Effect of energy density of diet on growth performance of Thai indigenous (50% crossbred) Korat chickens from hatch to 42 days of age

The aim of the current study was to investigate the effect of the energy density of diet on the growth performance of Thai indigenous crossbred (50%) chickens known as Korat chicken (KRC). A total of 1440 mixed-sex KRC (720 birds in each phase) were randomly allocated to 4 dietary treatments containing 2750, 2900, 3050, or 3200 kcal ME/kg diet with 6 replicates of each treatment in a completely randomized design. The experimental diets were tested from hatch to 21 days and from 22 to 42 days of age. In both age groups, body weight gain was not affected (P >?0.05) by the ME density of the diets. Feed intake however decreased with increasing (metabolizable energy) ME (P <?0.05), thereby significantly improving the feed conversion ratio (FCR). Broken-line analysis was performed to estimate the ME content of feed to obtain minimum FCR and maximum protein efficiency ratio (PER) values. Minimum FCR and maximum PER values were found when the diet contained 3000 kcal ME/kg from hatch to 21 days of age and 3175 kcal ME/kg from 22 to 42 days of age, respectively, using diets containing 7.5 and 6.6 g of protein/100 kcal ME, respectively. In conclusion, we established that the ME requirements of KRC from hatch to 21 days and 22 to 42 days of age were 3000 and 3175 kcal/kg, respectively.     

Replacing maize with pearl millet in laying hens’ diets

Pearl millet grain could be considered as an alternative feed ingredient for poultry. In a 12 wks experiment, the performance of laying hens fed diets containing pearl millet were compared with those fed diets containing corn. Maize grain was replaced by pearl millet on an equal-weight at either 0, 25, 50, 75 or 100%. Results showed that use of 25, 50 and 75% of pearl millet in place of maize in the diet resulted in similar (P > 0.05) hen-day egg production, egg mass, egg weight, feed intake and feed conversion ratio to those of control group. Totally replacement of maize grain with pearl millet significantly (P < 0.05) reduced all production parameters. Egg quality parameters did not affect by using pearl millet in the diet. These results showed that maize grain can be replaced by pearl millet up to 75% in the diets of laying hens without any adverse effect on hen performance or egg quality.     

Effect of dietary monensin inclusion on performance,nutrient utilisation,rumen volatile fatty acid concentration and blood status of West African dwarf bucks fed with basal diets of forages

This experiment investigated the effect of dietary monensin on performance, nutrient utilisation, rumen volatile fatty acid and blood status in West African dwarf (WAD) goats fed with basal diets of forages. Four concentrate supplements were formulated to include 0 (MO), 15 (M15), 30 (M30) and 45 (M45) mg monensin/kg dry matter. Twenty-four WAD bucks (7.3 ± 1.20 kg initial body weight, aged 9–12 months) were randomly allotted to four experimental diets in a completely randomised design for 90 days, six animals per diet. Results indicated that animals fed M15, M30 and M45 diets had lower (P < 0.01) dry matter and water intake than those fed M0 diet. Crude protein and neutral detergent fibre intakes by the bucks followed similar trend. Animals on M15, M30 and M45 had better (P < 0.001) feed and protein efficiency ratio than those fed M0 diet. Rumen pH and total volatile fatty acid concentration were maintained (P > 0.05) while monensin decreased (P < 0.001) acetate/propionate ratio. Blood glucose increased (P < 0.001) from 59.1 mg/dl in animals on M0 diet to 67.8, 66.0 and 66.3 mg/dl in animals on M15, M30 and M45 diets. Overall, there were no variations among animals on M15, M30 and M45 diets. It is concluded that feeding monensin at 15 to 45 mg/kg DM of supplemental concentrate diets to West African dwarf bucks could be effective in improving feed and protein efficiency, manipulating the rumen for increased propionate production and increasing blood glucose levels.     

