Influence of energy intake on protein and lipid deposition in Creole and Large White growing pigs in a humid tropical climate

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.

Fasting heat production and metabolic BW in group-housed broilers

Fasting heat production (FHP) is used for characterizing the basal metabolic rate of animals and the corresponding maintenance energy requirements and in the calculation of net energy value of feeds. In broilers, the most recent FHP estimates were obtained in the 1980s in slow-growing and fatter birds than nowadays. The FHP values (n=73; six experiments) measured in 3 to 6-week-old modern lines of broilers weighing 0.6 to 2.8 kg and growing at 80 to 100 g/day were used to update these literature values. Each measurement was obtained in a group of fasting broilers (5 to 14 birds) kept in a respiration chamber for at least 24 h. The FHP estimate corresponds to the asymptotic heat production corrected for zero physical activity obtained by modeling the decrease in heat production during the fasting day. The compilation of these data indicates that FHP was linearly related to the BW(0.70) (in kg), which can be considered as the metabolic BW of modern broilers. The 0.70 exponent differs from the conventional value of 0.75 used for mature animals. The FHP per kg of BW(0.70) ranged between 410 and 460 kJ/day according to the experiment (P<0.01). An experiment conducted with a shorter duration of fasting (16 h) indicated that FHP values are higher than those obtained over at least 24 h of fasting. Our values are similar to those obtained previously on fatter and slow-growing birds, even though the comparison is difficult since measurement conditions and methodologies have changed during the last 30 years. The FHP values obtained in our trials represent a basis for energy nutrition of modern broilers.

Effect of feeding level on ileal and total tract digestibility of nutrients and energy from soybean meal-based diets for piglets

A total of 36 piglets with an initial body weight (BW) of 5.6 ± 0.7 kg, fitted with simple T-cannulas at the distal ileum, were used to evaluate the effect of three graded feeding levels (50, 75 or 100 g/kg BW(0.75) day) on apparent ileal digestibility (AID) and total tract digestibility (ATTD) of dry matter (DM), nitrogen (N) and energy, and on ATTD of organic matter (OM), ether extracts (EE), neutral detergent fibre (NDF), acid detergent fibre (ADF) and digestible (DE), metabolisable (ME) and net energy (NE) content in soybean meal (SBM)-casein-cornstarch-based diets. The AID of DM, N and energy and ATTD of NDF, ADF and EE in the diets were not affected (p > 0.05) by the feed intake (FI) level. There was a small decrease in ATTD of DM, N (CP), OM, ash and energy, and in DE, ME and NE content in the diets (p < 0.05) with increasing FI level. The net disappearance in the large intestine (in % of ileal recovery) decreased for DM, N and energy (p < 0.05) with increasing FI level. The design of the study allowed for estimating ileal endogenous loss of N and total tract endogenous loss of ash, N and EE, for estimating corresponding true ileal and total tract digestibility values, and for estimating urinary endogenous N loss. High variability in estimates of ileal endogenous N loss and total tract endogenous losses of N, EE and ash reflects great variation in individual endogenous losses between animals. Estimation of true total tract digestibility of N, EE and ash by regression analysis was affected by their decrease in ATTD with increasing FI level, as estimates for true digestibility were lower compared to their apparent values. The present results suggest that FI level can affect both apparent and true total tract nutrient digestibility in piglets.

Forage plants as an alternative feed resource for sustainable pig production in the tropics: a review

Globally, pressure on concentrate feed resources is increasing, especially in the tropics where many countries are net importers of food. Forage plants are a possible alternative, but their use as feed ingredients for pigs raises several issues related to their higher fibre and plant secondary metabolites contents as well as their lower nutritive value. In this paper, the nutritive value of several forage species and the parameters that influence this nutritive value in relationship to the plant family, the physiological stage, the plant part and the preservation method (fresh, hay and silage) are reviewed. The influence of the breed and the physiological status of the animal on animal voluntary intake of fibre-rich ingredients, digestibility as related to gastrointestinal volume and transit time and growth performances are also discussed. The final section highlights the advantages and drawbacks of forage plants in pig diets and stresses the need for proper economic evaluation to conclude on the benefits of the use of forage plants in pig feed.

Nutritional values of sugarcane products in local Caribbean growing pigs

A total of 24 castrated male Creole were used for digestibility studies on three sugarcane (SC) products: final molasses, SC juice and ground SC. Digestibility of macronutrients were determined in three consecutive experimental trials between 35 and 60 kg BW. The first trial measured the effect of a constant rate of incorporation of those SC products in a control diet (23% on a dry matter (DM) basis) on digestibility of energy and nutrients. The second and the third trials were designed to determine the effects of increasing rates of inclusion of SC juice and ground SC in the control diet on the digestibility of nutrients and energy. The DM content of molasses, SC juice and ground SC were 74.3%, 19.3% and 25.8%, respectively. Free sugar contents were 73.8%, 81.6% and 51.5% of DM for molasses, SC juice and ground SC, respectively. In contrast with molasses and SC juice, NDF content of ground SC was very high (40.3% DM). Energy digestibility coefficients (DC) were 99.0% and 83.6% for SC juice and molasses, respectively. For ground SC, amounts and composition of intakes differed from feed allowance as a consequence of chewing-then-spitting out most of the fibrous contents of ground SC. Expressed as a percentage of energy intake and energy allowance, DC of energy for ground SC were 68.6% and 31.9%, respectively. On an intake basis, digestible energy (DE) and metabolisable energy (ME) values were higher for SC juice (17.3 and 17.2 MJ/kg DM, respectively) than for molasses (13.1 and 12.6 MJ/kg DM, respectively) or ground SC (12.3 and 11.8 MJ/kg DM, respectively). On an allowance basis, the corresponding values for ground SC were only 5.7 and 5.6 MJ/kg DM, respectively. The gradual inclusion rate of SC juice in the diet up to 66% resulted in a linear increase of the DC of the diet organic matter and energy (P < 0.001) by 0.10% per 1% in SC juice DM. On the other hand, the partial substitution of the control diet by ground SC up to 74% resulted in a linear (P < 0.05) reduction of digestibility of nutrients and energy. Each 1% increase of ground SC incorporation rate resulted in a 0.13% and 0.61% linear decrease of DC of the energy, expressed as a percentage of energy intake or energy allowance, respectively. In conclusion, our study provides updated energy values of SC products usable as energy sources for feeding pigs.

