Daily Metabolizable Energy Intake Research Articles

10 Effects of different feeding levels during gestation on gilt reproductive performance during the first lactation

Abstract Our objective was to determine the effects of different feeding levels for gilts during gestation on reproductive performance during the first lactation. A total of 1,187 PIC Camborough gilts were used. Gilts were randomly allotted in a randomized complete block design based on breeding week, body weight (BW), and age to one of four treatments differing in daily metabolizable energy (ME) intakes per day during gestation. Gilts were housed in stalls throughout the entire gestation and individually fed with a gestation diet containing 2.95 Mcal of ME/kg via feed boxes that were weekly calibrated. Treatments consisted of 1) 5.0 Mcal of ME/d (1.7 kg feed/d) throughout the entire gestation; 2) 5.9 Mcal of ME/d (2.0 kg feed/d) throughout the entire gestation; 3) 6.8 Mcal of ME/d (2.3 kg feed/d) throughout the entire gestation; and 4) 5.0 Mcal of ME/d (1.7 kg feed/d) from breeding until d 90 of gestation, and then 5.9 Mcal of ME/d (2.0 kg feed/d) from d 90 to d 112 of gestation. Gilt was the experimental unit and data were analyzed using generalized linear mixed models with the lmer and glmer functions of R. There was no evidence (P > 0.10) for treatment differences on gilt BW and age at breeding, with gilts averaging 156.7 kg at 210 d of age (Table 1). Gilts receiving 6.8 Mcal of ME/d during gestation were heavier (P < 0.05) at farrowing compared with all other treatments; however, these gilts lost (P < 0.05) more BW during lactation. Gilts receiving 5.0 Mcal ME/d throughout the entire gestation had less (P < 0.05) maternal net BW gain from breeding to weaning compared with gilts receiving 6.8 Mcal ME/d. Gilts receiving 6.8 Mcal of ME/d gained more (P < 0.05) caliper scores (CS) from breeding to d 90 of gestation compared with gilts receiving 5.0 Mcal ME/d. Regardless of feeding level, gilts lost an average of 0.85 CS from d 90 to d 112 of gestation. Overall, gilts receiving 6.8 Mcal of ME/d gained more CS during gestation, but lost more CS during lactation (P < 0.05). There was no evidence for differences in gilt backfat depth measurements (P > 0.10). Gilt feeding levels did not impact (P > 0.10) total piglets born, percentage sillborn, or percentage of mummified fetuses. Gilts receiving 5.0 Mcal of ME/d had greater (P < 0.05) percentage piglets born alive compared with gilts receiving 5.9 Mcal of ME/d, with other treatments intermediate. There was no evidence (P > 0.10) for treatment differences in average piglet BW, average piglet daily gain during lactation, piglet mortality from cross foster to weaning, or wean to estrus interval in the next cycle. In summary, increasing energy intake of gilts during the first gestation did not impact reproductive performance during the first lactation, but gilts receiving 5.0 Mcal of ME/d throughout the entire gestation had less maternal net BW gain.

Effect of Replacing Rice Impurities Instead of Wheat Bran or Barley on Digestibility and Productive Performance of Awassi Lambs

This experiment was conducted to evaluate the effect of substitution three levels of rice impurities 0%, 50% and 100% instead of wheat bran or barley grains on digestibility and productive performance of Awassi lambs. In the morning, concentrated feed was given individually at 3% of live body weight as a dry matter basis for 56 days preceded by 14 days as an adaptation period. Roughage intake (wheat straw) was given ad-libitum (with residue) and recorded. Twenty-four male lambs aged 3-4 months with an initial weight 24.66 ± 2.81kg divided into six treatments with replacing rice impurities 0%, 50% and 100% instead of wheat bran (T1), T2, T3) or barley grains (T4, T5, T6) in a 2×3 factorial experiment/Completely Randomized Design. The results showed no significant differences in daily intake of dry matter (DM), organic matter (OM), crude protein (CP), soluble carbohydrates (NFE) and metabolizable energy (Me), and an increase (P < 0.05) in the intake of ether extract (EE), crude fiber (CF) (P < 0.01) and ash in T6 (100% rice impurities instead of barley), while daily gain and total gain increased significantly (P<0.05) for treatment T3 (100% rice impurities instead of wheat bran) 198.21g/day and 11.1kg in contrasted to others. feed efficiency and digestibility didn’t differ when replacing rice impurities. In conclusion: It’s possible to use rice impurities instead of barley grain or wheat bran to achieve low-priced feed ingredients with a higher weight gain and sustainable development.

