RESEARCH ARTICLE
Nitrogen Requirements of White
‐Lipped Peccary
(Mammalia, Tayassuidae)
Sérgio L. G. Nogueira‐Filho,1* Rogério M. Borges,1Alcester Mendes,1and Carlos T. S. Dias2 1Laboratório de Nutrição de Animais Neo‐tropicais, Departamento de Ciências Agrárias e Ambientais, Universidade Estadual de Santa Cruz, Ilhéus, Bahia, Brazil
2Departamento de Ciências Exatas, Escola Superior de Agricultura Luiz de Queiroz, Universidade de São Paulo, Piracicaba, São Paulo, Brazil
A study was conducted to determine the protein requirement of the white‐lipped peccary (Tayassu pecari) performing a nitrogen (N) balance digestion trial. In a 4 4 Latin square design, four adult captive male peccaries were fed four isoenergetic diets containing four different levels of N (13.3, 19.2, 28.7, and 37.1 g N/kg dry matter). After 15 days of adaptation, the total collection of feces and urine was carried out forfive consecutive days. By regression analysis between N intake and N in feces and urine, the metabolic fecal nitrogen (MFN¼ 3.1 g/kg of dry matter intake) and daily endogenous urinary N (EUN ¼ 91.0 mg/kg0.75) were determined. Likewise, by regression analyses between consumption of nitrogen and the nitrogen balance [NBN consumed– (fecal Nþ Urine N)] we estimated the daily requirement of 336.5 mgN/kg0.75. Therefore, if food intake is unrestricted, white‐ lipped peccaries require a minimum content in their diet of about 4.5% crude protein as percentage of dry diet. These values are similar to those found in frugivorous wild ruminants, which reinforces the proposition that peccaries have a digestive physiology nearer to that of ruminants than of domestic pigs. Furthermore, the low nutritional maintenance requirements for white‐lipped peccary may explain how this species thrive in the Neo‐tropical region eating predominantly palm‐fruits that normally have low crude protein contents. Zoo Biol. 33:320–326, 2014. © 2014 Wiley Periodicals, Inc.
Keywords: animal nutrition; balance trials; comparative physiology; endogenous urinary nitrogen; metabolic fecal nitrogen; wildlife feeding
INTRODUCTION
The white‐lipped peccary (Tayassu pecari) is one of the three recognized living species of peccaries [Sowls, 1997]. This pig‐like mammal, despite being restricted to the Neo‐ tropical region, occupies a wide diversity of habitats from northern Argentina to south‐eastern Mexico, which include primarily humid tropical forests but also wet and dry grasslands and woodlands, xerophitic areas, tropical dry forests, and coastal mangroves [Keuroghlian et al., 2013]. This species is primarily frugivorous [Kiltie, 1981; Beck, 2006; Keuroghlian and Eaton, 2008; Desbiez et al., 2009], although it occasionally eats invertebrates andfish [Fragoso, 1999].
This ability to adapt to such diverse habitats, while mainly eating fruit that normally have low crude protein contents, could be explained by an anatomical/physiological characteristic of the species, the forestomach. Although the white‐lipped peccary does not ruminate, this species has a
forestomach that represents up to 85% of the total digestive tract volume [Cavalcante‐Filho et al., 1997]. The fermenta-tion of dietary fiber occurs in this organ, which allows the species to digest forage like ruminants, resulting in the production of short chain fatty acids used in energy metabolism [Moraes, 1992; Comizzoli et al., 1997]. Besides
Grant sponsor: Conselho Nacional de Desenvolvimento Científico e Tecnológico; grant number: 476033/2010‐1; grant sponsor: Coordena-ção de Aperfeiçoamento de Pessoal de Nível Superior (CAPES/PNPD).
Correspondence to: Sérgio L. G. Nogueira‐Filho, Departamento de
Ciências Agrárias e Ambientais, Universidade Estadual de Santa Cruz, Rod. Jorge Amado km 16, Ilhéus 45662‐900, Bahia, Brazil.
