Net energy of soybean oil and choice white grease in diets fed to growing and finishing pigs

Correlation between reproductive performance and sow body weight change during gestation

This study investigated the correlation between piglet performance and sow body weight change (BWC) during two gestational periods: 35-70, 70-105, and 35-105 days. A cohort of 70 sows was evaluated for BWC, backfat thickness change (BFC), caliper score change (CALC), feed intake, and weaning-to-estrus interval (WEI). The collected data were then analyzed according to the two specified periods. Our findings highlighted that piglet birth weight, weaning weight, and average daily weight gain (ADG) correlated with sow body characteristics, including BFC and CALC. The strongest correlation was observed with BWC. Piglet mortality was intimately associated with BFC. Piglet birth weight, weaning weight, and ADG showed a positive correlation with sow BWC, particularly during the 35-70 day period. Furthermore, sows displaying a higher BWC during the 70-105 day period, and also exhibiting a higher BW gain from 35-70 days, registered greater piglet weight gains and higher weaning weights. These trends became more apparent as the sow's BWC increased during the 70-105 day period. Piglet mortality increased when the sow exhibited a lower BWC during both the 35-70 and 70-105 day periods. No significant observations were found concerning the number of stillborn piglets, live-born piglets, or weaned piglets, and no interaction effects were detected between these periods. In conclusion, our findings underscore the significance of sow BWC during the early stages of gestation (d 35-70) for enhancing piglet performance from birth to weaning.

Effects of different starch structures on energy metabolism in pigs

BACKGROUND

Starch is a major component of carbohydrates and a major energy source for monogastric animals. Starch is composed of amylose and amylopectin and has different physiological functions due to its different structure. It has been shown that the energy supply efficiency of amylose is lower than that of amylopectin. However, there are few studies on the effect of starch structure on the available energy of pigs. The purpose of this study was to measure the effect of different structures of starch in the diet on the net energy (NE) of pigs using a comparative slaughter method and to establish a prediction equation to estimate the NE of starch with different structures. Fifty-six barrows (initial BW 10.18 ± 0.11 kg) were used, and they were housed and fed individually. Pigs were divided into 7 treatments, with 8 replicates for each treatment and 1 pig for each replicate. One of the treatments was randomly selected as the initial slaughter group (ISG). Pigs in the remaining treatments were assigned to 6 diets, fed with basic diet and semi-pure diets with amylose/amylopectin ratio (AR) of 3.09, 1.47, 0.25, 0.15 and 0.12, respectively. The experiment lasted for 28 d.

RESULTS

Results showed that compared with the high amylose (AM) groups (AR 3.09 and 1.47), the high amylopectin (AP) group (AR 0.15) significantly increased the final BW, average daily weight gain and average daily feed intake of pigs (P < 0.05), but the F:G of the AM group was lower (P < 0.01). In addition, AR 0.15 and 0.12 groups have higher (P < 0.01) nutrient digestibility of dry matter, crude protein, gross energy and crude ash. Meanwhile, compared with other groups, AR 0.15 group has a higher (P < 0.05) NE intake and energy retention (RE). The regressive equation for predicting with starch structures was established as RE = 1,235.243 - 48.298AM/AP (R2 = 0.657, P = 0.05).

CONCLUSIONS

In conclusion, NE intake and RE of pigs augmented with the increase of dietary amylopectin content, indicating that diets high in amylopectin were more conducive to promoting the growth of pigs in the late conservation period.

Comparison of the meat quality and fatty acid profile of muscles in finishing Xiangcun Black pigs fed varied dietary energy levels

To study the effects of dietary energy level on the meat quality of different muscles in finishing pigs, 400 Xiangcun Black pigs (BW = 79.55 ± 4.77 kg) were randomly assigned to 5 treatments with varied calculated digestive energy (DE) at 3,050, 3,100, 3,150, 3,200 and 3,250 kcal/kg, respectively. Each treatment had 8 replicates with 10 pigs per replicate. Meat quality, amino acid and fatty acid composition were tested in this study. No differences in average daily gain, average daily feed intake or feed-to-gain ratio (P > 0.05) were observed among dietary treatments. Glycogen concentrations of longissimus dorsi (LD) muscle in DE3150 was higher than those in other groups (P < 0.05). The crude fat concentration of biceps femoris (BF) muscle in DE3250 tended to be higher than that in DE3150 and DE3100 groups (P < 0.05). Pigs in DE3250 and DE3200 had higher fiber density and smaller cross-sectional area of BF muscle than those in DE3150 (P < 0.05). Pigs in DE3150 had the highest Cu concentration in LD muscle compared with those in DE3200, DE3250 (P < 0.05). The C16:1 proportion of LD muscle was lower (P < 0.01) and C20:1 was higher (P < 0.05) in DE3050 than that in the other dietary treatments. The C18:3n6 and C20:3n6 proportions of BF muscle in DE3150 were higher than those in DE 3050, DE3200 and DE3250 (P < 0.05). For LD muscle, mRNA expressions of type I and IIa MyHC in group DE3150 were higher than other treatments (P < 0.01). The LD muscle in DE3150 expressed higher PPARd than in other groups (P < 0.01). Pigs in DE3100 expressed higher FOX1 than in DE3200 and DE3250 (P < 0.05). Sterol-regulatory element binding proteins (SREBPa) mRNA expression decreased linearly when dietary energy level increased in BF muscle (P < 0.01). In conclusion, a 200 kcal/kg decrease in digestible energy for 4 consecutive weeks did not affect growth performance of Xiangcun Black pigs. Furthermore, LD and BF muscle respond differently to dietary energy level, and meat quality was improved by the medium energy level during the finishing phase.

Methodologies for energy evaluation of pig and poultry feeds: A review

The cost of feed represents an important part of the total cost in swine and poultry production (>60%) with energy accounting for at least 70% of feed cost. The energy value of ingredients or compound feeds can be estimated as digestible (DE), metabolisable (ME) and net energy (NE) in pigs and ME and NE in poultry. The current paper reviews the different methods for evaluating DE, ME and NE of feeds for monogastric animals and their difficulties and limits, with a focus on NE. In pigs and poultry, energy digestibility depends on the chemical characteristics of the feed, but also on technology (pelleting, for instance) and animal factors such as their health and body weight. The ME value includes the energy losses in urine that are directly dependent on the proportion of dietary N excreted in urine resulting in the concept of ME adjusted for a zero N balance (MEn) in poultry. For poultry, the concept of true ME (TME, TMEn), which excludes the endogenous fecal and urinary energy losses from the excreta energy, was also developed. The measurement of dietary NE is more complex, and NE values of a given feed depend on the animal and environmental factors and also measurement and calculation methods. The combination of NE values of diets obtained under standardised conditions allows calculating NE prediction equations that are applicable to both ingredients and compound feeds. The abundance of energy concepts, especially for poultry, and the numerous feed and animal factors of variation related to energy digestibility or ME utilisation for NE suggest that attention must be paid to the experimental conditions for evaluating DE, ME or NE content. This also suggests the necessity of standardisations, one of them being, as implemented in pigs, an adjustment of ME values in poultry for an N retention representative of modern production conditions (MEs). In conclusion, this review illustrates that, in addition to numerous technical difficulties for evaluating energy in pigs and poultry, the absolute energy values depend on feed and animal factors, the environment, and the methods and concepts. Finally, as implemented in pigs, the use of NE values should be the objective of a more reliable energy system for poultry feeds.

Measures Matter-Determining the True Nutri-Physiological Value of Feed Ingredients for Swine

Many types of feed ingredients are used to provide energy and nutrients to meet the nutritional requirements of swine. However, the analytical methods and measures used to determine the true nutritional and physiological ("nutri-physiological") value of feed ingredients affect the accuracy of predicting and achieving desired animal responses. Some chemical characteristics of feed ingredients are detrimental to pig health and performance, while functional components in other ingredients provide beneficial health effects beyond their nutritional value when included in complete swine diets. Traditional analytical procedures and measures are useful for determining energy and nutrient digestibility of feed ingredients, but do not adequately assess their true physiological or biological value. Prediction equations, along with ex vivo and in vitro methods, provide some benefits for assessing the nutri-physiological value of feed ingredients compared with in vivo determinations, but they also have some limitations. Determining the digestion kinetics of the different chemical components of feed ingredients, understanding how circadian rhythms affect feeding behavior and the gastrointestinal microbiome of pigs, and accounting for the functional properties of many feed ingredients in diet formulation are the emerging innovations that will facilitate improvements in precision swine nutrition and environmental sustainability in global pork-production systems.

