Dietary Energy Content Research Articles

Development of nutrigenomic based precision management model for Hanwoo steers.

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 on development of a nutrigenomic based precision management model, this study was to evaluated the response to the divergent selection on genetic merit for marbling score (MS), under different dietary total digestible nutrient (TDN) levels. Total of 111 calves were genotyped and initially grouped according to estimated breeding value (high and low) for marbling score (MS-EBV). Subsequently, managed under two levels of feed TDN%, over the calf period, early, middle, and final fattening periods following 2 × 2 factorial arrangement. Carcasses were evaluated for MS, Back fat 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 > 0.05) on the MS. Furthermore, no genetic-by-nutrition interaction for MS (p > 0.05) was also observed. The present results showed no correlation response on BFT (p > 0.05), which indicates 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 appear 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.

Food security during nuclear winter: a preliminary agricultural sector analysis for Aotearoa New Zealand.

We aimed to estimate the current dietary energy content of food exports for Aotearoa New Zealand and food security during "nuclear winter" scenarios following a nuclear war. From published sources we estimated dietary energy available from the major domains of food exports, with adjustments for wastage. The impacts on food production in New Zealand during three nuclear winter scenarios were based on those published in Nature Food in 2022 and from an earlier New Zealand Planning Council study. Current major food exports are equivalent to 3.9 times current dietary energy intakes for all New Zealand citizens i.e., 34,100 kJ (8150 kcal) per person per day. Exported dairy products were estimated to be able to provide 338% of this energy intake, followed by exports of meat (34%), fruit (8.6%), alcohol (4.8%), marine products (4.6%) and vegetables (2.7%). During the various nuclear winter scenarios considered (minimal to severe), food production available from diverted exported foods was estimated to still be 3.6 to 1.5 times current daily energy intakes. Nevertheless, the agriculture sector could be at risk of various levels of collapse from lack of imports (e.g., diesel, fertiliser, pesticides, seeds, and machinery parts) and from socio-economic collapse, including if the financial system collapsed. This analysis suggests that this country could theoretically have excess food production capacity, even after a severe nuclear winter scenario. But this benefit could be very short-term if the agricultural system was not made more resilient to potential lack of international trade and socio-economic collapse in a post-catastrophe setting.

Energy concentration and protein inclusion in diets for broilers: Effects on growth performance

We studied the effect of inclusion crude protein (CP) and energy concentration in the diet on growth performance, gastrointestinal tract (GIT) traits, and carcass weight in broilers from 0 to 42 d of age. The experimental design was completely randomized with six diets combined as a 2 x 3 factorial with two levels of CP (20 vs. 22%) and three levels of energy (2900, 3000, and 3100 kcal/kg). Each treatment was 4 replicate and the experimental unit was a pen with 20 birds. All diets were based on corn, soybean meal, wheat, and included sunflower oil. For the entire experiment, the inclusion of CP in the diet did not affect growth performance and the other variables studied. From 0 to 42 d of age, increase energy concentration up to 3100 kcal/kg in diet tended to reduce average daily feed intake (ADFI) (P = 0.053) and improve feed conversion ratio (FCR) (P < 0.01) than energy concentration at level of 2900 kcal/kg. However, average daily gain (ADG) was not affect. Most of the benefits of increase energy concentration on broiler growth was observed from 14 to 21 d and 28 to 35 d of age, a period in which energy concentration improved ADFI and FCR (P < 0.01), respectively. On d 42, increase energy levels in the diet did not affect GIT or carcass relative weight, except for the liver relative weight was heavier (P < 0.05) when intermedia energy concentration 3000 kcal/kg was included in the diet. It is concluded that energy concentration were well utilized by broilers, at level of inclusion.
 