Effects of Metabolizable Energy Intake and Body-Weight Restriction on Layer Pullets: 1-Growth, Uniformity, and Efficiency

This study aimed to determine the effects of dietary energy and body-weight (BW) restriction on layer pullets’ growth, uniformity, and feed efficiency. Two experiments were conducted using a precision feeding (PF) system (Experiment 1) and a conventional feeding (CON) system (Experiment 2). Experiment 1 consisted of a 2 × 4 factorial arrangement (eight treatments) with two feed allocation (FA) levels: meal every visit (MEV) or restricted to the lower boundary of Lohmann Brown-Lite pullets; and three dietary metabolizable energy (ME) levels: Low, Standard (Std), and High (2600, 2800, and 3000 kcal/kg, respectively); the fourth treatment enabled birds to choose from the three diets (Choice). Experiment 2 consisted of a 2 × 3 factorial arrangement (six treatments): two FA levels (ad libitum or restricted) and three dietary ME levels (Low, Std, and High). In each experiment, BW, coefficient of variation (CV), average daily feed intake (ADFI), average daily metabolizable energy intake (MEI), and feed conversion ratio (FCR) were recorded. Diet ADFI preferences and feeding motivation were determined only in the PF experiment. ANOVA was conducted on each experiment with the two main effects as fixed factors (FA and dietary ME), and age or period as the sources of variation. Differences were reported at p ≤ 0.05. MEV (PF experiment) and ad libitum-fed (CON experiment) pullets had greater BW compared to restricted-fed pullets (p &lt; 0.05). The lowest CV was observed in the restricted-fed pullets from the PF experiment (p &lt; 0.05). ADFI was greater in pullets fed the Low ME diet in the PF experiment compared to all the other groups, and the lower the dietary ME, the greater the ADFI in the CON experiment (p &lt; 0.05). Choice-feeding pullets preferred feed with greater ME content in the PF experiment (p &lt; 0.05). The lower the dietary ME, the greater the FCR in the CON experiment (p &lt; 0.05). Restricted-fed pullets had greater daily visits, and lower daily meals, meal size, and successful visits to the PF system (p &lt; 0.05). In conclusion, the results of this trial indicated that lower dietary ME increased FCR and ADFI, whereas feed restriction decreased BW and increased feeding motivation. Future steps after this trial will include examining the effects of dietary energy and feed restriction on carcass composition and sexual maturation.

Estimation of the metabolisable energy requirements of feedlot light lambs and comparison with the U. S. National Research Council predictions

The aim of the present work was to compare the estimated metabolisable energy requirements (MER) of fattening light lambs raised in feedlot with the U. S. National Research Council (NRC) predictions. Body weight (BW) gain and feed intake were collected from 15 pens (7 lambs/pen) of Manchega male lambs under on-farm conditions over six weeks. The pens were randomly assigned to three dietary treatments (5 pens/treatment) consisting of three concentrates of different composition and barley straw. Feeds were offered for ad libitum consumption throughout the experimental period. Average daily metabolisable energy intake (MEI) was calculated on a weekly basis for each pen from the average daily consumption of concentrate and barley straw and their respective ME contents. Following, the average daily MER was predicted for each pen from the weekly average of both BW and BW gain, according to two models: One including the adjustment of ME for body maintenance (MEm) for the effect of level of MEI on visceral organ tissue energy use as described by NRC (Model 1), and the other excluding such adjustment (Model 2). Model 1 had no mean bias, and exhibited a higher concordance correlation coefficient and a lower underprediction, supporting the need for the upward adjustment of MEm in accordance with MEI to enhance the precision and accuracy of predicted MER. It was concluded that the NRC method was precise and accurate enough to support its application for calculating the MER of feedlot light lambs.

Effects of using Water Hyacinth (Eichhornia crassipes L.) in the Diet of Swamp Buffaloes on Nutrient Digestibility, Rumen Environment, Purine Derivatives, and Nitrogen Retention

The present experiment aims to evaluate the effects of incremental levels of water hyacinth (WH) in Para grass (Brachiaria mutica) based on the diet on nutrient intake, digestibility, and nitrogen retention of growing swamp buffaloes. Four male buffaloes of 305 ± 8.40 kg were allocated in a 4x4 Latin square design. The treatments were 25, 50, 75, and 100% WH (DM basis), replacing the Para grass (PG) corresponding to WH25, WH50, WH75, and WH100 treatment. Urea-molasses cake was used to supply the dietary crude protein intake so that this was 210 g/100 kg live weight per day for all the treatments (DM basis). The results showed that although the dry matter (DM), neutral detergent fiber (NDF), and metabolizable energy (ME) intake were not significantly different (P&gt;0.05) among the treatments, these were numerically higher for the WH50 treatment. Especially in the daily ME intake (MJ/k g LW) was 39.1, 43.4, 41.7, and 39.9 for the WH25, WH50, WH75, and WH100 treatments, respectively. With 50% WH replacing PG in the diet, it gave potential for better nutrient digestibility, nitrogen retention, and daily weight gain in the present study. In conclusion, WH could be used to replace PG in buffalo diet up to 100%. At a level of 50% replacement of WH to PG in the buffalo, the diet was optimum based on the utilization of nutrients and energy of WH, lower feed cost, and environmental improvement.