E‐mail: slgnogue@uesc.b
Received 22 November 2013; Revised 07 May 2014; Accepted 15 May 2014
DOI: 10.1002/zoo.21141
Published online 24 June 2014 in Wiley Online Library (wileyonlinelibrary.com).
energy metabolism, the peccary’s forestomach could also be related to microbial protein synthesis, which could later be used by the host after reaching the lower digestive tract, as occurs in true ruminants [Pond et al., 2004; Barboza et al., 2009]. These characteristics, therefore, allow the species to survive in different habitats eating fruit and vegetative parts of plants, such as Astrocaryum sp. fruit and Mauritiaflexuosa palm fruit [Kiltie, 1981], which contain just 6.0% and 7.4% crude protein (CP) in the dry matter, respectively [Silva et al., 2003; Darnet et al., 2011]. The same was verified in the collared peccary (Pecari tajacu), a sympatric frugivorous species whose daily protein require-ment of just 6.8% CP as percentage of dry diet [Carl and Brown, 1985] is near to the relatively low requirement of the blue duiker (Cephalophus monticola), which is a true ruminant known for its largely fruit diets and which requires just 4.0% CP as percentage of dry diet [Shipley and Felicetti, 2002]. There is, however, no information on protein requirements for the white‐lipped peccary.
Nitrogen compounds in crude protein are the basis for the structure and function of animals, acting in the building and repair of tissues, and promoting proper biological functioning [Pond et al., 2004; Barboza et al., 2009]. The determination of nitrogen requirements is thus vital for formulating proper diets in zoos.
To better understand the protein requirements of white‐ lipped peccaries, and thus support good husbandry in zoos, we conducted a digestion trial on diets ranging in nitrogen contents. Our objective was to quantify minimum nitrogen (N) requirement of white‐lipped peccaries. In addition, we sought to compare the nutritional requirements of white‐ lipped peccaries with data from the literature concerning ruminants and pigs. We expected that white‐lipped peccaries would have similar protein requirements to those of ruminants and lower than that of domestic pigs (Sus scrofa).
METHODS
Place of Study and Experimental Animals
This study was conducted at the Laboratório de Nutrição de Animais Silvestres, Universidade Estadual de Santa Cruz (UESC), Ilhéus, Bahia, Brazil. The protocol for this experiment was in compliance with the“Guidelines for the use of animals in research” published in Animal Behavior, Vol. 43, 1992 and was approved by the Ethics Committee on Animal Use (CEUA) of UESC.
Four adult male white‐lipped peccaries aged two to three years and with an average initial body mass of 36.7 2.7 kg were used. They were selected according to their body mass and docile temperament. After being weighed and dewormed, the animals were housed in individual 11.3 m2 (7.5 m 1.5 m) pens. Each pen was divided into two sections: one covered area of 3.0 m2— named the metabolism pen—had a wooden lattice suspended floor that allowed feces and urine separation. A net wire
fence, equipped with a wooden guillotine type door, separated the metabolism pen from the rest of the pen, which wasfloored in concrete. Furthermore, each metabolism pen had a feeder (1.10 m 0.25 m 0.15 m) and a drinking trough (0.2 m 0.2 m 0.2 m). So as to permit physical, visual, auditory and olfactory contact among animals, in an attempt to reduce the stress caused by isolation, since this is a species with highly social behavior, the partitions between pens consisted of 1.5 m‐high wire fencing. Only animals that lived in the same paddock were placed side by side so as to avoid the common conflicts between individuals from different herds [Nogueira‐Filho et al., 1999]. The chemical analyses were carried out at the Laboratório de Nutrição Animal, UESC, Ilhéus, Bahia, Brazil.
Procedures
The peccaries were once again weighed after 30 days of adaptation to the experimental conditions. Then, the animals randomly received one of the four diets in a 4 4 Latin square design, containing different proportions of nitrogen (13.3; 19.2; 28.7, and 34.1 g N/kg of dry matter‐DM) with the same amount of gross energy (18.3 0.1 MJ/kg DM) (Table 1). The order of rotating the animals on each diet was randomized by chance as well. These diets were composed of chopped hay made from Bermuda grass (Cynodon dactylon) and a mixture of ground corn and soybean meal in a constant ratio of concentrate: forage (0.9: 0.1). Likewise, fixed values of common salt (3.0 g/kg DM) and mineral salt (5.0 g/kg DM) were added. The feed and water were offered ad libitum. The daily feed intake was calculated by taking the difference between the amount of diet furnished and the refused leftovers weighed the next day.
