Metabolizable Energy Requirements Research Articles

Modelling nitrogen-corrected apparent metabolisable energy requirement for egg production of 3 BW types of Yellow Broiler breeder hens during the egg-laying period

Accurate prediction of energy requirement is important in formulating diets, but an energy model for Yellow Broiler breeder hens is publicly unavailable. The objective of this study was to establish energy prediction models for the nitrogen-corrected apparent metabolisable energy (AMEn) requirement of different categories of Yellow Broiler breeder hens during the egg-laying period. Data for modelling were collected from research papers, public databases and production data from companies. Breeder hens were generally categorised into three BW types: heavy, medium and light (HBWT, MBWT and LBWT). Published articles were cited for providing coefficients of AMEn maintenance requirement (AMEnm, 101 kcal/kg BW0.75, 423 KJ/kg BW0.75) and growth requirement (AMEng, 5.33 kcal/g, 22.3 KJ/g), respectively. Models of AMEn for egg production (AMEnp) were established from the known daily intake of AMEn (AMEni) and those of maintenance and growth by the factorial approach: AMEnp = AMEni − AMEnm − AMEng. For the three types of hens, AMEnp HBWT (kcal, KJ) = 2.55 kcal (10.7 KJ) × egg mass (EM, g); AMEnp MBWT (kcal, KJ) = 2.70 kcal (11.3 KJ) × EM (g), and AMEnp LBWT (kcal, KJ) = 2.94 kcal (12.3 KJ) × EM (g) were determined. The total AMEni requirements, depending on Gompertz models, were HBWT: BW (g) = 3 144 × e−EXP(−0.162×(week of age (wk)−15.6)); MBWT: BW (g) = 2 526 × e−EXP(−0.333×(wk−19.1)); LBWT: BW (g) = 1 612 × e−EXP(−0.242×(wk−16.5)). Models of egg production, HBWT: egg production (%) = 124 × e−0.017×wk/(1 + e−0.870×(wk−26.2)); MBWT: egg production (%) = 144 × e−0.020×wk/(1 + e−0.751×(wk−24.9)); LBWT: egg production (%) = 163 × e−0.024×wk/(1 + e−0.476×(wk−26.5))) and egg weight for each wk of the three types of hens during the egg-laying period were all established. These models showed good applicability in simulating and predicting the literature or production data.

154 Supplementation of Late Gestation Metabolizable Energy in Beef Cows Reduces Mobilization of Body Reserves Prepartum

Abstract This study evaluated how late gestation metabolizable energy (ME) intake affects performance and metabolism in beef cattle. Primiparous (PP; n = 45) and multiparous (MP; n = 107) Angus-Simmental cows were blocked by calving date and randomly assigned to treatments providing 80 (LME; n = 52), 100 (CME; n = 51), or 120% (HME; n = 49) of ME requirements for 53 d prior to calving. Postpartum, cows were fed the same diet. Rib and rump fat depths were measured by ultrasonography on d -54, -40, -26, -13, 13, 27, and 55 relative to calving. Plasma and serum were collected on d -53, -39, -25, -10, -3, 7, 13, 27, and 55 relative to calving. Serum glucose, beta-hydroxybutyrate, non-esterified fatty acids (NEFA), and urea, and plasma insulin were measured. Data were analyzed using PROC GLIMMIX with the fixed effects of treatment, parity, and treatment×parity, and random effects of block and cow (block), accounting for repeated measures. Absolute loss of rib and rump fat prepartum was lesser (P ≤ 0.03) for HME. Primiparous heifers lost more (P < 0.01) rib fat prepartum. Prepartum serum urea and NEFA were elevated (P < 0.01) for LME, whereas glucose was elevated (P < 0.01) for HME compared to LME. Multiparous cows had greater (P ≤ 0.02) serum NEFA and plasma insulin prepartum, whereas PP heifers had elevated (P < 0.01) glucose. Treatment did not affect (P ≥ 0.56) the absolute loss of rib nor rump fat postpartum. Serum urea was greater (P < 0.01) in LME than HME postpartum. Multiparous cow serum urea and beta-hydroxybutyrate postpartum was elevated (P ≤ 0.01) postpartum, whereas PP cows had elevated (P < 0.01) plasma insulin. Supplementing excess ME during late gestation reduced mobilization of body reserves before calving but prepartum effects did not continue postpartum.

