Pithecellobium dulce, Tagetes erecta and Cosmos bipinnatus on reducing enteric methane emission by dairy cows

Pithecellobium dulce, Tagetes erecta e Cosmos bipinnatus na redução de emissão de metano por vacas leiteiras

ABSTRACT:

The aim of the present research was to evaluate the effect of Pithecellobium dulce, Tagetes erecta and Cosmos bipinnatus on methane emission, milk yield and dry matter intake in dairy cattle. A 4×4 Latin square experimental design was employed, using four multiparous Holstein cows of 553±72.4kg body weight, at mid lactation and average milk yield of 17.3±3kg/day. The experiment lasted 92 days, divided into four experimental periods of 23 days each. All cows had free access to maize and alfalfa silage in a 50:50 proportion, 4kg of concentrate/day and ad libitum access to water. Treatments consisted in supplementation of 0.5kg/day of the experimental plants, with one control treatment without supplementation. Each cow received one of each treatment in turn during one of the four periods. The C. bipinnatus reduced methane production by 16% (P<0,05) in comparison with the control diet. Milk production, milk composition and dry matter intake were not affected (p>0 0.05) by the use of C. bipinnatus or any other plant species. Supplementation at low doses of C. bipinnatus showed a reduction in ruminal methane production in dairy cows.

Key words:
methane; cattle; climate change; mitigation; tannins

RESUMO:

O objetivo deste estudo é avaliar o efeito do Pithecellobium dulce, Tagetes erecta e o Cosmos bipinnatus na emissão do metano, a produção de leite e de ingestão diária de matéria seca pelo gado. Um desenho experimental do quadrado latino 4x4 foi usado, com quatro vacas da raça Holandesa, multíparas, de 553±72,4kg, no seu segundo terço da lactação e rendimento médio de leitedo de 17,3±3kg/dia. O experimento durou 92 dias e foi dividido em quatro períodos de 23 dias cada um. Das vacas tinham acesso livre a milho e silagem de alfafa, numa proporção de 50:50, com 4kg de concentrado por dia, com acesso a água ad libitum. Os tratamentos consistiram na ingestão de 0,5kg por dia, com as plantas experimentais; as vacas no tratamento de controle não receberam nenhuma planta, porém, elas receberamum tratamento, em cada um dos quatro períodos. O C. bipinnatus reduziu significativamente a produção de metano em 16% (P<0,05), em comparação com a dieta controle. A produção de leite, sua composição e o consumo de matéria seca não foram afetados (P>0,05) pelo uso de C.bipinnatus ou outras espécies de plantas. A ingestão com doses baixas de C. bipinnatus, que é uma planta arbustiva com um centéudo moderado de taninos, mostrou ter potencial para reduzir a produção de metano ruminal em vacas leiteiras.

Palavras-chave:
metano; gado; mudança climática; mitigação; taninos

INTRODUCTION:

The main sources of anthropogenic methane (CH₄) are the production of ruminants for meat and milk production, the extraction and use of fossil fuels, and rice production. Agriculture contributes to approximately 13% of the total global emission of greenhouse gases (GHG) (IPCC, 2014), of which cattle are responsible for 53% (CHARMLEY et al., 2016). Thus, several studies, mostly in vitro experiments, have been conducted on the effect of tanniferous plants on reducing rumen CH₄ production, in order to find natural alternatives to mitigate the environmental impact generated by the emissions of this GHG by the cattle industry (CUARTAS et al., 2014). However, results in literature are contradictory, because in some cases a small methane reduction has been observed whereas in others a large reduction potential was identified. For example, NAUMANN et al. (2013) observed a small CH₄ reduction of 3.2% and 0.5% in an experiment conducted to evaluate the in vitro effect of two types of Acacia angustissima - the South Texas ecotype and Cross timbers ecotype - with a condensed tannin content of 8.4% and 8.9%, respectively. Similarly, in a study conducted by BHATTA et al. (2009) in order to evaluate the effect of different tannins (in their pure form) on in vitro CH₄ production, it was observed that hydrolysable tannins reduced CH₄ production by only 0.6%, while a mixture of hydrolysable and condensed tannins reduced it by 5.5%. Unfortunately, there are few studies where the effects of entire tanniferous plants on rumen methano genesis in cattle and animal performance have been evaluated in vivo (PATRA & SAXENA 2010). For example, BEAUCHEMIN et al. (2007) conducted an experiment to determine if 1% and 2% of dietary DM as condensed quebracho tannin extract could be used to reduce enteric CH₄ emissions in cattle. They used six spayed Angus heifers and 6 Angus steers and concluded that feeding with up to 2% of dietary DM as quebracho tannin extract failed to reduce enteric methane emissions from growing cattle. No information was reported in the literature on the in vivo anti-methanogenic properties of Tagetes erecta, Cosmos bipinnatus and Pithecellobium dulce. However, our group conducted several in vitro studies to evaluate the potential of Tagetes erecta for reducing CH₄ production; for example, ANDRADE et al. (2012) observed a reduction of 39% in comparison with a control diet. Similarly, MAHMOUD et al. (2016) reported a 35% reduction (p<0.05) in methane production in comparison with a control diet when only 10% dietary dry matter (DM) of T. erecta was included in the diet. Likewise, a reduction of 11% (P<0,001) in methane production was also reported by MAHMOUD et al. (2017) with the inclusion of only 10% of dietary DM of C. bipinnatus in the experimental diet. These studies also suggested that the anti-methanogenic capacity of T. erecta and C. bipinnatus is not linear but quadratic, and that the best effect was observed at low inclusion levels. Therefore, it was hypothesized that T. erecta, C. bipinnatus and P. dulce could reduce in vivo methane production and that this effect could be detected at low inclusion levels without affecting animal productive performance. The objective of the present study was to evaluate the effect of supplementation of Tagetes erecta, Cosmos bipinnatus and Pithecellobium dulce on reducing enteric methane emission, and on milk production and dry matter intake in dairy cattle.