A Nutritional Investigation of Major Feed Types and Feed Rations Used in Medium-Scale Dairy Production Systems in Sri Lanka.

Simple SummaryLittle information is available regarding the feeding of dairy cattle in Sri Lanka or the impact of feeding on productivity. The aim of this study was to catalogue the availability, quantity, and composition of feeds, to identify the feeding regimens used, and to calculate dietary metabolisable energy (ME) and crude protein (CP) in order to investigate shortfalls in dietary requirements. The ME and CP contents of the abundantly used forages (representing > 50% of the cow diet) Guinea ecotype A and Hybrid Napier CO-3 grasses were generally low (7.5–8.0 MJ/kg DM, 8.0–8.8% DM, respectively), and were lower than that of legumes (i.e., Gliricidia: 10.0 MJ/kg DM, 17.7% DM, respectively). Daily ME intake was consistently 10% lower than the calculated daily energy requirements as a consequence of the low nutritive values of these forages and of farmers’ consistent overestimation of their quality. The CP intake of lactating cows (13.5% DM) was inadequate to meet their requirements (16–18.5% DM), whereas the CP intake of dry cows (11.8% DM) adequately met requirements (11–12% DM). Based on the results of this study, limitations on nutritional requirements adversely affect milk production of dairy cows in Sri Lanka.In this paper, the nutritional quality, digestibility, and chemical composition of major feed types as well as the use of those feeds in rations by medium-scale dairy farmers in the Kurunegala district of Sri Lanka were studied. Nine dairy farms were visited fortnightly over a five-month period to identify the feeds that were commonly used. All farms operated under a stall-feeding system in which a manually mixed ration (MMR) was fed 2–3 times daily. Four forages were identified: Guinea grass ecotype A (Panicum maximum), called Guinea grass; Hybrid Napier CO-3 (Pennisetum purpureum × Pennisetum americanum), called CO-3 grass; Gliricidia (Gliricidia sepium); and maize stover (Zea mays L.), along with three other supplementary feeds (maize silage, barley distillers’ by-products, and commercially formulated cattle feed). These feeds were subjected to proximate analysis and in vitro digestibility analysis. The metabolisable energy (ME) of the forages ranged from 7.5–10.0 MJ/kg dry matter (DM), with the ME of Guinea grass and CO-3 grass (7.5 and 8.0 MJ/kg DM, respectively) being lower than that of Gliricidia (10.0 MJ/kg DM). The neutral detergent fibre (NDF) concentration of both Guinea grass and CO-3 grass (both 72% DM) was much higher than that of Gliricidia (47% DM). Crude protein (CP) was higher in Gliricidia (17.5% DM) than in either Guinea grass or CO-3 grass (8.0 and 8.8% DM, respectively). The ME of the supplementary feeds varied between 11.0 and 12.8 MJ/kg DM, while CP varied between 15.0 and 24.0% DM. The daily ME intake of cows was consistently 10% lower than their calculated daily energy requirement; for dry cows, the mean intake was 90 MJ/cow/day supplied vs. 101 MJ required, while for cows in early lactation the mean intake was 126 MJ/cow/day supplied vs. 140 MJ required. The average CP intake of lactating cows (13.5% DM) was inadequate (requirements: 16 to 17.5% DM), while the average CP intake of dry cows (11.8% DM) was satisfactory (requirements: 11 to 12% DM). The current study shows that the majority of the feed types used in these medium-scale dairy farms provide insufficient ME or CP to meet the nutritional requirements of either lactating or dry cows irrespective of the quantity of feed provided.

Effects of supplementing a CP-reduced diet with rumen-protected methionine on Fleckvieh bull fattening