Sarcopenia: prevalence and its main risk factors in older women

Introduction: Sarcopenia is a major public health concern. It is defined as a progressive and gen­eralized skeletal muscle disorder that is associated with an increased likelihood of falls, fractures, physical disability, and ultimately, premature death. Objective: The aim of the study was to assess the prevalence and determine the role of physical activity, nutrient intake, and selected risk factors for the development of sarcopenia in older women. Methods: The study involved 302 women aged ≥65 years (mean age: 72.1± 5.9 years). Bioelectrical impedance analysis of body composition, static muscle strength measurements, Timed Up and Go test, and the assessment of current physical activity using accelerometers were performed. Diets were assessed using the 24-h recall method from two non-consecutive days. The energy and nutrient content of diets was calculated using the computer program DIETA 6. Results: Sarcopenia was present in 28.8% of the women studied. The most important factor in the decrease in the risk of sarcopenia was protein intake ≥ 0.9 g/kg b.m. (OR=0.08;p<0.001), and physical activity ≥ 4000 steps/day. However, these results were not statistically significant (OR=0.58; p=0.08). Furthermore, the risk of developing sarcopenia increased as BMI (OR=1.36; p<0.001) or percent of body fat (OR=1.29; p<0.001) increased.

The effect of temperature and dietary energy content on female maturation and egg nutritional content in Atlantic salmon.

The environment experienced by a female influences reproductive traits in many species of fish. Environmental factors such as temperature and diet are not only important mediators of female maturation and reproduction but also of egg traits and offspring fitness through maternal provisioning. In this study, we use 3-year-old tank-reared Atlantic salmon from two Finnish populations to investigate the effect of temperature and diet on maturation and egg traits. We show that a temperature difference of 2°C is sufficient to delay maturation in female Atlantic salmon whereas a 22% reduction in dietary energy content had no effect on maturation. Diet did not influence the body size, condition or fecundity of the mature females or the size or protein content of the eggs. However, a higher energy diet increased egg lipid content. Neither female body size nor condition were associated with egg size or fat/protein composition. Our results indicate that female salmon that have a poorer diet in terms of energy content may have a reproductive disadvantage due to the lower energy provisioning of eggs. This disadvantage has the potential to translate into fitness consequences for their offspring.

High energy diet of beef cows during gestation promoted growth performance of calves by improving placental nutrients transport.

The aim of this study was to explore the effects of dietary energy level during gestation on growth performance and serum parameters in offspring using beef cattle as research objects. Additionally, the gene expressions associated with nutrients transport in the placenta were evaluated. Eighteen Simmental crossbred cows (body weight = 338.44 ± 16.03 kg and 760 ± 6 days of age) were randomly assigned to 3 dietary treatment groups: low energy (LE, metabolic energy = 8.76 MJ/kg), medium (ME, 9.47 MJ/kg) and high (HE, 10.18 MJ/kg). The dietary treatments were introduced from day 45 before expected date of parturition. The pre-experiment lasted for 15 days and formal experiment lasted for 30 days. Growth performance data and blood samples of calves were collected at birth and day 30 post-birth. The placental tissue was collected at parturition. The results indicated that the birth weight and average daily gain of calves in HE group were higher (P < 0.05) than those in LE group. After parturition, the serum contents of glucose, total protein, cortisol and leptin in neonatal calves were significantly increased (P < 0.05) with the elevation of dietary energy levels. At 30 days postpartum, the glucose, glutathione peroxidase, growth hormone, insulin-like growth factor 1 and leptin concentrations of HE group were significantly increased (P < 0.05) as compared with LE group, while the serum amyloid protein A displayed an opposite trend between two groups. With the increase of dietary energy concentration, placental mRNA expressions of vascular endothelial growth factor A, glucose transporter 1 and 3 were significantly up-regulated (P < 0.05). Furthermore, the amino acid transporter solute carrier family 38 member 1, hydroxysteroid 11-beta dehydrogenase 2, insulin-like growth factor 1 and 2 mRNA expressions of HE group were higher (P < 0.05) than those of LE and ME groups. In conclusion, the improved growth performance of calves from the high energy ration supplemented beef cows may be attributed to the increased placental nutrients transport, which may lead to the increased nutrient supply to the fetus.