162 Differential Late Gestation Metabolizable Energy Intake Alters Adipose-Specific Insulin Responsiveness in Antepartum Beef Cattle

Abstract We evaluated how metabolizable energy (ME) intake influences antepartum insulin sensitivity in beef cattle. Angus-Simmental cattle (primiparous: n = 17; multiparous: n = 21) were randomly assigned to treatments supplying 80 (LowME, n = 19) or 120% (HighME, n = 19) of predicted ME requirements for 53 d prepartum. At 7 d antepartum, intravenous glucose tolerance tests (IVGTT) were imposed by infusing 1.36 g glucose/kg BW0.75 and sampling from -3 to 90 min to measure plasma glucose and insulin and serum non-esterified fatty acids (NEFA) concentrations. Data were analyzed using PROC GLIMMIX with the fixed effects of treatment, parity, time (repeated), and treatment×time and considering cow(treatment) as random. Baseline glucose concentration increased (P = 0.03) and baseline insulin concentration tended to increase (P = 0.06) for HighME relative to LowME cattle irrespective (P ≥ 0.33) of parity, whereas baseline NEFA concentration was elevated (P < 0.01) for LowME vs. HighME. Plasma glucose-insulin concentrations during the IVGTT did not differ (P ≥ 0.25) by treatment, treatment×time, or parity. However, serum NEFA was elevated (P < 0.01) throughout the IVGTT for LowME vs. HighME cattle and tended to be affected (P = 0.09) by the treatment×time interaction as NEFA concentrations became similar at 90 min due to HighME cattle having a shallower (treatment×time: P < 0.01) decremental NEFA response than LowME cattle. Low ME cattle cleared NEFA more quickly (75% increase; P < 0.01) than HighME. The glucose positive incremental area-under-the-curve throughout the IVGTT tended to be lesser (P = 0.06) for heifers than cows but heifers had a blunted (P ≤ 0.05) glucose-stimulated reduction in NEFA and NEFA clearance rate compared to cows. These data demonstrate that ME provision may alter adipose insulin responsiveness in antepartum beef cattle and that heifers respond to excess glucose and NEFA differently than cows.

274 Effects of Feeding Levels in Early Gestation on PIC Camborough Sows and Litter Performance

Abstract Our objective was to determine the effects of increasing feeding levels for PIC Camborough sows during early gestation on sow and litter performance. A total of 636 sows (PIC Camborough) were randomly assigned at weaning to 1 of 4 treatments that were balanced for weight and caliper scores within parity categories. Treatments consisted of feeding sows with daily feed allowances to meet 85, 115, 145, or 175% of the NRC (2012) maintenance metabolizable energy (MEm) requirement calculated as MEm, kcal/d = 100 × (body weight, kg)0.75. A common corn-soybean meal-distillers dried grains with solubles-based diet with 3,092 kcal of ME/kg and 0.64% standardized ileal digestible lysine was used. Treatments were applied from d 6 to 35 of gestation, after which sows were moved to gestation pens and fed according to body condition through an electronic sow feeder until moved to the farrowing room. Sow was the experimental unit and data were analyzed using generalized linear mixed models with the lmer and glmer functions of R. On average, females were ideal condition at weaning across treatment as determined by the caliper scores. Average feed allowances were 1.6, 2.1, 2.6, and 3.2 kg/day for the 85, 115, 145, and 175% treatments, respectively. Increasing feed allowances reduced (linear, P< 0.05) body weight loss (-13.8, -10.3, -4.7 and -0.5 kg, respectively) and increased caliper score gain (-0.43, -0.03, 0.64, 0.76 units, respectively) from weaning to d 35 of gestation. There was no evidence for treatment effects on farrowing rate, total born, stillborn rate, average litter weight, piglet throughput, or subsequent reproductive performance. In summary, increasing feed allowances to meet 85 to 175% of the MEm requirements during early gestation on Camborough sows resulted in a reduction in body weight loss and an improvement in caliper gain until d 35 of gestation without evidence of impact in reproductive performance.