The objective of this study was to evaluate the effect of supplementing a CP-reduced diet with rumen-protected methionine on growth performance of Fleckvieh bulls. A total of 69 bulls (367 ± 25 kg BW) were assigned to three feeding groups (n = 23 per group). The control (CON) diet contained 13.7% CP and 2.11 g methionine/kg diet (both DM basis) and was set as positive control. The diet reduced in CP (nitrogen) (RED) diet as negative control and the experimental RED + rumen-protected methionine (MET) diet were characterised by deficient CP concentrations (both 9.04% CP). The RED + MET diet differed from the RED diet in methionine concentration (2.54 g/kg DM vs. 1.56 g/kg DM, respectively) due to supplementation of rumen-protected methionine. Rumen-protected lysine was added to both RED and RED + MET at 2.7 g/kg DM to ensure a sufficient lysine supply relative to total and metabolisable protein intake. Metabolisable energy (ME) and nutrient composition were similar for CON, RED, and RED + MET. Bulls were fed for 105 days (d) on average. Individual feed intake was recorded daily; individual BW was recorded at the beginning of the experiment, once per month, and directly before slaughter. At slaughter, blood samples were collected and carcass traits were assessed. Reduction in dietary CP concentration reduced feed intake, and in combination with lower dietary CP concentration, daily intake of CP for RED and RED + MET was lower compared with CON (P < 0.01). Daily ME intake was reduced in RED and RED + MET compared with CON (P < 0.01). Consequently growth performance and carcass weights were reduced (both P < 0.01) in both RED and RED + MET compared with CON. Supplemental rumen-protected methionine was reflected in increased serum methionine concentration in RED + MET (P < 0.05) as compared to RED but it did not affect growth performance, carcass traits and serum amino acid (AA) concentrations, except for lysine which was reduced (P < 0.01) compared to CON and RED. In conclusion, bulls fed RED or RED + MET diets were exposed to a ruminal CP deficit and subsequently a deficit of prececal digestible protein, but methionine did not appear to be the first-limiting essential AA for growth under the respective experimental conditions.

Residual feed intake of Nellore calves is not repeatable across pre and post weaning periods

ABSTRACT: This study measured milk and solid feed intake in pre- weaning period and feed intake in postweaning period of Nellore calves, and to correlated them with performance traits and ingestive behavior of animals classified as most and least efficient. During pre weaning phase, feed efficiency was evaluated in 51 cow-calf pairs from 21±5 days after calving until weaning. During post-weaning phase, only male calves (n=23) were evaluated. Pre-weaning milk intake of calves was estimated based on cow’s milk production. Pre-weaning daily metabolizable energy intake (MEI) of calves was estimated as the sum of MEI from milk and solid diet. There was no difference in ADG between calves with negative and positive pre RFI, with a consequent better feed conversion to more efficient calves. The most efficient calves spent less time at the feed bunk, with a shorter feeding duration and higher rate of intake, compared to the least efficient animals. Correlations between feed intake and metabolic body weight of the animals during pre- and postweaning phases were positive, of medium to high magnitude, and significant, while correlation between ADG values was close to zero. Results suggested that part of the animals ranked based on pre weaning feed intake won’t maintain their rank during postweaning phase. In conclusion, calves classified as most efficient during pre-weaning phase have similar weight gain but lower milk intake and MEI than least efficient animals. The estimated pre RFI is weakly correlated with post RFI, showing that RFI is not consistent or repeatable across two periods.

Effect of Prebiotics and Probiotics as natural growth promoters in broiler chicks

Sixty day-old broiler chicks (Ross breed) were treated with or without prebiotics and probiotics (Natural growth promoters) containing immune extracts at the starter (1-5wks) and finisher (6-10wks) phases. The birds were allocated to no diets (one test and one control) in a contpletely randomized design. Each treatment had three replicates of ten birds per replicate. Energy and protein levels of the diets were 3000 Kcal ME/kg and crude protein (CP) of 20% and 3000 Kcal ME/kg and 17% CP at starter and finisher phases, respectively. The experiment lasted ten weeks. The daily metabolizable energy intake for body maintenance, 146.97 cal./ day for birds on the tesi diet was significantly (P&lt;0.05) higher than those birds on the control diet, 113.04 cal./day at the starter phase. At the finisher phase, efficiency of feed utilization (0.38 as against 0.19), mean weights of live (1920g as against /570g) and plucked (1740 as against 1380g) parts of the treated birds were significantly (P&lt;0.05) betier than the untreated birds. Other parameters measured increased more for the treated birds but were not significant (P&gt;0.05). The immune status conferred on the birds ensured adequate protection from death for the treated birds. The untreated birds suffered 67% more mortality than the treated birds. Though mortality rate was within the acceptable limits for both treated and untreated birds. The results of the experiment showed that Enterococcus faesium, inulin together with cell-wall fragments and immune stimulant extracts as probiotics and prebiotics enhanced growth performance of broiler chicks. The trial was successful.

Modeling life-time energy partitioning in broiler breeders with differing body weight and rearing photoperiods