Effect of varying dietary energy levels during the last trimester of pregnancy on subsequent first lactation performance in Sahiwal heifers

The aim of the study was to determine optimum dietary energy level during the last trimester of pregnancy for Sahiwal heifers in subtropical Pakistan. Sixteen Sahiwal heifers, 5–6 months pregnant, were assigned to four dietary treatments with four heifers on each treatment. Isonitrogenous (CP = 14.1%) diets having varying energy, namely, ME 88%, ME 100% (Control), ME 112% and ME 124% of NRC recommended level for pregnant heifers, were fed until calving. All were fed a similar diet after calving. Precalving weight gain was highest (P < 0.05) in heifers fed ME 112 and 124% (486 ± 13 and 497 ± 5 g/day, respectively) followed by ME 100% (444 ± 7 g/day), and the lowest weight gain was recorded for ME 88% (397 ± 8 g/day). A similar trend was observed for feed efficiency. Body condition score at calving in groups ME 124% and ME 112% was higher than ME 88% and ME 100%. Nutrient digestibility, birth weight of calves and milk composition except fat content were not influenced by energy levels. The highest daily milk yield was observed in heifers fed ME 100% followed by ME 112, 124, and 88%. We conclude that the NRC recommendation is applicable to the subtropical region.     

Effects of feeding different dietary protein and energy levels on the performance of 12–15-month-old buffalo calves

The study investigated the performance response of different dietary protein and energy levels of Nili-Ravi buffalo calves. Sixty buffalo calves of 12–15 months of age and similar body weight (140 ± 14 kg) were divided in to 12 groups, five animals in each group, according to 4 × 3 factorial arrangements. Twelve rations were formulated containing four levels of crude protein (CP; 10.5%, 12.20%, 13.80%, and 15.55%) each with three levels (1.72, 2.11, and 2.5 Mcal/Kg) of metabolizable energy (ME). Experiment lasted for 100 days; first 10 days were given for dietary adaptation. Daily feed consumption in calves fed all experimental diets were statistically significant (p < 0.05) across all treatments. Higher feed intake was observed in buffalo calves fed diets containing 12.20% and 13.85% CP with 2.11 Mcal/kg ME. Results of dry matter (DM) digestion were significantly different (p < 0.05) across all treatments. There was a quadratic (p < 0.05) response of DM digestibility for levels of dietary protein while, curvilinear (p < 0.05) trend with respect to dietary energy levels. Daily weight gain of buffalo calves did not show any treatment effect. The outcome of the present study indicate that 12–15-month-old buffalo calves perform adequately well when fed on diets containing 12.2% CP and 2.10 ME Mcal/Kg.     

Effects of space allocations and energy levels on growth performance and nutrient digestibility in growing and finishing pigs

Two experiments were conducted to investigate effects of different space allocations and different dietary metabolizable energy (ME) levels on growth performance and nutrient digestibility in growing and finishing pigs. In experiment 1, a total of 84 growing pigs [(Yorkshire × Landrace) × Duroc] with an initial body weight (BW) of 27.10 ± 1.60 kg were used in a 5‐week trial. Pigs were blocked based on initial BW into a 2 × 2 factorial design with the following factors: (i) 0.60 or 0.80 m²/pig space allocations; and (ii) 3,400 or 3,550 kcal/kg ME of diets. In experiment 2, a total of 84 finishing pigs with an initial BW of 67.43 ± 1.97 kg were used in a 10‐week trial. Pigs were allotted based on initial BW into a 2 × 2 factorial design with the following factors: (i) 0.81 or 1.08 m²/pig space allocations; and (ii) 3,300 or 3,450 kcal/kg ME of diet. In experiment 1, high ME diet improved gain‐to‐feed ratio (G:F) in pigs with low space allocation but not in pigs in high space allocation (p < .05). Additionally, high ME diet increased apparent total tract digestibility (ATTD) of nitrogen in low space allocation but decreased ATTD of nitrogen in high space allocation (p < .05). In experiment 2, high ME diet improved average daily gain (ADG) and G:F in early‐finishing pigs with low space allocation but not in pigs with high space allocation (p < .05). In conclusion, the provision of high ME diets was not enough to overcome the reduction in growth performance due to low space allocation but can improve feed efficiency in growing pigs and daily gain and feed efficiency early‐finishing pigs.     

