Digestible Energy Intake Research Articles

Estimating Apparent Nutrient Digestibility of Diets Containing Leucaena leucocephala or Moringa oleifera Leaf Meals for Growing Rabbits by Two Methods.

This study aimed to evaluate the nutrient digestibility of growing rabbits fed diets with different levels of either Leucaena leucocephala (LLM) or Moringa oleifera (MOLM) leaf meals and also to compare total collection and TiO2 marker methods for estimating digestibility. A total of 30 California growing rabbits (1.81±0.19 kg live weight on average) were randomly distributed into five experimental groups of six rabbits each and were housed in individual cages. The groups were control, 30% LLM, 40% LLM, 30% MOLM, and 40% MOLM. All groups received pelleted diets for two weeks; diets also contained 4 g/kg titanium dioxide as dietary marker. Daily feed intake was recorded during the whole experimental period and total feces were collected daily and weighed individually during four days. The results showed that there were no difference (p>0.05) in feed, dry matter (DM), organic matter (OM), crude protein (CP), digestible energy, and crude fiber (CF) intake between the control group and the other experimental groups. The apparent digestibility values of DM, OM, CP, CF, acid detergent fiber, and gross energy were the highest for control group (p = 0.001), meanwhile MOLM diets had generally higher nutrient digestibility coefficients than LLM diets. Increasing the inclusion level of leaf meal in the diet from 30% to 40% improved the digestibility of CF from 45.02% to 51.69% for LLM and from 48.11% to 55.89% for MOLM. Similar results for apparent nutrient digestibility coefficients were obtained when either total collection or indigestible marker method was used. In conclusion, the digestibility of MOLM containing diets were better than LLM diets, furthermore TiO2 as an external marker could be used as a simple, practical and reliable method to estimate nutrients digestibility in rabbit diets.

Quantitative Feed Restriction Rather Than Caloric Restriction Modulates the Immune Response of Growing Rabbits1–3

Background: Short-term feed restriction strategies are used in rabbits to reduce postweaning digestive disorders, but little is known about the involvement of the immune system in these beneficial effects.Objective: In the present study, the consequences of feed and energy restriction on immune response were investigated.Methods: At weaning, 320 male and female rabbits were assigned to 4 groups differing in dietary digestible energy (DE) concentrations and intake levels: a low-energy ad libitum–feed (LE100) group, a low-energy restricted-feed (LE75) group, a high-energy ad libitum–feed (HE100) group, and a high-energy restricted-feed (HE75) group. The high-energy groups consumed 10.13 MJ DE/kg of feed, whereas the low-energy groups consumed 9.08 MJ DE/kg (formulated values). Intake amounts for the restricted groups were 75% those of the ad libitum groups. Rabbits consumed these diets until age 63 d, after which they consumed feed ad libitum for 9 d. Ten rabbits per group and per age were killed at ages 42, 50, 63, and 72 d. Spleens and appendixes were weighed; Peyer’s patch surface area was determined by image analysis; plasma total immunoglobulin (Ig) G and anti-ovalbumin IgG; and fecal and plasma IgA concentrations were determined by ELISA; and ileal expressions of cytokines were measured by quantitative reverse transcriptase-polymerase chain reaction at ages 50 and 63 d.Results: The relative weight and size of the lymphoid organs were not affected by treatments. Concentrations of plasma total IgA (−41% at 63 d and −29% at 72 d), IgG (−22% at 72 d), and anti-ovalbumin IgG (−41% at 63 d) were lower with feed restriction. Fecal IgA concentrations were lower with quantitative restriction (−40%, −52%, and −65% at age 42, 50, and 63 d, respectively) and energy restriction (−56%, −46%, and −73% at ages 50, 63, and 72 d, respectively). Feed-restricted rabbits tended to have greater expressions of interleukin (IL) 1β and IL-2 and lower expressions of tumor necrosis factor α (P < 0.1).Conclusion: These results demonstrated that, in rabbits, restriction and, to a lesser extent, dietary energy concentration modulate gut immunity.