PSII-A-5 Effects of Time Postpartum and Late Gestational Nutrient Restriction on Beef Heifer Colostrum

Abstract Our objectives were to determine changes in colostrum yield and composition across the 36 hours post-calving and effects of late gestational nutrient restriction (NR) on these changes. Fall-calving, crossbred beef heifers (BW: 472 ± 33 [SD] kg; BCS: 5.4 ± 0.5) were individually fed 100% (control; CON; n = 13) or 70% (NR; n = 13) of NASEM metabolizable energy and metabolizable protein requirements for maintenance, growth, and pregnancy from d 160 of gestation to parturition. Calves were removed from dams immediately post-calving and pre-suckling. Colostrum was hand-milked from all quarters at 1, 12, 24, and 36 h to determine total colostrum volume and weight. Colostrum protein, triglycerides, and milk urea nitrogen (MUN) concentration were analyzed using colorimetric assays on a UV-visible light microplate reader. Data were analyzed using fixed effects of treatment, hour, treatment × hour (repeated measures); calf sex, maternal sire, and treatment initiation date were covariates. Colostrum yield was affected (P < 0.02) by the treatment × hour interaction. Colostrum volume and weight were 28% less (P ≤ 0.03) for NR than CON at 1 h. For both treatments, colostrum volume and weight decreased (P ≤ 0.04) from 1 to 12 h, before increasing (P ≤ 0.02) from 12 to 36 h. Triglyceride concentration was greater (P = 0.03) in NR than CON. Both triglyceride concentration and total protein decreased (P ≤ 0.01) from 1 to 24 h. Protein concentration decreased (P < 0.001) from 1 to 36 h. Total triglycerides and MUN decreased (P < 0.001) from 1 to 12 h, before total MUN increased (P < 0.001) from 12 to 36 h and total triglycerides increased (P = 0.004) from 24 to 36 h. In conclusion, nutrient restriction may only affect colostrum yield at 1 h, and colostrum nutrient content decreases dramatically after the first milking.

298 Late Gestational Nutrient Restriction of Primiparous Beef Heifers Decreases Neonatal Calf Body Weight and Organ Mass

Abstract We hypothesized that late gestational nutrient restriction (NR) would decrease organ mass in neonatal calves. Fall-calving crossbred beef heifers (BW: 466 ± 30 [SD] kg; BCS: 5.4 ± 0.5) bred to a single sire were individually fed 100% (control; n = 10) or 70% (nutrient restricted; NR; n = 12) of NASEM metabolizable energy and metabolizable protein requirements for maintenance, pregnancy, and growth from d 160 of gestation to calving. Diets were based on chopped sorghum sudan hay and supplemented to meet targeted nutritional planes. Calves were removed immediately post-calving and fed colostrum and milk replacer relative to BW until euthanasia (48.7 ± 0.4 h of age) for organ mass determination. Nutritional plane was a fixed effect, and maternal sire, calf sex (when P < 0.25), and date of study initiation were covariates. Post-calving, NR dams were 62 kg BW and 2.1 BCS less (P < 0.001) than controls. Calf BW, liver, large intestine, omental/mesenteric fat, kidney, and heart weights were less (P ≤ 0.05) and carcass, rumen/reticulum/omasum, stomach complex, and total gastrointestinal tract weights tended to be less (P ≤ 0.09) in offspring from NR dams. Maternal nutrient restriction did not affect (P ≥ 0.11) weights of the small intestine, pancreas, abomasum, spleen, perirenal fat, adrenals, lungs, femur, and brain. Expressed per BW, lung weight was greater (P = 0.05), and brain and femur weight tended to be greater (P ≤ 0.10) in calves from NR dams, but other organ masses were unaffected (P ≥ 0.15). Expressed relative to brain weight, liver and large intestine weights were less (P ≤ 0.04) and carcass, total gastrointestinal tract, omental/mesenteric fat, and kidney weights tended to be less (P ≤ 0.08) in NR. In summary, late gestational NR decreased some organ masses in neonatal calves while sparing other tissues via asymmetric growth.