MATERIALS AND METHODS:

Area of study

The experiment was conducted at the Laboratory for Research on Livestock, Environment and Renewable Energies of the Faculty of Veterinary Medicine and Animal Science of the Universidad Autónoma del Estado de México, located in Toluca, State of Mexico, Mexico at 19°27’N and 98° 38’W and 2600m.a.s.l.

Experimental design:

A 4×4 Latin square experimental design was employed, using four multiparous Holstein cows of 553±72.4kg of body weight, at mid lactation and average milk yield of 18±3kg/day. The experiment lasted 92 days, which were divided into four experimental periods of 23 days each. All cows had free access to maize-alfalfa silage in a 50:50 proportion, 4kg of concentrate/day and ad libitum access to water. The concentrate was composed of 48.7% corn, 20% soya bean, 14.8% canola bean, 14.7% wheat bran and 1.8% of mineral premix. The four treatments consisted of the supplementation of 0.5kg DM/day/cow for each of the three experimental plants plus the control, which was the diet alone without the addition of experimental plants. Each cow received each treatment in turn, once in each of the four periods. Before the beginning of the trial, the experimental plants were dried over a period of 8 weeks away from sunlight to prevent denaturalization of phenolic compounds as indicated in MAKKAR et al. (1993). Once dried they were ground and incorporated into the concentrate to ensure that the cows would eat the entire daily ration provided, as the aim of the experiment was to evaluate the effect of the entire plants and not only the effect of the phenolic compounds within them. Samples of the experimental plants were collected for later chemical analysis in the laboratory. For each 23-day experimental period, 15 days were used for diet adaptation and the remaining to measure methane production, dry matter intake and digestibility of the diet. The cows were confined in individual pens of 4×4m, equipped with drinker and trough, throughout the experiment. Milk yield was weighed daily during the entire 23-day period and milk composition was evaluated daily during the measuring period of eight days. A Lactichek ^™-01 (Rapi Read, Page & Pedersen International Ltd. Hopkinton, Massachusetts) analyzer was used to determine milk composition: fat, lactose, protein, non-fat milk solids. Body weight was measured once at the beginning and once at the end of each experimental period. We used adult cows and the body weight was recorded only. Dry matter intake (DMI) was determined by weighing the silage and concentrate offered in the morning and collecting and weighing the rejected feed the next morning. The difference between the offered feed minus the rejected feed was the daily DMI. Digestibility of the dry matter (DMD) was calculated as shown in equation (1). Samples of silage were taken every week for later chemical analyses in the laboratory.

$\mathit{DMD}\left(\%\right)=\left(\frac{(\mathit{DMI}-\mathit{FAe})}{\mathit{DMI}}\right)\times 100$ Eq. (1)

Where: DMI=dry matter intake in kg ofDM,FAe=feces weight in kg of DM.