Performance and carcass measurements of ewe lambs reared in a feedlot and fed wheat (<Emphasis Type="BoldItalic">Triticum durum</Emphasis> Desf.) middlings total mixed rations in the summer season

The effect of total mixed ratios containing wheat middlings (WM) as a corn grain substitute on the growth performance and carcass traits of Comisana ewe lambs was evaluated. Forty ewe lambs, with average live body weight of 13 ± 0.3 kg (mean ± SEM), were allocated randomly to two isocaloric and isonitrogenous diets for 50 days. Control diet contained 400 g/kg of dry matter (DM) of corn as the main starchy source, whereas experimental diet contained 600 g/kg DM of WM. In vivo nutrient apparent digestibility of the two diets was determined using Comisana rams (mean body weight, 65 ± 2.3 kg) and indicated significant (P < 0.05) differences for neutral detergent fibre, acid detergent fibre, cellulose and hemicellulose fractions. Results from the trial using Comisana ewe lambs showed that growth traits were unaffected by dietary treatments as well as none of the carcass measurements examined (P > 0.05). These findings indicate that WM results as a suitable feed ingredient for growing ewe lambs that can be a satisfactory substitute to conventional grain source.     

Effect of feeding calcium salts on performance of nursing Awassi ewes

Twenty nursing Awassi ewes (BW = 50 ± 2.35 kg, age = 4.5 ± 1.2 years) with their lambs were used to evaluate the effects of feeding calcium salts in lactation diets on performance and pre-weaning growth of their lambs. Treatments were 0% calcium salts (CON) or 5% calcium salts (FAT). At the end of the study, a digestibility experiment was performed. Milk yield was greater (P < 0.05) for ewes fed the FAT diet than the CON diet. Milk composition was similar (P > 0.05) between diets. However, milk energy value (kcal/day) tended to be greater (P = 0.07) for the FAT diet than the CON diet. Concentrations of milk C18:1c9 and C20:0 were greater (P < 0.05) in ewes fed the FAT diet than the CON diet. However, concentration of trans-10, cis-12 CLA was lower (P = 0.05) in the FAT diet than in the CON diet. No differences in feed intake and body weight change were detected between diets. Digestibility of dry matter, organic matter, crude protein, ether extract, neutral detergent fiber, and acid detergent fiber were similar (P > 0.05) for diets. For lambs, weaning weight was not affected by treatments. However, average daily gain and total gain were greater (P = 0.053) for the FAT diet than the CON diet. Results suggest that supplementing lactating ewes with calcium salts at the beginning of lactation phase improves daily milk yield of ewes and pre-weaning growth of their lambs with no major negative impact on feed intake and digestibility.     

Effect of commercial diets quality on bio-economic performances of broilers in Benin

The objective of this study was to assess the quality of commercial poultry feeds in Benin. The performances of 396 unsexed broilers chickens Ross 308 fed with a control diet (R1) and five commercial diets (R2 to R6) were evaluated. Broilers fed commercial diets showed significantly low (P < 0.001) body weight gain (BWG) and economic feed efficiency (EFE) and significantly high (P < 0.001) mortality rate, feed conversion ratio and feed cost (FC). At 42 days of age, the body weight of broilers fed control diet was 1662 g versus 838 to 1041 g for broilers fed commercial diets. In R1 diet, overall FC was 388 Fcfa/kg BWG, and EFE was 2.7 Fcfa BWG/Fcfa feed. These values represented respectively 50 to 64% and 1.6 to 2.0 times the FC and the EFE recorded in commercial diets. A deficiency in crude protein and metabolisable energy, combined with high contents of crude fibre and total ash was found in some commercial diets. These results suggest the necessity to organize the market of poultry feed in Benin in the perspective to reduce the production cost by using more efficient and cheap commercial diets.     

