and tibiae mineralization, was studied in brown egg-laying hens from 16 to 63 wk of age. The experimental design was completely randomized with 4 prelay diets organized as a 2 × 2 factorial with 2 levels of Ca (2.5 vs. 3.8%) and 2 standardized ileal digestible Lys (g/kg) to AMEn (Mcal/kg) ratios (DLys:ME; 2.84 vs. 3.13) as main effects. From 20 to 63 wk of age, all hens received a common diet with 2.75 Mcal AMEn/kg, 0.75% DLys, and 3.8% Ca. Each treatment was replicated 18 times and the experimental unit was a cage with 10 hens. Hen production and egg quality traits were measured by period (4 wk), feeding phase (prelay and lay), and cumulatively (16-63 wk of age) and tibiae mineralization was measured at 63 wk of age. During the prelay phase, an increase in Ca delayed egg production (P = 0.065), reduced feed intake (P < 0.05), and increased BW gain (P < 0.01) and percentage of shell of the egg (P < 0.05). An increase in the DLys:ME ratio increased feed intake (P < 0.01) and reduced egg size (P < 0.01). Nutrient content of the prelay diets did not affect hen production during the lay phase, except egg weight that increased (P < 0.05) in hens previously fed the low DLys:ME ratio. Eggshell quality (weight, percentage, strength, and thickness) in this phase was better (P < 0.05) in hens previously fed 3.8% Ca. Cumulatively (16-63 wk of age), hens fed the high Ca prelay diets had better shell quality but tibiae mineralization was not affected. In conclusion, an increase in Ca content of the prelay diet from 2.5 to 3.8% improved shell quality for the entire egg cycle without showing any negative effect on hen production.

Influence of feed form and source of soybean meal of the diet on growth performance of broilers from 1 to 42 days of age. 1. Floor pen study.

In total, 3,120 broilers were used to study the effects of feed form and source of soybean meal (SBM) of the diet on growth performance. From 1 to 21 d of age, there were 12 treatments arranged factorially with 3 feed forms (mash, crumbles, and pellets) and 4 commercial sources of SBM that differed in the CP content [48.1 and 46.2% CP from the United States (USA-1 and USA-2), 47.6% CP from Brazil (BRA), and 46.3% CP from Argentina (ARG)]. From 21 to 42 d of age, diets were fed as pellets. Diets were formulated assuming that all SBM had similar digestible amino acid content per unit of CP. From 1 to 21 d of age, chicks fed crumbles or pellets had higher (P < 0.001) ADG than chicks fed mash. Also, chicks fed pellets had better (P < 0.001) feed-to-gain ratio (F:G) than chicks fed crumbles, and both were better than chicks fed mash. However, from 21 to 42 d of age, F:G was best (P < 0.001) for chicks previously fed mash. For the entire experimental period, broilers that were fed crumbles or pellets from 1 to 21 d of age had higher (P < 0.001) ADG than broilers that were fed mash. Also, broilers that were fed pellets had better (P < 0.05) F:G than broilers fed mash, with broilers fed crumbles being intermediate. Broilers fed the USA-2 meal had higher (P < 0.01) ADG than broilers fed the BRA or the ARG meals, with broilers fed the USA-1 meal being intermediate. Feed efficiency tended (P = 0.07) to be hindered in broilers fed the BRA meal. The results show that pelleting improved growth performance of broilers from 1 to 42 d of age with effects being less evident at 42 d than at 21 d of age. Source of SBM affected growth performance suggesting the need for a better control of chemical composition and quality of this ingredient before diet formulation.

Effects of wheat inclusion and xylanase supplementation of the diet on productive performance, nutrient retention, and endogenous intestinal enzyme activity of laying hens.