Evaluation of dietary metabolizable energy concentrations on meat quality and lipid metabolism-related gene expression in yellow-feathered chickens.

This study evaluated the effects of different dietary metabolizable energy (ME) concentrations on the meat quality, carcass traits, volatile flavourand lipid metabolism-related gene expression levels in yellow-feathered chickens. In total, 600 Huxu female chickens aged 90 days were randomly assigned to six dietary treatments, each with 10 replicates of 10 birds. During the finisher phase, the birds were fed diets containing 2880 (low), 2940, 3000, 3060, 3120and 3180 (high) kcal ME/kg. The results showed that the average daily gain of chickens increased as the dietary ME concentration increased, while the feed to gain improved (p < 0.05), and the intramuscular fat content of breast muscle increased (p < 0.05). The energy concentration had no effect on the breast muscle pH (45 min and 24 h), colour parameter (L*)or percentage of drip loss (p > 0.05), but the shear force values decreased significantly (p < 0.05). The diameter and area of the breast muscle fiber decreased and the muscle fibre density increased as the dietary ME concentration increased (p < 0.05). The highest ME concentration (3180 kcal) increased the percentages of aldehydes (hexanal, heptanal, 2,4-nonadienal, octanal, nonanaland 2-decenal), alcohols (2-nonen-1-ol, trans-2-undecen-1-ol, 7-hexadecenal, 2-hexyl-1-decanoaland n-nonadecanol-1,3,7,11-trimethyl-1-dodecanol), alkanes (2,6-dimethyl-heptadecane)and carboxylic acids (9-hexadecenoic acid), but reduced the percentages of octadecanal, octadecane, heneicosaneand tetradecanal (p < 0.05). In addition, the mRNA gene expression levels of fatty acid-binding protein 3 and apolipoprotein B were significantly upregulated in the liver, whereas that of cholesteryl ester transfer protein was significantly downregulated. In conclusion, increasing the ME diet to 3180 kcal/kg significantly improved the quality and flavour of the meat from yellow-feathered broilers. our finding may help poultry producers to improve the taste of meat by regulating genes related to lipid metabolism, thereby achieving the flavour and taste characteristics preferred by consumers.

The Effect of Alternating High-Sucrose and Sucrose Free-Diets, and Intermittent One-Day Fasting on the Estrous Cycle and Sex Hormones in Female Rats.

Relationships between diet, sex hormone concentrations, and the estrous cycle are important from the perspective of infertility and estrogen-dependent disease prevention and treatment. Four dietary interventions reflecting modern eating behaviors were explored. The study involved 50 female rats divided into five feeding groups. The impact of the amount of sucrose consumed (9% and 18% of the dietary energy content), alternating high-sucrose and sucrose-free diets, and a high-sucrose diet combined with intermittent one-day fasting on the estrous cycle and sex hormone concentrations in female rats was assessed. Even low amounts of dietary sucrose (9% of the dietary energy content) were found to lead to increased estradiol (E2) concentrations and decreased progesterone (Pg) concentrations. A high-sucrose diet, even when periodically applied, additionally led to a reduced concentration of luteinizing hormone (LH). The largest changes in the hormones tested were observed with one-day fasting coupled with the high-sucrose diet; in addition, the estrous phase was shortened and the estrous cycle was disrupted. The results of this study show that both the amount of dietary sucrose and also its uptake pattern affect the estrous cycle and sex hormone concentrations in female rats.