Nutrient digestibility and feedlot performance of lambs fed diets varying protein and energy contents

Thirty-six Thalli male growing lambs were used in a completely randomized design with 2 × 2 factorial arrangement of treatments to evaluate the effect of varying levels of energy and protein on nutrient intake, digestibility, weight gain, and gain to feed ratio. Four experimental diets, i.e., low energy–low protein (LE-LP), low energy–high protein (LE-HP), high energy–low protein (HE-LP), and high energy–high protein (HE-HP) were formulated. The low- and high-energy diets contained 2.3 and 2.7 MJ/kg dry matter (DM) with 12% and 14% of crude protein. The lambs were fed ad libitum. Dietary energy and protein levels and their interactions influenced the nutrient intake. Maximum dry matter intake was noted in animals fed LE-HP diet followed by LE-LP, HE-HP, and HE-LP diets. Digestibility of DM and N increased (P < 0.01) and that of neutral detergent fiber decreased (P < 0.01) linearly with increasing levels of dietary energy and protein. Digestibility of N was only affected by protein level and interaction between energy and protein levels. Average daily gain was higher (P < 0.01) in lambs fed HE-HP diet followed by LE-HP, LE-LP, and HE-LP diets. Dietary energy and protein levels and their interaction had significant effect (P < 0.01) on gain to feed ratio.     

Feed intake and production parameters of lactating crossbred cows fed maize-based diets of stover,silage or quality protein silage

Thirty-six Boran × Friesian dairy cows (392 ± 12 kg; mean ± SD) in early parity were used in a randomised complete block design. Cows were blocked by parity into three blocks of 12 animals and offered normal maize (NM) stover (T1), NM silage (T2) or quality protein maize (QPM) silage (T3) basal diets supplemented with a similar concentrate mix. Feed intake, body weight and condition changes and milk yield and composition were assessed. The daily intake of DM, OM, NDF and ADF for cows fed the NM stover-based diet was higher (P < 0.05) than for the cows fed the NM silage and QPM silage-based diets. However, the daily intake of DOM (9.3 kg) and ME (140.8 MJ) for cows on QPM silage-based diet was higher (P < 0.05) than for cows on NM stover-based diet (8.4 kg and 124.2 MJ) and NM silage-based diet (7.9 kg and 119.1 MJ). Body weight of cows was affected (P < 0.05) by the diet, but diet had no effect (P > 0.05) on body condition score, milk yield and milk composition. The digestible organic matter in the NM stover-based diet (724 g/kg DM) was lower (P < 0.05) than that in the NM (770 g/kg DM) and QPM silage-based diet (762 g/kg DM). It was concluded that the performances of the cows on the NM silage and QPM silage diets were similar and were not superior to that of the NM stover-based diet.     

Effect of cooking and methionine supplementation on nutritional value of bitter vetch seed as a feed ingredient for broilers

The present study was conducted to evaluate the adequacy of applying heat treatment and methionine (Met) supplementation to improve the use of bitter vetch (BV) as a feed ingredient in the growth diet of broilers. A total of 540 Ross-308 chicks were fed various BV-supplemented diets between the ages of 35 and 49 days. The chicks were assigned randomly to one of nine experimental treatments, including raw and cooked bitter vetch seeds at two levels (100 and 200 g/kg) with or without Met (210 mg/kg) supplement and a corn–soybean-based diet as control. Results showed that feeding the 200-g/kg raw BV decreased feed intake by 52% in relation to the control diet (P < 0.05). Cooking the BV did not improve the feed intake. Met supplementation of 100 g/kg raw or cooked BV and 200 g/kg cooked BV resulted to a similar feed intake in the control group. Chicks fed with the 200 g/kg raw BV had an average depressed body weight gain of 90% in comparison to the birds fed with the control diet. The combination of cooking and Met supplementation of this diet resulted to a similar body weight gain to the control diet. Feeding 100 g/kg of raw or cooked BV also reduced (P < 0.05) body weight gain, and Met supplementation of these diets resulted in a body weight gain similar to the control group. Chicks fed with 100 g/kg of raw or cooked BV supplemented with Met or 200 g/kg of cooked BV plus Met has similar feed conversion ratio to the control group. In conclusion, heating BV seeds is not sufficient to overcome the limiting effects of BV seeds on feed intake and weight gain, and that Met supplementation does provide some improvement. The combination of cooking and Met supplementation was more efficient.     

