Dietary Energy Content Research Articles

Study of growth performance of Desi growing chickens reared under confinement on varying levels of energy and protein

The effects of dietary energy and protein concentration on desi growing chickens under confined management system were evaluated through conductive feeding trial with 72 female desi growing chickens of 12-22 weeks of age. Four experimental diets were i) Conventional diet (CD), ii) low nutrient density (ME 2500 kcal/kg + CP 15%), iii) moderate nutrient density (ME 2700 kcal/kg + CP 17%) and iv) high nutrient density (ME 2900 kcal/kg + CP 19%). The contents of other nutrients including calcium and total phosphorous in the formulated diets were fitted with the requirements of the chickens. Results indicated that feed intake and weight gain increased significantly in birds received increased levels of nutrients in diets. It is concluded that the ME and CP requirements for indigenous (desi) female chicks between 12 and 22 weeks of age may be 2700 kcal/kg and 17% diet respectively for achieving proper weight gain before reaching sexual maturity.
 Bangladesh J. of Livestock Res. 20(1-2): 42-47, Jan-Dec 2013

Dimethylglycine Supplementation in Reduced Energy Broilers' Diets Restores Performance by Improving Nutrient Digestibility.

Simple SummaryNutritional emulsifiers are used to counteract any negative impact on birds’ performance by improving fat digestibility. Reducing the energy content of broiler diets, which can be achieved by decreasing the quantity of supplemented fat, could contribute to the formulation of diets with a lower production cost. Dimethylgycine (DMG) is a bioactive compound with multiple applications and functions, which has been used as a dietary supplement in the feed of monogastric animals. The aim of the present study was to investigate the effects of DMG supplementation in reduced-energy diets in broilers on performance and nutrient digestibility. It was shown that DMG supplementation in reduced energy broiler diets restored performance indicators to the levels obtained with a standard diet. This effect was probably mediated by the positive effects on the gastrointestinal function of the broilers after DMG supplementation, as evidenced by the improved nutrient digestibility. It is essential for the digestive system in broilers to function optimally, in order to correspond to increased feed consumption and their high production potential. The dietary supplementation of DMG and ingredients with similar emulsifying properties could be used as supportive means for sustainable broiler production.Reducing the energy content of broiler diets could lead to the formulation of diets with reduced production cost. Dimethylgycine (DMG) has been used as a dietary supplement to enhance dietary fat utilization in poultry. The objective of the present study was to investigate the effects of DMG supplementation in reduced energy diets on performance and nutrient digestibility in broiler chickens. Four hundred and eighty day-old broilers were randomly allocated to three dietary treatments: a standard energy diet (PC treatment), a reduced energy diet by 66 kcal/kg (NC treatment) and the reduced energy diet supplemented with 500 mg/kg of DMG (DMG treatment). Fat digestibility was significantly higher in DMG group, compared to PC and NC groups. Intestines and gizzard lesion scores were found to be lower in the DMG group compared to PC. DMG supplementation resulted in lower jejunum pH and ileum viscosity in broilers. Overall, the present study showed that DMG supplementation in reduced energy broiler diets restored growth performance to the levels obtained with a standard diet. This result was probably mediated by the positive effects on the gastrointestinal function of the broilers after DMG supplementation, as evidenced by the improved nutrient digestibility, the reduced gross lesion scores and the lower values in intestinal pH and viscosity.

Effects of Dietary Amino Acid Regimens on Live Performance and Processing Characteristics of Cobb MV × 700 Male and Female Broilers

The magnitude and timing of broiler responses to dietary amino acid (AA) density can vary between sexes and among genetic lines. Two experiments (Exp) were conducted to determine the responsiveness of Cobb MV × 700 broilers to changes in dietary AA density. In Exp 1, low (L), medium (M), and high (H) AA density diets were maintained across starter and grower phases in a 28 d growth performance trial (all males). In Exp 2, combinations of L, M, and H-AA density diets were varied across 4 feeding phases to evaluate the effect of 6 AA feeding regimens (HHHH, HHHM, HHMM, HMMM, MMMM, and HHLL) on growth performance, carcass composition, and breast muscle myopathies of broilers reared sex-separately. Body weight gain, feed intake (FI), and FCR responded positively to increased AA density during the starter and grower phases (0 to 28 d) of Exp 1. In Exp 2, broiler responses to AA density from 0 to 28 d diminished by the conclusion of the finisher phase (day 35), and FCR was the only measurement influenced by dietary AA density through day 46. Carcass characteristics and breast muscle myopathies were unaffected by AA density, with the exception of fat pad percentage, which decreased with increasing AA density. These data indicate that Cobb MV × 700 broilers may be less responsive to dietary AA density than other high-yielding broiler strains and further research to establish digestible AA:Lys ratios or dietary energy concentrations that optimize responses to increased AA density are warranted.