Methane production measurement:

The CH₄ production was measured with a respiration chamber of the head-box type as described previously in PEDRAZA-BELTRÁN et al. (2016). The CH₄ analyzer that was used measures emissions highly accurately over a wide range by combining noise amplification and signal processing with a computerized controller and digital filtering to provide a maximum resolution of 0.0001% to 0.01%. Before each assay two calibrations of this instrument were performed: a zero calibration using high-purity nitrogen (N₂) (Praxair Inc., Mexico), and a calibration against a reference gas, which is also known as a span gas. The N₂ in the zero calibration was first passed through a drying unit to remove moisture and then through the analyzer at a flow rate of 0.3L/min to obtain a reading close to zero. The span calibration was performed using a known CH₄ concentration gas mixture (1000ppm of CH₄ in high-purity N₂). The span gas passed through the analyzer (0.3L/min) to obtain a reading corresponding to the concentration of CH₄ in the span gas. Every assay started at 10:00h, the mass flow generator was set at 480L/min, the analyzer was set to measure CH₄ concentration every second and then the chamber was closed. The CH₄ emissions were measured for 24-h period. The cows were removed from the chamber for milking at 6:00h and 15:00h, and each milking lasted 1.5h, subsequently they were returned to the chamber. The diet was weighed before the beginning of the assay, and all animals were given the same amount at the same time (9:00h and 16:00h). The next morning, the orts were removed and weighed to calculate DMI. Diet samples were collected and kept in a freezer until laboratory analysis. Feces were collected and weighed at the end of each measurement. A sample of approximately 1kg of feces was obtained and kept frozen until laboratory analysis. Four assays were completed in each experimental period.

Chemical analysis of the feed

Silage, concentrate feed and stool samples were dried in a forced air oven at 60°C for 72h until constant weight was obtained, then later ground and passed through a 1-mm sieve. The DM and organic matter (OM) contents were determined according to the procedures of the Official Methods of Analysis (AOAC, 1997). The nitrogen content in the silage and concentrate was determined by the Kjeldhal method (AOAC, 1997), and subsequently multiplied by a factor of 6.25 to obtain the protein content. The neutral detergent fiber (NDF), acid detergent fiber (ADF) and lignin contents were determined by the method of VAN SOEST et al. (1991) using an ANKOM A200 fiber analyzer (Technology Corporation, Fairport, NY, USA). The DM content in the silage was corrected as in HAIGH (1995) to include the volatile solids in the DM. The concentration of total phenols in the experimental plants was determined by the Folin-Ciocalteu method and the tannin content by the polyvinylpolypyrrolidone method as described in MAKKAR (1993). Table 1 shows the chemical composition of silage and concentrates, and the phenol and tannin content of the experimental plants.

Table 1
Chemical composition of the silage and concentrate; and chemical composition, total phenols and total tannin concentration of the experimental plants (all in g/Kg of DM, except DM, which is g/Kg).

Item	Concentrate	Silage	Pithecellobium dulce	Cosmos bipinnatus	Tagetes erecta
DM	888.5	367.2	931.5	928.1	931.5
OM	826.4	890.8	852.8	821.7	846.6
CP	221.1	108.4	90.5	115.2	137.2
NDF	340.7	517.8	527.1	470.5	458.7
ADF	123.5	390.3	468.3	387.3	403.8
Lignin	40.2	102.2	184.0	96.2	76.4
Hemicellulose	217.2	127.5	58.7	83.2	54.9
Cellulose	83.3	288.1	284.3	291.1	327.4
Total phenols	-	-	49.2	80.6	99.4
Total tannins	-	-	22.8	69.7	78.1

• OM organic matter, CP crude protein, NDF neutral detergent fiber, ADF acid detergent fiber.

Analysis of results

The experimental variables were analyzed with an analysis of variance for a Latin square experimental design as shown in equation 2. In order to eliminate Type II error (KAPS & LAMBERSON 2009) the Fisher’s Least Significant Difference (LSD) test between control and treatment means was also carried out. The analytical procedures were carried out using the lmer function of the lme4 package (BATES et al., 2015) in R software (R core team, 2016). Post hoc pairwise comparison was carried out using the Tukey HSD test using the lsmeans function in the lsmeans package (LENTH, 2016).

$Y_{\mathit{ijk}}=\mu +{\mathit{TX}}_i+{\mathit{Per}}_j+{\mathit{Cow}}_k+\mathrm{ijk\epsilon }$…Eq. (2) where Y_ijk is the individual observation, µ is the overall mean, TX_i is the fixed effect of treatment (i =1, 2, 3, and 4), Per_j is the effect of period (j=1, 2, 3, and 4; treated as a random effect), Cow _k is the effect of cow (k=1, 2, 3, and 4; treated as a random effect) and ε_ijk is the residual error term. A multiple correlation analysis between all variables was also performed in order to find associations that help in explaining CH₄ production. The corr plot routine from the corr plot v.0.77 package (WEI & VILIAM 2016) of the R software v.3.2.2. was used (R, CORE TEAM, 2011).