Saturated fat supplementation interacts with dietary forage neutral detergent fiber content during the immediate postpartum period in Holstein cows: Energy balance and metabolism

Forty-eight multiparous cows were used in a randomized complete block design experiment with a 2×2 factorial arrangement of treatments to determine the interaction between a highly saturated free FA supplement (SFFA) and dietary forage NDF (fNDF) content on energy balance and metabolic responses in postpartum cows. Treatment diets were offered from 1 to 29 d postpartum and contained 20 or 26% fNDF and 0 or 2% SFFA (Energy Booster 100; 96.1% FA: 46.2% C18:0, and 37.0% C16:0). Overall, low fNDF versus high fNDF and 2% SFFA versus 0% SFFA increased digestible energy intake (DEI; 67.5 vs. 62.2 Mcal/d and 68.1 vs. 61.6 Mcal/d, respectively). The low fNDF diet with SFFA increased energy balance compared with the other treatments early during the treatment period, but treatment differences diminished over time. Overall, low fNDF versus high fNDF diets and 2% SFFA versus 0% SFFA improved energy balance (−13.0 vs. −16.3 Mcal/d and −12.0 vs. −17.3, respectively) decreasing efficiency of utilization of DEI for milk (milk NEL/DEI; 0.575 vs. 0.634 and 0.565 vs. 0.643). Low fNDF diets increased plasma insulin (308 vs. 137µg/mL) and glucose concentrations (50.5 vs. 45.7mg/dL) and decreased plasma nonesterified FA (606 vs. 917µEq/L) and β-hydroxybutyrate (9.29 vs. 16.5mg/dL) concentrations and liver triglyceride content. Compared with 0% SFFA, 2% SFFA decreased plasma nonesterified FA concentration during the first week postpartum (706 vs. 943µEq/L) and tended to decrease plasma nonesterified FA overall throughout the treatment period, but did not affect liver triglyceride content. During a glucose tolerance test, 2% SFFA increased plasma insulin concentration more in the low fNDF diet (84.5 vs. 44.6µIU/mL) than in the high fNDF diet (40.4 vs. 38.0µIU/mL). After glucose infusion, 2% SFFA increased insulin area under the curve by 64% when included in the low fNDF diet, but only by 5.2% when included in the high fNDF diet. Even though 2% SFFA did not affect weekly plasma insulin concentration, it increased plasma insulin baseline concentration before the tolerance tests. Supplementation of 2% SFFA and low fNDF diets increased DEI and improved energy balance, but decreased apparent efficiency of utilization of DEI for milk production. Fat supplementation affected energy partitioning, increasing energy balance and decreasing body condition score loss, especially in the lower fNDF diet. The decrease in body condition score loss observed was likely related to an increase in plasma insulin concentration. Feeding SFFA in a low fNDF diet during the first 29 d postpartum might have primed the cows to limit fat mobilization at the expense of milk.

Metabolic changes induced by the biliopancreatic diversion in diet-induced obesity in male rats: the contributions of sleeve gastrectomy and duodenal switch.

The mechanisms underlying the body weight and fat loss after the biliopancreatic diversion with duodenal switch (BPD/DS) remain to be fully delineated. The aim of this study was to examine the contributions of the two main components of BPD/DS, namely sleeve gastrectomy (SG) and duodenal switch (DS), on energy balance changes in rats rendered obese with a high-fat (HF) diet. Three different bariatric procedures (BPD/DS, SG, and DS) and three sham surgeries were performed in male Wistar rats. Sham-operated animals fed HF were either fed ad libitum (Sham HF) or pair weighed (Sham HF PW) by food restriction to the BPD/DS rats. A group of sham-operated rats was kept on standard chow and served as normal diet control (Sham Chow). All three bariatric surgeries resulted in a transient reduction in food intake. SG per se induced a delay in body weight gain. BPD/DS and DS led to a noticeable gut malabsorption and a reduction in body weight and fat gains along with significant elevations in plasma levels of glucagon-like peptide-1(7-36) and peptide YY. BPD/DS and DS elevated energy expenditure above that of Sham HF PW during the dark phase. However, they reduced the volume, oxidative metabolism, and expression of thermogenic genes in interscapular brown adipose tissue. Altogether the results of this study suggest that the DS component of the BPD/DS, which led to a reduction in digestible energy intake while sustaining energy expenditure, plays a key role in the improvement in the metabolic profile led by BPD/DS in rats fed a HF diet.

Relationship between locomotor play of dairy calves and their weight gains and energy intakes around weaning

Play behaviour has been proposed as a measure of good welfare in growing animals and locomotor play by calves is often reduced after weaning off milk. Adjusting weaning age according to individual calves’ abilities to eat solid feed maintains energy intake and weight gain during weaning. We investigated the effects of this method of weaning on locomotor play of calves and the relationship between locomotor play and energy intake and weight gains. We measured the running behaviour of 56 Holstein heifer calves before and after weaning. Calves were housed in groups of eight, fed milk, grain starter and hay from automated feeders. Weaning began when their voluntary intake of grain starter reached either 200 or 400 g/day, and weaning was completed when starter intake reached either 800 or 1600 g/day. Before weaning, older calves ran less than young ones; and the duration of running correlated with weight gains and digestible energy intake. Immediately after weaning, digestible energy intake and locomotor play decreased but no correlation was observed between these variables. One week after weaning, the duration of running was correlated with both energy intake and weight gain. Digestible energy intake increased but locomotor play continued to decrease. The amount of running a calf does after weaning partly reflects energy intake and weight gain, supporting suggestions that locomotor play is good indicator of welfare and fitness of growing animals. However, the decline in locomotor play following weaning is not solely due to decreased energy intake.