The Implications of Nutritional Strategies that Modify Dietary Energy and Lysine for Growth Performance in Two Different Swine Production Systems

Simple Summary

Reducing dietary energy is a common practice for dealing with the price volatility of high energy sources, such as fats and oils, which are the costliest constraints in swine feed formulation. Theoretically, pigs can overcome a reduced energy density by increasing feed intake; however, as other factors like fibrous ingredients limit feed intake physically rather than metabolically, reducing dietary energy could also entail a lower energy intake. The expected effect on feed intake also influences lysine intake, and therefore, when NE trials are conducted, it is necessary to ensure that lysine is not a limiting factor for growth. In the present work, the effects of two dietary energy and lysine levels were tested in a factorial arrangement. The same approach of different levels was analyzed in two different swine production systems targeting different carcass traits. The experiment showed that in one system, reducing energy density did not impair growth; however, in the other system, it limited growth slightly by limiting fat deposition. Although reducing energy density increased feed intake, pigs could not reach a similar energy intake, and consequently were more efficient using energy for growth.

Abstract

This work aimed to determine the impacts of lowering dietary net energy (NE) density in two swine production systems that produce pigs with different carcass traits. To ensure that dietary lysine was not limiting growth, two studies were conducted in a 2 × 2 factorial arrangement with NE and standardized ileal digestible lysine (SID Lys) as experimental factors. A total of 1248 pigs were used in each study, Pietrain (Exp. 1, males non-castrated) or Duroc (Exp. 2, males castrated) sired. Reducing NE resulted in a greater feed intake; however, this was not sufficient to reach the same NE intake. While in Exp. 1 a 3.2% lower NE intake did not impair average daily gain (ADG; p = 0.220), in Exp. 2 a 4.7% lower NE intake reduced ADG by 1.4% (p = 0.027). Furthermore, this effect on ADG entailed a reduced ham fat thickness (p = 0.004) of the first marketed pigs. Increasing SID Lys only had a positive effect in Exp. 1, but no significant interaction between NE and SID Lys was reported (p ≥ 0.100). Therefore, dietary NE can be reduced without impairing growth performance when pigs can increase feed intake sufficiently, and thus, limit energy deficiencies.

Impact of increasing the levels of insoluble fiber and on the method of diet formulation measures of energy and nutrient digestibility in growing pigs

The objective of this study was to determine the differences in response to distillers dried grains with solubles (DDGS) level under constant nutrient or floating nutrient concentrations. A total of 21 ileal-cannulated gilts (33.1 ± 0.4 kg body weight) were randomly allotted to one of seven dietary treatments in a 3-period incomplete Latin square design (n = 9). Treatments consisted of a 0% DDGS basal diet, plus diets containing 15%, 30%, or 45% DDGS. Diets were formulated using one of two different formulation methods: 1) constant nutrient (CNU) where nutrients were held equal to the basal diet or 2) constant ingredients (CIN) where DDGS were added at the expense of corn and all other ingredients remained constant, so nutrient levels were allowed to "float." Chromic oxide was added to the diets at 0.5% as an indigestible marker. Increasing the level of DDGS decreased the apparent ileal digestibility (AID) of dry matter (DM), gross energy (GE), starch, dispensable amino acids (AA), and fiber components (P < 0.050). The decrease in the AID of Lys, Met, Thr, and Trp was more pronounced under CNU compared with the CIN formulation method (P < 0.050). The decrease in the AID of hemicellulose was less pronounced under CNU compared with the CIN formulation method (P = 0.045). There was a DDGS level × formulation method interaction for the AID of acid hydrolyzed ether extract (AEE; P = 0.015); for the CNU formulation method, increasing level of DDGS decreased the AID of AEE from 0% to 30% and remained similar from 30% to 45% DDGS, whereas the CIN had no effect on the AID of AEE. Increasing the level of DDGS decreased the apparent total tract digestibility (ATTD) of DM, GE, and fiber components (P < 0.050), except for acid detergent fiber, which was not affected. The decrease in the ATTD of insoluble dietary fiber and total dietary fiber was less pronounced under CNU compared with CIN (P < 0.050). The ATTD of AEE decreased for CNU compared with CIN (P < 0.010). In conclusion, increasing the insoluble fiber level in the form of DDGS decreased the digestibility of most dietary components, including DM, GE, starch, insoluble fiber, and AA. The CNU and CIN formulation methods are equivalent when evaluating the digestibilities of DM, GE, starch, crude protein, and AA (when they were not added in purified synthetic forms). Differences between CNU and CIN formulation methods were detected for the digestibility of insoluble fiber, fat, and essential AA (when added as crystalline AA).

Net Energy Net Energy Net EnergyNet EnerNet Energy of high-protein sunflower meal fed to growing pigs and effect of dietary phosphorus on measured values of NE

An experiment was carried out to determine energy values of high-protein sunflower meal (HP-SFM) and to compare the energy values of HP-SFM determined using either a phosphorus (P)-deficient basal diet or a P-adequate basal diet. Twenty-four growing barrows were randomly assigned to 1 of 4 dietary treatments with 6 replicates per treatment. Four experimental diets including 2 basal diets containing 2 levels of standardized total tract digestible P (i.e., P-deficient and P-adequate) and the other 2 diets containing 30% HP-SFM with each basal diet (i.e., HP-SFM 1 diet and HP-SFM 2 diet) were formulated to determine the energy values of HP-SFM and to compare energy values of HP-SFM determined by the difference method using 2 basal diets. Pigs were fed diets for 15 d including 10 d for adaptation and 5 d for total collections. Pigs were then moved to indirect calorimetry chambers to determine total heat production (THP) and fasting heat production (FHP). A reduced (P < 0.01) amount of nitrogen was retained in pigs fed the P-deficient basal diet compared with those fed the other diets. The THP of pigs fed the HP-SFM 1 and 2 diets was greater (P < 0.01) than those fed the P-deficient basal diet with the intermediate value for pigs fed the P-adequate basal diet. The retained energy (RE) as protein of pigs fed the P-deficient basal diet was less (P < 0.01) but RE as lipid was greater (P < 0.01) than those fed the P-adequate basal, or HP-SFM 1 and 2 diets. However, there was no difference in FHP of pigs among the dietary treatments. The NE of HP-SFM determined using the P-deficient basal diet was 2,062 kcal/kg, as-fed basis, whereas the value determined using the P-adequate basal diet was 2,151 kcal/kg. Although no differences were observed in energy values, the amount of P in basal diet might affect energy balance by modifying N utilization, thus, a diet containing adequate amount of P is a more suitable basal diet when the difference method is used for calculation of NE in a feed ingredient.

Effects of dietary energy and crude protein levels on growth performance, blood profiles, and carcass traits in growing-finishing pigs

This experiment was conducted to evaluate the effect of dietary energy and crude protein (CP) levels on growth performance, blood profiles, and carcass traits in growing-finishing pigs. A total of 180 crossbred pigs ([Yorkshire × Landrace] × Duroc) with an average body weight of 30.96 ± 3.068 kg were used for a 12-week feeding trial. Experimental pigs were allotted to a 2 × 3 factorial arrangement using a randomized complete block (RCB) design. The first factor was two levels of dietary metabolizable energy (ME) density (13.40 MJ/kg or 13.82 MJ/kg), and the second factor was three dietary CP levels based on subdivision of growing-finishing phases (high: 18%/16.3%/16.3%/13.2% middle: 17%/15.3%/15.3%/12.2% and low: 16%/14.3%/14.3%/11.2%). Average daily gain (ADG) and gain-feed ratio (G:F ratio) decreased as dietary CP level was decreased linearly (linear, p < 0.05; p < 0.05, respectively) in the early growing period, and G:F ration also decreased as dietary CP level was decreased linearly (linearly, p < 0.05) over the whole growing phase. Over the entire experimental period, G:F ratio decreased as dietary ME level decreased (p = 0.01). Blood urea nitrogen (BUN) concentration was increased as dietary energy level decreased in growing period (p < 0.01). During finishing period, total protein concentration was decreased by lower dietary energy level (p < 0.05). In this study, there were no significant differences in proximate factors, physiochemical properties, muscle TBARS assay results, pH changes, or color of pork by dietary treatments. However, saturated fatty acid (SFA) increased (p < 0.01) and polyunsaturated fatty acid (PUFA) decreased (p < 0.05) when ME was decreased by 0.42 MJ/kg in growing-finishing pig diets. In addition, monounsaturated fatty acid (MUFA) tended to increase when CP level was decreased in growing-finishing pig diets (p = 0.06). A growing-finishing diet of 13.82 MJ/kg diet of ME with the high CP level can improve growth performance and show better fatty acids composition of pork.