79 Effects of Nutrient Restriction During Late Gestation of the First Parity on cow and Calf Performance During the Second Lactation

Abstract Fall-calving Herford-SimAngus heifers were individually fed either 100% (control; CON, n = 10) or 70% (nutrient restricted; NR, n = 12) of NASEM metabolizable energy and metabolizable protein requirements from d 160 of gestation to calving. Postpartum cows were individually fed 100% of energy and protein requirements until d 149 of lactation, then fed tall fescue hay or pasture as a single group through parity 2. Second parity cow performance and calf size were measured at birth, d 30, and d 60 post-calving. Single-quarter colostrum yield was collected pre-suckling. At d 30 and 60 of lactation, 4-hour milk yield was collected. Data were analyzed with the fixed effect of first parity nutritional plane, and calving or breeding date, calf sex, and calf sire (calf measures) were covariates. Milk yield included day and day x treatment (repeated measures). We previously reported that in parity 1, NR reduced (P ≤ 0.04) colostrum and milk yield, calf weaning weight, and dam weaning BCS. From calving to d 60 of parity 2, CON cows had greater (P ≤ 0.008) BCS and greater (P = 0.003) backfat on d 30. Additionally, CON cows had greater (P ≤ 0.002) BW compared with NR at d 30 and 60 of lactation. Calf size was not affected (P ≥ 0.17) by first parity nutritional plane except that cannon length at birth and d 60 tended (P ≤ 0.08) to be longer in CON calves. Colostrum and milk volume and weight were not affected (P ≥ 0.37) by first parity nutritional plane. Milk yield was greater (P ≤ 0.001) at d 30 than d 60. These data indicate that cow BW and energy reserves remained less in parity 2 when heifers experienced late gestational nutrient restriction, but calf size, colostrum yield, and milk yield were unaffected in the second parity.

257 Effect of the Essential Amino Acid-Nitrogen to Total Nitrogen Ratio on Lysine Requirement for Nitrogen Retention in Growing Pigs

Abstract Low-protein (LP) diets may become limiting in nitrogen (N), affecting utilization of essential amino acids (EAA) for nitrogen retention (NR). The objective of the present study was to determine the effect of the EAA-N to total N ratio (EAA-N:TN) on lysine (Lys) requirement for NR. A total of 80 growing barrows (21.5±0.89 kg initial BW) were randomly assigned to 1 of 10 dietary treatments (n=8 pigs/treatment) in 8 blocks in a 2 × 5 factorial arrangement with factors of EAA-N:TN (low vs. high) and Lys content (0.82, 0.92, 1.02, 1.12, and 1.22% standardized ileal digestible [SID] Lys). Diets were formulated to meet EAA requirements with the low ratio diet (LR; 16.8% crude protein) having an ideal EAA-N:TN of 0.48 and the high ratio diet (HR; 15.5% crude protein) formulated to be limiting in NEAA with an EAA-N:TN of 0.55. Diets were fed at 2.8 × maintenance metabolizable energy requirements. After a 7-d dietary adaptation, a 4-d N-balance period was conducted where fresh fecal samples were collected daily and quantitative urine samples were collected over a 24-h period. Nitrogen-balance was determined as the difference between N intake minus fecal and urinary N output. Data were analyzed using a MIXED model with fixed effects of ratio, Lys, and their interactions, and block as a random effect. Lysine requirement based on two-phase linear or quadratic modeling was estimated using PROC NLIN. Nitrogen retention increased linearly with increasing Lys levels regardless of ratio (P< 0.01). Quadratic modelling estimated the Lys requirement to maximize NR at 17.83 g/d in pigs fed HR diets at 1.21% SID (R2 = 0.53; P< 0.05), but no breakpoint was achieved for pigs fed LR diets, which showed a linear response (R2 = 0.79; P< 0.05). These results suggest that NR is limited by NEAA or TN in HR diets.

Energy requirements of Holstein, Gyr, and Holstein × Gyr crossbred heifers using the respirometry technique