Understanding energy partitioning in broiler breeders is needed to provide efficiency indicators for breeding purposes. This study compared 4 nonlinear models partitioning metabolizable energy (ME) intake to BW, average daily gain (ADG), and egg mass (EM) and described the effect of BW and rearing photoperiod on energy partitioning. Ross 708 broiler breeders (n = 180) were kept in 6 pens, controlling individual BW of free run birds with precision feeding stations. Half of the birds in each chamber were assigned to the breeder-recommended target BW curve (Standard) or to an accelerated target BW curve reaching the 21-week BW at week 18 (High). Pairs of chambers were randomly assigned to 8L:16D, 10L:14D, or 12L:12D rearing photoschedules and photostimulated with 16L:8D at week 21. Model [I] was: MEId = a × BWb + c × ADG × BWd + e × EM + ε, where MEId = daily ME intake (kcal/day); BW in kg; ADG in g/day; EM in g/day. Models [II–IV] were nonlinear mixed versions of model [I] and included individual [II], age-related [III], or both individual and age-related [IV] random terms to explain these sources of variation in maintenance requirement (a). Differences were reported as significant at P ≤ 0.05. The mean square error was 2,111, 1,532, 1,668, and 46 for models [I–IV] respectively, inferring extra random variation was explained by incorporating 1 or 2 random terms. Estimated ME partitioned to maintenance [IV] was 130.6 ± 1.15 kcal/kg0.58, and the ME requirement for ADG and EM were 0.63 ± 0.03 kcal/g/kg0.54 and 2.42 ± 0.04 kcal/g, respectively. During the laying period, maintenance estimates were 124.2 and 137.4 kcal/kg0.58 for standard and high BW treatment, and 130.7, 132.2, and 129.5 kcal/kg0.58 for the 8L:16D, 10L:14D, or 12L:12D treatments, respectively. Although hens on the standard BW treatment with a 12L:12D rearing photoschedule were most energetically conservative, their reproductive performance was the poorest. Model IV provided a new biologically sound method for estimation of life-time energy partitioning in broiler breeders including an age-related random term.

Effects of dietary beef tallow on performance, rumen fermentation, carcass traits and meat quality of growing lambs

Growing lambs were evaluated for the effect of increasing dietary levels of beef tallow (BT) on performance, rumen fermentation, and carcass and meat characteristics. Twenty-one 5-month-old male Rambouillet lambs were assigned randomly to one of three diets with 0, 20, and 40 g BT/kg dry matter (DM) and similar energy and protein contents. Lambs were adapted to the diets for 15 days, followed by a 45-day evaluation trial. Data were analysed using a mixed model. Growth, feed intake and ruminal fermentation were not affected by the dietary level of BT. Daily metabolizable energy intake (MEI), carcass yield and degree of fatness, increased linearly as the BT level increased. Carcass classification and muscle conformation were not affected by BT. Most meat characteristics (texture, pH, myoglobin, protein content, colour, cathepsins, and chemical composition) five and eight days post-mortem were not affected, except for fat content in meat, which increased linearly as diet BT level increased. Fatty acid (FA) profiles of the meat from lambs fed the three diets were similar. In conclusion, addition of BT at 20 and 40 g/kg DM to diets for growing lambs allowed reduced grain usage and increased forage levels (from 0 to 270 g/kg DM), increasing energy intake, carcass yield and fatness, and intramuscular fat without causing harmful effects on growth, feed intake or ruminal fermentation characteristics.&#x0D; Keywords: dietary fat, fatty acids, meat colour, sheep

Combined supplementation of chromium-yeast and selenium-yeast on finishing barrows

ABSTRACT: The present study was performed to evaluate the association of chromium-yeast and selenium-yeast as nutritional additives to enhance performance and quantitative characteristics in the carcass of finishing barrows. A total of 48 barrows, commercial hybrid, with initial weight of 68.3±3.5 kg and final weight of 99.6±3.6 kg, were utilized for the study. The animals were distributed in a randomized complete block design, consisting of three levels of chromium-yeast and selenium-yeast (i.e., without supplementation of chromium-yeast and selenium-yeast, supplementation of 0.4 mg kg-1 chromium-yeast and 0.3 mg kg-1 selenium-yeast, and supplementation of 0.8 mg kg-1 chromium-yeast and 0.6 mg kg-1 selenium-yeast) with eight replicates and two animals per experimental unit. The supplementation of chromium and selenium-yeast did not significantly affect (P&gt;0.05) the average daily feed intake, digestible lysine, crude protein and metabolizable energy intake, average daily weight gain, feed conversion, weight and carcass length, back fat thickness, muscle depth, percentage and amount of lean meat, and carcass allowance. These findings suggest that supplementation of chromium and selenium-yeast does not affect the performance or quantitative characteristics in the carcass of finishing barrows.

Impacts of Graded Levels of Metabolizable Energy on Growth Performance and Carcass Characteristics of Slow-Growing Yellow-Feathered Male Chickens.