Effect of different sources and inclusion levels of dietary fat on productive performance and egg quality in laying hens raised under hot environmental conditions

Objective

This experiment aimed to investigate the effect of different sources and inclusion levels of dietary fat on productive performance and egg quality in laying hens raised under hot environmental conditions.

Method

A total of 480 Hy-Line Brown laying hens at 31 wk of age were randomly allotted to 1 of 5 experimental diets. The control diet contained 2,800 kcal/kg AMEn with no fat addition. Four additional diets were prepared by adding 2.0 or 4.0% of animal fat (AF) or soybean oil (SO). Energy and nutrient concentrations were consistent among all diets. Diets were fed to hens for 4 weeks. Average daily room temperature and humidity were 26.7 ± 1.52°C and 77.4 ± 4.50%. The heat stress index was approximately 76, indicating that hens were raised under heat stress conditions.

Results

Final BW was greater (p<0.05) for hens fed diets containing 2.0 or 4.0% AF than for those fed the control diet or diets containing 2.0 or 4.0% SO. The BW gain and feed intake were greater (p<0.05) for hens fed diets containing additional AF or SO than those fed the control diet. Eggshell thickness were the greatest (p<0.05) for hens fed the control diet, but the least (p<0.05) for hens fed diets containing 4.0% SO. Egg yolk color was the greatest (p<0.05) for hens fed to the control diet, but the least (p<0.05) for hens fed diets containing 4.0% SO.

Conclusion

Inclusion of supplemental fat (AF and SO) in diets exhibits preventative effects on BW loss for hens raised under hot environmental conditions when energy and nutrient concentrations in diets were maintained. The effects were greater for AF than for SO. However, inclusion of supplemental fat in diets decreases eggshell thickness and egg yolk yellowness, possibly due to a reduction in Ca absorption and intake of egg yolk colorants.

Supplementation of different fat sources affects growth performance and carcass composition of finishing pigs

Background

There are various fat sources with different energy values and fatty acid compositions that may affect growth performance and carcass composition of grow-finishing pigs. A higher net energy was recently reported in choice white grease compared with soybean oil. Therefore, two experiments were conducted to determine whether practical responses confirm that difference between choice white grease and soybean oil, and to extend the observations to other fat sources.

Results

In Exp. 1, pigs fed fats had lower (P < 0.05) average daily feed intake in phase II and overall period, greater (P < 0.05) gain:feed in phase I, phase II, and overall period than pigs fed the control diet. Pigs fed fats tended (P = 0.057) to have thicker backfat depth at the last rib than those fed control. Pigs fed 6% fats had greater (P < 0.01) gain:feed in phase II and overall period than pigs fed 3% fats. During phase I, pigs fed choice white grease grew faster (P < 0.05) than pigs fed soybean oil. In Exp. 2, pigs fed dietary fats (soybean oil, choice white grease, animal-vegetable blend, palm oil, or tallow) had greater (P < 0.01) gain:feed in each phase and overall period, greater (P < 0.01) average daily gain in phase I, but lower (P < 0.01) average daily feed intake in phase II an overall than pigs fed the control diets. The choice white grease also increased (P < 0.05) average daily gain during phase I compared with soybean oil. Pigs fed palm oil had thicker (P < 0.05) backfat depth at the 10^th rib than those fed soybean oil, animal-vegetable blend, or tallow.

Conclusions

Inclusion of 6% dietary fat improved feed efficiency of finishing pigs, while different fats produced different practical results that may be consistent with their different energy values. Results from the early stage indicate that dietary fats with relatively more saturated fatty acids may provide greater energy than those with relatively more unsaturated fatty acids for growing pigs.

Determination of net energy content of dietary lipids fed to growing pigs using indirect calorimetry

The objective of this experiment was to determine the NE content of different dietary lipids fed to growing pigs using indirect calorimetry. Thirty-six growing (initial BW: 41.1 ± 3.1 kg) barrows were allotted to 6 diets based on completely randomized design with 6 replicate pigs per diet. Diets included a corn-soybean meal basal diet and 5 test diets each containing 10% palm oil, poultry fat, fish oil, corn oil, or flaxseed oil at the expense of corn and soybean meal. During each period, pigs were individually housed in metabolism crates for 14 d, which included 7 d for adaptation to feed, metabolism crates, and environmental conditions. On day 8, pigs were transferred to the open-circuit respiration chambers and fed 1 of the 6 diets at 2.3 MJ ME/kg BW0.6/day. Total feces and urine were collected and daily heat production (HP) was also calculated from day 9 to day 13. On the last day of each period (day 14), pigs were fasted and the fasting heat production (FHP) was measured. The results show that the FHP of pigs averaged 809 kJ/kg BW0.6·day-1 and was not affected by diet characteristics. The DE values were 35.98, 36.84, 37.11, 38.95, and 38.38 MJ/kg DM, the ME values were 35.79, 36.56, 36.92, 37.73, and 38.11 MJ/kg DM, and the NE values were 32.42, 33.21, 33.77, 34.00, and 34.12 MJ/kg DM, for the palm oil, poultry fat, fish oil, corn oil, and flaxseed oil, respectively. Based on our result, we concluded that the DE content of dietary lipid varied from 91% to 98% of its GE content, the ME content of dietary lipid was approximately 99% of its DE content, and the NE content of dietary lipid was approximately 90% of its ME content in growing pigs.

Methodologies on estimating the energy requirements for maintenance and determining the net energy contents of feed ingredients in swine: a review of recent work

In the past two decades, a considerable amount of research has focused on the determination of the digestible (DE) and metabolizable energy (ME) contents of feed ingredients fed to swine. Compared with the DE and ME systems, the net energy (NE) system is assumed to be the most accurate estimate of the energy actually available to the animal. However, published data pertaining to the measured NE content of ingredients fed to growing pigs are limited. Therefore, the Feed Data Group at the Ministry of Agricultural Feed Industry Centre (MAFIC) located at China Agricultural University has evaluated the NE content of many ingredients using indirect calorimetry. The present review summarizes the NE research works conducted at MAFIC and compares these results with those from other research groups on methodological aspect. These research projects mainly focus on estimating the energy requirements for maintenance and its impact on the determination, prediction, and validation of the NE content of several ingredients fed to swine. The estimation of maintenance energy is affected by methodology, growth stage, and previous feeding level. The fasting heat production method and the curvilinear regression method were used in MAFIC to estimate the NE requirement for maintenance. The NE contents of different feedstuffs were determined using indirect calorimetry through standard experimental procedure in MAFIC. Previously generated NE equations can also be used to predict NE in situations where calorimeters are not available. Although popular, the caloric efficiency is not a generally accepted method to validate the energy content of individual feedstuffs. In the future, more accurate and dynamic NE prediction equations aiming at specific ingredients should be established, and more practical validation approaches need to be developed.

Determination of net energy content of soybean oil fed to growing pigs using indirect calorimetry

The objectives of this experiment were: (i) to determine the net energy (NE) of soybean oil (SBO) fed to growing pigs using indirect calorimetry (IC); and (ii) to evaluate the effects of inclusion rate of SBO on heat production, oxidative status and nutrient digestibility in growing pigs. Eighteen growing barrows were allotted to three diets based on completely randomized design with six replicate pigs (period) per diet. Diets included a corn-soybean meal basal diet and two test diets containing 5% or 10% SBO at the expense of corn and soybean meal. During each period, pigs were individually housed in metabolism crates for 14 days, including 7 days to adapt to feed, metabolism crate and environmental conditions. On day 8, pigs were transferred to the open-circuit respiration chambers for measurement of daily O₂ consumption and CO₂ and CH₄ production. During this time, pigs were fed one of the three diets at 2.4 MJ metabolizable energy/kg body weight (BW)^0.6 /day. Total feces and urine were collected and daily total heat production (THP) was measured from days 9 to 13 and fasted on day 14 to evaluate their fasting heat production (FHP). The results show that trends of decreased apparent total tract digestibility of neutral detergent fiber (linear, P = 0.09) and acid detergent fiber (linear, P = 0.07) were observed as the content of dietary lipids increased. The average THP for the three diets were 1326, 1208 and 1193 kJ/kg BW^0.6 /day, respectively. The FHP of pigs averaged 843 kJ/kg BW^0.6 /day and was not affected by diet characteristics. A reduction of the respiratory quotients in the fed state as the inclusion level of SBO increased was observed. In conclusion, the NE values of SBO we determined by indirect calorimetry were 33.45 and 34.05 MJ/kg dry matter under two inclusion levels. THP could be largely reduced when SBO is added in the feed, but the THP of SBO included at 5% in a corn-soybean meal diet is not different from the THP of SBO included at 10%.