We aimed to determine the energy requirements for maintenance and gain of 18 prepubertal dairy heifers of three breed compositions (BC; Holstein, Gyr, and Holstein × Gyr). Diets were formulated for gains of 0, 400, and 800 g/day, corresponding to 1.0×, 1.5×, and 2.0× maintenance, respectively. Each dairy BC had six animals with an initial body weight (iBW) of 219.8 ± 32 kg, 215.8 ± 33 kg, and 228.3 ± 33 kg for Holstein, Gyr, and Holstein × Gyr, respectively. The experiment was designed as a completely randomized design in a factorial scheme 3 × 3 [three BC and three feeding levels (FL)]. Digestibility and metabolism assays were performed to determine energy losses through feces and urine. Heat production was determined using the continuous measurement of oxygen consumption, carbon dioxide production, and methane emissions in respiration chambers. Energy requirements for maintenance (NEm) were calculated based on the relationship between heat production (HP) and metabolizable energy intake (MEI). The efficiency of use of metabolizable energy for maintenance (km) was obtained from the ratio between NEm and metabolizable energy requirements for maintenance. The net energy requirements for growth (NEg) were estimated from the model RE = β0 × EBW0.75 × EBGβ1, where RE is the retained energy (Mcal/day), EBW is empty body weight (kg0.75), and EBG is the empty body gain (kg/day). The efficiency of use of metabolizable energy for gain (kg) was estimated as the slope of the regression between RE and MEI for gain. Gyr heifers presented NEm 15% lower (98 kcal/kg of BW0.75) than HG crossbred animals. Holstein and crossbred heifers had similar NEm, 102 and 112 kcal/kg of BW0.75, respectively. The km was 0.71, 0.74, and 0.75 for HG, Holstein, and Gyr, respectively. Net energy requirement for gain (NEg) did not differ across BC, and a single equation was fit for all BC: RE = 0.069 × BW0.75 × BGW0.852. A single kg of 0.65 was observed for all three BC. Breed composition affected the energy requirements for maintenance and the energy partition, and those differences should be considered when estimating requirements for Gyr, Holstein × Gyr crossbred, and Holstein heifers.

Differences between Yaks and Qaidam Cattle in Digestibilities of Nutrients and Ruminal Concentration of Volatile Fatty Acids Are not Dependent on Feed Level

The Qinghai–Tibetan Plateau (QTP) is characterized by highly fluctuating seasonal pastures. Yaks (Bos grunniens) graze at higher altitudes than Qaidam cattle (Bos taurus), but the two bovine species co-graze in their overlapping ranges. We hypothesized that yaks would digest nutrients to a greater extent and utilize energy more efficiently than cattle at low dietary intakes, but the difference between bovine species would not be apparent at high intakes. To test this hypothesis, six yaks (203 ± 6.0 kg) and six Qaidam cattle (214 ± 9.0 kg), all 3.5-year-old castrated males, were used in two concurrent 4 × 4 Latin square designs with two extra steers of each species in each period. The digestibilities of dry matter, organic matter, crude protein, ether extract, neutral and acid detergent fiber were greater (p < 0.05) in yaks than in cattle and decreased linearly (p < 0.05) when feed level (FL) increased. The average daily gain (ADG), the ratios of digestible energy (DE) to gross energy and metabolizable energy (ME) to DE, and ruminal total volatile fatty acids and ammonia-N concentrations were greater (p < 0.001) in yaks than in cattle and increased linearly (p < 0.001) when FL increased. Based on the regression equations of ADG on ME intake, the daily ME requirement for maintenance in yaks was 0.53 MJ BW−0.75 d−1, which was lesser (p < 0.05) than the 0.62 MJ BW−0.75 d−1 in cattle. We concluded that: (1) when differences between breeds emerged, the differences existed for all FLs; (2) maintenance energy requirement was lesser and ADG was greater in yaks than in cattle; (3) the digestibilities of nutrients were greater in yaks than in cattle when consuming only oat hay pellets. These findings indicate that yaks adapt to fluctuating dietary intakes in harsh environments by having a low energy requirement and high digestibility of nutrients, independent of the FL.

The apparent metabolisable energy requirement of Sansui ducks from hatch to 21 days of age

A dose-response experiment was conducted to estimate optimal dietary apparent metabolisable energy requirement (AME) in Sansui ducks (Sansui Sheldrake duck) from hatch to 21 days of age. Three hundred thirty-six one-day-old male Sansui ducks were randomly assigned to six experimental treatments, each consisting of seven replicate pens with eight birds per pen. Birds were fed diets containing either 10.92, 11.38, 11.8, 12.26, 12.68 and 13.14 MJ AME/kg, respectively. At 21 d of age, the body weight, weight gain, feed intake, protein intake, energy intake and feed conversion ratio of ducklings from each pen were measured. Increasing AME content from 10.92 MJ/kg to 13.14 MJ/kg significantly improved body weight, weight gain, feed intake, feed conversion ratio and crude protein intake (P<0.05). No significant changes in energy intake were found among treatments (P>0.05). Based on broken-line regression analysis, the AME requirement of male Sansui ducks from hatch to 21 d of age was 11.49 and 11.59 MJ/kg for maximum body weight and best feed conversion ratio, respectively.

