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The influence of grinding size of the main cereal of the diet on production and egg quality traits was studied in brown hens from 33 to 65 wk of age. The experiment was completely randomized with 6 treatments arranged as a 3 × 2 factorial with 3 main cereals (barley, corn, and wheat) and 2 grinding size of the cereal (6 and 10 mm screen). Each treatment was replicated 11 times (10 hens/replicate). Diets were isonutritive and contained 2,740 kcal/kg AMEn and 16.8% CP. Egg production, ADFI, egg weight, and feed conversion ratio (FCR) were determined by period (4 wk) and for the entire experiment. Egg quality traits (percentage of undergrades, Haugh units, thickness, strength, color of the shell, and proportion of albumen, yolk, and shell) were measured also by period. No interactions between main cereal and grinding size of the main cereal of the diet were observed for any of the traits studied. Feed intake, egg production, and BW gain were not affected by diet or grinding size. Eggs were heavier (P < 0.01) in hens fed barley than in hens fed corn or wheat, probably because of the higher fat content of the barley diets. Also, FCR tended to improve in hens fed barley compared with hens fed corn or wheat (P = 0.07). Diet did not affect any of the egg quality traits studied. In summary, barley and wheat conveniently supplemented with enzymes, can be used in substitution of corn at levels of up to 55% in diets for laying hens, without any adverse effect on egg production or egg quality traits. Moreover, the substitution of corn by a combination of barley and supplemental fat increased egg size. Consequently, the inclusion of one or other cereal in the diet will depend primarily on their relative cost. Within the range studied, screen size (6 vs. 10 mm) of the cereal had limited effects on hen production.

The influence of the screen size used to grind the main cereal of the diet on egg production, gastrointestinal tract (GIT) development, and body measurements was studied in hens from 17 to 49 wk of age. Diets formed a 2 × 5 factorial with 2 main cereals (corn vs. barley) and 5 screen sizes of the cereal (4, 6, 8, 10, and 12 mm). Each treatment was replicated 5 times. No interactions between main cereal and screen size were observed for any of the traits studied. Cereal type and screen size did not affect feed intake, egg production, BW gain, or quality traits of the eggs. Eggs tended to be larger (P = 0.092) in hens fed the barley diet than in hens fed the corn diet. Also, feed conversion ratio tended to increase (P = 0.081) when the cereal of the diet was ground with a 4-mm screen as compared with the average of the other diets. At 49 wk of age, the relative weight (% BW) of the GIT and gizzard was greater (P < 0.05) in hens fed barley than in hens fed corn. An increase in the screen size increased linearly the relative weight of the GIT (P = 0.089), gizzard (P < 0.01), and liver (P = 0.056). None of the other GIT traits or body measurements was affected by the main cereal or the screen size. In summary, barley can substitute up to 45% of the corn in diets for laying hens without any adverse effect on egg production. Therefore, the use of one or other cereal will depend on their relative cost. An increase in screen size improved gizzard development but had little effect on hen productivity. Within the range studied, the size of the screen used for grinding the cereal had little effect on hen productivity, although the use of a 4-mm screen might increase feed conversion ratio and gizzard development.