RESULTS:

Table 2 shows the effect of the experimental plants on DMI, DMD, milk yield and CH₄ production. Results show that no differences (P>0,05) were observed between the control and the treatments for all variables except for CH₄ production. The treatment with C. bipinnatus reduced CH₄ production by 98.2L/day (<16%) relative to the control (P<0,05), whereas P. dulce and T. erecta showed no effect on CH₄ production (P>0,05). The LSD between the control and P. dulce was 86.9L/day (P<0,05). All the productive parameters, such as body weight, milk yield, DMI and DMD were not affected by any of the plants tested at the level they were supplemented. Percentages of each plant in relation to the total dry matter intake for the treatments of control, P. dulce, C. bipinnatus and T. erecta were 3.5, 2.6, 3.6 and 3.1%, respectively. Milk composition was also unaffected (P>0,05) by the experimental plants, as shown in Table 3. The multiple correlation analysis showed positive associations between CH₄ L/day and DMI (r=0,5, P<0,05), and between DMD and CH₄ L/day (r=0.6, P<0,01). In contrast, a negative association (r=-0.64, P<0,001) was observed between milk yield and CH₄ in L/Kg of milk. No other association was observed among the studied variables. A large numerical difference of 22.4L was observed between the control and P. dulce treatments for the variable CH₄, L/kg of DMD; however, this was not significant since the LSD is 53 L (P>0,05).

Table 2
Effect of supplementation with P. dulce, C. bipinnatus and T. erecta on methane production, dry matter intake, dry matter digestibility, live weight and milk yield.

--------------------------------------------Treatment----------------------------------------------
Item	Control	Pithecellobium dulce	Cosmos bipinnatus	Tagetes erecta	S.E.	P value
Live weight, Kg	568±63	583±57	576±68	569±69	5.6	0.31
DMI, kg DM/d	14.7±3	19.7±6	14.5±3	16.8±4	1.9	0.28
DMD, %	55.6±6	62.8±9	58.8±16	62.5±12	7.3	0.71
CH4, L/d	613.5±97a	635.5±105a	515.3±41b	541.5±49ab	25.1	0.04
Milk, Kg/d	17.3±3	17.4±3	16.9±3	15.7±3	0.95	0.6
CH4 , L/Kg of DMI	43±11	34±8	36.7±7	33.3±7	4.8	0.41
CH4, L/Kg of DMD	76.9±29	54.5±20	64.8±25	55.4±25	15.3	0.7
CH4, L/Kg of milk	36.9±9	38±12	30.8±3	34.9±5	2.63	0.35

• ±= standard deviation, S.E.= standard error, DMI= dry matter intake, DMD= dry matter digestibility, values in the same row with different superscripts indicate differences p<0.05.

Table 3
- Effect of supplementation with P. dulce, C. bipinnatus and T. erecta on milk composition (%).

----------------------------------------Treatment------------------------------------------
Item	Control	Pithecellobium dulce	Cosmos bipinnatus	Tagetes erecta	S.E.	P value
Fat	4.2±0.70	3.7±0.10	3.9±0.86	4.0±0.55	0.18	0.41
Protein	3.4±0.08	3.3±0.07	3.4±0.16	3.4±0.08	0.03	0.19
Non-fat solids	9.0±0.20	8.8±0.20	9.1±0.41	9.0±0.21	0.09	0.15
Density	31.2±0.36	30.7±0.82	31.8±1.10	31.4±0.49	0.30	0.18

• ±= standard deviation. S.E.= standard error.

DISCUSSION:

The CH₄ production for individual cows in the control treatment was within the range reported for animals of similar body live weight and intake (NIU et al., 2016). On the other hand, the percentage of CH₄ reduction was achieved due to the inclusion of C. bipinnatus and was comparable to the values reported in similar studies, even though the percentage of plants in the diet and the tannin content, 2.6% and 69.7g/kg of plant’s DM respectively, were lower than in most published studies. This confirmed our hypothesis that the supplementation of small quantities of this experimental plant can reduce in vivo methane emission by adult cows. The inclusion rate of experimental plants in our research ranged from 2.6 to 3.1% of the average total DMI, whereas in similar studies the supplementation rate is significantly higher. For example, PIÑEIRO et al. (2017) evaluated the effect of increasing levels of Leucaena leucocephala (0, 20, 40, 60 and 80%) on methane production in heifers fed with a low-quality diet. The DM intake in their work ranged from 7 to 7.15kg of DM/day, meaning that the intake of L. leucocephala reached up to 5.72kg of DM/day at an 80% inclusion level. In other studies, the tanniferous plant constituted 100% of the diet, as in in WOODWARD et al. (2002), where dairy cows were fed only with Hedysarum coronarium with no effect on daily CH₄ production. The reduction in methanogenesis observed for C. bipinnatus may be attributed to the higher content of total tannins than P. dulce, although T. erecta has more tannins than C. bipinnatus. This suggested that it may be the type of tannins, particularly condensed tannins that may be responsible for the reduction in methane emissions. For example, it was reported by MAHMOUD et al. (2017) that the percentage of condensed tannins in the total tannin content of C. bipinnatus (same plant, same region) is 11.7%, whereas that for T. erecta is only 1.2%. This is in line with IVES et al. (2015), who evaluated the effect of condensed tannins from an extract of Acacia molissima (50g/Kg of diet DM) on in vitro CH₄ production in five different species of ruminants and found that tannins from A. molissima reduced CH₄ production by up to 12% in Holstein cows. Similarly, MOREIRA et al. (2013) tested the effect of condensed tannins from Leucaena leucocephala, Styzolobium aterrimum and Mimosa caesalpiniaefolia on CH₄ production in sheep, and reported that condensed tannins (40g/Kg of diet DMI) of L. leucocephala reduced CH₄ production by 25%, S. aterrimum by only 1%, while M. caesalpiniaefolia increased it by 7%. However, they had to increase the inclusion level of L. leucocephala and S. aterrimum by up to 82% and 69%, respectively, in order to achieve the reduction reported. Furthermore, at the inclusion level employed by MOREIRA et al. (2013), it is difficult to elucidate if the mitigation effect can be attributed to the condensed tannins in the legumes alone, as they stated, to other secondary metabolites in the plants (VERCOE 2015), or to the chemical composition of the plants themselves. This is because it is well established that diets with a high content of legumes produce less CH₄, due to their low fiber content, than diets rich in grasses (ARNDT et al., 2014). TAVENDALE et al. (2005), who conducted an in vitro experiment to evaluate the CH₄-reducing potential of Lotus pedunculatus and Medicago sativa, also reported a discrete reduction in CH₄ production. They observed that M. sativa reduced CH₄ production by 5% despite the fact that it only had 0.2g/kg of DM of condensed tannins, whereas L. pendunculatus, with a higher concentration of condensed tannins (107g/kg of DM), had no effect on CH₄ production. The approximate content of condense tannins of the diet with C. bipinnatus was 0.28g/Kg of diet DM, which is very similar to that reported by TAVENDALE et al. (2005). Indeed, it seems that the CH₄ reduction potential of tannins is not dose dependent, because high doses do not always lead to less CH₄ production (BHATTA et al., 2009); whereas “low doses, as in the present study, seem to produce similar effects to those reported by the previous authors. This pattern of response was elegantly demonstrated by MAHMOUD et al. (2017) in an in vitro experiment that established that the response is not linear, but quadratic, and that there is an interaction (P<0,01) between the plants species and the level of inclusion in the diet for CH₄ production. The positive associations between CH₄ L/day and DMI (r=0.5, P<0,05) and between DMD and CH₄ L/day have been reported before, because intake is the most important variable that determines CH₄ production; similarly, more CH₄ will be produced in response to more degraded substrate (HALES et al., 2013). In contrast, the negative association observed between milk yield and CH₄ in L/Kg of milk has been reported before by GARG et al. (2013) where increased milk yield per cow was associated with lower methane production per kilogram of milk produced. In fact, intensification of milk production is considered an option for mitigating CH₄ production in dairy systems (GERBER et al., 2011).

CONCLUSION:

It can be concluded that supplementation at low doses with C. bipinnatus has the potential to reduce ruminal methane production in dairy cows without affecting animal production parameters. More research is needed in order to determine whether higher levels of C. bipinnatus may lead to further reduction in rumen methanogenesis. Also more research is needed for higher supplementation doses of T. erecta because it showed a trend towards reducing methanogenesis.

ACKNOWLEDGEMENT

The authors acknowledge the financial support from the Molina Center for Energy and the Environment (UNEP Contract GFL-4C58), the Universidad Autónoma del Estado de México (grant UAEM 3474/2013CHT), and CONACYT (grant CB2013-223418). Gloria Hernández-Pineda thanks CONACYT, Mexico for the scholarship for her MSc. The advice of Dr. Juan Carlos Ángeles-Hernández on the statistical analysis is acknowledged.