Inclusion of quebracho tannin extract in a high-roughage cattle diet alters digestibility, nitrogen balance, and energy partitioning.

Condensed tannins (CT) might improve animal and system-level efficiency due to enhanced protein efficiency and reduced CH4. This study evaluated the impact of quebracho tannin (QT) extract fed at 0%, 1.5%, 3%, and 4.5% of dry matter (DM), within a roughage-based diet on apparent digestibility of DM, organic matter (OM), fibrous fractions, and N retention and energy partitioning of growing steers (236 ± 16 kg BW). A Latin rectangle design with eight animals and four periods was used to determine the whole-animal exchange of CO2, O2, and CH4 as well as the collection of total feces and urine over a 48-h period, using two open-circuit, indirect calorimetry respiration chambers. Following the removal of steers from respiration chambers, rumen inoculum was collected to determine ruminal parameter, including volatile fatty acids (VFA) and ammonia. Animals were fed a 56.5% roughage diet at 1.7% BW (dry matter basis). Dry matter and gross energy intakes were influenced by the level of QT inclusion (P ≤ 0.036). Digestibility of DM, OM, and N was reduced with QT inclusion (P < 0.001), and fiber digestibility was slightly impacted (P > 0.123). QTs altered the N excretion route, average fecal N-to-total N ratio excreted increased 14%, and fecal N-to-urinary N ratio increased 38% (P < 0.001) without altering the retained N. Increased fecal energy with QT provision resulted in reduced dietary digestible energy (DE) concentration (Mcal/kg DM; P = 0.024). There were no differences in urinary energy (P = 0.491), but CH4 energy decreased drastically (P = 0.007) as QT inclusion increased. Total ruminal VFA concentration did not differ across treatments, but VFA concentration increased linearly with QT inclusion (P = 0.049). Metabolizable energy (ME) was not affected by the QT rate, and the conversion efficiency of DE-to-ME did not differ. Heat energy decreased (P = 0.013) with increased QT provision likely due to changes in the DE intake, but there was no difference in retained energy. There were no differences for retained energy or N per CO2 equivalent emission produced (P = 0.774 and 0.962, respectively), but improved efficiency for energy retention occurred for 3% QT. We concluded that QT provided up to 4.5% of dry matter intake (about 3.51% of CT, dry matter basis) does not affect N and energy retention within the current setting. Feeding QT reduced energy losses in the form of CH4 and heat, but the route of energy loss appears to be influenced by the rate of QT inclusion.

Carcass parameters and meat quality of Tibetan sheep and Small-tailed Han sheep consuming diets of low-protein content and different energy yields.

Today, consumers are very health conscious and are more aware of the nutritional value of food, especially of meat, than they were in the past. The aim of this study was to evaluate the carcass parameters and meat quality of Tibetan sheep and Small-tailed Han sheep when consuming a diet of low-protein (~7%) and different energy yields (digestible energy, 8.21, 9.33, 10.45 and 11.57MJ/kg) in the cold season. Twelve sheep of each breed were divided randomly into four treatments of different diets with three replicates per treatment per breed. Crude protein of the meat decreased linearly (p<.05), whereas energy increased linearly (p<.05) with an increase in energy level. Tibetan sheep tended to have a higher (p<.1) dressing percentage and rib eye area, while live body weight and hot carcass weight did not differ between breeds but increased linearly (p<.01) with an increase in energy level. Water holding capacity, as indicated by pressing loss and drip loss, did not differ between breeds and was not affected by dietary energy. The concentration of n-3 polyunsaturated fatty acids (PUFAs) was greater in Tibetan sheep meat but saturated fatty acids (SFAs), monounsaturated fatty acids (MUFAs) and n-6 PUFA did not differ between breeds. With an increase in energy content of the diet, SFA decreased (p<.05), whereas MUFA increased (p<.05). The n-6:n-3 PUFA ratio was lower (p<.001) in Tibetan sheep meat, while the atherogenic index did not differ between breeds, but tended to decrease (p<.1) with an increase in dietary energy content. The essential amino acid (EAA) content and ratio of EAA:NEAA (non-essential amino acid) were close to the world standards for healthy meat. In summary, (a) Tibetan sheep meat was preferable to Small-tailed Han sheep meat, although differences between breeds were small; and (b) some carcass parameters and meat quality were improved with an increase in dietary energy level when a low-protein diet was offered.