After 15 days of adaptation to the new diets, which is enough to prevent the previous diet from interfering with the next one [Moraes, 1992], the peccaries were maintained in the metabolism pens and fecal and urine collections were carried out forfive consecutive days. The diets were furnished once a day at 8:00 am. They were duly mixed for daily sampling before being fed to the animals and the samples were placed in labeled plastic bags. Twice a day, at 8:00 am and 5:00 pm,
TABLE 1. Chemical composition of the diets supplied, based on dry matter, g/kg dry matter (DM), unless stated
Item Diet 1 Diet 2 Diet 3 Diet 4
Nitrogen 13.3 19.2 28.7 34.1 NDF 209.3 208.5 207.4 206.6 ADF 75.0 79.0 84.5 88.5 Common salt 3.0 3.0 3.0 3.0 Mineral salta 5.0 5.0 5.0 5.0 GE, MJ kg1DM 18.4 18.0 18.2 18.4
NDF, neutral detergentfiber; ADF, acid detergent fiber; GE, gross energy.
aMineral salt formulated for use in beef cattle feeding with levels of
assurance (/kg): Ca 167 g, P 130 g; S 9,400 mg; Mn 89 mg; Fe 2,200 mg; Cu 20 mg; Co 4 mg; Mg 80 g; Zn 140 mg; I 90 mg; Se 15 mg.
the feces were collected, by moving the animals out of the metabolism pen. All voided feces were collected and packed in previously identified plastic bags. After collection, the animals returned to the metabolism pen. Feces were then weighed and stored, along with diet samples and refusals, in a freezer at minus 20°C for further analysis.
The total urine produced was drained via a sloping floor into 1.5 L glass containers. Each container had 0.1 L of sulfuric acid solution 100 ml/L for preventing nitrogen loss. The containers were replaced twice daily to avoid contami-nation and possible nitrogen losses. After the urine volume in the containers had been measured using a beaker, the amount of acid was deducted and an aliquot of 10 ml of urine was transferred to a previously identified plastic container and weighed for density determination. These aliquots were stored in a refrigerator at 4°C for further analysis. After the last day of the sample collection period, the animals were weighed again and received another diet, starting successive new diet adaptation/sample collection periods until all four individuals had received all diets.
Diets, feces, and feed residue samples were thawed to room temperature, weighed and dried to constant mass at 65°C. The dried samples were ground through a 1.0 mm mesh screen in a laboratory mill. The chemical composition was determined according to standard methods of the Association of Official Analytical Chemists [AOAC, 1990] including dry matter (method 930.15). Nitrogen content was determined by micro‐Kjeldahl (method 988.05), crude protein (CP) was calculated as N 6.25 and gross energy content was determined in an adiabatic calorimetric bomb (Parr Instru-ment Company, Moline IL). Urine samples were analyzed just for N content, while diets and feed residue samples, besides DM, N, and gross energy (GE), were also analyzed for fiber composition using sequential detergent analysis [Goering and Van Soest, 1970].
Calculations and Statistical Analysis
The apparent total‐tract in vivo digestibility coefficients of DM, CP, and energy were determined by the differences between the amount of nutrients and GE ingested and the amount excreted as: (g of nutrient or energy in g of nutrient or energy out)/(g of nutrient or energy in). The data of body mass change, apparent digestibility coefficients of dry matter, energy, and nitrogen, plus the digestible energy intake, nitrogen intake, fecal and urinary nitrogen, and nitrogen balance were compared by repeated‐measure ANOVA tests followed by Tukey post‐hoc test, when appropriate, using Statistica 7.0 (StatSoft, Inc., 1984–2004). The Pearson correlation matrix between body mass change, digestible energy intake, the dietary contents of NDF, the apparent digestibility coefficients of nitrogen, and nitrogen balance was employed using the same software.
Metabolic fecal nitrogen (MFN, g N/kg of dry matter intake‐DMI) was estimated as the negative y‐intercept of the regression of digestible nitrogen (g/kg DMI) against dietary
nitrogen (g/kg DM). True nitrogen digestibility was estimated as the slope of the regression line. The y‐intercept of the regression of daily excretion of urinary nitrogen (mg N/kg0.75) against daily dietary nitrogen intake (mg N/kg0.75) provided an estimate of daily endogenous urinary nitrogen (EUN, mg N/kg0.75). The daily maintenance nitrogen requirement of peccaries was estimated as the x‐intercept of the regression of N balance (N ingested N excreted, mg N/kg0.75) against daily dietary N intake (mg N/kg0.75). Data from two peccaries, animal 2 on diet 1 and animal 3 on diet 2 were omitted when calculating MFN and EUN because they inexplicably lost> 5% of their body mass during the trial. The lost body mass may have included metabolized body protein, biasing estimates of MFN and EUN.