REFERENCES:

• AOAC International. 1997. Official Methods of Analysis. 16th ed. AOAC Int., 344 Gaithersburg, Maryland : Association of Official Analytical Chemists International.
• ARNDT C, et al, Performance digestion, nitrogen balance, and emission of manure, ammonia, enteric methane, and carbon dioxide in lactating cows fed diets with varying alfalfa silage-to corn silage ratios. J. Dairy Sci, v.98, p.418-430, 2014. Available from: <Available from: https://www.journalofdairyscience.org/article/S0022-0302(14)00774-7/pdf >. Accessed: Aug. 29, 2018. doi: 10.3168/jds.2014-8298.
  » https://doi.org/10.3168/jds.2014-8298.» https://www.journalofdairyscience.org/article/S0022-0302(14)00774-7/pdf
• ANDRADE RE, et al. Producción de metano utilizando plantas taníferas como substrato en fermentación ruminal in vitro y efecto de extractos fenólicos en la microflora ruminal. Trop Sub Agro, v.15, p.301-312, 2012. Available from: <Available from: http://www.revista.ccba.uady.mx/urn:ISSN:1870-0462-tsaes.v15i2.841 >. Accessed: Aug. 29, 2018.
  » http://www.revista.ccba.uady.mx/urn:ISSN:1870-0462-tsaes.v15i2.841
• BATES D, et al. Fitting Linear Mixed-Effects Models Using lme4. Journal of Statistical Software. 2015: 67(1): 1-48. Available from: <Available from: https://www.jstatsoft.org/article/view/v067i01/0 >. doi: 10.18637/jss.v067.i01. Accessed: Aug. 29, 2018.
  » https://doi.org/10.18637/jss.v067.i01» https://www.jstatsoft.org/article/view/v067i01/0
• BEAUCHEMIN KA, et al. Use of condensed tannin extract from quebracho trees to reduce methane emissions. J. Anim. Sci. 85; 1990-1996, 2007. Available from: <Available from: https://academic.oup.com/jas/article-abstract/85/8/1990/4778278?redirectedFrom=fulltext >. doi: 10.2527/jas.2006-686. Accessed: Aug. 29, 2018.
  » https://doi.org/10.2527/jas.2006-686» https://academic.oup.com/jas/article-abstract/85/8/1990/4778278?redirectedFrom=fulltext
• BHATTA R, et al. Difference in the nature of tannins on in vitro ruminal methane and volatile fatty acid production and on methanogenic archaea and protozoal populations. J. Dairy Sci. 2009; 92:5512-5522. Available from: <Available from: https://www.journalofdairyscience.org/article/S0022-0302(09)70886-0/pdf >. doi: 10.3168/jds.2008-1441. Accessed: Aug. 29, 2018.
  » https://doi.org/10.3168/jds.2008-1441» https://www.journalofdairyscience.org/article/S0022-0302(09)70886-0/pdf
• CHARMLEY E, et al. A universal equation to predict methane production of forage-fed cattle in Australia. Anim. Prod. Sci. 2016; 56: 2-3. Available from: <Available from: http://www.publish.csiro.au/AN/an15365 >. doi: 10.1071/AN15365. Accessed: Aug. 29, 2018.
  » https://doi.org/10.1071/AN15365» http://www.publish.csiro.au/AN/an15365
• CUARTAS CA, et al. Contribution of intensive silvopastoral systems to animal performance and to adaptation and mitigation of climate change. Rev. Colomb. Cienc. Pecu. 2014; 27:76-94. Available from: <Available from: http://www.scielo.org.co/scielo.php?script=sci_arttext&pid=S0120-06902014000200003 >. Accessed: Aug. 29, 2018.
  » http://www.scielo.org.co/scielo.php?script=sci_arttext&pid=S0120-06902014000200003
• GARG MR, et al. Effects of feeding nutritionally balanced rations on animal productivity, feed conversion efficiency, rumen microbial protein supply, parasitic load, immunity and enteric methane emissions of milking animals under field conditions. Anim. Feed. Sci. and Tech. 2013; 179: 24-35. Available from: <Available from: https://www.sciencedirect.com/science/article/pii/S0377840112003902 >. doi: 10.1016/j.anifeedsci.2012.11.005. Accessed: Aug. 29, 2018.
  » https://doi.org/10.1016/j.anifeedsci.2012.11.005» https://www.sciencedirect.com/science/article/pii/S0377840112003902