An Investigation into the Effects of Stevia on food intake, satiety and blood glucose levels in adults: a small-scale study

AbstractNon-nutritive sweeteners (NNS) are suggested to reduce sugar and energy content of diet, but there is growing evidence that they can exacerbate obesity and diabetes through increasing appetite and energy intake. Stevia (stevioside extract), a natural sweetener, is being increasingly consumed, yet limited studies have looked at their effects on satiety and energy intake. The aim of this study is to investigate the effects of preloads of stevia on food intake, satiety and postprandial blood glucose levels when compared to water and sugar. Thirty participants (10 males/20 females; 26 ± 10.5 years; BMI: 23.44 ± 3.42 Kg/m2) took part in a three-arm single-blinded crossover trial. On separate test days, they received three different preloads (300 ml) containing water, sugar (60g) and stevia (1g) followed by an ad-libitum pizza lunch after 30 minutes. Breakfast was standardized. Blood glucose samples were collected before preload and lunch, and then at 30-minute intervals until 120 min post lunch. Volunteers recorded their feelings of satiety and hunger on visual analogue scales (VAS) before preload and after meal intake. A one-day diet diary was collected for each test day. Data was analysed using repeated measures ANOVA (SPSS Inc., Chicago, IL, USA). Despite the difference in energy content between preloads, there were no significant differences in energy intake at lunch between the three interventions (F (2, 56) = 0.25, p = 0.78). Furthermore, participants did not compensate by consuming more energy during the day after the stevia preload (1660 ± 584 Kcal) compared to sugar preload (1770 ± 763 Kcal, p = 0.82). There were no significant differences in VAS scores between stevia and sugar preloads, but participants scored significantly higher rates of hunger (before and after lunch) and desire to eat (before lunch) following water preload (p &lt; 0.05). No significant differences between water, sugar and stevia were noted for postprandial glucose levels (120 min post lunch) when adjusted from baseline (F (2, 58) = 2.56, p = 0.09). Area under the curve (AUC) for glucose did not differ between water and stevia (p = 0.2). Results are in line with several clinical trials showing that the consumption of sweeteners does not lead to an increase in hunger and energy intake, and could therefore present a useful strategy to assist with weight loss. Further studies looking at long-term effects of stevia on weight regulation are needed to support these findings.

Evaluation of Sodium Stearoyl-2-Lactylate and 1, 3-Diacylglycerol Blend Supplementation in Diets with Different Energy Content on the Growth Performance, Meat Quality, Apparent Total Tract Digestibility, and Blood Lipid Profiles of Broiler Chickens.

We evaluated the effects of supplementing an emulsifier blend (sodium stearoyl-2-lactylate and 1, 3-diacylglycerol) in diets with different energy content (normal and 100 kcal/kg reduced) on the growth performance, meat quality, apparent total tract digestibility (ATTD), and blood lipid profile of broiler chickens. Male broiler chickens (n = 1024), with an initial body weight (BW) of 43.60±0.2 g, were used in a 35-day trial. Broiler chickens of similar body weight were randomly allocated to one of four treatment groups in a 2 × 2 factorial arrangement with two levels of dietary energy content and with or without emulsifier blend. Broiler chickens fed on emulsifier blend supplemented diet had a higher body weight gain (BWG) during d 7–21, d 21–35, and overall period (P<0.05), higher BW during overall period (P<0.05), and lower feed conversion ratio (FCR) during d 7–21, d 21–35, and overall period (P<0.05) compared with broilers fed on diets without emulsifier supplementation. Broiler chickens fed on the diet with low energy content had a lower BWG during d 1–7, d 21–35, and overall period (P<0.05), lower BW during overall period, and higher FCR during d 1–7, d 21–35, and overall period (P<0.05). The ATTD of energy tended to decrease in response to low-energy content diet (P<0.10). Drip loss at 7 d post slaughter tended to decrease in response to dietary emulsifier blend supplementation (P<0.10). However, no interactive effects of dietary energy content and emulsifier blend supplementation (P>0.10) were observed on the growth performance, ATTD, blood lipid profiles, meat quality and relative organ weight. In conclusion, dietary emulsifier blend supplementation could improve growth performance, while low dietary energy content would decrease growth performance and ATTD of energy.

Response of roe deer (Capreolus capreolus) to seasonal and local changes in dietary energy content and quality