Does the metabolizable energy influence the performance, carcass characteristicsand biochemical parameters of European quails from 28 to 42 days of age?

This study was conducted to determinethe metabolizable energy (ME) requirement for quails (Cortunix cortunix cortunix) from 28 to 42 days of age. Four hundred and twenty quails were distributed in a completely randomized design, with 5 treatments (2950, 3000, 3050, 3100 and 3150 kcal of ME/kg of feed), 7 replicates and 12 birds per experimental unit. Performance, relative weights of organs and viscera, carcass characteristics, meat quality, body composition and blood parameters of the birds were evaluated. There was a reduction in feed intake (ADFI) with the use of 3150 kcal ME/kg (p < 0.01), with a quadratic effect on feed efficiency (p < 0.01), estimating the energy requirement in the 3009.4 kcal ME/kg. The breast yield (BY) and the colour b* had an effect (p < 0.01), with better results for 2950 kcal ME/kg, while the meat texture reduced when the birds were fed with 3150 kcal ME/kg. HDL and LDL showed the quadratic effect (p < 0.01) when ME increased to 3111.6 and 3157.4 kcal/kgrespectively. Very lowdensity lipoproteinincreased linearly (p < 0.01) in birds that received diets with 3000 kcal ME/kg. We conclude that the use of 3009.4 kcal of ME/kg for European quail meets the nutritional needsand provides an improvement in feed efficiency, without affecting the carcass parameters of the birds. Information regarding the nutritional requirements for European quails is still recent; therefore, it is essential to know the adequate levels of metabolizable energy, an important nutritional component for the maximum productive performance of birds.

Refeeding ewes ad libitum after a moderate energy restriction during mid gestation did not affect the onset of breeding and ovulating rate of female offspring

Sub-nutrition during pregnancy might affect the offspring´s reproductive performance through effects on the development and function of gonads. This study evaluated a maternal energy restriction in ewes from day 48–106 of gestation, on pre- and post-weaning female lambs` performance, onset of female lambs’ breeding and ovulation rate during their first breeding season. Adult Polwarth ewes sired by Finnish rams bearing single or twin lambs were assigned to two dietary treatments from day 48 to day 106 of gestation: restricted (R; n = 60) at 60 % of their metabolizable energy (ME) requirements, or non-restricted (NR; n = 54) at 100 % of their ME requirements. After the restriction period, ewes grazed all together ad libitum until weaning. The ewe lambs were evaluated from birth to weaning, as well as during their first breeding season. Although NR ewes weighed 17.7 % more than R ewes (P < 0.05) at the end of the restriction period, the nutritional treatment of the dams had no effect on the weight of the ewe lambs at birth, weaning or final weight (P > 0.05). Fat depth, rib eye area, the percentage of ewe-lambs cycling and their ovulation rate during the first breeding season was not affected by the ewe´s dietary treatment. Ewes restricted at 60 % of their ME requirements in mid-gestation seemed to have the capacity to compensate any detrimental effects on growth and development as well as the reproductive potential of female lambs if adequate refeeding conditions are provided in late gestation, throughout lactation and post-weaning.

Comparison of Global Metabolite for Growing Pigs Fed at Metabolizable Energy Requirement for Maintenance.

Though the energy requirement for maintenance is an important part of net energy system, little is known of the metabolic characteristics of maintenance energy expenditure. This study was investigated the effect of feeding level at metabolizable energy requirement for maintenance (FLM) on plasma metabolites in growing pigs. Ten barrows (22.5 ± 0.5 kg BW) were kept in metabolism crates and catheterized in the precaval vein during adaptation period. Pigs were fed a corn-soybean meal diet at 782 kJ ME/kg BW0.6·d−1 during d 1 to 8 and then were refeeding at 2,400 kJ ME/kg BW0.6·d−1 on d 9. Plasma samples of each pig were collected by catheter on the morning of d 1, 3, 5, 7, 9, and 10, respectively, for metabolomics testing. Results showed that the concentration of plasma urea nitrogen decreased under FLM (p < 0.01) and increased significantly after refeeding (p < 0.01). The concentration of total cholesterol, high-density lipoprotein, low-density lipoprotein, and albumin in plasma were decreased significantly after refeeding (p < 0.01). Eleven identified compounds were up-regulated and six ones were down-regulated under FLM. In conclusion, the energy metabolism of growing pigs was relatively stable after 4 days of feeding at FLM.