• GERBER P, et al. Productivity gains and greenhouse gas emissions intensity in dairy systems. Liv. Sci. 2011; 139: 100-108. Available from: <Available from: https://www.sciencedirect.com/science/article/pii/S1871141311000953 >. doi: 10.1016/j.livsci.2011.03.012. Accessed: Aug. 29, 2018.
  » https://doi.org/10.1016/j.livsci.2011.03.012.» https://www.sciencedirect.com/science/article/pii/S1871141311000953
• HAIGH PM. A note on the relationship between oven and toluene 374 determined dry matter concentrations in Maize silages. Irish J. Agr. Food. Res. 1995; 375 (34): 193-195.
• HALES KE, et al. Effects of increasing concentrations of wet distillers grains with solubles in steam-flaked, corn-based diets on energy metabolismo, carbono-nitrogen balance, and methane emissions of cattle. J. Anim. Sci. 2013; 91:819-828. Available from: <Available from: https://pdfs.semanticscholar.org/2d4d/9a6d9a817c3b7db728d22f09f4eb801162f9.pdf >. doi:10.2527/jas2012-5418. Accessed: Aug. 29, 2018.
  » https://doi.org/10.2527/jas2012-5418» https://pdfs.semanticscholar.org/2d4d/9a6d9a817c3b7db728d22f09f4eb801162f9.pdf
• Intergovernmental Panel on Climate Change (IPCC). Summary for Policymakers. En: Climate Change. Mitigation of climate change. Contribution of Working Group III to the fifth Assessment Report of the Intergovernmental Panel on Climate Change. 2014.
• IVES CV, et al. In vitro methane production and tolerance to condensed tannins in five ruminant species. Animal Feed Science and Technology. 2015; 205:1-9. Available from: <Available from: https://www.sciencedirect.com/science/article/pii/S037784011500108X >. doi: 10.1016/j.anifeedsci.2015.03.008. Accessed: Aug. 29, 2018.
  » https://doi.org/10.1016/j.anifeedsci.2015.03.008» https://www.sciencedirect.com/science/article/pii/S037784011500108X
• KAPS M, LAMBERSON W. Biostatistics for animal science: an introductory text. 2nd Ed. CABI. Oxfordshire, UK, 2009. 244-245p.
• LENTH RV. Least-Squares Means: The R Package lsmeans. Journal of Statistical Software. 2016: 69(1): 1-33.
• Makkar HS, et al. Gravimetric determination of tannins and their correlations with chemical and protein precipitation methods. Journal of the Science of Food and Agriculture. 1993; 61:161-165. Available from: <Available from: https://onlinelibrary.wiley.com/doi/abs/10.1002/jsfa.2740610205 >. doi: 10.1002/jsfa.2740610205. Accessed: Aug. 29, 2018.
  » https://doi.org/10.1002/jsfa.2740610205» https://onlinelibrary.wiley.com/doi/abs/10.1002/jsfa.2740610205
• MAHMOUD GR, et al. Reduction of methane production from ruminant livestock using tropical tanniferous plants: a sustainable option for mitigation. In Proceedings of the 6th Greenhouse Gas and animal Agriculture Conference, Melbourne, Australia, February 14 to 18, 2016. PO 119.
• MAHMOUD GR, et al. Effect of tanniferous plants on in vitro digestion and methane production. Ecosist. Recur. Agropec. 2017. 4(11):371-380. Available from: <Available from: http://era.ujat.mx/index.php/rera/article/view/1160 >. doi: 10.19136/era.a4n11.1160. Accessed: Aug. 29, 2018.
  » https://doi.org/10.19136/era.a4n11.1160» http://era.ujat.mx/index.php/rera/article/view/1160
• MOREIRA GD, et al. Tropical tanniniferous legumes used as an option to mitigate sheep enteric methane emission. Trop. Anim. Health Prod. 2013; 45:879-882. Available from: <Available from: https://link.springer.com/article/10.1007/s11250-012-0284-0 >. doi: 10.1007. Accessed: Aug. 29, 2018.
  » https://doi.org/10.1007» https://link.springer.com/article/10.1007/s11250-012-0284-0
• NAUMANN DH, et al. Effect of molecular weight of condensed tannins from warm-season perennial legumes of ruminal methane production in vitro Biochemical Systematics and Ecology. 2013; 50:154-162. Available from: <Available from: https://www.sciencedirect.com/science/article/pii/S0305197813000963 >. doi: 10.1016/j.bse.2013.03.050. Accessed: Aug. 29, 2018.
  » https://doi.org/10.1016/j.bse.2013.03.050» https://www.sciencedirect.com/science/article/pii/S0305197813000963