Context In terms of their nutritional physiology, roe deer have been called ‘concentrate selectors’. This implies that they select proteins in their diet and are not able to digest fibre. It is, thus, suggested that in an agricultural landscape, they are unable to digest the high fibre content of arable crops and, thus, suffer and need to be given supplementary feed. Aims Our aim was to determine the nutrient composition and energy content of the roe deer diet in an agricultural habitat compared with that in a natural forest habitat. Methods Rumen contents of 245 roe deer were collected to represent each month of the year for 3 years, weighed, and analysed by standard methods for nutrient and fibre content. Key results Roe deer in the agricultural habitat had rumen contents with significantly higher metabolisable energy (ME) concentrations, with a median of 6.2 MJ ME/kg DM, than did roe deer in the forest habitat, where the median was 5.4 MJ ME/kg DM. The mass of rumen contents in the forest habitat was, on average, 240 g higher than that in the agricultural habitat. Roe deer in the forest habitat compensate for the lower energy concentration in their natural diet by increasing their food intake. The concentration in the agricultural habitat is a result of the higher proportion of easily digestible carbohydrates in the diet. The concentration of crude protein in the rumen contents did not differ statistically between the two areas. In both habitats, the mean crude fibre concentration varied between 24% DM and 34% DM, and was significantly higher in the forest. The concentration of crude fibre selected by the roe deer is similar to the concentration of crude fibre known to be selected by red deer and fallow deer (intermediate feeders) and mouflon (a grazer) (Hofmann 1989). Conclusions The term ‘concentrate selector’ should be replaced by ‘selector’ to avoid misinterpretations. Energy shortfalls were not observed in either of the populations during the study period. Implications Supplemental feeding was not necessary to maintain the population.

Nutritional characterization of various classes of Egyptian beef luncheon.

Objectives:The present work was conducted to investigate the nutritional profile of the highly consumed beef luncheon in Egypt. Besides, the potential health hazards associated with the consumption of luncheon were highlighted.Material and methods:A total of 60 beef luncheon samples were collected from Egyptian markets. They were classified into three classes: A, B, and C based on their prices. The collected samples were examined for their chemical composition by determining moisture, protein, fat, ash, carbohydrate, and energy percentage. The contents of trace elements were also investigated.Results:The obtained findings showed a comprehensive dissimilarity in the chemical composition. According to the fresh weight base, moisture, protein, fat, ash, and carbohydrate fluctuated from 56.97 to 64.52, 3.50 to 16.10, 4.73 to 13.39, 3.30 to 3.51, and 11.32 to 27.44% w/w, respectively. The highest price class A Egyptian beef luncheon had more accepted nutritive value and dietary energy content. All the examined classes were low in calcium, potassium, zinc, and magnesium. The target hazard quotient indicated that the trace elements did not present any risks for consumers except for sodium. High phosphorous content and high phosphorus–protein ratio were observed in all categories which had a harmful health effect, hence named “new cholesterol.”Conclusion:Based on the information, this study is the leading work that deeply investigated the chemical composition of the Egyptian luncheon classes, and the obtained data could be beneficial to update the nutritional knowledge used by dietitians and the responsible for nutrition assessment and surveillance by the government.

Saturated fat supplemented in the form of triglycerides decreased digestibility and reduced performance of dairy cows as compared to calcium salt of fatty acids

The two most popular rumen-protected fatty acid supplements in dairy cow rations are calcium salts of palm oil fatty acid calcium salts of palm oil fatty acid (CSFA) and prilled saturated fatty acids (SFAs). The objectives of this study were to determine the effects of supplementing SFA in the form of triglycerides (TSFA), as compared to CSFA, on yields, efficiency and diet digestibility in high-yielding dairy cows. Twenty-eight (14 cows in each group) multiparous cows were fed a basal diet supplemented (on DM basis) with either 12 g/kg TSFA (~350 g/cow per day – contained 980 g/kg fat; 882.3 g/kg SFAs) or 14 g/kg CSFA (~440 g/cow per day – contained 800 g/kg fat; 566.4 g/kg SFAs). The supplement amounts in the diet were balanced according to fat content. Rumen samples were taken for measurements of ammonia and volatile fatty acids concentrations, and fecal samples were taken for digestibility measurements. The CSFA cows produced 3% higher milk yields (47.6 v. 46.2 kg/day; P < 0.0001) and 4.7% higher 4% fat-corrected milk (FCM; 44.7 v. 42.7 kg/day; P = 0.02) than the TSFA cows. No difference in milk-fat content was observed, but milk-protein content was higher in the TSFA than CSFA cows. Yields of fat and protein were similar, but lactose yields were higher in TSFA cows. There were no differences in dry matter intake or efficiency calculations between groups. The ruminal ammonia concentrations were similar between groups, whereas acetate concentrations and acetate : propionate ratio were greater for CSFA than TSFA cows. The apparent total-tract digestibility of dry (P < 0.0007) and organic matters (P < 0.0003), fat (P < 0.0001), NDF and ADF (P = 0.02) were lower in the TSFA v. CSFA cows. In conclusion, the CSFA-supplemented cows produced 3% higher milk and 4.7% higher 4% FCM than the TSFA cows. However, TSFA supplementation did not depress milk-protein content. The apparent total-tract digestibility was lower for all dietary components in the TSFA cows, which was probably due to the effects of both degree of saturation and triglyceride form of the TSFA supplement. Considering that diets were balanced according to the fat content of the supplements, the lower yields of milk and FCM observed in the TSFA than CSFA cows were likely due to the lower digestibility of the fat and other nutrients in the TSFA cows, which might have negatively influenced the dietary energy content.