Minimum dietary crude protein (%CP as percentage of dry diet) was derived from the equation [(EUNþ MFN (DMI) 6.25)/DMI/0.74 100] [Robbins, 1993]. Where EUN and MFN are the maintenance nitrogen requirements estimated as function of the body‐weight and dry‐matter intake (DMI), 6.25 is the nitrogen to crude protein correction factor; 0.74 is the usefulness of dietary protein in meeting the maintenance requirements and is composed of digestion (0.93) and retention (0.80) coefficients. To apply this equation, we used the metabolic weight and dry matter intake‐DMI of the animals when receiving each one of the four diets.
The data, where appropriate, are presented scaled to the 0.75 power of body mass (kg0.75) to allow for easier between‐ species comparisons. The regression analyses were per-formed with GLM and REG of SAS, besides the SAS/ INSIGHT and SAS/GUIDED procedures (version 8.02, 2001; Statistical Analysis Systems, Cary, NC) and, prior to all analyses, the Lilliefors test was applied for testing the normal distribution of data using Statistica 7.0 (StatSoft, Inc., 1984– 2004). In all statistical tests, a P value< 0.05 was considered significant.
RESULTS
We found no difference in dry matter (DM) intake, digestible energy (DE) intake, or apparent dry matter digestibility and apparent energy digestibility among the four diets (Table 2). Mean daily intake of digestible energy over all diets was 557.7 80.4 kJ/kg0.75. Two peccaries, animal 2 on diet 1 and animal 3 on diet 2, however, showed DE intake of just 364.1 and 387.3 kJ/kg0.75, respectively. Despite this, there was no relationship between body mass change either with the digestible energy intake (rPearson¼ 0.17, P > 0.05) or with the nitrogen balance (rPearson¼ 0.44, P > 0.05, Table 2). There was, however, a relation-ship between the different intakes of N, according to the fed diets, and the apparent digestibility coefficients of nitrogen (rPearson¼ 0.74, P < 0.05). Also there was an inverse correlation between the dietary contents of NDF and the apparent digestibility coefficients of nitrogen (rPearson¼ 0.91, P < 0.05). In addition, there was no relationship
between the intake of N and the levels of fecal N (F¼ 2.36, P> 0.05) (Table 2). In contrast, apparent digestible N was linearly related to the N content of diets (F¼ 4822.91, P< 0.05), according to the regression equation y ¼ 0.98x 3.13; R2¼ 0.99 (P < 0.05). MFN was 3.1 g N/kg dry matter intake (DMI), and true N digestibility was 0.98. Urinary N excretion increased linearly with N intake (F¼ 20.29, P< 0.05, Fig. 1). EUN was 91 mg/kg0.75/day. Nitrogen balance was positively related to total N intake (F¼ 130.10, P< 0.05, Fig. 2). White‐lipped peccaries were estimated to require a minimum N intake of 336.5 mg N/kg0.75/day. Dietary protein requirements are predicted to vary with DMI, and they were estimated to require 4.5% CP in the diet for an adult white‐lipped peccary weighing 37 kg and showing a DMI equal or higher than 40 g/kg0.75or 588 g/day (Fig. 3).
DISCUSSION
In the present study, there was a correlation between the intake of N and the digestibility coefficient of N: the higher the level of N in the diet, the higher the digestibility coefficient. This probably explained why the apparent digestibility coefficients of N in this study, up to 0.95, were higher than the ones determined by Moraes [1992] and by Comizzoli et al. [1997], which ranged between 0.76 and 0.85. In these previous studies the authors used lower levels of crude protein than tested in the current trial. The apparent digestibility coefficients of N obtained were also higher than the ones determined for collared peccaries by Carl and Brown [1985], which ranged between 0.62 and 0.85, probably due to the higher levels offiber furnished in this previous study. Carl and Brown [1985] determined the protein requirements of the collared peccary, testing four diets withfiber levels ranging
TABLE 2. Means of body mass change, intake and apparent digestibility coefficients of dry matter, energy, nitrogen (N), of four captive white‐lipped peccaries fed four isoenergetic diets with different levels of N
Item Diet 1 Diet 2 Diet 3 Diet 4 SEM
Body mass, kga 36.0 38.4 37.2 37.3 0.8
Body mass change, g/day 24.2 21.2 17.8 25.6 6.0
Dry matter
Intake, g/kg0.75/day 35.6 33.1 32.7 32.4 1.4
Apparent digestibility coefficient 0.91 0.88 0.89 0.88 0.00
Digestible energy
Intake, kJ/kg0.75/day 596.6 522.9 561.0 525.9 5.9
Apparent digestibility coefficient 0.91 0.89 0.89 0.89 0.0
Nitrogen
Intake, mg/kg0.75/day 473.3a 636.8a 937.5b 1106.4b 36.8
Fecal, mg/kg0.75/day 81.2 76.6 49.6 48.0 25.4
Urinary, mg/kg0.75/day 215.5a 275.9a 389.6b 452.2b 21.0
Balance, mg/kg0.75/day 185.3a 306.5a 535.9b 603.2b 27.7
Apparent digestibility coefficient 0.83a 0.88b 0.95c 0.95c 0.19
SEM, standard error of the mean. Means on the same line with different letters differ (P< 0.05) by Tukey’s post hoc test.aMeans of all four white‐lipped peccaries when on each diet.