• NIU M, et al. Effect of dietary crude protein and forage contents on enteric methane emissions and nitrogen excretion from dairy cows simultaneously. Anim. Prod. Sci. 2016; 56:312-321. Available from: <Available from: http://www.publish.csiro.au/an/an15498 >. doi: 10.1071/AN15498. Accessed: Aug. 29, 2018.
  » https://doi.org/10.1071/AN15498» http://www.publish.csiro.au/an/an15498
• PATRA AK, SAXENA J. A new perspective on the use of plant secondary metabolites to inhibit methanogenesis in the rumen. Phytochemistry 2010; 71: 1198-1222. Available from: <Available from: https://www.sciencedirect.com/science/article/abs/pii/S0031942210001858 >. doi: 10.1016/j.phytochem.2010.05.010. Accessed: Aug. 29, 2018.
  » https://doi.org/10.1016/j.phytochem.2010.05.010» https://www.sciencedirect.com/science/article/abs/pii/S0031942210001858
• PEDRAZA-BELTRÁN PE, et al. Construction and operation of the first low cost ventilated-hood system for methane measurements in cattle in Mexico. In Proceedings of the 6th Greenhouse Gas and Animal Agriculture Conference, Melbourne, Australia, February 14 to 18, 2016. PO 07.
• PIÑEIRO-VÁZQUEZ AT, et al. Intake, digestibility, nitrogen balance and energy utilization in heifers fed low-quality forage and Leucaena leucocephala Anim. Feed Sci. and Tech. 2017 (228): 194-201. Available from: <Available from: https://www.sciencedirect.com/science/article/pii/S037784011630623X >. doi: 10.1016/j.anifeedsci.2017.04.009. Accessed: Aug. 29, 2018.
  » https://doi.org/10.1016/j.anifeedsci.2017.04.009» https://www.sciencedirect.com/science/article/pii/S037784011630623X
• TAVENDALE MH, et al. Methane production from in vitro rumen incubations with Lotus Pedunculatus and Medicago sativa, and effects of extractable condensed tannin fractions on methanogenesis. Animal Feed Science and Technology, 2005; 124:403-419. Available from: <Available from: https://www.sciencedirect.com/science/article/pii/S037784010500180X >. doi: 10.1016/j.anifeedsci.2005.04.037. Accessed: Aug. 29, 2018.
  » https://doi.org/10.1016/j.anifeedsci.2005.04.037» https://www.sciencedirect.com/science/article/pii/S037784010500180X
• R Development Core Team (2011), R: A Language and Environment for Statistical Computing. Vienna, Austria: the R Foundation for Statistical Computing. ISBN: 3-900051-07-0. Available from: <Available from: http://www.R-project.org/ >. Accessed: Aug. 29, 2018.
  » http://www.R-project.org/
• VAN SOEST PJ, et al. Methods for dietay fiber, neutral detergent fiber and non-starch polysaccharides in relation to animal nutrition. J. Dairy Sci . 1991; 74:3583-3597. Available from: <Available from: https://www.sciencedirect.com/science/article/pii/S0022030291785512 >. doi: 10.3168/jds.S0022-0302(91)78551-2. Accessed: Aug. 29, 2018.
  » https://doi.org/10.3168/jds.S0022-0302(91)78551-2» https://www.sciencedirect.com/science/article/pii/S0022030291785512
• VERCOE P. The mechanism of antimethanogenic bioactivity of plants in the rumen. Final Report. Meat & Livestock Australia Limited. 2015 Locked Bag 991 NORTH SYDNEY NSW 2059.
• WOODWARD SL, et al. Does feeding sulla (Hedysarum coronarium) reduce emissions from dairy cows? Proc. New Zeal. Anim. Prod. 2002; 62: 227-230. Available from: <Available from: http://www.nzsap.org/system/files/proceedings/2002/ab02058.pdf >. Accessed: Aug. 29, 2018.
  » http://www.nzsap.org/system/files/proceedings/2002/ab02058.pdf

• CR-2017-0484.R2

BIOETHICS AND BIOSECURITY COMMITTEE APPROVAL

• BIOETHICS AND BIOSECURITY COMMITTEE APPROVAL

  All the experimental procedures were approved by the Committee on Bio-ethics and Animal Welfare of the Universidad Autónoma del Estado de México on the 24^th of April 2015.

Publication Dates

• Publication in this collection
  2018

History

• Received
  14 July 2017
• Accepted
  20 Aug 2018
• Reviewed
  11 Sept 2018