Associations between milk intake and activity in the first days of a calf's life and later growth and health

We examined whether calves’ milk intake and activity in the days after birth predict later growth and the risk of illness. Female Holstein calves (n=130) were housed in individual pens where they were allowed ad libitum milk from birth to 5 days of age. Daily milk intakes were recorded and accelerometers attached to the calves measured time spent standing and lying down. After 5 days, calves were housed in group pens with four to nine calves per group and allowed 12L/day of milk and ad libitum hay and starter from automated feeders. Calves were weighed at birth (birth weight=BW) and at 28 days of age and health status was determined daily. Digestible energy (DE) intakes were calculated from feed intakes. During days 2–4, there were large differences among calves in the amount of milk consumed, which ranged from 7.3% BW/day (2.4L/day) to 30.5% BW/day (12L/day) with a median of 16.3% BW/day (6.7L/day). Twenty-one calves were treated for illness from days 6 to 28. These calves had lower milk intakes on days 2, 3 and 4 than calves that remained healthy (P<0.05). For the calves that did not become ill, milk intake on day 4 was correlated (r=0.29; P<0.01) with ADG from days 0 to 28 and correlated (r=0.33; P=0.03) with the residual body weight on day 28 (when birth weight and digestible energy intakes from days 5 to 28 were accounted for using multiple regression). Time spent standing from days 2 to 4 varied between calves but was not correlated with BW, milk intake during days 2–4, or weight gains to day 28 (P>0.10). Very young calves can drink large quantities of milk, and the calves that drink the largest amounts in the first days of life have greater long-term growth rates and are less likely to become ill. Milk intake may be a better sign of early calf vigour than activity levels.

Effect of inclusion of distillers dried grains and solubles from barley, wheat and corn in isonutritive diets on the performance and caecal environment of growing rabbits

To evaluate how the dietary inclusion of distillers dried grains and solubles (DDGS) could affect the performance and caecal environment of growing rabbits, four experimental diets were formulated from a control diet without DDGS (C), including 20% of barley DDGS (Db20), 20% of wheat DDGS (Dw20) and 20 (Dc20) or 40% (Dc40) of corn DDGS. Animals had free access to medicated versions of the diets until 49 d, and then to unmedicated diets until 59 d of age. The performance trial was done using 475 three-way crossbred weaned rabbits of 28 d of age, individually housed in 5 batches. Caecal fermentation traits were determined in 20 animals per diet and at 42 d and at 59 d of age. No significant effect of the growing diet on mortality, morbidity or sanitary risk index was observed. In the whole period and respect to the control group, animals fed with Db20 showed higher dry matter (DM) and digestible energy (DE) intake (+6 and +12%, respectively; P&lt;0.05), but similar daily weight gain (DWG) and increased feed conversion ratio (+9%; P&lt;0.05). Similarly, and regardless of its inclusion level, the increase in DE intake of animals fed with corn DDGS (+9, respectively; P&lt;0.05) did not increase DWG. In contrast, higher DM and DE intake of animals fed with Dw20 (+8; P&lt;0.05) resulted in a higher DWG (+2.8 g/d; P&lt;0.05) than those fed with C. Although inclusion of DDGS at 20% did not affected main caecal parameters controlled at 42 d, caecum of animals fed with the diet Dc40 was characterized by greater N-NH3 and valeric acid and lower total volatile fatty acids and acetic acid concentrations than the average of the other groups (on av. +5.2±1.7 mmol/L, +0.29±0.07 mol/100 mol, –17.17±4.41 μmol/L and –2.60±0.99 mol/100 mol, respectively; P&lt;0.05). At 59 d of age, higher caecal DM, and propionic and valeric acid concentration and lower values of total volatile fatty acids and acetic/propionic rate were observed for DDGS inclusion at 20% compared to the control (+1.6±0.5%, +0.95±0.44 mol/100 mol, –9.3±4.3 μmol/L and –2.7±1.2, respectively; P&lt;0.05). Linear inclusion of corn DDGS increased caecal DM, propionic acid proportion and total volatile fatty acids concentration and reduced acetate/propionic rate (+4.0±0.4%, +2.27±0.41 mol/100 mol, –21.27±3.9 μmol/L and –5.6±1.1, respectively for Dc40 compared to C; P&lt;0.05). Rabbits given Dc40were also characterized for a greater caecum N-NH3 content than the other groups (on av. –8.7±1.7 mmol/L; P&lt;0.05) at 59 d of age. The results of the present work reveal that inclusion of DDGS up to 20%, independently of the grain source (barley, wheat or corn), could be an interesting alternative in balanced diets for growing rabbits.