Effect of dietary net energy concentrations on growth performance and net energy intake of growing gilts

Objective

This experiment investigated the effect of dietary net energy (NE) concentrations on growth performance and NE intake of growing gilts.

Methods

Five diets were formulated to contain 9.6, 10.1, 10.6, 11.1, and 11.6 MJ NE/kg, respectively. A metabolism trial with 10 growing pigs (average body weight [BW] = 15.9±0.24 kg) was conducted to determine NE concentrations of 5 diets based on French and Dutch NE systems in a 5×5 replicated Latin square design. A growth trial also was performed with five dietary treatments and 12 replicates per treatment using 60 growing gilts (average BW = 15.9±0.55 kg) for 28 days. A regression analysis was performed to predict daily NE intake from the BW of growing gilts.

Results

Increasing NE concentrations of diets did not influence average daily gain and average daily feed intake of growing gilts. There was a quadratic relationship (p = 0.01) between dietary NE concentrations and feed efficiency (G:F), although the difference in G:F among treatment means was relatively small. Regression analysis revealed that daily NE intake was linearly associated with the BW of growing gilts. The prediction equations for NE intake with the BW of growing gilts were: NE intake (MJ/d) = 1.442+(0.562×BW, kg), R² = 0.796 when French NE system was used, whereas NE intake (MJ/d) = 1.533+(0.614×BW, kg), R² = 0.810 when Dutch NE system was used.

Conclusion

Increasing NE concentrations of diets from 9.6 to 11.6 MJ NE/kg have little impacts on growth performance of growing gilts. Daily NE intake can be predicted from the BW between 15 and 40 kg in growing gilts.

Effects of inclusion level and adaptation period on nutrient digestibility and digestible energy of wheat bran in growing-finishing pigs

Objective

This experiment was to evaluate the effect of different inclusion levels and adaptation periods on digestible energy (DE) and the apparent total tract digestibility (ATTD) of chemical constituents in diets supplemented with wheat bran.

Methods

Thirty-six crossbred barrows with an initial body weight of 85.0±2.1 kg were allotted to 6 diets in a completely randomized block design with 6 pigs per diet. Diets included a corn-soybean basal diet and 5 additional diets which were formulated by replacing corn and soybean meal in control diet with 15%, 25%, 35%, 45%, or 55% wheat bran. The experiment lasted for 34 d, and feces were collected from d 8 to 13, 15 to 20, 22 to 27, and 29 to 34 respectively.

Results

The results showed no interaction effects between inclusion level and adaptation period on the concentration of DE and the ATTD of gross energy (GE) and crude protein (CP) in wheat bran. The DE value and ATTD of GE in wheat bran decreased (p<0.05) significantly as the inclusion level of wheat bran increased, but no difference in the ATTD of CP was observed. The ATTD of CP in wheat bran increased (p<0.10) significantly as the adaptation period for pigs was prolonged. In addition, the concentration of DE and the ATTD of GE in wheat bran decreased linearly (p<0.05) when pigs were fed either an increased level of wheat bran or given an increased adaptation period to the diets.

Conclusion

Wheat bran showed a negative effect on the concentration of DE and ATTD of GE and CP as the inclusion level increased. A longer adaptation period can gradually increase the DE value and ATTD of GE and CP in wheat bran, and at least 14 to 21 d of adaptation might be recommended for growing-finishing pigs fed the high-fiber diets with wheat bran.

Digestibility of energy and lipids and oxidative stress in nursery pigs fed commercially available lipids

An experiment was conducted to evaluate the impact of lipid source on GE and ether extract (EE) digestibility, oxidative stress, and gut integrity in nursery pigs fed diets containing 10% soybean oil (SO), choice white grease (CWG), palm oil (PO), distillers' corn oil with approximately 5% FFA (DCO-1), or distillers' corn oil with approximately 10% FFA (DCO-2). Fifty-four barrows weaned at 28 d of age were fed a common starter diet for 7 d, group fed their respective experimental diets for an additional 7 d, and then moved to metabolism crates and individually fed their respective diets for another 10 d. Following this period, a 4-d total fecal and urine collection period was used to determine apparent total tract digestibility (ATTD) of GE and EE and to determine the DE and ME content of each lipid source (11.03 ± 0.51 kg final BW). Following the last day of fecal and urine collection, pigs were given an oral dose of lactulose and mannitol and fed their respective experimental diets with urine collected for the following 12 h. A subsequent urine collection occurred for 5 h to determine thiobarbituric acid reactive substances (TBARS) and isoprostane (IsoP) concentrations. Following this urine collection, serum was obtained and analyzed for TBARS and endotoxin concentrations. Soybean oil had the greatest ( < 0.05) DE (9,388 kcal/kg) content compared with DCO-1, DCO-2, CWG, and PO (8,001, 8,052, 8,531, and 8,293 kcal/kg lipid, respectively). Energy digestibility was greatest for SO compared with the other lipid sources ( < 0.05). The ATTD of EE averaged 85.0% and varied slightly (84.4 to 85.6%) among treatments. Differences in ME content among lipids were similar to those reported for DE, with ME values for DCO-1, DCO-2, CWG, PO, and SO being 7,921, 7,955, 8,535, 8,350, and 9,408 kcal/kg lipid, respectively. Metabolizable energy as a percentage of DE did not differ among lipid sources. Pigs fed lipid diets had greater ( < 0.05) serum TBARS compared with pigs fed the control diet, but no differences were observed in urinary TBARS excretion among the lipid treatments. Urinary IsoP excretion differed among treatments ( < 0.01) but was highly variable (34.0 to 104.6 pg). However, no differences were observed among treatments for the urinary lactulose:mannitol ratio and serum endotoxin. These results indicate that DE and ME content of SO are greater than that of other lipid sources evaluated, but feeding these lipids has no effect on gut integrity while producing variable effects on oxidative stress.

Digestion and nitrogen balance using swine diets containing increasing proportions of coproduct ingredients and formulated using the net energy system

Rising feed expenditures demand that our industry pursues strategies to lower the cost of production. One option is the adoption of the NE system, although many producers are hesitant to proceed without proof that NE estimates are reliable. The objective of this experiment was to compare the apparent total tract digestibility (ATTD) of energy and nutrients and the N retention (NR) of diets formulated using the NE system with increasing quantities of coproduct ingredients. The 5 dietary treatments included a control corn-soybean meal diet (CTL); the CTL plus 6% each of corn distiller's dried grains with solubles (DDGS), corn germ meal, and wheat middlings and NE equal to the CTL by adding soybean oil (CONS-18); the CONS-18 diet, without oil added, with NE content lower than the CTL (DECL-18); the CTL plus 12% each of corn DDGS, corn germ meal, and wheat middlings and NE equal to the CTL by adding soybean oil (CONS-36); and the CONS-36 diet, without oil added, with NE content lower than the CTL (DECL-36). Diets were formulated for both the growing period (GP; 40 to 70 kg) and the finishing period (FP; 70 to 110 kg). Forty gilts (PIC 337 × C22 or C29; 38.5 ± 0.4 kg initial BW) were randomly assigned to treatment and received feed and water ad libitum (8 pigs per treatment). For the last 13 d of the GP and FP, pigs were transferred to metabolism crates, where 2 total urine and fecal collections (d 4 to 6 and d 11 to 13) were performed. The GP fed diets with coproduct ingredients had lower ATTD of DM, N, and GE than those fed the CTL ( < 0.050). The ATTD of N and GE progressively decreased as coproduct inclusion increased from 0 to 18 to 36% in the FP ( < 0.010). In the GP and FP, there were no differences in ATTD of DM, N, or GE between CONS-18 and DECL-18 or between CONS-36 and DECL-36 ( > 0.050). The NR declined on all coproduct diets in the GP ( = 0.010) and tended to decline in the FP ( = 0.079). There were no differences in NR between CONS-18 and DECL-18 or between CONS-36 and DECL-36 ( > 0.050). In conclusion, digestion of diets containing up to 36% coproducts and formulated using NE resulted in expected DE and ME values; NR of diets with coproducts was lower than that of the simple CTL, which is not related to the accuracy of the energy estimations but rather to other factors such as imbalances in the AA concentrations or to postabsorptive energy metabolism, factors not accounted for by the current energy systems approach.