Simple SummaryInadequate feed inhibits the potential performance of birds, and giving birds excess nutrients or levels higher than the requirement reduces production profits and may lead to negative effects on performance. Although recently there has been an expanding market worldwide for slower growing chickens to meet the consumer demand for a better tasting meat, little effort has gone into optimizing their dietary nutrient levels. Using fiv e different dietary energy levels, this study evaluated the optimal requirement of dietary energy for maximal growth rate, feed:gain ratio, meat quality indices, and blood metabolites of a Chinese yellow-feathered breed.A dose-response study was conducted to investigate the metabolizable energy (ME) requirement for Lingnan chickens from 9 to 15 weeks of age. One thousand two hundred 8-week-old slow-growing yellow-feathered male chickens were allotted to five dietary ME levels (2805, 2897, 2997, 3095 and 3236 kcal/kg). The results revealed that the daily metabolizable energy intake increased (p < 0.01), whereas the feed intake and feed:gain ratio decreased linearly (p < 0.01) with the increment in dietary ME level. The final body weight and daily gain of the highest ME treatment tended (p > 0.05) to be greater than those obtained with the lower ME levels. The fat content in breast muscle showed a quadratic response (p < 0.05) to the increase in dietary energy level. The shear force values of breast muscle in the 2897, 3095 and 3236 kcal/kg treatments were lower (p < 0.05) than those of the 2997 kcal/kg treatment. In conclusion, among the tested ME levels, 3095 kcal/kg was adequate for feed intake, shear force, and plasma uric acid, and 3236 kcal/kg tended to increase the body weight, body gain, and feed conversion ratio of Lingnan males between 9 and 15 weeks of age; further studies are still required for testing higher levels.

The relation between energy intake and chewing index of diets fed to nursing ewes

The objective of this study was to determine whether a linear relation exists between the metabolizable energy intake (MEI) of nursing ewes in early lactation and the dietary chewing index (CI). This was investigated using five feeding trials with intake data from 108 nursing ewes in the first 4–6 weeks after lambing, giving a total of 528 observations. The ewes were fed grass silage ad libitum separately, supplemented with concentrates or fed a total mixed ration (TMR) ad libitum. The ewes were of different breeds, ranging from 2 to 7 years old, had a mean body weight (BW) in the first week after lambing of 91kg (SD=9.7), and nursed an average of 2.2 lambs (SD=0.37). The average daily MEI was 42.0MJ (SD=8.35). The NorFor CI (min/MJ ME) values of the diets was estimated from the content of neutral detergent fibre (NDF; g/kg DM), indigestible NDF (iNDF; g/kg NDF), and the theoretical chopping length (mm) of the forage. The CI values were adjusted for the BW of the ewes and for NDF intakes higher than 0.7% of BW. The mean corrected CI (CIcor) was 37.3min/MJ ME (SD=6.74). The relation between MEI and CIcor was analyzed using nonlinear mixed-effects modelling, using the equation MEI=ME0−k×ME02×CIcor, where MEI is the daily intake of metabolizable energy, ME0 is the theoretical maximum energy intake capacity of the animal in a situation with no physical constraints on intake, and k represents the decline in MEI with increasing CIcor. The model included random variation of week-within-experiment on the intercept and linear fixed effect of week after lambing on k. The maximum daily chewing time, CTmax, for the ewes was assumed to be 1/(4×k). The MEI declined linearly with increasing dietary CI (P<0.001), with difference within-experiment intercepts in relation to week after lambing (P<0.001), supporting the existence of a linear relation between MEI and CIcor for nursing ewes in early lactation. Despite an overestimated CTmax value, this model has the potential to predict the MEI of nursing ewes in early lactation.

The Influence of Seasonal Frugivory on Nutrient and Energy Intake in Wild Western Gorillas.

The daily energy requirements of animals are determined by a combination of physical and physiological factors, but food availability may challenge the capacity to meet nutritional needs. Western gorillas (Gorilla gorilla) are an interesting model for investigating this topic because they are folivore-frugivores that adjust their diet and activities to seasonal variation in fruit availability. Observations of one habituated group of western gorillas in Bai-Hokou, Central African Republic (December 2004-December 2005) were used to examine seasonal variation in diet quality and nutritional intake. We tested if during the high fruit season the food consumed by western gorillas was higher in quality (higher in energy, sugar, fat but lower in fibre and antifeedants) than during the low fruit season. Food consumed during the high fruit season was higher in digestible energy, but not any other macronutrients. Second, we investigated whether the gorillas increased their daily intake of carbohydrates, metabolizable energy (KCal/g OM), or other nutrients during the high fruit season. Intake of dry matter, fibers, fat, protein and the majority of minerals and phenols decreased with increased frugivory and there was some indication of seasonal variation in intake of energy (KCal/g OM), tannins, protein/fiber ratio, and iron. Intake of non-structural carbohydrates and sugars was not influenced by fruit availability. Gorillas are probably able to extract large quantities of energy via fermentation since they rely on proteinaceous leaves during the low fruit season. Macronutrients and micronutrients, but not digestible energy, may be limited for them during times of low fruit availability because they are hind-gut fermenters. We discuss the advantages of seasonal frugivores having large dietary breath and flexibility, significant characteristics to consider in the conservation strategies of endangered species.