Seasonal variation in body mass and energy budget in Chinese bulbuls (pycnonotus sinensis)

BackgroundSeasonal adjustments in body mass and energy budget are important for the survival of small birds in temperate zones. Seasonal changes in body mass, body temperature, gross energy intake (GEI), digestible energy intake (DEI), body fat content, as well as length and mass of the digestive tract, were measured in Chinese Bulbuls (Pycnonotus sinensis) caught in the wild at Wenzhou, China.MethodsBody mass was determined with a Sartorius balance. The caloric contents of the dried food and feces were then determined using a oxygen bomb calorimeter. Total fat was extracted from the dried carcasses by ether extraction in a Soxhlet apparatus. The digestive tract of each bird was measured and weighed, and was then dried to a constant mass.ResultsBody mass showed a significant seasonal variation and was higher in spring and winter than in summer and autumn. Body fat was higher in winter than in other seasons. GEI and DEI were significantly higher in winter. The length and mass of the digestive tract were greatest in winter and the magnitude of both these parameters was positively correlated with body mass, GEI and DEI. Small passerines typically have higher daily energy expenditure in winter, necessitating increased food consumption.ConclusionsThis general observation is consistent with the observed winter increase in gut volume and body mass in Chinese Bulbuls. These results suggest that Chinese Bulbuls adjust to winter conditions by increasing their body mass, body fat, GEI, DEI and digestive tract size.

Increasing the digestible energy intake under a restriction strategy improves the feed conversion ratio of the growing rabbit without negatively impacting the health status

Post-weaning feed restriction strategies have proved to reduce mortality and morbidity, but result in decreased growth and lower slaughter yield. To compensate for those deleterious effects without negatively impacting the health parameters, we have studied the possibility of increasing the dietary energy level of the feed. Four treatments differing in dietary digestible energy content (“low” energy content, LE=9.08MJ/kg vs “high” energy content, HE=10.13MJ/kg), and feeding level (ad libitum or restricted at 75%) were formed in a 2×2 factorial arrangement. Animals were fed the experimental diets from weaning (32–36 days of age) to slaughter age (70–74 days of age), and feed restriction was applied from weaning to 63–64 days of age. Digestive efficiency was assessed during feed restriction and after one week of ad libitum feeding in 48 animals housed in individual cages. A performance experiment was carried out in four different sites involving a total of 1888 animals housed in collective cages, including carcass and meat quality measurements in 400 animals. Feed restriction and the HE diet improved the faecal digestibility of organic matter (+0.04 and +0.06 respectively; P<0.001), crude protein (+0.05 and +0.05; P<0.001) and NDF (+0.06 and +0.07; P<0.001). When returning to an ad libitum feeding, no effect of the previous feeding level was observed while the effect of the diet was similar to that observed during feed restriction. Restricted feeding reduced the growth by 7% during the whole fattening period (P<0.001), and the slaughter yield by 1.1% (P<0.001). It improved the feed conversion ratio by 9% (P<0.001), while the HE diet improved it by 11% (P<0.001). A 25% reduction in feed intake reduced the health risk index (HRi) in both good and poor health conditions (2.7% vs 7.1%, P<0.01 and 36.2% vs 44.3%, P<0.05 respectively). The use of a high energy diet increased the morbidity (4.6% vs 2.5%, P<0.05) in good health conditions and had the opposite effect in poor health conditions (17.5% vs 22.4%). Calculations of the gross margin confirmed the economic advantage of feed restriction in growing rabbits (+0.06€/kg), while the use of a restricted fed high energy diet was profitable only when mortality and morbidity was low.