Maintenance energy requirements of growing pigs and calves are influenced by feeding level

The conventional regression method for partitioning heat production (HP) in growing animals between HP associated with either maintenance or growth assumes maintenance HP to be independent of feeding level (FL). However, there are indications that this assumption is not correct and an alternative method is proposed in this study from a reanalysis of 3 trials. In trial 1, 73-, 152-, and 237-kg calves received one milk replacer at 77, 84, 92, and 100% of their ad libitum metabolizable energy (ME) intake. In trial 2, 70-kg barrows received one diet at 60, 80, and 100% of their ad libitum ME intake {2600 kJ ME/[kg body weight (BW)(0.60) · d]}. In trial 3, 60-kg barrows received a basal diet [1700 kJ ME/(kg BW(0.60) · d)] or 4 diets consisting of the basal diet plus 850 kJ ME/(kg BW(0.60)·d) of starch alone or starch with corn gluten, casein, or vegetable oil. In the 3 trials (n = 48, 18, and 28, respectively), HP and activity-related HP were measured on individuals pigs and calves in respiration chambers for 6 d (fed state) and fasting HP (FHP; at zero activity) was calculated as the asymptotic value of HP kinetics on d 7 (feed-deprived state). The FHP changed by 0.22 kJ in calves and 0.14 kJ in pigs/kJ ME intake change during the previous days. The efficiency of using ME for maintenance and growth [k(mg); 1- (HP - FHP)/ME] was not affected by FL (calves: 84%, pigs in trial 2: 74%). In trial 3, k(mg) varied between diets in connection with variations in efficiencies between nutrients (from 55% for corn gluten to 85% for lipid). This new method of representing partitioning of ME intake considers FHP as variable with FL, does not require estimates of maintenance ME requirements, includes efficiencies that depend on diet characteristics, and is not biased by metabolic adaptations of the animal to FL.

Effects of the level of sugarcane molasses on growth and carcass performance of Caribbean growing pigs reared under a ground sugarcane stalks feeding system

The influence of the level of sugarcane (SC) molasses on growth performance, carcass traits, and meat quality in Creole (CR) growing pigs fed with ground sugarcane stalks (GCS)-based diet was studied in a mixed farming system context. The aim of the study was to optimize the growth performance of CR pigs with SC-molasses as an energy source in this unconventional feeding. A total of 32 CR pigs were used from 30 to 60 kg of body weight (BW). The experimental dietary treatments consisted of four levels of inclusion of SC-molasses (200, 400, 600, and 800 g DM/d/pig) into a GCS diet, for diets 1, 2, 3 and 4 respectively. The GCS allowance was based on live BW (170 g/kg BW/d) and the diets were supplemented with a soya-bean meal supplement (350 g/d of a 49.2% CP and 16.6 MJ DE/kg). All the pigs were slaughtered at 60 kg BW. Increasing the level of molasses did not affect (p > 0.05) average BW gain (254 g/d), CP intake (154 g/d) and sugar extraction rate from the total ration (85%). A gradual inclusion of molasses in a GCS-based diet did not affect the carcass and meat quality of CR pigs. In conclusion, molasses supplementation does not allow the increase of growth performance in GCS fed pigs.

Effect of sugarcane diets and a high fibre commercial diet on fresh meat and dry-cured ham quality in local Caribbean pigs

The effects sugar cane (SC) diets and a milling by product diet on meat quality characteristics of fresh meat and dry-cured ham were studied on a total of 48 Creole (CR) pigs. Pigs were fed with a control soya-bean meal corn diet (C1), a soya-bean meal wheat diet (C2), a SC fresh juice diet (SC-J), or a ground cane diet (SC-G). Average BW gain was 657, 530, 546, and 200g/d for diets C1, C2, SC-J and SC-G, respectively. Lean cuts (i.e., ham and loin) were significantly higher in SC-G than in C1 pigs (472 vs. 424g/kg; P<0.01); intermediate values were found for C2 and SC-J pigs (427 and 412g/kg, respectively). The ultimate pH in LD muscle was lower in SC-J than the other groups (5.44 vs. 5.65; P<0.01). The intra muscular fat (IMF) content in LD was significantly higher in SC-J diet and lower in SC-G diet (1.9% and 1.0%, respectively); intermediates values were found for C1 and C2 diets (1.4% on average). Ham weight losses during 6 months drying period were lower for SC-G fed pigs (9.7% vs. 12.4%; P<0.05) whereas weight losses during the 12 months drying period were not affected by diet. The TBA value in dry-cured ham was not affected by diet (P>0.05) whereas the fatty acids profiles of subcutaneous fat in SC-J and SC-G pigs contained more mono-unsaturated and less polyunsaturated fatty acids than in C1 and C2 groups. Significant effects of dietary treatment were found for dry-cured ham sensory quality parameters.