Relationship between energy intake and chewing index of diets fed to pregnant ewes

The objective was to determine whether a linear relationship exists between the metabolizable energy (ME) intake of pregnant ewes and a dietary chewing index (CI). The relationship was studied using five feeding trials with intake data from 108 pregnant ewes, 4 to 1 weeks before lambing, giving a total of 324 observations. All ewes were fed grass silage ad libitum, supplemented with concentrates either separately or in a total mixed ration (TMR). The ewes were of different breeds, were between 2 and 7 years old, had a mean body weight (BW) in the 4th week before lambing of 95.1kg (SD=9.64), and gave birth to an average of 2.2 lambs (SD=0.37). The average daily ME intake was 29.4MJ/d (SD=5.26). The NorFor CI (min/MJ ME) of the feeds was estimated from the neutral detergent fibre (NDF) (g/kg DM), indigestible NDF (g/kg NDF) and the theoretical chopping length (mm) of the forage. The CI values were adjusted for the BW of the ewes and for NDF intake higher than 0.7% of forage NDF per kg of BW. The mean corrected CI (CIcor) was 27.2min/MJ ME (SD=5.10). The relationship between ME intake (MEI) and CIcor was analysed using nonlinear mixed effects modelling, using the equation MEI=ME0–k×ME02×CIcor, where MEI is the daily metabolizable energy intake, ME0 is considered the theoretical maximum intake capacity of the animal in a theoretical situation with no physical constraint on intake, and parameter k represents the decline in MEI with the increasing CIcor of the ration. The model includes random variation of week within experiment on the intercept and linear fixed effect of week before lambing on parameter k. The maximum daily chewing time, CTmax, for the pregnant ewes was predicted to be 1/(4×k). The MEI declined linearly with increasing dietary CI (P<0.001), with different within-experiment intercepts in relation to week before lambing (P<0.001), supporting the existence of a linear relationship between MEI and CIcor for pregnant ewes in the last 4 weeks before lambing. CTmax could be calculated for the ewes and had a mean of 1066min/d. The model appears to have a potential for predicting MEI in pregnant ewes fed forages ad libitum with concentrates restrictively or TMR diets, based on BW, energy value of feeds, NDF and iNDF concentration of forage.

Divergent selection for residual feed intake in group-housed growing pigs: characteristics of physical and behavioural activity according to line and sex

The aim of the study was to assess the impact of selection for residual feed intake (RFI) on the behavioural activity of lines divergently selected for RFI during seven generations. In all, six successive batches from the seventh generation of selection were raised in collective pens equipped with a single-place electronic feeder (SEF) from 10 weeks of age to 100 kg BW. Each batch included four groups of 12 pigs: high RFI (RFI+) castrated males, RFI+ females, low RFI (RFI−) castrated males, RFI− females. At 17 weeks of age, health criteria were evaluated using a gradient scale for increased severity of lameness, body lesions, bursae and tail biting. Individual behavioural activities were recorded by 24-h video tape on the day after health evaluation. The investigative motivation towards unfamiliar objects was quantified at 18 weeks of age. The daily individual feeding patterns were computed from SEF records during the 4 weeks surrounding 12, 17 and 22 weeks of age. All pigs spent significantly most of their time lying in diurnal (80% of total scan) and nocturnal (>89%) periods. The RFI− pigs showed a lower proportion of health problems (P<0.01) than RFI+ pigs. The RFI− pigs used the SEF less than the RFI+ pigs, in diurnal (5.3% v. 6.4% of video scans, P<0.05) and nocturnal periods (3.6% v. 4.5% of video scans, P<0.05). This was confirmed by a significantly lower daily number and duration of visits to the SEF computed from the SEF data. The feeding activity measured from the video recording was significantly correlated (R>0.34; P<0.05) with feeding patterns computed from the SEF. The RFI− pigs spent less time standing over the 24-h period (9.7% v. 12.2% of scans, i.e. 35 min/day, P<0.05). In terms of energy costs, this amounted to 14% of the line difference in terms of daily metabolizable energy intake. The castrated males used the SEF more than females, especially at night (4.7% v. 3.4% of total scans, P<0.05), whereas females displayed greater investigation of their environment (7.7±0.3% v. 6.6±0.2% of total scans, P<0.05) and the novel objects (10.7% v. 4.9% of total scans, P<0.05). In conclusion, the lower physical activity associated with reduced energy expenditure in RFI− pigs compared with RFI+ pigs contributed significantly to their improved efficiency and was not related to worsened health scores.