Effect of replacing barley by increasing levels of olive cake in the diet of finishing pigs: Growth performances, digestibility, carcass, meat and fat quality

The effect of the solid by-product from the olive oil industry (olive cake) on digestibility, growth performances, and carcass, meat and fat characteristics was studied in sixty Duroc×(Landrace×Large White) gilts, of 69.5±5.02kg of body weight and 126±3 days of age. Increasing levels of olive cake (0, 50, 100 and 150g/kg of feed) were included in the diet by replacing the same proportion of barley. Five pens with three pigs per treatment were assayed, considering the pen as replicate. The trial lasted 35 days, and animals were slaughtered with 96.7±7.45kg of body weight. Daily feed intake increased (P=0.04) and daily gain tended to increase (P=0.06), both quadratically, with olive cake inclusion reaching the maximum values at 100g olive cake/kg. The daily apparent digestible energy intake also increased quadratically (P=0.04) on increasing dietary olive cake content. The feed conversion ratio was not affected by diet. Also, the apparent organic matter digestibility tended to decrease quadratically (P=0.06) and energy digestibility decreased linearly (P<0.04) as the level of dietary olive cake level increased. The experimental treatment had scarce effects on carcass and meat characteristics; however, the inclusion of olive cake increased quadratically (P=0.04) carcass weight and decreased linearly (P=0.02) fat depth measured at Gluteus medius muscle. The experimental treatment did not modify the total polyunsaturated fatty acids proportion of subcutaneous fat but increasing levels of olive cake promoted a linear reduction (P=0.01) of total saturated fatty acid proportion and a linear increase (P=0.02) of total monounsaturated fatty acid percentage, especially that of C18:1 (P=0.01). We can conclude that olive cake might be included up to 100g/kg in finishing pig diets improving some aspects of growth performances and carcass quality and also providing a healthier fatty acid profile in fat tissues.

Malabsorption plays a major role in the effects of the biliopancreatic diversion with duodenal switch on energy metabolism in rats

BackgroundThe mechanisms underlying the metabolic benefits of the biliopancreatic diversion with duodenal switch (BPD/DS) have not been clarified. The objective of this study was to investigate the metabolic roles of sleeve gastrectomy (SG) and duodenal switch (DS) as main surgical components of BPD/DS. MethodsBPD/DS, SG, and DS surgeries were performed on chow-fed nonobese Wistar rats. Weight and energy intake were recorded during 8 postsurgical weeks. Glucagon-like peptide 1 (GLP-1), peptide tyrosine-tyrosine (PYY), glucose-dependent insulinotropic peptide, and ghrelin were measured pre- and postprandially at weeks 3 and 8, after surgery. Body composition, muscle, liver, and adipose tissue weights were measured. Gut morphometry and the presence and distribution of GLP-1 and PYY (L-cells) in the gut were determined using histochemical techniques. ResultsCompared with sham, BPD/DS and DS led to significant reductions in weight gain, percentage of fat, and adipose tissue weight. These effects were accompanied by a reduction in digestible energy intake associated with fecal energy loss due to DS. BPD/DS and DS produced intestinal hypertrophy, as well as higher plasma GLP-1 and PYY in both fasted and refed states. It is noteworthy that none of those alterations were observed after SG, which nonetheless led to transient postoperative reduction in gross energy intake and weight. Similar to BPD/DS, SG alone produced a reduced meal size and an enhanced postprandial depression of plasma ghrelin. ConclusionBPD/DS results in metabolic benefits, which appear largely caused by food malabsorption due to DS. The elevation of anorectic GLP-1 and PYY are additional consequences of DS, which, together with malabsorption, could promote the metabolic benefits of BPD/DS.

Dietary composition and nutritional outcomes in two marsupials,Sminthopsis macrouraandS. crassicaudata

Little is known about the specific dietary preferences of many marsupials. We undertook digestion studies in 2 species of insectivorous marsupials, the stripe-faced dunnart (Sminthopsis macroura) and the fat-tailed dunnart (Sminthopsis crassicaudata), because these are 2 species that are regularly kept in captivity, although nothing is known about their nutritional requirements in the wild. Morphology and dimensions of the gastrointestinal tract of both species also were assessed. The test diets included 2 laboratory-type diets: cat formulation and Wombaroo small carnivore mix; and natural insect diets: adult crickets (Acheta domesticus), Australian wood cockroaches (Panesthia australis), and mealworm larvae (Tenebrio molitor). Composition of the test diets on a dry-matter basis varied considerably; ranges included gross energy 16–27 kJ/g, crude protein 38–64%, lipids 9–51%, calcium (Ca) 340–17,800 mg/kg, and phosphorus 6,600–16,000 mg/kg. Depending on the diet, the digestible energy intake ranged from 359 to 816 kJ kg−0.75 day−1 for stripe-faced dunnarts and digestible energy intake ranged from 542 to 990 kJ kg−0.75 day−1 for fat-tailed dunnarts. No single diet was appropriate if fed alone, notably the insect diets, which required Ca supplementation. The morphology of the gastrointestinal tracts of both species was simple and consisted of a unilocular stomach and relatively uniform intestine. The morphometries of the gastrointestinal tracts of fat-tailed dunnarts were proportionally larger than for stripe-faced dunnarts. Fat-tailed dunnarts also needed to consume more nutrients per unit of body mass for maintenance in captivity compared to stripe-faced dunnarts.