Effect of energy and protein levels on performance,egg quality,and nutrient digestibility of laying pigeons

A total of 3,240 female Taisheng pigeons at 40 wk age were fed 9 diets containing 3 ME levels (2,630, 2,770, and 2,940 kcal/kg) and 3 CP levels (14.0, 15.0, and 16.0%) in a factorial arrangement. These diets were fed to investigate the effects of ME and CP on performance, egg quality, and nutrient digestibility. Female pigeons were housed under the same managerial conditions and randomly assigned into 9 treatments (6 replicates of 60 birds each). Two female–female paired pigeons housed in one cage were under a 16L:8D lighting cycle. Feed in pellet form and water were provided for ad libitum consumption. The study lasted 12 wk. As dietary ME level increased from 2,630 to 2,940 kcal/kg, BW, egg production, and apparent DM, crude fat (CF), and phosphorus (i.e., P) digestibilities increased (P < 0.05), feed intake decreased (P < 0.05), and feed conversion efficiency increased (P < 0.05). Increasing the level of dietary protein from 14 to 16% resulted in an increased (P < 0.05) BW, shell percentage, length of the major axis, and DM digestibility. Therefore, dietary ME had a greater influence on the performance of Taisheng laying pigeons than did dietary protein.     

Milk yield and quality in Guernsey cows fed cottonseed cake-based diets partially substituted with baobab (<Emphasis Type="BoldItalic">Adansonia digitata</Emphasis> L.) seed cake

The objective of this study was to determine the effects of partially substituting cottonseed cake with graded levels of baobab (Adansonia digitata L.) seed cake (BSC) on milk yield and quality in Guernsey cows. Sixteen cows in mid-lactation and in their third parity were allocated to diets containing 0% (control), 5%, 10%, and 15% BSC in a completely randomized design. Each cow was given a daily feed ration of 6 kg and a basal diet of soya bean stover ad libitum. There were no differences in daily feed intake (P > 0.05), but basal intake differed among all treatment groups with cows on the control diet having the highest intake (30 ± 0.34 kg/day). Mean daily milk yield differed (P < 0.05) among all treatment groups. However, the control had higher milk yield of 12.1 ± 0.73 kg/day, and the 15% BSC had the least yield of 7.46 ± 0.73 kg/day. Cows on the control diet had higher milk butterfat content (6.12%; P < 0.05) than those on the BSC-based diets. Protein content differed (P < 0.05) across all treatment groups with cows on 15% BSC producing the highest protein content (3.43%) while the control had the least (2.6%). The concentration of milk total solids for cows fed on 15% BSC was higher (P < 0.05) than that from cows on other diets. Lactose content was not affected by the diets (P > 0.05). These results indicate that BSC can substitute soya bean cake in dairy diets, but milk production and butterfat content are compromised.     

Effects of replacing fish meal with catfish (Pangasius hypophthalmus) processing waste water on the performance of growing pigs

A feeding trial with growing pigs was carried out in which fish meal was replaced by different levels of Tra catfish (Pangasius hypophthalmus) by-product processing waste water (WW). A control diet included fish meal (FM) as the sole protein supplement (WW0), and there were four experimental diets in which 100% (WW100), 75% (WW75), 50% (WW50), and 25% (WW25), respectively, of the crude protein from FM in WW0 was replaced by WW. Thirty crossbred castrated (Yorkshire × Landrace) male pigs with an initial average body weight of 23.6 ± 1.6 kg were allocated into 30 individual pens in a randomized complete block design with six replications. Average daily feed intake and essential amino acid intakes were higher (P < 0.01) in WW0 and WW25 compared with the other three diets, and ether extract intake was highest in WW100 (P < 0.01). The highest average daily gain was in WW0 (582 g/day) and lowest in WW100 (501 g/day; P < 0.01). Dry matter feed conversion ratio was lowest in WW100 (2.16 kg feed/kg gain) and highest in WW0 (2.42 kg feed/kg gain) (P < 0.01).The cost/gain in pigs fed WW100 was lowest (12,476 VND/kg gain), and was highest in WW0 (18,312 VND/kg gain). In conclusion, although performance is reduced, it is possible to replace up to 100% of the fish meal by catfish by-product processing waste water in diets for growing pigs, resulting in much lower feed costs.     