Fig. 1. Relationship between intake of nitrogen (N) and the amount of N excreted in urine, according to the regression equation: y¼ 91.0 0.30x; R2¼ 0.76, P < 0.05. Endogenous urinary nitrogen (EUN) is the y‐intercept.
from 285 to 340 g/kg of acid detergentfiber and from 421 to 473 g/kg of neutral detergentfiber, which were higher than the ones used in the current trial. Moreover, we verified that nitrogen apparent digestibility was inversely related with the dietary contents of NDF.
In line with this study, Carl and Brown [1985] also found relatively constant levels of fecal N, along with an increase in N intake by collared peccaries. According to the authors, this explained the increment in apparent digestibility coefficients of N, along with the increase in N in the diets. In beef cattle, Ribeiro et al. [2001] also recorded a linear
increase in N urinary excretion without influence on fecal excretion of N after an increase in N intake, and suggested that this is explained by excessive ammonia production by ruminal bacteria. This excess is absorbed by the walls of the rumen, leading to increased excretion of urea into urine [Ribeiro et al., 2001]. White‐lipped peccaries, therefore, apparently underwent the same process as true ruminants. Thus it is possible that, along with the increment of N in the peccaries’ diets, bacteria may have increased the synthesis of ammonia, which was not used because there was no increase in the intake of energy, which was similar between diets.
Fig. 2. Relationship between nitrogen (N) balance and daily intake of N according to the regression equation: y¼ 0.79x 265.72, R2¼ 0.94, P < 0.05.
Fig. 3. Minimum dietary protein content necessary to meet nitrogen balance for captive white‐lipped peccaries. Line was derived from the equation [(EUNþ MFN(DMI) 6.25)/DMI/0.74 100] [Robbins, 1993]. EUN, endogenous urinary nitrogen; MFN, metabolic fecal nitrogen; DMI, dry matter intake.
Despite the lack of references to absorption mechanisms in white‐lipped peccary, it is possible that the excess ammonia potentially was absorbed by the wall of the peccaries’ forestomach and metabolized in the liver, where it was transformed into urea and excreted in the urine, although this is speculative.
The MFN loss estimated in this study, at 3.1 g N/kg dry matter intake (DMI), is near to the one estimated at 2.6 g/ kg DMI for the frugivorous ruminant, blue duiker, living on fruit, browsing, and eating a concentrate diet [Shipley and Felicetti, 2002], but lower than the loss of MFN 4.1 g/kg DMI for collared peccary receiving concentrates and forage [Carl and Brown, 1985] and wild ruminants, such as Bison bison and Bos mutus on a forage diet, whose MFN are 4.1 and 4.6 g N/kg DMI, respectively [Robbins, 1993]. High‐fiber diets result in higher excretion of MFN than do more grain‐ based concentrate diets [Robbins, 1993]. As highlighted by Clauss et al. [2014], both MFN and true N digestibility are diet specific, thus, a different diet yields a different result. Therefore, the low level of MFN excretion in white‐lipped peccary may probably be explained by the low levels offiber used in this study.