Niveles de proteína para cerdos en fase starter: un meta-análisis

The objective of this study was to evaluate the effect of different fat sources in finishing diets on performance of feedlot steers. Twenty steers, with average age of 20 months and initial live weight of 260 ± 41.3 kg, were feedlot fed during 126 days. The animals received corn silage as roughage and the tested concentrates were: basic concentrate (BC); basic concentrate + whole rice bran and rice oil (WRB); basic concentrate + 3 % of fatty acids calcium salts (M3) and basic concentrate + 6 % of fatty acids calcium salts (M6). Each treatment had animals with the following genetic group: 1 pure Charolais (CH), 1 pure Nellore (NE), 2 11/16 CH 5/16 NE, 1 21/32 NE 11/32 CH. No significant differences were observed for crude protein, digestible energy, neutral and acid detergent fibers intakes. The animals that consumed 6 % of fatty acid calcium salts presented higher ether extract intake (0.77 kg/day), while those that consume 3 % or whole rice bran and oil showed intermediate value (0.51 kg/day) and the ones that consumed basic concentrated presented lower value (0.25 kg/day). Similar averages were observed for average daily weight gain (1.142, 1.199, 1.365 and 1.391 kg/day, for BC, WRB, M3 and M6, respectively) and final weight (421 kg).

Desempenho de novilhos alimentados com rações contendo silagem de capim papuã (Urochloa plantaginea) x silagem de sorgo (Sorghum bicolor (L.) Moench)

This study aimed to evaluate the parameters related to feedlot beef steers fed with Alexander grass silage or sorghum silage as roughage source. Twelve animals with initial average of weight and age of 245 kg and 20 months, respectively, belonging to Nellore (N), Charolais (C), 21/32 N 11/32 C, 21/32 C 11/32 N; 43/64 N 21/64 C and 43/64 C 21/64 N genetic groups were used. The ration was composed by a roughage:concentrate relation of 50:50 (dry matter basis), offered at ease. The dry matter, crude protein, ether extract, neutral detergent fiber and acid detergent fiber daily intake didn’t differ between roughage sources, being the medium values of 10.18; 1.28; 0.20; 4.96 and 2.51 kg/day, respectively. However, the ether extract intake by metabolic size and by corporal weight percentage were higher for the one that consumed sorghum silage, obtaining values of 2.74 and 2.36 g/metabolic size and 0.06 and 0.05 kg/100 kg of live weight. The same behavior was observed for digestible energy intake, presenting values of 364.87 and 302.83 g/metabolic size and 8.10 and 7.02 kg/100 kg of live weight. The daily average gain, final corporal score and feed conversion weren’t influenced by roughage type, being the values of 1.31 kg; 4.05 points and 7.78 kg of DM/kg of weight gain, respectively. The Alexander grass silage is a feasible alternative as its substitution in relation to sorghum silage.

Effects of supplemental chromium propionate and rumen-protected amino acids on productivity, diet digestibility, and energy balance of peak-lactation dairy cattle

Chromium (Cr) feeding in early lactation increased milk production in some studies, but responses to dietary Cr during peak lactation have not been evaluated. Furthermore, interactions of essential amino acids (AA) and Cr have not been explored. Our objective was to evaluate responses to CrPr (KemTRACE chromium propionate 0.04%, Kemin Industries Inc., Des Moines, IA) and rumen-protected Lys (LysiPEARL, Kemin Industries Inc.) and Met (MetiPEARL, Kemin Industries Inc.) and their interaction in peak-lactation cows. Forty-eight individually fed Holstein cows (21 primiparous, 27 multiparous, 38±15d in milk) were stratified by calving date in 12 blocks and randomly assigned to 1 of 4 treatments within block. Treatments were control, CrPr (8mg/d of Cr), RPLM (10g/d of Lys and 5g/d of Met, intestinally available), or CrPr plus RPLM. Treatments were premixed with ground corn and top-dressed at 200g/d for 35d. Diets consisted of corn silage, alfalfa hay, and concentrates, providing approximately 17% crude protein, 31% neutral detergent fiber, and 40% nonfiber carbohydrates. Dry matter intake (DMI) significantly increased with the inclusion of CrPr (22.2 vs. 20.8±0.67kg/d), and energy-corrected milk (ECM) yield tended to increase. In addition, CrPr increased milk protein yield and tended to increase DMI in primiparous cows but not in multiparous cows. A CrPr×week interaction was detected for milk lactose content, which was increased by CrPr during wk 1 only (4.99 vs. 4.88±0.036%). As a proportion of plasma AA, lysine increased and methionine tended to increase in response to RPLM, but the inclusion of RPLM decreased N efficiency (milk protein N:N intake). Digestible energy intake, gross energy digestibility, and energy balance were not affected by treatments. We observed no treatment effects on feed efficiency or changes in body weight or body condition score. In summary, feeding CrPr increased DMI and tended to increase ECM in cows fed for 5wk near peak lactation, with primiparous cows showing greater responses in DMI and milk protein yield than multiparous cows.