The influence of feed form and energy content of the rearing phase diets on hen productivity,gastrointestinal tract (GIT) traits and body measurements was studied in brown-egg layinghens fed diets differing in energy concentration from 17 to 46 wk of age. The experimentwas completely randomized with 12 treatments arranged as a (2 × 3) × 2 factorial with twofeed forms (mash vs. crumbles) and three AMEnconcentrations of the rearing phase diets(low, medium and high) and two AMEnconcentrations (11.10 vs. 11.52 MJ/kg) of the layingphase diets. The AMEnof the rearing phase diets differed in 0.42 MJ/kg in all three periods(1?5 wk, 5?10 wk and 10?17 wk of age). Hen productivity was determined from 17 to 46wk and GIT and body traits were measured at 46 wk of age. The characteristics of the rearingphase diets did not affect any of the production, GIT traits or body measurements studiedduring the laying phase, except body weight gain (BWG) from 17 to 46 wk of age that washigher (P < 0.01) in hens that were fed mash during the rearing phase than in hens thatwere fed crumbles. An increase in the energy content of the laying phase diet from 11.10to 11.52 MJ AMEn/kg reduced feed intake (P < 0.001) and improved feed conversion ratio(P < 0.001) from 17 to 46 wk and reduced gizzard contents (P < 0.01) at 46 wk of age butdid not affect any of the other production trait studied. The characteristics of the rearingand laying hen diets did not affect any of the GIT traits or body measurements at 46 wk ofage. Body weight of the hens was positively (P < 0.001) related with body length, body massindex, tarsus length and tarsus diameter at this age. The data indicate that neither feed formnor energy concentration of the rearing phase diets affected subsequent hen performance.An increase in the AMEncontent of the layer diet from 11.10 to 11.52 MJ/kg decreased feedintake and improved feed conversion ratio but did not affect hen production or egg quality.

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.

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 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 0.10) 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.

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.

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.

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 0.05) 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

The objective of the study was to determine the pregnancy rate of fresh and frozen-thawed in vitro produced embryos transferred into recipients in the north coast of Peru. Artificial insemination results of frozen-thawed semen inseminated to cows in the same herd and season (summer) where the embryo transfers were performed was evaluated as control. For the in vitro embryo production, the rate obtained was 374 oocytes from 21 ovum pickup sessions (15.24 ± 8.91 oocytes/session). Of these oocytes, 246 were matured in bicarbonate buffered TCM-199 supplemented with 10% heat inactivated FCS as well as epidermal growth factor (EGF), insulin-like growth factor-1 (IGF-1), FSH, LH, oestradiol, and cysteamine for 24 h of incubation at 38.5°C, 5% CO2, and 90% humidity. The oocytes selected post-maturation were fertilised with the frozen-thawed sperm that was subjected post-thawing to Percoll gradient (90 and 45% Percoll), centrifugated, and resuspended in a TALP-IVF medium supplemented with 20 μM D-penicillamine, 10 μM hypotaurine, and 1 μM epinephrine. The oocytes were then inseminated with a concentration of 1.5 million sperm mL–1 in TALP IVF fertilization medium and incubated for 24 h at 38.5°C, 5% CO2, and 90% humidity. Subsequently, the presumptive zygotes were transferred to medium of 50 μL drops of SOFaa supplemented with 5% heat-inactivated FCS which was later replaced by SOFaa and 1% heat-inactivated FCS on Day 5 after fertilization. The embryos were inspected and graded on Days 7 and 8 post-fertilization and incubation at 38.5°C, 5% CO2 and 90% humidity. The blastocyst rate was evaluated on Day 7 post-fertilization. The blastocyst rate was 25.3% (21/83) and 4.19 ± 3.37 embryos per ovum pickup session were obtained. The embryo freezing media contained 1.5 M ethylene glycol as a cryo-protectant, and the method of thawing the embryo was the direct method (1 step). The pregnancy rate was compared by chi-squared analysis. The pregnancy rate for artificial insemination was 23.9% (1103/4612), and the pregnancy rate of fresh and frozen-thawed in in vitro embryos was 30% (13/43) and 20% (8/40), respectively (P > 0.05). Overall the pregnancy rates in the herd were relatively low, probably due the high environmental temperature during the season when the embryos were transferred and the semen was inseminated. Under those conditions, pregnancy rate was not affected by the use of fresh and frozen-thawed in vitro embryo transfer in comparison to the conventional artificial insemination of frozen semen in the coast north of Peru.

Author(s): Mendoza, A.; Salazar, C.; Alvarado, O.; Cruz, M. A.; Rodriguez, M. A.; Saldana, H. A. B.