Effects of diet energy concentration and an exogenous carbohydrase on growth performance of weanling pigs fed diets containing canola meal produced from high protein or conventional canola seeds

The objectives were to determine effects of diet NE and an exogenous carbohydrase on growth performance and physiological parameters of weanling pigs fed a corn-soybean meal (SBM) diet or diets containing high protein canola meal (CM-HP) or conventional canola meal (CM-CV). A total of 492 pigs (initial BW: 9.15 ± 0.06 kg) were used in a randomized complete block design with 12 dietary treatments and 9 pens per treatment. A control diet based on corn and SBM and 4 diets containing 20% or 30% CM-HP or 20% or 30% CM-CV were formulated to a similar NE by adjusting inclusion of choice white grease. Four additional diets also contained 20% or 30% CM-HP or 20% or 30% CM-CV, but no additional choice white grease, and NE in these diets, therefore, was less than in the control diet. The control diet and the diets containing 30% CM-HP or CM-CV without increased choice white grease were also formulated with inclusion of an exogenous carbohydrase. Pigs were fed experimental diets for 22 d and 1 pig per pen was sacrificed at the conclusion of the experiment. Results indicated that compared with the control diet, there was no impact of canola meal on final BW, ADG, ADFI, or G:F, but pigs fed CM-CV had greater ( < 0.05) final BW, ADG, and ADFI than pigs fed CM-HP, and pigs fed diets with reduced NE had greater ( < 0.05) ADG and ADFI than pigs fed diets with constant NE. Only minor effects of CM-HP or CM-CV on intestinal weight, gut fill, digesta pH, cecal VFA concentrations, and serum concentrations of urea N, total N, or albumin were observed, but the weight of the thyroid gland increased ( < 0.05) as the concentration of dietary canola meal increased. Serum concentrations of IgG were reduced if canola meal was included in the diets without the carbohydrase, but that was not the case if the carbohydrase was included in the diet (interaction, ( < 0.05). In conclusion, up to 30% CM-HP or CM-CV in diets fed to weanling pigs from 2 wk postweaning did not impact growth performance compared with pigs fed a corn-SBM diet, and NE in diets containing canola meal does not have to be similar to that of corn-SBM diets. However, inclusion of CM-CV containing 4.43 µmol/g glucosinolates in the diets resulted in improved growth performance compared with inclusion of CM-HP containing 12.60 µmol/g glucosinolates.

Evaluation of available energy and total tract digestibility of acid-hydrolyzed ether extract of cottonseed oil for growing pigs by the difference and regression methods

Objective

The objective of this study was to determine the effect of inclusion level on the digestible energy (DE), metabolizable energy (ME), and total tract digestibility of acid-hydrolyzed ether extract (AEE) of cottonseed oil when fed to growing pigs.

Methods

Forty-two barrows (initial body weight = 35.51±2.01 kg) were randomly allotted to a completely randomized design with a corn-soybean meal basal diet, five levels of cottonseed oil (2%, 4%, 6%, 8%, and 10%) and a 10% soybean oil diet. Each diet was replicated six times with one pig per replicate. The experiment lasted 19 days, 7 d for cage adaptation, 7 d for diets adaptation and last 5 d for feces and urine collection. The energy values and apparent total tract digestibility (ATTD) of cottonseed oil and soybean oil were calculated by the difference method, and regression equations were established to predict the energy values of cottonseed oil. The apparent digested fat of the entire intestinal tract was also regressed against dietary fat intake to determine the true total tract digestibility (TTTD) and endogenous loss of fat for cottonseed oil.

Results

The results showed that the DE and ME contents of cottonseed oil were not different as the inclusion level increased. The DE and ME values determined by the regression equation were 36.28 MJ/kg and 34.96 MJ/kg, respectively, and the values were similar to the mean DE and ME values calculated by the difference method (36.18 and 35.56 MJ/kg, respectively). The ATTD of cottonseed oil was also not affected by the inclusion level of cottonseed oil, and the TTTD and EFL determined by the regression method were 92.40% and 13.83 g/kg of dry matter intake for corn-soybean basal diet. The DE, ME, and ATTD of AEE in soybean oil determined by the difference method were 35.70 MJ/kg, 35.20 MJ/kg and 92.31%, respectively. There were no differences in the DE, ME, and ATTD between cottonseed oil and soybean oil, although the ratio of unsaturated to saturated fatty acids for soybean oil was higher than for cottonseed oil.

Conclusion

The DE, ME, and ATTD values of cottonseed oil were not affected by its dietary inclusion level. The energy values of cottonseed oil determined by the difference and regression methods were similar. Furthermore, the ratio of unsaturated to saturated fatty acid for oils was not the decisive factor to influence the energy values and ATTD of oils.

Determination of the energy value of corn distillers dried grains with solubles containing different oil levels when fed to growing pigs

This experiment used indirect calorimetry to determine the net energy (NE) content of five corn distillers dried grains with solubles (corn DDGS) containing different oil levels and to compare the NE obtained using indirect calorimetry with that calculated using previously published prediction equations. There were two samples of high-oil DDGS, one sample of medium-oil DDGS and two samples of low-oil DDGS. Twelve barrows (initial BW of 32.8 ± 2.0 kg) were used in a repeated 3 × 6 Youden square design with three periods and six diets. The diets were comprised of a corn-soybean meal basal diet and five diets containing 29.25% of one of the corn DDGS added at the expense of corn and soybean meal. During each period, the pigs were individually housed in metabolism crates for 16 days which included 7 days for adaption to feed and environmental conditions. On day 8, the pigs were transferred to respiration chambers and fed one of the six diets at 2300 kJ ME/kg BW^0.6 /day. Faeces and urine were collected from day 9 to 13 and heat production (HP) was also measured. From day 14 to 15, the pigs were fed 893 kJ ME/kg BW^0.6 /day to allow them to adapt from the fed to the fasted state. On the last day of each period (day 16), the pigs were fasted and fasting HP was measured. The digestible energy value was 16.0, 17.1 and 15.3 MJ/kg DM, the metabolizable energy value was 14.6, 15.5 and 13.7 MJ/kg DM and the NE value was 10.7, 11.0 and 9.4 MJ/kg DM, for the high-oil, medium-oil and low-oil corn DDGS, respectively. The NE obtained with indirect calorimetry in the present study did not differ from values calculated using previously published prediction equations.

The effect of inclusion level and basal diet on the determination of the digestible and metabolisable energy content of soybean oil and its digestibility when fed to growing pigs

This experiment was conducted to determine the effect of inclusion level and type of basal diet on the digestible (DE) and metabolisable (ME) energy content of soybean oil and its digestibility when fed to growing pigs. Thirty-six barrows (Duroc × Landrace × Yorkshire weighing 34.2 ± 3.8 kg) were randomly allotted to a 2 × 3 factorial arrangement involving two basal diets and three levels of soybean oil (0%, 5% and 10%). One basal diet was based on corn and soybean meal. The other basal diet was based on corn starch and casein. The barrows were housed in individual metabolism crates to facilitate separate collection of faeces and urine, and were fed the assigned test diets at 4% of initial bodyweight per day. A 5-day total collection of faeces and urine followed a 7-day diet-adaptation period. The DE and ME contents of soybean oil were significantly affected by the dietary inclusion level (P < 0.05), but not by the type of basal diet. The DE contents of soybean oil at the 5% and 10% inclusion level were 34.99 and 37.63 MJ/kg, respectively, for the corn–soybean meal basal diet and 33.72 and 35.21 MJ/kg, respectively, for the corn starch–casein basal diet. The respective corresponding values for ME were 33.91, 37.07, 33.06 and 34.83 MJ/kg. The DE values calculated from regression equation were 38.05 and 37.85 MJ/kg, respectively, for corn–soybean meal and corn starch–casein basal diet. The DE value calculated from regression equation was greater than the values determined from the difference method for corn starch–casein basal diet. The value of endogenous loss for acid-hydrolysed ether extract was greater (P < 0.05) for corn–soybean meal basal diet than for corn starch–casein (13.06 g/kg of dry matter intake for corn–soybean meal basal diet and 1.37 g/kg of dry matter intake for corn starch–casein basal diet, respectively). The values of the true total tract digestibility and apparent total tract digestibility of soybean oil determined from the corn–soybean meal basal diet were not different from those determined from the corn starch–casein basal diet (true total tract digestibility: 97.1% and 95.4%; apparent total tract digestibility: 95.8% and 95.3%, respectively). In conclusion, the DE and ME values of soybean oil are affected by its inclusion level but not by basal diet. The type of basal diet did not affect the digestibility of soybean oil, but affected the endogenous loss of acid-hydrolysed ether extract for soybean oil.