DIET COMPOSITION, FOOD INTAKE, APPARENT DIGESTIBILITY, AND BODY CONDITION SCORE OF THE CAPTIVE ASIAN ELEPHANT (ELEPHAS MAXIMUS): A PILOT STUDY IN TWO COLLECTIONS IN THAILAND

Limited data are available regarding the nutrition and feeding of captive Asian elephants in range countries. In this study, feeding regimens of two collections in northern Thailand and their actual diets shaped by availability of forage and mahout preferences were assessed for nutritional quality. The composition of dietary intake, fecal output, and the dietary regimen were individually recorded for 5 days in 10 elephants. The proportion of forage in the diet represented 41 to 62% of the dry matter intake (DMI) in one collection whereas in the other collections it varied between 68 and 72%. Between 8.5 and 24% of the diet consisted of commercial pellets, and hulled rice represented up to 25% of the DMI in one collection. Sugar cane, corn cobs, and fruits such as bananas were eaten in smaller amounts. Body condition scores and weights were measured, which revealed that nine animals were in good condition. Representative samples of each food as well as fecal samples were analyzed for dry matter, crude protein, fat, crude fiber, gross energy, ash, calcium, and phosphorus. Diet adequacy was assessed by calculating the digestible nutrients in the rations and by comparing them to the recommendations from literature. The digestible energy (DE) intake varied between 0.6 and 1.4 megajoules (MJ) per kg(0.75) per day; therefore, higher than the estimated recommendations of 0.65 MJ per kg(0.75) per day for nine of the elephants. In all elephants the crude protein intake was less than the maintenance recommendations and ranged between 6.01 and 7.56% of the DMI. Calcium intake was low in one collection and there was an inverse calcium: phosphorus ratio, which was inadequate. The present study adds to the knowledge of captive elephant diets in Asia and is a starting point for further research, which is necessary to design optimum diet plans for captive Asian elephants in Thailand.

Field monitoring of feed digestibility in Atlantic salmon farming using crude fiber as an inert marker

Abstract Modern feeds for industrial salmon farming are presently formulated to fulfill specific digestible protein (DP, grams per kg feed, hereafter called units) and digestible energy (DE, Mega Joule (MJ) per kg feed) specifications. In the present study, 299 feed samples and accompanying fecal samples were obtained from 43 different farming sites for Atlantic salmon along the coast of Norway between October 2010 and February 2013. Apparent digestibility coefficients for protein and fat were calculated from protein and fat in feed and fecal matter, using analyzed crude fiber contents as a digestibility marker. Overall mean apparent protein and fat digestibilities were 87.1% (± 4.9; overall mean ± S.D.) and 92.5% (± 3.7), respectively. Linear mixed models with rearing site as random effect were applied to evaluate factors that influenced the apparent digestibility of protein and fat, feeding intensity and energy intake. Apparent digestibility of fat tended to increase over the study period, and both feed type and feed manufacturing company, and water temperature influenced the digestibility significantly. Digestible energy content (DE, MJ/kg) was significantly negatively associated with feeding intensity, but not with total digestible energy intake. Variation at site level was significant in all analyses, and was moderate for the digestibility analyses and high regarding feeding intensity and energy intake. Digestibility assessments were used to assess accuracy, precision and agreement between optimized and realized digestible protein (DP, %) and DE level of feeds, using the mean difference between the two sets of observations and a fixed contribution of dietary energy from starch. Overall mean difference between realized and optimized DP and DE was − 0.28 units and − 0.56 MJ/kg, respectively, and there were significant differences between feed manufacturing companies. The results indicated that field digestibility assessments can be used to validate nutritional and economical value of feeds in commercial salmon farming.

Effects of temperature acclimation on body mass and energy budget in the Chinese bulbul Pycnonotus sinensis.