Production Response of Athulya Layer Chicken to Dietary Energy Concentration and Feed Particle Size

Production Response of Athulya Layer Chicken to Dietary Energy Concentration and Feed Particle Size

Milk Urea Concentration in Dairy Sheep: Accounting for Dietary Energy Concentration

Simple SummaryIn this paper, we show that milk urea concentration (MUC) of dairy ewes is markedly affected not only by dietary protein concentration, as evidenced by previous research, but also by dietary energy concentration. Thus, to avoid misleading interpretations, the utilization of MUC as indicator of the protein status of ewes should account for the dietary energy concentration. Minimal, optimal, and maximal MUC values for different combinations of dietary energy and protein are proposed. Because frequent bulk tank MUC analysis is easy to perform and cost-effective, the reference values proposed here can be used for optimizing sheep milk and reproductive performances while curbing N release from excreta.In dairy sheep milk urea concentration (MUC) is highly and positively correlated with dietary crude protein (CP) content and, to a lesser extent, with protein intake. However, the effect of dietary energy and carbohydrate sources on MUC of lactating ewes is not clear. Thus, the objective of this study was to assess the effects of diets differing in energy concentration and carbohydrate sources on MUC values in lactating dairy ewes. Two experiments were conducted (experiment 1, E1, and experiment 2, E2) on Sarda ewes in mid and late lactation kept in metabolic cages for 23 d. In both experiments, homogeneous groups of five ewes were submitted to four (in E1) or three (in E2) dietary treatments, consisting of pelleted diets ranging from low energy (high-fiber diets: 1.2–1.4 Mcal of net energy for lactation (NEL)) to high energy (high-starch diets: 1.7–1.9 Mcal of NEL) contents, but with a similar CP concentration (18.4% dry matter (DM), on average). Each diet had a different main ingredient as follows: corn flakes, barley meal, beet pulp, or corn cobs in E1 and corn meal, dehydrated alfalfa, or soybean hulls in E2. Regression analysis using treatment means from both experiments showed that the best predictor of MUC (mg/100 mL) was the dietary NEL (Mcal/kg DM, MUC = 127.6 − 51.2 × NEL, R2 = 0.85, root of the mean squared error (rmse) = 4.36, p < 0.001) followed by the ratio CP/NEL (g/Mcal, MUC = −14.9 + 0.5 × CP/ NEL, R2 = 0.83, rmse = 4.63, p < 0.001). A meta-regression of an extended database on stall-fed dairy ewes, including the E1 and E2 experimental data (n = 44), confirmed the predictive value of the CP/ NEL ratio, which resulted as the best single predictor of MUC (MUC = −13.7 + 0.5 × CP/NEL, R2 = 0.93, rmse = 3.30, p < 0.001), followed by dietary CP concentration (MUC = −20.7 + 3.7 × CP, R2 = 0.82, rmse = 4.89, p < 0.001). This research highlights that dietary energy content plays a pivotal role in modulating the relationship between MUC and dietary CP concentration in dairy sheep.

Endogenous fat losses and true and apparent fat digestibility in adult and growing dogs fed diets containing poultry offal fat.

The objective of this study was to evaluate the coefficient of total tract apparent digestibility (CTTAD) of dietary nutrients, endogenous fat loss (EFL), dietary metabolizable energy (ME) content, coefficient of true digestibility (CTD) of fat and faecal parameters of dogs. A total of 16 puppies and 8 adult dogs were distributed according to a double Latin square experimental design. A basal diet was formulated, to which increasing levels (60, 120 and 180g/kg) of poultry offal fat oil were added. EFL was estimated using hyperbolic and linear regression as a function of LW/day and dry matter (DM) intake, respectively, and the CTD of fat was calculated. The CTTAD of acid-hydrolysis ether extract (AHEE) and ME content increased as dietary poultry offal fat level increased both in adult dogs and in puppies (p<.05). The CTTAD of DM and crude protein were higher in adult dogs than in puppies. EFL was estimated by hyperbolic regression as y=98.1094-13.6202/x and y=99.1280-26.1366/x, where y=CTTAD of AHEE (%) and x=AHEE intake/kgBW, for adult dogs and puppies, respectively, which yielded EFL values of 138 and 262mgAHEE per kgBW per day for adult dogs and puppies respectively. The EFL estimated by linear regression was 7.89g and 8.97g/kgDM intake for adult dogs and puppies respectively. The CTD estimated by both methodologies was higher in puppies than in adults (p<.05). Lower faecal DM and score, and higher ammonia production were obtained in puppies than adult dogs (p<.05). The results indicate good fat utilization and that fat digestibility is underestimated, as the CTTAD of AHEE does not take into account EFL, particularly at low-fat inclusion levels and in growing dogs, which have greater EFL than adult dogs.