The Effect of Inclusion Level of Soybean Oil and Palm Oil on Their Digestible and Metabolizable Energy Content Determined with the Difference and Regression Method When Fed to Growing Pigs

This experiment was conducted to determine the effects of inclusion level of soybean oil (SO) and palm oil (PO) on their digestible and metabolism energy (DE and ME) contents when fed to growing pigs by difference and regression method. Sixty-six crossbred growing barrows (Duroc×Landrace×Yorkshire and weighing 38.1±2.4 kg) were randomly allotted to a 2×5 factorial arrangement involving 2 lipid sources (SO and PO), and 5 levels of lipid (2%, 4%, 6%, 8%, and 10%) as well as a basal diet composed of corn and soybean meal. The barrows were housed in individual metabolism crates to facilitate separate collection of feces and urine, and were fed the assigned test diets at 4% of initial body weight per day. A 5-d total collection of feces and urine followed a 7-d diet adaptation period. The results showed that the DE and ME contents of SO and PO determined by the difference method were not affected by inclusion level. The DE and ME determined by the regression method for SO were greater compared with the corresponding respective values for PO (DE: 37.07, ME: 36.79 MJ/kg for SO; DE: 34.11, ME: 33.84 MJ/kg for PO, respectively). These values were close to the DE and ME values determined by the difference method at the 10% inclusion level (DE: 37.31, ME: 36.83 MJ/kg for SO; DE: 34.62, ME: 33.47 MJ/kg for PO, respectively). A similar response for the apparent total tract digestibility of acid-hydrolyzed ether extract (AEE) in lipids was observed. The true total tract digestibility of AEE in SO was significantly (p<0.05) greater than that for PO (97.5% and 91.1%, respectively). In conclusion, the DE and ME contents of lipid was not affected by its inclusion level. The difference method can substitute the regression method to determine the DE and ME contents in lipids when the inclusion level is 10%.

Characteristics of lipids and their feeding value in swine diets

In livestock diets, energy is one of the most expensive nutritional components of feed formulation. Because lipids are a concentrated energy source, inclusion of lipids are known to affect growth rate and feed efficiency, but are also known to affect diet palatability, feed dustiness, and pellet quality. In reviewing the literature, the majority of research studies conducted on the subject of lipids have focused mainly on the effects of feeding presumably high quality lipids on growth performance, digestion, and metabolism in young animals. There is, however, the wide array of composition and quality differences among lipid sources available to the animal industry making it essential to understand differences in lipid composition and quality factors affecting their digestion and metabolism more fully. In addition there is often confusion in lipid nomenclature, measuring lipid content and composition, and evaluating quality factors necessary to understand the true feeding value to animals. Lastly, advances in understanding lipid digestion, post-absorption metabolism, and physiological processes (e.g., cell division and differentiation, immune function and inflammation); and in metabolic oxidative stress in the animal and lipid peroxidation, necessitates a more compressive assessment of factors affecting the value of lipid supplementation to livestock diets. The following review provides insight into lipid classification, digestion and absorption, lipid peroxidation indices, lipid quality and nutritional value, and antioxidants in growing pigs.

Net energy content of dry extruded-expelled soybean meal fed with or without enzyme supplementation to growing pigs as determined by indirect calorimetry

Two experiments were conducted to determine the NE content of dry extruded-expelled soybean (DESBM) and the effect of a multienzyme carbohydrase (MC) mixture on the NE content of DESBM and to determine the effect of diet design on NE values in growing pigs using indirect calorimetry (IC). In Exp. 1, 24 barrows (19.6 ± 0.51 kg BW) were allotted in a completely randomized design to 4 dietary treatments: a corn–soybean meal basal diet (Diet A), a diet containing Diet A and DESBM in an 80:20 ratio with a constant CP (Diet B), a diet with an 80:20 ratio of Diet A and DESBM with a constant corn:soybean meal ratio (Diet C), and a diet with simple substitution of Diet A with DESBM in an 80:20 ratio (Diet D). Pigs were fed in metabolism crates for a period of 16 d to determine the DE and ME and thereafter were moved into an indirect calorimeter where O2 consumption and CO2 production were measured to determine heat production and fasting heat production. The NE content of DESBM was calculated (difference method) to be 2,632, 2,548 and 2,540 kcal/kg DM in diets B, C, and D, respectively. Respective values obtained with published prediction equations were 2,624, 2,530 and 2,436 kcal/kg. In Exp. 2, 24 barrows (16.9 ± 0.76 kg BW) were randomly allotted to 1 of 4 treatments. The diets were a corn–soybean meal basal diet and a diet containing the basal diet and DESBM in an 80:20 ratio with a constant corn:soybean meal ratio with or without 2 levels (0.05% and 0.1%) of MC. The experimental procedures were similar to those described in Exp. 1. Enzyme supplementation improved (P < 0.0001) the DE, ME, and NE content of the DESBM. Multienzyme carbohydrase at 0.05% and 0.1% of the diet improved NE values of DESBM by 4.9% and 3.7%, respectively. In conclusion, the NE values of DESBM obtained with the IC method were higher than the values obtained with prediction equations; the disparity was least when diets were formulated with a constant CP level. However, as the difference method was used to determine the NE of ingredient, it is more appropriate to maintain a constant ratio between the ingredients. Also, the NE value of DESBM obtained for diets C and D were not different. Hence, the average NE value of DESBM evaluated was 2,544 kcal/kg DM. Enzyme supplementation improved the NE content of DESBM fed to growing pigs.

Empiric narrowing of the net energy value of reduced-oil corn distillers’ dried grain with solubles for growing-finishing pigs

Smit, M. N., Zamora, V., Young, M. G., Campbell, N., Uttaro, B. and Beltranena, E. 2015. Empiric narrowing of the net energy value of reduced-oil corn distillers’ dried grain with solubles for growing-finishing pigs. Can. J. Anim. Sci. 95: 225–241. This study attempted to empirically narrow down the net energy (NE) value of reduced-oil corn distillers’ dried grains and solubles (RO-cDDGS) by evaluating the response in pig growth performance, live backfat and loin depth, carcass traits, and primal pork cuts tissue composition to feeding diets formulated increasing the assumed NE value of RO-cDDGS, expecting a brisk change in slope of the response at the point at which the NE value of RO-cDDGS would be identified. In total, 1056 cross-bred pigs (31.7 kg) housed in 48 pens by gender were fed dietary regimens including 30% RO-cDDGS (6.7% ether extract) with assumed NE values of 1.7, 1.85, 2.0, 2.15, 2.3, or 2.45 Mcal kg−1over five growth periods (Grower 1: days 0–21, Grower 2: days 22–42, Grower 3: days 43–63, Finisher 1: days 64–76, Finisher 2: day 77 to market weight). Pig body weights were measured and feed disappearance (ADFI) was calculated by pen on days 0, 21, 42, 63, 76 and weekly thereafter until target slaughter weight (120 kg). For the entire trial (days 0–76), increasing the assumed NE value of RO-cDDGS linearly increased (P<0.01) ADFI and total lysine intake, did not affect NE intake and daily weight gain (ADG), quadratically decreased (P<0.05) feed efficiency, linearly decreased (P<0.05) live backfat depth and backfat:loin depth ratio, and did not affect carcass characteristics or pork primal cut tissue composition. Segmented regression only identified a change in slope for carcass ADG and lean ADG at 1.85 Mcal kg−1. These results indicate that the experimental approach taken was not reliable in narrowing down the NE value of RO-cDDGS because the decrease in dietary NE was too small (0.03 Mcal kg−1d), which limited the change in dietary Lys:NE ratio with increasing assumed NE value of RO-cDDGS. The approach resulted in progressive, but small changes in slope rather than a clearly identifiable point where one could conclude that the incremental dietary energy contribution from RO-cDDGS changed the response in a given variable.