PSXIII-11 Avemix XG 10 Improves Piglet Performance When Dietary net Energy Content is Decreased

Abstract Plant-based dietary ingredients contain non-starch polysaccharides (NSP) fibers. Both soluble and insoluble NSP fibers are anti-nutritional factors for monogastrics that limit intestinal absorption and digestion of dietary nutrients. Increased digesta viscosity also occurs, which results in satiety and potential health issues. AveMix XG 10, containing high endo-1,4-β-xylanase and endo-1,3(4)-β-glucanase activity, hydrolyzes NSP fibers resulting in increased nutrient availability and digestibility. Therefore, it was hypothesized that AveMix XG 10 enables gain of some extra net energy (NE) content from piglet diets, optimizing the cost of live-weight growth. A 47-day trial was conducted with 3-week old weaned piglets (6.0 kg) allocated to three groups: control (CON), low energy (-56 kcal/kg feed; LE), and low energy + enzyme (LE+E). All groups had 13 pens of 28 pigs (n=364) and received wheat and corn mix based diets that had a similar NSP fiber content (11.4 %). Overall, CON diets had greater NE (2,456 kcal/kg feed) relative to the LE and LE+E groups (2,400 kcal/kg feed). The diet of the LE+E group was supplemented with AveMix XG 10 (Palital Feed Additives B.V.) at 100 g/T. For each pen the daily feed intake, weekly weight, diarrhea index and mortality were recorded. Compared with both CON and LE, LE+E significantly increased average daily gain (ADG) and average daily feed intake (ADFI) during weeks 4-7 and overall, and also significantly increased final weight (Table 1). During weeks 1-3, ADG and ADFI did not differ between CON and LE+E groups, and the LE+E group was significantly greater than LE. Overall, LE detrimentally increased the feed conversion ratio (FCR) compared with CON; however, during weeks 4-7 the LE+E had similar FCR compared with CON. No significant effects were observed on mortality or diarrhea index. In conclusion, AveMix XG 10 improved piglet performance when dietary NE content is decreased.

271 Effects of Increasing Lactation Dietary Energy Concentration by Adding fat During the Summer Period on sow and Litter Performance

Abstract The objective was to determine the effects of increasing energy in lactation diets fed during the summer period on sow and litter performance. A total of 356 sows (PIC Camborough) were randomly assigned at entry into the farrowing room to 1 of 4 treatments within parity in a randomized complete block design with body weight and breeding day blocks. Pre-farrowing caliper scores were balanced across treatments. The trial was conducted from July to September 2021 in Carthage, Illinois, with external barn minimum and maximum temperatures averaging 21-32°C. Treatments consisted of increasing levels of added fat in the lactation diet: 0, 1.67, 3.34, and 5.00% of corn oil. Diets were corn-soybean meal-based with a fixed soybean meal inclusion rate of 28.90%. Net energy (NE) concentrations of the treatment diets consisted of 2.345, 2.427, 2.509, and 2.591 Mcal NE/kg. Sow was the experimental unit and data were analyzed using generalized linear mixed models with the lmer and glmer functions of R. Increasing corn oil inclusion rates marginally (linear, P=0.086) reduced lactation average daily feed intake but did not significantly (P&amp;gt;0.10) impact total or average daily NE intakes. There was no evidence (P&amp;gt;0.05) for treatment effects on sow body weight, sow caliper score or sow backfat depth changes during lactation, percentage of removed and fall-off piglets, pre-weaning mortality, number of weaned pigs, litter weaning weight, total litter weight gain, and piglet average daily gain. In summary, increasing energy in the lactation diet by adding up to 5% corn oil during the summer period resulted in a marginal linear reduction in lactation average daily feed intake, but did not influence daily NE intake. Under the conditions of this study, no evidence for treatment effects were observed for sow or for litter performance during the nursing period.