Short communication: Prediction of energy requirements of Murciano-Granadina preruminant female kids using the National Research Council

Data collected on metabolizable energy (ME) intake and growth performance of preruminant female kids of the Murciano-Granadina breed was used to assess the accuracy of the latest U. S. National Research Council (NRC) recommendations to predict their energy requirements. Female kids were fed a milk replacer individually, according to appetite three times a day from two to five weeks of age. The mean initial body weight and average daily weight gain (&plusmn; SE) were 3.31 &plusmn; 0.08 kg/d and 120 &plusmn; 3 g/d. Daily ME intake, expressed relative to metabolic body weight (BW0.75), decreased linearly with age from 1085 to 970 kJ/kg BW0.75/d, and there was nearly a constant ratio of ME requirements for maintenance. The observed ME intake was 5.4% higher than the ME requirements, calculated according to NRC, probably due to the energy content of the weight gain. It was concluded that the energy system model of the NRC is accurate enough to calculate the ME requirements of preruminant female kids of the Murciano-Granadina breed.Keywords: Goats, pre-weaning period, suckling female kids, NRC

Energy-intake and activity risk factors for owner-perceived obesity in a defined population of Swedish dogs

Our main objective was to obtain baseline data on daily metabolisable energy (ME) intake, activity, and risk factors for obesity in a population of 460 privately owned Swedish dogs in 1999. A previously validated mail-and-telephone questionnaire was used ( Sallander et al., 2001a). The dogs were of 124 breeds, 1–3 years old, and had body weights (BW) between 1 and 75 kg. The ME intakes of this population could be described with the equation ME intake (kilojoules, kJ/d) = 554BW 0.66 ( r sp = 0.73, P = 0.0001). The energy intake originating from commercial foods was 79% (median, range 45–97). Table foods generally had a higher fat content (median 13 g/megajoule, MJ, range 1–122) than commercial foods (median 8 g/MJ, range 2–18; P = 0.0001). The median energy density was 1603 kJ/100 g (median; range 1106–2105). Almost all (97%) dogs were taken for walks, and there was a significant difference between the duration of the walks during weekdays and weekends (medians 60 and 90 min/d, respectively, P = 0.006). Sixty percent of all dogs were trained in activities such as obedience (31%), hunting (27%) or tracking (18%) for a median of 35 min/d (range 1–146). The final regression model for obesity included the factors sex, appetite and feeding a home-made diet/table foods. Dogs that were perceived to have good or very good appetite had 3.42-fold greater odds for obesity than individuals with bad or very bad appetite (95% CI 1.19–9.80; P = 0.022). Females had 2.17-fold greater odds of being obese than males did (95% CI 1.30–3.70; P = 0.003). Also, dogs fed table foods or home-made diets had 2.06-fold greater odds of obesity than those that were not given these food items (95% CI 0.97–4.35; P = 0.050).

A nutrition mathematical model to account for dietary supply and requirements of energy and nutrients for domesticated small ruminants: the development and evaluation of the Small Ruminant Nutrition System

A mechanistic model that predicts nutrient requirements and biological values of feeds for sheep (Cornell Net Carbohydrate and Protein System; CNCPS-S) was expanded to include goats and the name was changed to the Small Ruminant Nutrition System (SRNS). The SRNS uses animal and environmental factors to predict metabolizable energy (ME) and protein, and Ca and P requirements. Requirements for goats in the SRNS are predicted based on the equations developed for CNCPS-S, modified to account for specific requirements of goats, including maintenance, lactation, and pregnancy requirements, and body reserves. Feed biological values are predicted based on carbohydrate and protein fractions and their ruminal fermentation rates, forage, concentrate and liquid passage rates, and microbial growth. The evaluation of the SRNS for sheep using published papers (19 treatment means) indicated no mean bias (MB; 1.1 g/100 g) and low root mean square prediction error (RMSPE; 3.6 g/100g) when predicting dietary organic matter digestibility for diets not deficient in ruminal nitrogen. The SRNS accurately predicted gains and losses of shrunk body weight (SBW) of adult sheep (15 treatment means; MB = 5.8 g/d and RMSPE = 30 g/d) when diets were not deficient in ruminal nitrogen. The SRNS for sheep had MB varying from -34 to 1 g/d and RSME varying from 37 to 56 g/d when predicting average daily gain (ADG) of growing lambs (42 treatment means). The evaluation of the SRNS for goats based on literature data showed accurate predictions for ADG of kids (31 treatment means; RMSEP = 32.5 g/d; r2= 0.85; concordance correlation coefficient, CCC, = 0.91), daily ME intake (21 treatment means; RMSEP = 0.24 Mcal/d g/d; r2 = 0.99; CCC = 0.99), and energy balance (21 treatment means; RMSEP = 0.20 Mcal/d g/d; r2 = 0.87; CCC = 0.90) of goats. In conclusion, the SRNS for sheep can accurately predict dietary organic matter digestibility, ADG of growing lambs and changes in SBW of mature sheep. The SRNS for goats is suitable for predicting ME intake and the energy balance of lactating and non-lactating adult goats and the ADG of kids of dairy, meat, and indigenous breeds. The SRNS model is available at http://nutritionmodels.tamu.edu.