Evaluation of the metabolizable energy value for growing lambs of the Mucuna pruriens seed and the whole pod

Whole pod and seeds of velvet bean (Mucuna pruriens) were included in diets for growing sheep used to validate previously estimated ME values of 9.7 MJ and 12.6 MJ for whole pod and seed respectively. Twenty-four lambs, 15 females and nine males of 18.7 ± 2.4 kg average weight, were allocated in three treatments using a completely randomized block design with eight replicates per treatment. Each group was given a diet with a ratio of 60% of Napier grass (Pennisetum purpureum) and 40% of a supplement with the addition of 0%, 50% whole pod or 66% of M. pruriens seeds, for TI, TII and TIII respectively. Diets were formulated to meet the requirements for 100-g daily live weight gain (LWG). The total dry matter intake (836 g a⁻¹ d⁻¹, forage + supplement), LWG (90 g a⁻¹ d⁻¹) and feed conversion (9.66 kg DM/kg LWG) of lambs from TIII were lower (P < 0.05) compared to 941 g, 121 g, and 7.78 kg DM/kg LWG from TII and 976 g, 132 g and 7.50 kg DM/kg LWG from TI respectively. No difference was found (P > 0.05) between TI and TII in the three evaluated variables. The ME values of whole pod and seeds of M. pruriens used in this work were validated. It was concluded that M. pruriens can be included as a component in diets for growing sheep, as a partial replacement of conventional feedstuffs.     

Pig performance increases with the addition of dl-methionine and l-lysine to ensiled cassava leaf protein diets

Two studies were conducted to determine the impact of supplementation of diets containing ensiled cassava leaves as the main protein source with synthetic amino acids, dl-methionine alone or with L-lysine. In study 1, a total of 40 pigs in five units, all cross-breds between Large White and Mong Cai, with an average initial body weight of 20.5 kg were randomly assigned to four treatments consisting of a basal diet containing 45% of dry matter (DM) from ensiled cassava leaves (ECL) and ensiled cassava root supplemented with 0%, 0.05%, 0.1% and 0.15% dl-methionine (as DM). Results showed a significantly improved performance and protein gain by extra methionine. This reduced the feed cost by 2.6%, 7.2% and 7.5%, respectively. In study 2, there were three units and in each unit eight cross-bred (Large White × Mong Cai) pigs with an initial body weight of 20.1 kg were randomly assigned to the four treatments. The four diets were as follows: a basal diet containing 15% ECL (as DM) supplemented with different amounts of amino acids l-lysine and dl-methionine to the control diet. The results showed that diets with 15% of DM as ECL with supplementation of 0.2% lysine +0.1% dl-methionine and 0.1% lysine +0.05% dl-methionine at the 20–50 kg and above 50 kg, respectively, resulted in the best performance, protein gain and lowest costs for cross-bred (Large White × Mong Cai) pigs. Ensiled cassava leaves can be used as a protein supplement for feeding pigs provided the diets contain additional amounts of synthetic lysine and methionine.     

Efficacy of bentonite clay in ameliorating aflatoxicosis in piglets fed aflatoxin contaminated diets

The efficacy of locally produced bentonite was evaluated with respect to ameliorating the adverse effects of aflatoxins (AF) in piglets fed AF contaminated diets. Forty eight piglets were randomly assigned to one of four treatments: 1) 0 g of bentonite and 0 μg AF/kg feed (control); 2) 4 g of bentonite plus 200 μg AF/kg feed (AF + Bento 4); 3) 5 g of bentonite plus 200 μg AF/kg feed (AF + Bento 5) and 4) 0 g of bentonite plus 200 μg AF/kg feed (AFA). Piglets in the AFA treatment had lower overall average daily weight gain (ADG), feed conversion efficiency, albumin (ALB) and total protein (TP) compared to the control diet, while mean serum leukocyte and enzyme activities (glutamic-oxalacetic transaminase (GOT), glutamic-pyruvic transaminase (GPT), gamma glutamyltransferase (GGT), alkaline phosphate (ALP) and lactic dehydrogenase (LDH)) were significant increased. The inclusion of bentonite at 0.4% or 0.5% in the AF contaminated diet restored the lower performance, feed efficiency and abnormal blood profiles of the piglets given AF and no differences between 0.4 and 0.5% inclusion of bentonite. The findings in the present study provide critically needed confirmation that bentonite has the ability to reduce the adverse effects of AF.     