Influence of production system and feeds on performance, carcass traits and estimated energy balance of autochthonous Gochu Asturcelta pigs

Aim of study: To assess the effects of rearing system (extensive, ES; semi-extensive, SES) and feeds (grazed woodland, acorns, chestnuts, compound feed) on the performance, carcass traits and energetic balance of autochthonous Gochu Asturcelta pigs. Area of study: Asturias (Spain). Material and methods: In two successive years, a total of 58 immunocastrated Gochu Asturcelta pigs (25 females, 33 males), with an initial weight of 93.39 ± 3.36 kg and mean age of 6.82 ± 0.24 months, were randomly divided between ES and SES plots from July to December. ES pigs grazed woodland, acorns (Quercus robur L.) and chestnuts (Castanea sativa Mill.) and they were given additionally 1.5 kg compound-feed/pig·day. SES animals received only 2.5 kg compound-feed/pig·day. Chemical composition and metabolizable energy (ME) of feeds, energetic balance, growth performances and pig carcass traits were analysed. Main results: Acorns and chestnuts were both very close in their chemical composition, except for the polyphenol content and profile, and had a lower omega-6/omega-3 ratio than compound feeds. Live weight for the ES pigs was 25% lower and carcass weight 30% lower than for SES pigs (p&lt;0.001). Total ME requirement (MJ/day) was lower in ES than in SES pigs. Research highlights: The productive and carcass parameters observed are a consequence of a lower energy intake for pigs in ES than in SES, it being necessary to drastically reduce the stocking rate to increase weight gain and to improve carcass traits when Gochu Asturcelta pigs are reared in ES.

Chronic Fatigue Syndrome: A Quantum Mechanical Perspective

Chronic Fatigue Syndrome: A Quantum Mechanical Perspective

Methane production inventory between 1960–2020 in the Finnish dairy sector and the future mitigation scenarios

Enteric methane (CH4) represents about half of the climatic footprint of milk production in Finland. Methane is generated from the surplus hydrogen produced during the anaerobic feed digestion process in the rumen. Methane intensity per liter of energy corrected milk (g CH4 kg-1 ECM) is a function of the number of cows, milk yield (MY), replacement rate (RR), and the diet composition. This study aimed to model and report the inventory of CH4 from milk production in Finland between 1960 and 2020. Furthermore, we report the potential future scenarios of CH4 mitigation strategies based on the further development in MY and feed efficiency with constant or changing BW of cows. The diet composition of cattle was formulated for 5-year periods according to feed consumption statistics (ProAgria 2021) and the current metabolizable energy (ME) requirements for dairy cattle (Luke 2021a). The CH4 production from cattle was simulated using the formulated diets with the Nordic dairy cow model Karoline. The future CH4 mitigation scenarios of increased MY and improved feed efficiency were simulated using Lypsikki® dairy farm model. During the inventory period, the number of cows (1000) decreased from 1150 to less than 258, and MY increased three-fold. The total milk and CH4 production peaked in 1965 being 3650 and 110 million kg per year and decreased to 2300 and 48 million kg per year in 2020, respectively. Consequently, decreased number of cows and increased MY reduced the total CH4 production by 56%. In addition, CH4 intensity improved by 36% during the inventory period. Of the future scenarios, increased MY and improved feed efficiency had a substantial potential to improve CH4 intensity. In both scenarios maintaining the current BW of cows resulted in higher mitigation potential. We conclude that selecting more efficient animals has a significant CH4 mitigation potential.

Performance and behavior of the progeny of ewes fed with different sources and energy feed

This study aimed to investigate the effects of increased dietary energy intake and different feeds (starch, calcium salts of palm oil, and chromium propionate) in the nutrition of ewes, at gestation and lactation, evaluating the effects on the progeny. Seventy-two Dorper x Santa Inês ewes were allocated in a completely randomized block design, in five treatments. CTL (n=14) with 100% of predicted ME requirement, LOW (n=14) with 90% of predicted ME requirement, ST (n=15) with 110% of predicted ME requirement, and the energy source was starch, ST+Cr (n=15) treatment ST more chromium propionate, and ST+PF (n=14) treatment ST more calcium salts of palm oil. The data were evaluated by the Tukey test, at 5% significance, and behavior analyses by Kruskal-Wallis at 10% significance. Energy levels influenced ewes to body weight (BW), body condition score (BCS), and Famacha® score before and after lambing and during lactation, being that the use of calcium salts of palm oil had greater benefits. Although the dam's diet did not influence the offspring's weight gain, body measurements, BCS, and Famacha® at 260 days old. ST+Cr produced heavier offspring. A lower energy diet negatively influenced the degree of Famacha® on ewes and offspring and mother-lamb behavior. This work showed that diets with 10% less metabolizable energy resulted in ewes with lower body weight and body condition scores during pregnancy and lactation, and the progeny had lower body condition weight. The type of feed affects maternal filial behavior and fetal programming.