An experiment was conducted to study the effects of inclusion of a wheat cultivar (high in nonstarch polysaccharides) and xylanase supplementation of the diet on productive performance, pH of the gastrointestinal tract, nutrient retention, and intestinal enzyme activity of Hy-Line W-36 laying hens from 25 to 47 wk of age. The experiment was completely randomized with 8 treatments arranged factorially with 4 levels of wheat (0, 23, 46, and 69%) that corresponded to a dietary arabinoxylan content of 3.0, 3.3, 3.6, and 3.9%, with or without xylanase supplementation. Each treatment was replicated 5 times. For the entire experimental period, egg weight (P < 0.05) and egg mass (P < 0.01) were reduced and the feed conversion ratio was hindered (P < 0.05) with increased levels of wheat in the diet, but ADFI and egg production were not affected. Xylanase supplementation improved egg production (P < 0.05), egg mass (P < 0.01), and the feed conversion ratio (P < 0.01). Diet did not affect egg quality at any age, except for shell thickness at 47 wk that was improved with xylanase supplementation (P < 0.05). Digesta pH of the different organs of the gastrointestinal tract was not affected by wheat inclusion or xylanase supplementation. Ileal viscosity increased (P < 0.001) with wheat inclusion and decreased (P < 0.001) with xylanase supplementation at all ages. Fat digestibility (P < 0.001) decreased with increased levels of wheat but AME(n) content of the diets (P < 0.05) and nitrogen retention were not affected. Wheat inclusion increased (P < 0.001) amylase (33 wk), lipase (33 wk), and aminopeptidase (47 wk) activity in the duodenum as well as lipase activity in the jejunum at 47 wk of age. However, xylanase supplementation did not affect the activity of any of the enzymes studied. It is concluded that most of the negative effects of wheat inclusion in the diet were reduced or even disappeared with xylanase supplementation. Wheat with a high nonstarch polysaccharide content (Pishtaz cultivar) can be used at levels of up to 69% in laying-hen diets without negatively affecting bird performance, provided that feeds are supplemented with xylanase.

Effects of feeding regimen, fiber inclusion, and crude protein content of the diet on performance and egg quality and hatchability of eggs of broiler breeder hens.

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.

Dietary fibers and crude protein content alleviate hepatic fat deposition and obesity in broiler breeder hens.

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.

Effects of energy concentration of the diet on productive performance and egg quality of brown egg-laying hens differing in initial body weight.

The influence of AME(n) concentration of the diet on productive performance and egg quality traits was studied in Hy-Line brown egg-laying hens differing in initial BW from 24 to 59 wk of age. Eight treatments were arranged factorially with 4 diets varying in energy content (2,650, 2,750, 2,850, and 2,950 kcal of AME(n)/kg) and 2 initial BW of the hens (1,733 vs. 1,606 g). Each treatment was replicated 5 times (13 hens per replicate), and all diets had similar nutrient content per unit of energy. No interactions between energy content of the diet and initial BW of the hens were detected for any trait. An increase in energy concentration of the diet increased (linear, P < 0.05; quadratic P < 0.05) egg production, egg mass, energy efficiency (kcal of AME(n)/g of egg), and BW gain (P < 0.05) but decreased ADFI (linear, P < 0.001) and feed conversion ratio per kilogram of eggs (linear, P < 0.01; quadratic P < 0.01). An increase in energy content of the diet reduced Haugh units and the proportion of shell in the egg (P < 0.01). Feed intake (114.6 vs. 111.1 g/hen per day), AME(n) intake (321 vs. 311 kcal/hen per day), egg weight (64.2 vs. 63.0 g), and egg mass (58.5 vs. 57.0 g) were higher for the heavier than for the lighter hens (P < 0.01), but feed conversion ratio per kilogram of eggs and energy efficiency were not affected. Eggs from the heavier hens had a higher proportion of yolk and lower proportion of albumen (P < 0.01) and shell (P < 0.05) than eggs from the lighter hens. Consequently, the yolk-to-albumen ratio was higher (P < 0.001) for the heavier hens. It is concluded that brown egg-laying hens respond with increases in egg production and egg mass to increases in AME(n) concentration of the diet up to 2,850 kcal/kg. Heavy hens had higher feed intake and produced heavier eggs and more egg mass than light hens. However, feed and energy efficiency were better for the lighter hens.

Effect of crude protein and fat content of diet on productive performance and egg quality traits of brown egg-laying hens with different initial body weight.

A trial was conducted to study the influence of CP and fat content of the diet on performance and egg quality traits of brown egg-laying hens from 22 to 50 wk of age. The experiment was conducted as a completely randomized design with 8 treatments arranged factorially with 4 diets and 2 initial BW of the hens (1,592 vs. 1,860 g). Three of these diets differed in the CP content (16.5, 17.5, and 18.5%) and included 1.8% added fat. The fourth diet also had 18.5% CP but was supplemented with 3.6% fat instead of 1.8% fat. Each treatment was replicated 4 times, and the experimental unit consisted of 21 hens allocated into groups of 7 in 3 adjacent cages. All diets were isocaloric (2,750 kcal of AME/kg) and met the recommendations of brown egg-laying hens for digestible Arg, Ile, Lys, Met, Thr, Trp, TSAA, and Val. Productive performance and egg quality were recorded by replicate every 28 d. For the entire experimental period, diet did not affect any of the productive performance traits studied, but the heavier hens had higher ADFI (120.6 vs. 113.9 g; P < 0.001), egg production (92.5 vs. 89.8%; P < 0.01), and egg weight (64.9 vs. 62.4 g; P < 0.001) than the lighter hens. Initial BW did not affect feed conversion per kilogram of eggs or hen mortality, but BW gain was higher (289 vs. 233 g; P < 0.01) and feed conversion ratio per dozen of eggs was better (1.52 vs. 1.57; P < 0.01) for the lighter than for the heavier hens. None of the egg quality variables studied was affected by dietary treatment or initial BW of the hens. It is concluded that brown egg-laying hens, irrespective of their initial BW, do not need more than 16.5% CP to maximize egg production, provided that the diet meets the requirements for key indispensable amino acids. Heavier hens produce more eggs that are larger than lighter hens but feed efficiency per kilogram of eggs is not affected.