Regression analysis to predict growth performance from dietary net energy in growing-finishing pigs

Data from 41 trials with multiple energy levels (285 observations) were used in a meta-analysis to predict growth performance based on dietary NE concentration. Nutrient and energy concentrations in all diets were estimated using the NRC ingredient library. Predictor variables examined for best fit models using Akaike information criteria included linear and quadratic terms of NE, BW, CP, standardized ileal digestible (SID) Lys, crude fiber, NDF, ADF, fat, ash, and their interactions. The initial best fit models included interactions between NE and CP or SID Lys. After removal of the observations that fed SID Lys below the suggested requirement, these terms were no longer significant. Including dietary fat in the model with NE and BW significantly improved the G:F prediction model, indicating that NE may underestimate the influence of fat on G:F. The meta-analysis indicated that, as long as diets are adequate for other nutrients (i.e., Lys), dietary NE is adequate to predict changes in ADG across different dietary ingredients and conditions. The analysis indicates that ADG increases with increasing dietary NE and BW but decreases when BW is above 87 kg. The G:F ratio improves with increasing dietary NE and fat but decreases with increasing BW. The regression equations were then evaluated by comparing the actual and predicted performance of 543 finishing pigs in 2 trials fed 5 dietary treatments, included 3 different levels of NE by adding wheat middlings, soybean hulls, dried distillers grains with solubles (DDGS; 8 to 9% oil), or choice white grease (CWG) to a corn-soybean meal-based diet. Diets were 1) 30% DDGS, 20% wheat middlings, and 4 to 5% soybean hulls (low energy); 2) 20% wheat middlings and 4 to 5% soybean hulls (low energy); 3) a corn-soybean meal diet (medium energy); 4) diet 2 supplemented with 3.7% CWG to equalize the NE level to diet 3 (medium energy); and 5) a corn-soybean meal diet with 3.7% CWG (high energy). Only small differences were observed between predicted and observed values of ADG and G:F except for the low-energy diet containing the greatest fiber content (30% DDGS diet), where ADG and G:F were overpredicted by 3 to 6%. Therefore, the prediction equations provided a good estimation of the growth rate and feed efficiency of growing-finishing pigs fed different levels of dietary NE except for the pigs fed the low-energy diet containing the greatest fiber content.

Characterization of dietary energy in Swine feed and feed ingredients: a review of recent research results

Feed is single most expensive input in commercial pork production representing more than 50% of the total cost of production. The greatest proportion of this cost is associated with the energy component, thus making energy the most important dietary in terms of cost. For efficient pork production, it is imperative that diets are formulated to accurately match dietary energy supply to requirements for maintenance and productive functions. To achieve this goal, it is critical that the energy value of feeds is precisely determined and that the energy system that best meets the energy needs of a pig is used. Therefore, the present review focuses on dietary supply and needs for pigs and the available energy systems for formulating swine diets with particular emphasis on the net energy system. In addition to providing a more accurate estimate of the energy available to the animal in an ingredient and the subsequent diet, diets formulated using the this system are typically lower in crude protein, which leads to additional benefits in terms of reduced nitrogen excretion and consequent environmental pollution. Furthermore, using the net energy system may reduce diet cost as it allows for increased use of feedstuffs containing fibre in place of feedstuffs containing starch. A brief review of the use of distiller dried grains with solubles in swine diets as an energy source is included.

Effects of co-products from the corn-ethanol industry on body composition, retention of protein, lipids and energy, and on the net energy of diets fed to growing or finishing pigs

BACKGROUND

Conventional distillers dried grains with solubles (DDGS-CV), uncooked distillers dried grains with solubles (DDGS-BPX) and high-protein distillers dried grains (HP-DDG) are used in diets for pigs to provide protein and energy. These ingredients may have different effects on body composition and energy retention. Therefore, an experiment was conducted to determine effects of DDGS-CV, DDGS-BPX and HP-DDG on body composition and on retention of protein, lipids, and energy when fed to growing or finishing pigs.

RESULTS

The total organ weight was greater (P < 0.05) for finishing pigs fed the HP-DDG diet than for finishing pigs fed the basal diet or the DDGS-CV diet. Finishing pigs fed the DDGS-CV diet had greater (P < 0.05) lipid gain than pigs fed the other diets, and the net energy (NE) for DDGS-CV was greater (P < 0.05) than for DDGS-BPX, but the NE value of HP-DDG was not different from that of DDGS-CV or DDGS-BPX.

CONCLUSION

Inclusion of up to 30% DDGS or HP-DDG in diets fed to growing or finishing pigs will not affect body composition or the retention of energy, protein and lipids, regardless of the stage of growth of pigs. The NE value of DDGS-BPX and HP-DDG is not affected by the stage of growth of pigs, but the NE value of DDGS-CV is greater in finishing than in growing pigs.

Feed energy evaluation for growing pigs

Pigs require energy for maintenance and productive purposes, and an accurate amount of available energy in feeds should be provided according to their energy requirement. Available energy in feeds for pigs has been characterized as DE, ME, or NE by considering sequential energy losses during digestion and metabolism from GE in feeds. Among these energy values, the NE system has been recognized as providing energy values of ingredients and diets that most closely describes the available energy to animals because it takes the heat increment from digestive utilization and metabolism of feeds into account. However, NE values for diets and individual ingredients are moving targets, and therefore, none of the NE systems are able to accurately predict truly available energy in feeds. The DE or ME values for feeds are important for predicting NE values, but depend on the growth stage of pigs (i.e., BW) due to the different abilities of nutrient digestion, especially for dietary fiber. The NE values are also influenced by both environment that affects NE requirement for maintenance (NE_m) and the growth stage of pigs that differs in nutrient utilization (i.e., protein vs. lipid synthesis) in the body. Therefore, the interaction among animals, environment, and feed characteristics should be taken into consideration for advancing feed energy evaluation. A more mechanistic approach has been adopted in Denmark as potential physiological energy (PPE) for feeds, which is based on the theoretical biochemical utilization of energy in feeds for pigs. The PPE values are, therefore, believed to be independent of animals and environment. This review provides an overview over current knowledge on energy utilization and energy evaluation systems in feeds for growing pigs.

Determination of the net energy content of canola meal from Brassica napus yellow and Brassica juncea yellow fed to growing pigs using indirect calorimetry

The net energy (NE) content of canola meals (CM; i.e. Brassica napus yellow and Brassica juncea yellow) in growing pigs was determined using an indirect calorimetry chamber or published prediction equations. The study was conducted as a completely randomized design (n=6), with (i) a basal diet and (ii) 2 diets containing 700 g/kg of the basal diet and 300 g/kg of either of the two varieties of CM. A total of 18 growing barrows were housed in metabolism crates for the determination of digestible (DE) and metabolizable (ME) energy. Thereafter, pigs were transferred to the indirect calorimetry chamber to determine heat production (HP). The NE contents of diets containing Brassica napus yellow and Brassica juncea yellow determined with the direct determination technique and prediction equations were 9.8 versus 10.3 MJ/kg dry matter (DM) and 10.2 versus 10.4 MJ/kg DM, respectively. Retained energy (RE) and fasting heat production (FHP) of diets containing Brassica napus yellow and Brassica juncea yellow were 5.5 versus 5.7 MJ/kg and 4.3 versus 4.5 MJ/kg, respectively, when measured with the direct determination technique and prediction equations. The NE contents of Brassica napus yellow and Brassica juncea yellow were determined to be 8.8 and 9.8 MJ/kg DM, respectively, using the direct determination technique.