Balanced nutrient density for broiler chickens using a range of digestible lysine-to-metabolizable energy ratios and nutrient density:Growth performance,nutrient utilisation and apparent metabolizable energy

Currently, specific nutrient concentration, metabolizable energy (ME) and digestible amino acids are used as feed formulation criteria. A balanced nutrient density (BND) concept based on 2 criteria of nutrient density and balanced amino acids-to-ME ratio may offer more flexibility in optimisation of profit in formulation of diets compared with current formulation based on set values per unit of feed mass. A total of 672 one-d-old off-sex male Ross 308 broiler chickens were used across two 42-d performance trials in a 3 × 2 factorial arrangement of treatments with each diet replicated 8 times (14 birds per replicate). The experimental factors were 2 nutrient density levels (low [LD] and high [HD]) and 3 digestible lysine-to-ME ratios (DLYS:ME; low, medium, and high). Low density diets had ME of 2,876 and 3,023 kcal/kg for starter and finisher, respectively, while values for HD diets were 3,169 and 3,315 kcal/kg with proportionally higher non-nitrogenated nutrients. Separate digestibility and apparent metabolizable energy (AME) assays were conducted at d 21 and 42. Digestibility assays at d 7 were conducted on birds used for performance trials. Regardless of the diet density, birds fed low DLYS:ME had a lower (P < 0.01) feed intake (d 0 to 42) than medium and high DLYS:ME. Without interaction, birds fed low and medium DLYS:ME had a similar body weight gain being the heaviest while birds low DLYS:ME were the lightest. By an interaction (P < 0.05), the highest overall FCR value was observed for birds fed LD × low DLYS:ME and improved linearly when DLYS:ME increased to the highest level reaching a limit for birds fed HD × medium DLYS:ME. Calorie conversion linearly decreased (P < 0.001) with increments in DLYS:ME. Jejunal and ileal starch and protein digestibility were affected on d 21 and 42 but not on d 7 of age. Given the independence of response on BW and feed consumption, the use of BND as a flexible system in diet formulations has the potential to enable more accurate formulation for optimisation of growth performance of broiler chickens.     

Effect of dietary energy,protein, and a versatile enzyme on hen performance,egg solids,egg composition,and egg quality of Hy-Line W-36 hens during second cycle,phase two

This study was conducted to evaluate the effect of Rovabio, dietary energy, and protein on performance, egg composition, egg solids, and egg quality of commercial Leghorns in phase 2, second cycle. A 4 × 2 × 2 factorial arrangement of treatments comprising 4 dietary energy levels (2,791, 2,857, 2,923, and 2,989 kcal of ME/kg) and 2 protein levels (15.5 and 16.1%) with and without Rovabio was used. Hy-Line W-36 hens (n = 1,920, 87 wk old) were randomly divided into 16 dietary treatments (8 replicates of 15 hens per treatment). The trial lasted 12 wk. Dietary protein significantly increased feed consumption but decreased yolk color. As dietary energy increased from 2,791 to 2,989 kcal of ME/kg, feed consumption decreased from 98.0 to 94.9 g per hen daily, and yolk color increased from 5.27 to 5.56. There was a significant interaction among dietary protein, energy, and Rovabio on egg production, BW, egg mass, feed conversion, and yolk solids. Egg weight of hens fed the diets supplemented with Rovabio was significantly greater than that of hens fed the diets without Rovabio during wk 3 and 4. However, Rovabio did not significantly influence average egg weight (87 to 98 wk of age). Rovabio supplementation significantly increased BW of hens. These results suggest Rovabio had a small but significant influence on nutrient utilization of commercial Leghorns during phase 2 of the second cycle.