The effect of gradually decreasing the dietary energy content, at constant or increased lysine:energy ratio on broiler performance, carcass yield, and body composition

Formulating diets with high AME, especially in the grower and finisher phases, hinders the inclusion of alternative ingredients that are usually cheaper and have lower AME. Moreover, as the chicken grows the feed intake capacity is greater and may be able to maintain BW over a wide range of AME. The objective of this study was to evaluate the performance of chickens fed diets with progressive AME reductions, at constant or increased standardized ileal digestible (SID) lysine:AME ratio (Lys:AME). Treatment 1 (control) was formulated following the SID lysine and AME recommendations for a 4-phase feeding program. Treatment 5 was formulated with −4, −8, and −12% AME in the grower-1, grower-2, and finisher phases, respectively, and with the same Lys:AME compared with the control. Treatment 9 had the same AME as treatment 5 but higher SID lysine, increasing the Lys:AME by 1.5, 3.5, and 5.0% compared with treatment 5. In the grower-1, grower-2, and finisher phases, the final 9 dietary treatments were prepared by mixing the control diet with either treatment 5 or 9 at different proportions (75:25, 50:50, or 25:75). All birds were fed the same starter control diet. Treatments were replicated in 10 pens with 31 male chickens each, and the growth performance of birds was monitored for 42 d. Final BW linearly decreased (P < 0.05) when lowering dietary AME, but it followed a positive quadratic response with higher Lys:AME (P < 0.05). Feed intake increased (P < 0.05) with low AME, independently of the Lys:AME; but the linear regression in the feed conversion ratio (FCR) had a lower slope when the Lys:AME increased. At the end of the study, there were no differences in carcass or breast meat yield (P > 0.10). Progressively reducing AME in the last feeding phases may be a viable nutritional strategy to increase the inclusion of alternative ingredients and potentially reduce feeding costs, despite increments in feed intake and FCR. Adjusting the Lys:AME in low AME diets may help maintain the final BW of birds.

Consumption of low-calorie sweetened drinks is associated with ‘sweet satiation’, but not with ‘sweet-taste confusion’: A virtual study

Originating from studies on rats, the ‘taste confusion’ hypothesis predicts that exposure to low-calorie sweeteners (LCS) will impair compensatory responses to sugar intake, resulting in increased overall calorie intake. We conducted a virtual study in which young adult human participants (n = 332), who differed in their history of exposure to sweet drinks (e.g., drank ‘diet’ (LCS) soft drinks or ‘regular’ (sugar-sweetened) soft drinks), imagined consuming a cheese sandwich and two-thirds of a 500 ml drink (still water, sparkling water, diet Coca Cola, regular Coca Cola, or semi-skimmed milk), or no drink, as a hypothetical lunch-time meal. They then used a screen-based tool to select the amount of a sweet snack (chocolate M&M's) or savoury snack (salted peanuts) that they would eat immediately with the remaining third of their drink (i.e., a total of 12 drink and snack combinations per participant). The results were inconsistent with the predictions of the taste confusion hypothesis; specifically, the extent to which consumption of sugar cola compared with water (still or sparkling) reduced snack intake did not differ between habitual diet (LCS) and habitual sugar soft-drink consumers. Other results showed a ‘sweet satiation’ effect (i.e., lower sweet versus savoury snack intake when the drink accompanying the meal was sweet compared with when it was water), and negligible compensation in snack food intake for the difference in the energy content of diet versus sugar cola.

Exploring effects of slice thickness, pretreatment and drying air temperature on nutritional, functional and pasting properties of Gardenia erubescens Stapf. &amp; Hutch. fruit powder