Effects of dietary soybean oil on pig growth performance, retention of protein, lipids, and energy, and the net energy of corn in diets fed to growing or finishing pigs

The objectives of this experiment were 1) to determine if dietary soybean oil (SBO) affects the NE of corn when fed to growing or finishing pigs, 2) to determine if possible effects of dietary SBO on the NE of corn differ between growing and finishing pigs, and 3) to determine effects of SBO on pig growth performance and retention of energy, protein, and lipids. Forty-eight growing (initial BW: 27.3 ± 2.5 kg) and 48 finishing (initial BW: 86.0 ± 3.0 kg) barrows were used, and within each stage of growth, pigs were allotted to 1 of 6 groups. Two groups at each stage of growth served as an initial slaughter group. The remaining 4 groups were randomly assigned to 4 dietary treatments and pigs in these groups were harvested at the conclusion of the experiment. A low-lipid basal diet containing corn, soybean meal, and no added SBO and a high-lipid basal diet containing corn, soybean meal, and 8% SBO were formulated at each stage of growth. Two additional diets at each stage of growth were formulated by mixing 25% corn and 75% of the low-lipid basal diet or 25% corn and 75% of the high-lipid basal diet. Results indicated that addition of SBO had no effects on growth performance, carcass composition, or retention of energy, protein, and lipids but increased (P < 0.05) apparent total tract digestibility of acid hydrolyzed ether extract and GE. Addition of SBO also increased (P < 0.05) DE and NE of diets, but had no effect on the DE and NE of corn. Finishing pigs had greater (P < 0.05) growth performance and retention of energy, protein, and lipids than growing pigs. A greater (P < 0.05) DE and NE of diets was observed for finishing pigs than for growing pigs and the DE and NE of corn was also greater (P < 0.05) for finishing pigs than for growing pigs. In conclusion, addition of SBO increases the DE and NE of diets but has no impact on the DE and NE of corn. Diets fed to finishing pigs have greater DE and NE values than diets fed to growing pigs and the DE and NE of corn are greater for finishing pigs than for growing pigs.

The effects of medium-oil dried distillers grains with solubles on growth performance, carcass traits, and nutrient digestibility in growing-finishing pigs

A total of 288 mixed-sex pigs (PIC 327 × 1050; initially 68.9 kg BW) were used in a 67-d study to determine the effects of increasing medium-oil dried distillers grains with solubles (DDGS; 7.63% ether extract, 30.1% CP, 19.53% ADF, 36.47% NDF, and 4.53% ash; as-fed basis) on growth performance and carcass traits in finishing pigs. Treatments consisted of a corn-soybean meal control diet or the control diet with 15, 30, or 45% medium-oil DDGS. Diets were fed over 2 phases (69 to 100 and 100 to 126 kg) and were not balanced for energy. Diets were formulated to meet or exceed the AA, vitamin, and mineral requirements and contained constant standardized ileal digestible lysine levels within phase. Increasing medium-oil DDGS decreased (linear, P < 0.02) ADG and G:F. Average daily gain decreased approximately 2.3% for every 15% added medium-oil DDGS whereas G:F decreased approximately 1.3% with every 15% added DDGS. In addition, final BW, HCW, carcass yield, and loin-eye depth decreased (linear, P < 0.03) and jowl iodine value (IV) increased (linear, P < 0.001) with increasing medium-oil DDGS. Nutrient digestibility of the DDGS source was determined using pigs (initially 25.6 kg BW) that were fed either a corn-based basal diet (96.6% corn and 3.4% vitamins and minerals) or a DDGS diet, which was a 50:50 blend of the basal diet and medium-oil DDGS. There were 12 replications for each diet consisting of a 5-d adaptation period followed by 2 d of total fecal collection on a timed basis. Feces were analyzed for GE, DM, CP, crude fiber, NDF, ADF, and ether extract. On an as-fed basis, corn was analyzed to contain 3,871 and 3,515 kcal/kg GE and DE, respectively. Medium-oil DDGS was analyzed to contain 4,585 and 3,356 kcal/kg GE and DE, respectively (as-fed basis). Digestibility coefficients of the medium-oil DDGS were 70.3% DM, 82.9% CP, 61.4% ether extract, 77.4% ADF, 67.5% NDF, and 67.2% crude fiber. Caloric efficiency (ADFI × kcal energy intake/kg BW gain) was not different when expressed on a DE or a calculated ME or NE basis, which suggests that the energy values derived from the nutrient balance study were accurate. In conclusion, increasing dietary inclusion of medium-oil DDGS decreased ADG, G:F, final BW, HCW, and carcass yield and increased jowl fat IV relative to those fed a corn-soybean meal-based diet.

Effects of dietary soybean hulls and wheat middlings on body composition, nutrient and energy retention, and the net energy of diets and ingredients fed to growing and finishing pigs

The objectives of this experiment were 1) to determine the effect of dietary soybean hulls (SBH) and wheat middlings (WM) on body composition, nutrient and energy retention, and the NE of diets and ingredients fed to growing or finishing pigs and 2) to determine if finishing pigs use the energy in SBH and WM more efficiently than growing pigs. Forty growing barrows (initial BW: 25.4 ± 0.7 kg) and 40 finishing barrows (initial BW: 84.8 ± 0.9 kg) were randomly allotted to 5 groups within each stage of growth. Two groups at each stage of growth served as the initial slaughter group. The remaining pigs were randomly assigned to 3 dietary treatments and harvested at the conclusion of the experiment. The basal diet was based on corn and soybean meal and was formulated to be adequate in all nutrients. Two additional diets were formulated by mixing 70% of the basal diet and 30% SBH or 30% WM. In the growing phase, ADG, G:F, and retention of lipids were greater (P < 0.05) for pigs fed the basal diet than for pigs fed the diets containing SBH or WM. Retention of energy was also greater (P < 0.05) for pigs fed the basal diet than for pigs fed the SBH. In the finishing phase, pigs fed the SBH diet tended (P = 0.10) to have a greater ADG than pigs fed the WM diet, and energy retention was greater (P < 0.05) for pigs fed the basal diet than for pigs fed the WM diet. The NE of the basal diet fed to growing pigs was greater (P < 0.01) than the NE of the diets containing SBH or WM, and there was a tendency for a greater (P = 0.05) NE of the basal diet than of the other diets when fed to finishing pigs. The NE of SBH did not differ from the NE of WM in either growing or finishing pigs, and there was no interaction between ingredients and stage of growth on the NE of diets or ingredients. The NE of diets for growing pigs (1,668 kcal/kg) was not different from the NE of diets for finishing pigs (1,823 kcal/kg), and the NE of the diets containing SBH (1,688 kcal/kg) was not different from the NE of the diets containing WM (1,803 kcal/kg). Likewise, the NE of SBH (603 kcal/kg) did not differ from the NE of WM (987 kcal/kg). In conclusion, inclusion of 30% SBH or WM decreases the performance and nutrient retention in growing pigs but has little impact on finishing pigs. The NE of the diets decreases with the inclusion of SBH and WM, but the NE of diets and ingredients is not affected by the BW of pigs. The NE of SBH is not different from the NE of WM.

Net energy of diets containing wheat-corn distillers dried grains with solubles as determined by indirect calorimetry, comparative slaughter, and chemical composition methods

The NE content of diets containing wheat-corn distillers dried grains with solubles (wcDDGS; 1:1 ratio) fed to growing pigs was determined using the comparative slaughter (CS), indirect calorimetry (IC), and chemical composition (CH) methods. The experimental diets were a corn-soybean meal control diet (CTRL), CTRL + 15% wcDDGS, and CTRL + 30% wcDDGS. In Exp. 1, 56 barrows (18.5 kg BW) were used to determine the NE value of diets using the CS method. Pigs were initially placed in 8 groups (7/group), based on BW and 1 pig/group was killed at the start of the experiment to obtain baseline body composition. The remaining 48 pigs were housed in pairs and allotted to the 3 diets (n = 8). Pigs had free access to feed and water for a 28-d period, after which 1 pig/pen was slaughtered to determine final body composition. Based on the CS method, NE values of 2,430, 2,427, and 2,429 kcal/kg DM were obtained for diets containing 0%, 15%, and 30% wcDDGS, respectively. In Exp. 2, 18 barrows (20.4 kg BW) were used to determine the NE value of diets using the IC and CH methods. Pigs were individually housed in metabolism crates and fed the 3 diets (n = 6) at 550 kcal ME/kg BW/d for a 16-d period. Feces and urine were collected from d 11 to 16, followed by measurement of O(2) consumption, CO(2) production, and urinary N, over a 36-h period using an IC system. For the IC method, NE values of 2,586, 2,513, and 2,520 kcal/kg DM were obtained for diets containing 0%, 15%, and 30% wcDDGS, respectively, and corresponding values for the CH method were 2,447, 2,451, and 2,368 kcal/kg DM, respectively. The NE values that were obtained with the CS, IC, and CH methods were not different.