Influence of the energy concentration and the standardized ileal digestible lysine content of the diet on performance and egg quality of brown-egg laying hens from 18 to 41 weeks of age.

The influence of the energy and the standardized ileal digestible lysine (DLys) content of the diet on egg production and egg quality, was studied in brown-egg laying hens from 18 to 41 wk of age. The experimental design was completely randomized with 10 treatments organized as a 2 × 5 factorial with 2 energy concentrations (2,750 and 2,800 kcal AMEn/kg) and 5 levels of DLys (values varied from 0.66 to 0.78% and 0.67 to 0.79%, for the low and high energy diets, respectively). Each treatment was replicated 10 times (10 hens per replicate). The data were analyzed using the MIXED procedure of SAS with energy concentration and DLys content of the diets as main effects. In addition, the effects of the DLys on the variables studied were partitioned into its lineal and quadratic components. From 18 to 21 wk of age (pre-peak phase), diet composition had limited effects on egg production. From 22 to 41 wk of age (peak phase), however, an increase of 50 kcal AMEn/kg diet increased egg weight (P < 0.05) and tended to improve energy intake (P = 0.083) and feed conversion ratio (P = 0.074). An increase in DLys improved linearly (P < 0.001) egg production, egg weight, egg mass, feed conversion, and energy conversion ratio, and tended to increase BW gain (P = 0.074). Diet composition did not any affect egg quality trait except shell strength that increased linearly (P < 0.05) with increases in the DLys. Cumulatively (18-41 wk of age), egg weight increased (P < 0.05) as the energy and the DLys content of the diet increased. In summary, an increase in energy and DLys content of the diet had limited effects on egg production during the prepeak phase but improved egg production, feed conversion ratio, and BW gain during the peak phase. The data indicate that hens require at least 839 mg DLys/d to maximize egg production in the peak production phase.

Effect of beak trimming at hatch and the inclusion of oat hulls in the diet on growth performance, feed preference, exploratory pecking behavior, and gastrointestinal tract traits of brown-egg pullets from hatch to 15 weeks of age.

The influence of infrared beak trimming at hatch (IRBT) and the inclusion of oat hulls (OH) in the diet on growth performance, feed preference, exploratory pecking behavior, and gastrointestinal tract (GIT) development, was studied in brown-egg pullets from 0 to 15 wk of age. The experimental design was completely randomized with 4 treatments arranged as a 2 × 2 factorial with IRBT (sham vs. treated) and OH inclusion (0 vs. 3%) as main effects. Each treatment was replicated 20 times and the experimental unit was a cage with 10 pullets. Feed intake (FI), BW gain, feed conversion ratio (FCR), energy intake (EI, kcal AMEn/d), and energy conversion ratio (ECR, kcal AMEn/g of BW gain) were determined by feeding period (0 to 6, 7 to 10, and 11 to 15 wk of age) and cumulatively. Particle size preference was measured at 7 wk and exploratory pecking behavior of the pullets and at 8 to 14 wk of age. From 0 to 6 wk of age, beak trimming decreased FI (P < 0.01) and increased pullet mortality (P < 0.001) but did not affect BW gain. From 0 to 15 wk of age, OH inclusion improved BW uniformity (P = 0.090) but impaired FCR (P < 0.05) without showing any effect on BW gain or ECR. Preference for coarse particles was greater for the sham than for the treated pullets. Beak trimming and OH feeding reduced (P < 0.05) the exploratory pecking behavior of the pullets from 8 to 12 wk of age but not thereafter. Oat hulls increased the relative weights of the full gizzard and intestines at all ages (P < 0.05). In summary, beak trimming did not affect pullet performance at 15 wk of age or GIT development at any age. Oat hulls improved GIT development at all ages but did not affect BW or ECR. Both beak treatment and OH inclusion affected particle size preference and reduced the exploratory pecking behavior of the birds.