Gardenia erubescens fruits are outstanding sources of essential nutrients as well as health-promoting phytochemicals and minerals. However, fresh fruits are highly perishable and difficult to store. To reduce losses and extend their uses, fresh G. erubescens fruits could be converted into powder. The present study investigated the effect of slice thickness, pretreatment, and drying air temperature on the nutritional, functional, and pasting properties of G. erubescens fruits. Fresh G. erubescens fruits were sliced into 3 mm and 5 mm thickness, subjected to different pretreatments (steam blanching at 100 °C for 3 min, dipping in 2% (w/v) ascorbic acid solution for 3 min and no treatment) and then dried at 40 °C, 50 °C, 60 °C and 70 °C. The treatments significantly (p < 0.05) affected almost all the quality properties with trends only observed in terms of main effects. The 5 mm thick samples had relatively higher fibre, carbohydrate, zinc, iron, magnesium, manganese, swelling capacity (SC), swelling index (SI), water absorption capacity (WAC), and final viscosity (FV) but lower protein, fat, dietary energy, calcium, potassium, and sodium contents as compared to the 3 mm samples. Futher, the pretreated samples had lower protein, fat and dietary energy contents as compared to the control. Generally, potassium, calcium, zinc, iron, SI, and FV of the fruits improved by blanching but reduced by dipping in ascorbic acid solution. The SC, SI, and FV generally corresponded linearly with drying temperature with the peaks at 60 °C while WAC decreased as drying temperature increased. Blanching and dipping in ascorbic acid solution reduced SC and WAC. Though there was no three-factor combination that was ultimately the best, drying 5 mm thick G. erubescens fruit slices at 60 °C without pretreatment preserves most of the proximate and mineral contents, functional and pasting properties. • The effect of slice thickness, pretreatment and drying temperature on nutritional, functional and pasting properties of Gardenia erubescens fruit powders was studied. • The treatments affected the quality attributes of the fruit powders with no linear trends for the interactions. • The 5 mm thickness resulted in better quality attributes of the fruit powders compared to the 3 mm. • Steam blanching and dipping in ascorbic acid reduced most of the quality attributes when compared with the control. • Drying of 5 mm fruit slices at 60 °C preserves most of the proximate and mineral contents, functional and pasting properties.

Reevaluating trophic discrimination factors (Δδ13C and Δδ15N) for diet reconstruction

AbstractStable isotope analysis is increasingly being used to assess diet and trophic positions of animals. Such assessments require estimates of trophic discrimination factors (TDFs)—offset between the isotopic composition of diet and animal tissues—with imprecise applications of TDFs leading to biased conclusions in resource use. Because TDFs are unavailable for most species, ecologists often apply values from taxonomically similar species or use trophic step increases of approximately 1‰ for carbon (TDF‐δ13C) and 3‰ for nitrogen (TDF‐δ15N). Such practices may yield inaccuracies since TDFs vary greatly, even within a species. To better understand the factors that influence TDFs, we conducted a meta‐analysis of TDF‐δ13C and TDF‐δ15N for mammals and quantified variation in relation to consumer type (herbivore, omnivore, carnivore) and diet source (C3‐based, C4‐based, marine‐based, mixture). Additionally, to guide TDF choice, we used an isotopic data set of small mammal tissues and diet items to assess how predicted dietary contributions vary with TDFs estimated using (1) taxonomic relatedness, (2) consumer type and diet source, or (3) values derived from wild animals eating natural diets. Our meta‐analysis revealed that metabolic routing and interactions between consumer class, dietary source, and the protein versus energy content of diets best explained variation in TDF‐δ13C values (−1.5‰ to 7.3‰), whereas consumer class best explained variation in TDF‐δ15N values (−0.5‰ to 7.1‰). Our test of methods to estimate TDFs indicated that ecologists should avoid relying on taxonomic relatedness when selecting TDF‐δ13C because mixed‐diet lab studies may produce misleading results for herbivores and omnivores. Additionally, field‐derived estimates could help fill TDF gaps where diets within a consumer class are absent. Overall, we suggest that using standard TDF trophic step values should be abandoned, because feeding studies are often poor proxies for natural diets, particularly for herbivores and omnivores. Instead, we make recommendations on how to select TDFs, along with a range of TDF‐δ13C and TDF‐δ15N values depending on diet source, consumer class, and tissue type. Use of these more refined recommendations and TDF values in isotopic assessments will improve estimates of diets and trophic interactions in natural systems, leading to a better understanding of ecological interactions and communities.