PSX-11 Effects of lamb’s breed and energy concentration of diet on nutrient digestibility and growth performance

Abstract The accumulation of subcutaneous adipose deposits occurs in many genotypes of animals adapted to tropical arid conditions. In sheep, good adaptation of fat-tailed sheep breeds, as Rabo Largo, to arid environmental conditions and food shortages can also undergo digestive and metabolic adaptation, including a greater capacity for digestion of poor roughage. Forty lambs (18±3 kg initial BW) were assigned in a randomized completely block design with a 2x2 factorial arrangement of treatments, with 2 breeds – B (Santa Inês- SI and Rabo Largo-RL) and 2 diets – D (low and high energy), resulting in four treatments: SILE, SIHE, RLLE and RLHE. Lambs (20 SI and 20 RL) were individually penned during 43 d and fed 1 of 2 diets with different concentrate: roughage ratio: low energy-LE (with 70% hay and 10.7% CP, DM basis) and high energy-HE (70% concentrate and 12.7% CP, DM basis). At the end of performance period, the intake was recorded and total feces collected for 5 d. Data were analyzed by ANOVA and when a significant effect (P &amp;lt; 0.05) was found, means were compared using Tukey’s method. The G:F ratio had effect only for D (0.12, 0.22, 0.10 and 0.24 for SILE, SIHE, RLLE and RLHE, respectively). There was observed an effect of D and B (P &amp;lt; 0.05) for all variables related to growth and digestibility, with higher means for SI and HE, except for NDF intake (495, 322, 340 and 268 g/d for SILE, SIHE, RLLE and RLHE, respectively) and NDF digestibility (63, 58, 59 and 45% for SILE, SIHE, RLLE and RLHE). It was observed an interaction D x B on CP intake, NDF intake and NDF digestibility. Breed and diets affected the performance and digestibility of lambs. However, RLLE increased the NDF digestibility, but decreased the ADG, suggesting higher fat depots accumulation.

172 Effects of net energy levels on feed intake pattern and growth performance of growing-finishing gilts monitored using a computerized feed intake recording system

Abstract This study evaluated the effects of dietary net energy concentrations on feeding behavior and growth performance of growing-finishing pigs monitored using a feed intake recording equipment (FIRE). Two hundred and sixteen (48.8 ± 5.6 kg) gilts were blocked by bodyweight and assigned randomly to 1 of 3 dietary treatments, which included low (2,350 kcal/kg), medium (2,450 kcal/kg), and high (2,550 kcal/kg) dietary NE levels. Pigs were housed in 18 pens for 68 d in four phases with 12 pigs and one FIRE station per pen. Bodyweight, feed consumption, and the amount of time and visit at the station of individual pigs were monitored every day by using FIRE. Pigs fed low NE diet spent more time (min) at the station during the first two weeks and visited the station more times with fewer amounts of time (min) per visit after two weeks compared with pigs fed medium and high levels of NE diets (P &amp;lt; 0.05). The speed (g/min) and amount (g/visit) of feed intake were lower (P &amp;lt; 0.05) during phase 3 and the overall period in low NE diet compared with pigs fed medium NE diet. Pigs fed medium NE diet tended to have a greater (P = 0.066) average daily feed intake at phase 4 than pigs fed low NE diet. Increasing NE levels linearly improved (P &amp;lt; 0.05) average daily gain, feed conversion ratio, and final BW during phase 3 and the overall period. However, the overall energy efficiency (Mcal NE/ kg gain) was linearly decreased with increasing NE levels. In conclusion, decreasing dietary NE to 2350 Mcal/kg resulted in more visits to feeders with slow ingestion speed compared with pigs fed diets with 2450 or 2550 Mcal/kg NE. Increasing dietary NE levels linearly improved daily gain and feed conversion ratio, but linearly decreased energy efficiency.