Chinese bulbuls (Pycnonotus sinensis) are small passerine birds that inhabit areas of central, southern and eastern China. Previous observations suggest that free-living individuals of this species may change their food intake in response to seasonal changes in ambient temperature. In the present study, we randomly assigned Chinese bulbuls to either a 30℃ or 10℃ group, and measured their body mass (BM), body temperature, gross energy intake (GEI), digestible energy intake (DEI), and the length and mass of their digestive tracts over 28 days of acclimation at these temperatures. As predicted, birds in the 30℃ group had lower body mass, GEI and DEI relative to those in the 10℃ group. The length and mass of the digestive tract was also lower in the 30℃ group and trends in these parameters were positively correlated with BM, GEI and DEI. These results suggest that Chinese bulbuls reduced their absolute energy demands at relatively high temperatures by decreasing their body mass, GEI and DEI, and digestive tract size.

Effects of alginate and resistant starch on feeding patterns, behaviour and performance in ad libitum-fed growing pigs

This study assessed the long-term effects of feeding diets containing either a gelling fibre (alginate (ALG)), or a fermentable fibre (resistant starch (RS)), or both, on feeding patterns, behaviour and growth performance of growing pigs fed ad libitum for 12 weeks. The experiment was set up as a 2×2 factorial arrangement: inclusion of ALG (yes or no) and inclusion of RS (yes or no) in the control diet, resulting in four dietary treatments, that is, ALG−RS− (control), ALG+RS−, ALG−RS+, and ALG+RS+. Both ALG and RS were exchanged for pregelatinized potato starch. A total of 240 pigs in 40 pens were used. From all visits to an electronic feeding station, feed intake and detailed feeding patterns were calculated. Apparent total tract digestibility of energy, dry matter (DM), and CP was determined in week 6. Pigs’ postures and behaviours were scored from live observations in weeks 7 and 12. Dietary treatments did not affect final BW and average daily gain (ADG). ALG reduced energy and DM digestibility (P<0.01). Moreover, ALG increased average daily DM intake, and reduced backfat thickness and carcass gain : digestible energy (DE) intake (P<0.05). RS increased feed intake per meal, meal duration (P<0.05) and inter-meal intervals (P=0.05), and reduced the number of meals per day (P<0.01), but did not affect daily DM intake. Moreover, RS reduced energy, DM and CP digestibility (P<0.01). Average daily DE intake was reduced (P<0.05), and gain : DE intake tended to be increased (P=0.07), whereas carcass gain : DE intake was not affected by RS. In week 12, ALG+RS− increased standing and walking, aggressive, feeder-directed, and drinking behaviours compared with ALG+RS+ (ALG×RS interaction, P<0.05), with ALG−RS− and ALG−RS+ in between. No other ALG×RS interactions were found. In conclusion, pigs fed ALG compensated for the reduced dietary DE content by increasing their feed intake, achieving similar DE intake and ADG as control pigs. Backfat thickness and carcass efficiency were reduced in pigs fed ALG, which also showed increased physical activity. Pigs fed RS changed feeding patterns, but did not increase their feed intake. Despite a lower DE intake, pigs fed RS achieved similar ADG as control pigs by increasing efficiency in DE use. This indicates that the energy utilization of RS in pigs with ad libitum access to feed is close to that of enzymatically digestible starch.

Effects of Potassium Fertilizer on Water-Soluble Carbohydrate Content of Timothy (&amp;lt;i&amp;gt;Phleum pratense&amp;lt;/i&amp;gt; L.), Silage Fermentation, Nutritive Values, and Nutrient Intake

The objective of this study was to examine the effects of potassium fertilizer (standard (S) and high (H) levels) on water-soluble carbohydrate (WSC) content of timothy (Phleum pratense L.), silage fermentation, nutritive values, and nutrient intake. The silage treatments were as follows: S level without inoculant (SC), S level plus inoculant (SI), H level without inoculant (HC), and H level plus inoculant (HI). The K content was increased by 14.5% in timothy grown with the H level compared with the S level. The WSC contents of the S and H treatments were 75.9 and 66.1 g·kg-1 dry matter (DM), respectively. The silage fermentation quality was low with both SC and HC treatments. The addition of inoculant significantly improved the fermentation quality in SI and HI treatments. The addition increased the DM and organic matter digestibilities of silage. The total digestible nutrient (TDN) content of silage was highest with the HI treatment. The DM, TDN, and digestible energy intakes with the SI and HI treatments were improved compared with the SC and HC treatments, respectively. This study demonstrated negligible effects of K fertilizer levels and significant effects of the lactic acid bacteria inoculant on the fermentation quality, nutritive values, and feed intake of silage.