Effect of dietary energy concentration on the growth of slow-growing Korat chickens from 43 to 84 days old

The aim of this study was to estimate the effect of diets with different energy levels on the growth performance of slow-growing chickens (so-called Korat chicken (KRC)). The KRC is a cross between a male Thai native chicken (Leung Hang Khoa) and females from crosses among modern broiler and layer lines. The study was divided into two experimental periods when the birds were from 43 to 63 days old and 64 to 84 days old. Birds received feed and water ad libitum throughout the trial. In this study, 1200 mixed-sex KRC(624 and 576 chicks in phases 1 and 2, respectively) were distributed equally to four diets, which provided 2750, 2900, 3050 and 3200 kcal ME/kg. There were six replicate pens of each treatment. At both ages,increased energy content of the diet resulted in decreased feed intake (FI) and thus improved the feed conversion ratio (FCR). Weight gain was unaffected by the treatments. Using a broken-line analysis, dietary energy containing about 3200 kcal ME/kg was found to have the most beneficial effect on FCR during both periods. Thus, the optimal ME for KRC between 43 and 84 days old was 3200 kcal/kg.

Associations among body energy status, feeding duration and activity with respect to diet energy and protein content in housed dairy cows.

The study in this research paper was undertaken with a hypothesis that accelerometer data can be used to improve monitoring of energy balance in dairy cows. Animals of high (select, S) and average (control, C) genetic-merit lines were allocated to two feeding systems, by-product (BP) and homegrown (HG). This culminated in four production systems referred to as BPS, BPC, HGS and HGC. Cows between their first and fourth lactations were included and a total of 8602 records were used. The target crude protein (CP) and metabolisable energy (ME) content in the BP diet was 185 g/kg DM and 12.3 MJ/kg DM while it was 180 g/kg DM, and 11.5 MJ/kg DM for the HG diet, respectively. Milk yield, body energy content (BEC) and animal activity were monitored while the animals were all housed for winter. Results showed that cows on homegrown feeds were significantly (P < 0.05) more active than cows on by-product feeds as indicated by higher motion index and number of steps per day. Feeding duration was not significantly different (P > 0.05) between cows under by-product feeding system irrespective of the energy balance of the cows. However, there were significant differences for cows under homegrown feeding system. Cows in negative energy balance had a longer feeding duration per day than cows in positive energy balance. Milk yield was negatively correlated (P < 0.05) to motion index and number of steps per day but not to lying time and feeding duration. The results showed differences in cow activity were related to diet content and body energy status. This is useful in precision farming where feeds are provided according to specific animal behaviour and feed requirements.

Interactive effects of protein and energy intake on nutrient partitioning and growth in Nile tilapia

Studies of fish growth response to changes in dietary protein and energy content are often conducted with fish fed to apparent satiation or at fixed percentages of their body mass. Such designs result in simultaneous changes in protein and non-protein energy intake, thereby failing to distinguish their separate effects on nutrient partitioning and growth. The present study was designed to address this limitation and test the existence of distinct protein- and non-protein energy-dependent growth phases in Nile tilapia (Oreochromis niloticus). All-male Nile tilapia (63 g, SD = 1.3) were subjected to an 8 × 2 factorial design consisting of eight levels of digestible protein (DP) intake (0.44–1.25 g/day) and two levels of non-protein digestible energy (NPDE) intake (16.0 and 22.4 kJ/day). Fish (n = 960) were housed in 60-litre tanks with two replicates per treatment and hand-fed twice a day for 42 days. Nutrient balances were calculated from changes in body mass, analysed body composition and digestible nutrient intake. Linear regression models were compared to linear-plateau regression models to determine whether protein gain followed distinct protein- and non-protein energy-dependent phases or not. Body mass gain increased linearly with increasing DP intake and was significantly higher (2.6 vs 2.3 g/d, P < 0.05) in fish receiving a high NPDE intake. This increase mainly reflected a higher mean fat gain (0.29 vs 0.20 g/d) rather than a higher protein gain (0.42 vs 0.39 g/d) in fish fed a high vs low level of NPDE intake. The comparison of linear and linear-plateau models did not give clear support for the presence of distinct protein and non-protein energy-dependent phases in protein gain. These results indicate that non-protein energy intake has a modest protein-sparing potential, and that protein gain is simultaneously limited by protein and energy intake in Nile tilapia.