96 Development of genomics-based precision management model for Hanwoo steers; response to the divergent selection for marbling tested under different dietary energy levels

Abstract Focusing high marble deposition, Hanwoo feedlot system uses high-energy diet over the prolonged fattening period. However, due to the individual genetic variation, around 40% of them are graded into inferior quality grades (QG), despite they utilized the same resources. Therefore, focusing to develop a genomic-based precision management model, this study was to evaluate the response to the divergent selection on genetic merit for marbling score (MS), under different dietary TDN (total digestible nutrient) levels. Total of 112 calves were genotyped and initially grouped for estimated breeding value (high and low) for marbling score (MS-EBV). Subsequently, managed under two levels of feed TDN%, over the growing period, early, middle, and final fattening periods following 2X2 factorial arrangement (figure 1). Carcasses were evaluated for MS, Backfat thickness (BFT) and Korean beef quality grading standard. As the direct response to the selection was significant, the results confirmed the importance of initial genetic grouping of Hanwoo steers for MS-EBV. However, dietary TDN level did not show an effect (P &amp;gt; 0.05) on the MS. Further, no genetic-by-nutrition interaction for MS (P &amp;gt; 0.05) was also observed. The present results showed no correlation response on BFT (P &amp;gt; 0.05), indicating that the selection based on MS-EBV can be used to enhance the MS without undesirable effect on BFT. Ultimate turnover of the Hanwoo feedlot operation is primarily determined by the QGs. The present model shows that the initial grouping for MS-EBV increased the proportion of carcasses graded for higher QGs (QG1++ and QG1+) by approximately 20%. Moreover, there appears to be a potential to increase the proportion of QG 1++ animals among the high-genetic group by further increasing the dietary energy content. Overall, this precision management strategy suggests the importance of adopting an MS based initial genetic grouping system for Hanwoo steers with a subsequent divergent management based on dietary energy level.

PSXII-26 Withdrawing monensin by the end of finishing period increases intake and changes ruminal fermentation patterns of cannulated Nellore cattle

Abstract This study, conducted at São Paulo State University feedlot, Dracena, Brazil, was designed to evaluate the effects of increasing diet energy content and withdrawing monensin (MON) by the end of the finishing period, while combined with virginiamycin (VM), on rumen fermentation patterns and DMI of Nellore cattle. The experiment was designed as a 5 x 5 Latin square, in which five 32-mo-old Nellore steers (531 ± 22 kg) cannulated in the rumen were utilized. Each period lasted 28-d, which was divided into phases as follows: 14-d adaptation (66% to 78% concentrate), 7-d finishing 1 (84% concentrate) and 7-d finishing 2 (88% concentrate). The treatments were: MON throughout phases, VM throughout phases, MON+VM throughout phases, MON+VM during adaptation and only VM during finishing 1 and 2, and MON+VM during adaptation and finishing 1 and only VM during finishing 2. Monensin and VM were added into diets at 30 and 25 ppm, respectively (DM basis). Rumen fermentation pattern was assessed by measuring ruminal pH and by collecting samples for SCFA determination on the last day of each phase. No treatment effect was observed (P &amp;gt; 0.05) for any of the SCFA variables measured, except for acetate:propionate, where cattle fed MON+VM throughout phases had greater ratio than those fed MON throughout phases on finishing 1 (P = 0.02; Table 1). Cattle consuming only VM in the study presented greater DMI throughout phases (P &amp;lt; 0.01), which did not negatively impact rumen pH (Table 2). Feeding MON+VM and withdrawing MON on finishing 2 did not affect SCFA concentrations, but decreased DMI, when compared to cattle fed VM either throughout phases or just during finishing, without affecting rumen pH. Thus, increasing diet energy content and withdrawing MON by the end of finishing period negatively impacted DMI without altering ruminal fermentation pattern.

Dietary Metabolizable Energy Responses in Yellow-Feathered Broiler Chickens from 29 to 56 d

SUMMARY In this study, the metabolizable energy (ME) requirements were determined for Chinese yellow-feathered chickens aged from 29 to 56 d. In total, 1,200 29-d-old male yellow-feathered broilers were randomly assigned to 5 dietary treatments with 6 replicates each of 40 birds. Birds were fed 5 levels of dietary ME (2,799, 2,897, 2,997, 3,098, and 3,198 kcal ME/kg diet). Broilers that received high-energy diets had a higher (P 0.05), whereas the abdominal fat percentage and thigh intramuscular fat percentage increased significantly. The retention of energy and protein increased (P 0.05) on the energy, protein, and fat contents in the whole body. The plasma concentrations of total cholesterol and total triglyceride were not (P > 0.05) affected by the dietary energy concentration but the plasma concentration of uric acid increased significantly. According to broken-line regression analysis, the recommended dietary ME levels that maximized ADG, optimized FCR, and minimized the deposition of abdominal fat (%) in yellow-feathered broiler chickens aged from 29 to 56 d were 3,198 kcal, 3,213 kcal, and 2,920 kcal ME/kg, respectively.