The level of EUN obtained for white‐lipped peccary— 91 mg/kg0.75/day—was close to the values of EUN in browser ruminants such as the red deer (Cervus elaphus) and white‐tailed deer (Odocoileus virginianus), 90 and 115 mg N/kg0.75/day, respectively, when consuming concen-trates and forage diets [Robbins, 1993]. However, Carl and Brown [1985] estimated EUN values for collared peccary at 177 mg N/kg0.75/day, while Shipley and Felicetti [2002] estimated EUN at 194 for blue duiker, quite noticeably higher than those obtained in this study. This difference can be explained by the sub‐maintenance intake of energy in the collared peccary study. The same may possibly have occurred in the blue duiker study, because infive out nine diets the animals lost body mass [Shipley and Felicetti, 2002]. In N balance studies it is necessary to furnish an adequate amount of energy to prevent unnecessary loss of protein catabolism tissue of the animal by the gluconeogenesis process [Robbins, 1993]. In the current study, there was no correlation between digestible energy intake and nitrogen balance or between digestible energy intake and body mass change. The animals thus ingested enough energy without the catabolism of their protein tissues, as has previously occurred in a nutritional balance study with the collared peccary [Carl and Brown, 1985]. The white‐lipped peccary’s nitrogen daily requirement —minimum N intake of 336.5 mg N/kg0.75
/day—was near to that of domestic ruminants (Nellore cattle: 431 mg N/kg0.75) fed with forage and concentrate diets [Véras et al., 2007], but lower than that of red deer (680 mg N/kg0.75/day) and white‐tailed deer (710 mg N/kg0.75/day), receiving forage and concentrate diets [Robbins, 1993], and the blue duiker (643.3 mg N/kg0.75/day), receiving fruit, browsing, and eating a concentrate diet.
The slightly lower N requirement for white‐lipped peccaries than for ruminants can be explained by the low
MFN excretion, probably due to the low levels offiber used in this study, as mentioned above. This proximity to ruminants in relation to N requirement supports the proposition of Langer [1978, 1979] that peccaries have a digestive physiology that is closer to ruminants than to domestic pigs. Indeed, the minimum requirement for protein (4.5% CP as percentage of dry diet) for the white‐lipped peccary based on the current study, if food intake is unrestricted, is near to the requirements of the frugivourous ruminant blue duiker, which is around 4.0% CP as percentage of dry diet [Shipley and Felicetti, 2002]. In contrast, the white‐lipped peccary requirement for CP is almost 40% of the level recommended for the maintenance of domestic pigs which is 12% CP as percentage of dry diet [Rostagno et al., 2005]. However, free‐ranging wild swine species, which are herbivores most of the time and have some fermentative capacities in the hindgut, such as the babirusa (Babyrousa babyrussa) [Clauss et al., 2008], require a similar low proportion of crude protein in their diet to the white‐lipped peccary. The exact nutritional requirements of the babirusa remain unknown, but Leus and Morgan [1995] estimated from studies carried out on domestic pigs that an adult babirusa weighing 90 kg requires 82 g of crude protein per day. Such data allow us to estimate that, with a daily dry matter intake ranging from 1,170 g/day (40 g/kg0.75) to 2,000 g/day (68 g/ kg0.75), a 90 kg babirusa requires from 7.0 to 4.1% CP as percentage of dry diet. Despite this, the relatively low protein requirements of white‐ lipped peccaries, besides its high ability to digest protein described in this study, may explain how this species thrive in the Neo‐tropical region eating predominantly palm‐fruits that normally have low crude protein contents.
CONCLUSIONS
1. With MFN of 3.1 g/kg DMI, and EUN of 91 mg/kg0.75/day, the white‐lipped peccary requires 336.5 mg N/kg0.75/day, which is similar to the requirement of domestic ruminants and slightly lower than to those of browser and frugivorous wild ruminants. As a note of caution, however, we emphasize that these data are diet specific—a different diet yields a different result.
2. The low nitrogen maintenance requirements of white‐ lipped peccary reinforce the proposition that peccaries’ digestive physiology is nearer to that of domestic and wild ruminants than domestic pigs and may explain how white‐ lipped peccary thrive in the Neo‐tropical region eating predominantly palm‐fruits with low levels of crude protein. ACKNOWLEDGMENTS
The authors thank Marcus Clauss and an anonymous referee for their relevant valuable comments on the manuscript. Research for this manuscript was supported by the Conselho Nacional de Desenvolvimento Científico e Tecnológico(CNPq) (Process#476033/2010‐1). Sérgio Nogueira‐Filho, Rogério Borges and Carlos Dias were
supported by the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq Process# 305428/2012‐8, 555859/2010‐0, and 300306/2012‐1, respectively). Alcester Mendes was supported by the Coordenação de Aperfeiçoa-mento de Pessoal de Nível Superior (CAPES/PNPD).
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