Horizontal gene transfer provides insights into the deep evolutionary history and biology of Trichinella

Evolution involves temporal changes in the characteristics of a species that are subsequently propagated or rejected through natural selection. In the case of parasites, host switching also plays a prominent role in the evolutionary process. These changes are rooted in genetic variation and gene flow where genes may be deleted, mutated (sequence), duplicated, rearranged and/or translocated and then transmitted through vertical gene transfer. However, the introduction of new genes is not driven only by Mendelian inheritance and mutation but also by the introduction of DNA from outside a lineage in the form of horizontal gene transfer between donor and recipient organisms. Once introduced and integrated into the biology of the recipient, vertical inheritance then perpetuates the newly acquired genetic factor, where further functionality may involve co-option of what has become a pre-existing physiological capacity. Upon sequencing the Trichinella spiralis (Clade I) genome, a cyanate hydratase (cyanase) gene was identified that is common among bacteria, fungi, and plants, but rarely observed among other eukaryotes. The sequence of the Trichinella cyanase gene clusters with those derived from the Kingdom Plantae in contrast to the genes found in some Clade III and IV nematodes that cluster with cyanases of bacterial origin. Phylogenetic analyses suggest that the Trichinella cyanase was acquired during the Devonian period and independently from those of other nematodes. These data may help inform us of the deep evolutionary history and ecological connectivity of early ancestors within the lineage of contemporary Trichinella. Further, in many extant organisms, cyanate detoxification has been largely superseded by energy requirements for metabolism. Thus, deciphering the function of Trichinella cyanase may provide new avenues for treatment and control.

Compartment-specific energy requirements of photosynthetic carbon metabolism in Camelina sativa leaves

Main conclusionThe oxidative pentose phosphate pathway provides cytosolic NADPH yet reduces carbon and energy use efficiency. Repressing this pathway and introducing cytosolic NADPH-dependent malate dehydrogenase may increase crop yields by ≈5%.Detailed knowledge about plant energy metabolism may aid crop improvements. Using published estimates of flux through central carbon metabolism, we phenotype energy metabolism in illuminated Camelina sativa leaves (grown at 22 °C, 500 µmol photons m−2 s−1) and report several findings. First, the oxidative pentose phosphate pathway (OPPP) transfers 3.3% of the NADPH consumed in the Calvin–Benson cycle to the cytosol. NADPH supply proceeds at about 10% of the rate of net carbon assimilation. However, concomitantly respired CO2 accounts for 4.8% of total rubisco activity. Hence, 4.8% of the flux through the Calvin–Benson cycle and photorespiration is spent on supplying cytosolic NADPH, a significant investment. Associated energy requirements exceed the energy output of the OPPP. Thus, autotrophic carbon metabolism is not simply optimised for flux into carbon sinks but sacrifices carbon and energy use efficiency to support cytosolic energy metabolism. To reduce these costs, we suggest bioengineering plants with a repressed cytosolic OPPP, and an inserted cytosolic NADPH-dependent malate dehydrogenase tuned to compensate for the loss in OPPP activity (if required). Second, sucrose cycling is a minor investment in overall leaf energy metabolism but a significant investment in cytosolic energy metabolism. Third, leaf energy balancing strictly requires oxidative phosphorylation, cofactor export from chloroplasts, and peroxisomal NADH import. Fourth, mitochondria are energetically self-sufficient. Fifth, carbon metabolism has an ATP/NADPH demand ratio of 1.52 which is met if ≤ 21.7% of whole electron flux is cyclic. Sixth, electron transport has a photon use efficiency of ≥ 62%. Last, we discuss interactions between the OPPP and the cytosolic oxidation–reduction cycle in supplying leaf cytosolic NADPH.