Chicken adaptive response to low energy diet: main role of the hypothalamic lipid metabolism revealed by a phenotypic and multi-tissue transcriptomic approach

BackgroundProduction conditions of layer chicken can vary in terms of temperature or diet energy content compared to the controlled environment where pure-bred selection is undertaken. The aim of this study was to better understand the long-term effects of a 15%-energy depleted diet on egg-production, energy homeostasis and metabolism via a multi-tissue transcriptomic analysis. Study was designed to compare effects of the nutritional intervention in two layer chicken lines divergently selected for residual feed intake.ResultsChicken adapted to the diet in terms of production by significantly increasing their feed intake and decreasing their body weight and body fat composition, while their egg production was unchanged. No significant interaction was observed between diet and line for the production traits. The low energy diet had no effect on adipose tissue and liver transcriptomes. By contrast, the nutritional challenge affected the blood transcriptome and, more severely, the hypothalamus transcriptome which displayed 2700 differentially expressed genes. In this tissue, the low-energy diet lead to an over-expression of genes related to endocannabinoid signaling (CN1R, NAPE-PLD) and to the complement system, a part of the immune system, both known to regulate feed intake. Both mechanisms are associated to genes related polyunsaturated fatty acids synthesis (FADS1, ELOVL5 and FADS2), like the arachidonic acid, a precursor of anandamide, a key endocannabinoid, and of prostaglandins, that mediate the regulatory effects of the complement system. A possible regulatory role of NR1H3 (alias LXRα) has been associated to these transcriptional changes. The low-energy diet further affected brain plasticity-related genes involved in the cholesterol synthesis and in the synaptic activity, revealing a link between nutrition and brain plasticity. It upregulated genes related to protein synthesis, mitochondrial oxidative phosphorylation and fatty acid oxidation in the hypothalamus, suggesting reorganization in nutrient utilization and biological synthesis in this brain area.ConclusionsWe observed a complex transcriptome modulation in the hypothalamus of chicken in response to low-energy diet suggesting numerous changes in synaptic plasticity, endocannabinoid regulation, neurotransmission, lipid metabolism, mitochondrial activity and protein synthesis. This global transcriptomic reprogramming could explain the adaptive behavioral response (i.e. increase of feed intake) of the animals to the low-energy content of the diet.

Calcium Propionate Increased Milk Parameters in Holstein Cows

Background: In the early lactation, dairy cows go through a period of negative energy balance because they do not intake enough food to supply the energetic demand of milk production. In this period, dairy cows are susceptible to metabolic disorders, although has little evidence that milk production contribute to increase diseases occurrence. Some alternatives to minimize metabolic disorders, that reduce milk yield, has been suggested, as increase energy density in the diet of dry cows 21 days before the parturition and include additives in the diet pre and post-partum. The aim of this study was to measure the productive parameters in dairy cows fed calcium salts as energetic source. Materials, Methods &amp; Results: Two Latin square 4x4 were used, whereas one comprehended of early lactation cows and the other of mid lactation cows. Animals of 2nd and 3rd parity were used only. Parity was distributed evenly among groups. The trial consisted of 4 groups with 4 treatments as follow: T1: 300 g of calcium acetate, T2: 200 g of calcium propionate, T3: 200 g of calcium salts of fatty acids, and T4: control without any calcium additive. The animals were milked twice a day, the first milking at 07:00 am and the second milking at 05:00 pm. Milk samples were collected in plastic containers with potassium dichromate. These samples were sent to the Laboratory of Milk Analysis of the Paranaense Association of Breeders of the Holstein Breed for analysis of fat, protein, lactose and total solids through the infrared method. Throughout the experimental period, the daily production of the animals under study was recorded. The production of milk (kg) was corrected to 3.5% fat using the formula PLA 3.5% = (0.432 + kg milk) + (0.1623 x kg milk x fat content).Discussion: Greater supply of glucose or propionate stimulate milk protein production, but the mechanism of this stimulation is unclear. Milk protein is dependent on energy supply, and deficient energy intake reduces milk protein levels. Calcium propionate provided enough energy supply and increased milk protein levels. The synthesis of lactose has influence in water absorption in mammary gland and lactose determine milk osmolarity. The lactose levels vary according blood glucose, somatic cells count and energy availability for physiological processes. In the literature, rarely has been found greater lactose concentration caused by feed intake, becoming very important the results found in this work. The diet energy concentration and consumption rate determine energy intake, which limit milk yield. Dairy cows in early lactation has marked increased of nutrient requirements to support milk production. Support milk lactose synthesis in the mammary gland is the one of responsible for increase of nutrients requirements. In this period, the glucose demands increases 2 times more than during late gestation. Propionate is converted to glucose in the liver and it will be support lactose synthesis in the mammary gland. Propionate supplementation in this work provided better energetic supply and it is possible to consider, evaluating the milk yield. It was concluded that calcium propionate increased milk parameters like: milk protein, lactose and milk fat. Holstein cows fed calcium propionate had greater milk yield than other groups.