Energy systems and laying hens an evaluation of energy systems for the formulation of practical diets for laying hens

Robust energy systems ( ES ) are required to execute accurate feed formulation. Based on the premise that the more accurate an ES is, the better it will predict performance, a predictive model was developed to evaluate the veracity of five ES proposed for formulating layer diets. Data were derived from a meta-analysis of three experiments conducted on individually housed brown laying hens flocks. Congruency was demonstrated using a single model to predict feed intake (r = 0.802), justifying their combination into a single, consolidated flock. A matrix of energy values was determined for each ES, and dietary energy content was recalculated for all diets. Hen production parameters were predicted using each ES, and all predictions were similar. The correlation for energy utilisation efficiency for egg output between all ES was high (r > 0.96), suggesting that no one ES offered any advantage. Adjusting dietary energy values according to the lipid, protein or fiber content did not improve predictions. A least-cost feed formulation exercise, using the different ES, showed that the ingredient content of the diets varied considerably, depending on the ES used and the relative cost of ingredients. Differences in feed costs were negligible. The ideal ES system to use for formulation purposes depends on the relative cost of ingredients. In conclusion, the AME n system accurately predicts laying hen production parameters and allows for cost-effective feed formulation of layer diets. There was no advantage in predicting performance or the formulated feed cost for any ES evaluated.

Changes in the liver transcriptome and physiological parameters of Japanese Black steers during the fattening period

We investigated the physiological changes during the fattening period and production characteristics in Japanese Black steers bred and raised using the typical feeding system in Japan. Here, 21 Japanese Black steers aged 12 months were used, with experimental period divided into early (12–14 months of age), middle (15–22 months), and late fattening phases (23–30 months). The liver transcriptome, blood metabolites, hormones, and rumen fermentation characteristics were analyzed. Blood triglyceride and non-esterified fatty acid concentrations increased, whereas blood ketone levels decreased, with fattening phases. Blood insulin increased with fattening phases and was positively correlated with carcass weight and marbling in late fattening phases. Rumen fermentation characteristics showed high propionate levels and low butyrate levels in late fattening phases, likely due to increased energy intake. Genes related to glucose metabolism, such as SESN3, INSR, LEPR, and FOXO3, were down-regulated in late fattening phases. Genes related to lipid metabolism, such as FABP4, were up-regulated, whereas FADS1 and FADS2 were down-regulated. These findings suggest that the physiological changes resulted from changes in the energy content and composition of diets. Liver metabolism changed with changes in fat metabolism. Insulin was strongly associated with physiological changes and productivity in Japanese Black cattle.

Galyean Appreciation Club Review: revisiting nutrition and health of newly received cattle-what have we learned in the last 15 years?

Our objective was to review the literature related to the health and management of newly received cattle published since a previous review by Duff and Galyean (2007). Bovine respiratory disease (BRD) continues to be a major challenge for the beef industry. Depending on disease severity, animals treated for BRD have decreased performance and lowered carcass value. Diagnosis of BRD is less effective than desired, and progress on developing real-time, chute-side methods to diagnose BRD has been limited. Systems that combine lung auscultation with temperature and body weight data show promise. Assessment of blood metabolites and behavior monitoring offer potential for early identification of morbid animals. Vaccination and metaphylaxis continue to be important tools for the prevention and control of BRD, but antimicrobial resistance is a concern with antibiotic use. Dietary energy concentration and roughage source and level continue to be important topics. Mineral supplementation has received considerable attention, particularly the use of organic vs. inorganic sources and injectable minerals or drenches given on arrival. The use of probiotics and prebiotics for newly received cattle has shown variable results, but further research is warranted. The health and nutrition of newly received cattle will continue to be an important research area in the years to come.