Abstract

The objective of this study was to evaluate the forage availability and performance of goats in thinned Caatinga enriched with Urochloa trichopus subjected to grazing fallowing and levels of phosphorus fertilization. Twenty-four F1 crossbred goats (Boer x Non-descript breed), whole, 15.0 ± 2.6 kg body weight were distributed in four paddocks (n = 6) according to body weight, age and physiological status. Animals grazed on Caatinga, under continuous stocking, and were gathered and kept in individual pens overnight. The experiment to evaluate animal performance was a randomized block design with 4 treatments (0, 11, 33 and 60 days of fallowing) and six replications. To determine dry mass production and floristic composition, phosphate fertilization was used in the doses of x P₂O₅ in a randomized block design with five treatments, 0, 30, 60, 90 and 120 kg P₂O₅ with 4 replications. Phosphate fertilization had an effect on the floristic composition of dicots and U. trichopus (P<0.05). There was an effect of pasture fallowing on the final weight of goats, with the lowest weight (20.40 kg) observed after 60 days of fallowing (P<0.05). Fallowing is not suitable for an area of vegetation in the caatinga, because there was a decrease in forage availability and quality in the dry period, resulting in a lower performance of animals.

Keywords:
Food management; forage availability; native pasture; semiarid

Resumo:

Objetivou-se avaliar a disponibilidade de forragem e desempenho de caprinos em Caatinga raleada e enriquecida com Urochloa trichopus submetida ao diferimento de pastejo e doses de adubação fosfatada. Foram utilizados 24 caprinos mestiços F1 (Boer x SPRD), inteiros, com peso corporal de 15,0 ± 2,6 kg, distribuídos em quatro piquetes (n = 6) de acordo com o peso vivo, idade e estado fisiológico. Os animais realizaram pastejo na Caatinga, com lotação contínua, sendo recolhidos e colocados em baias individuais permanecendo nesse local durante a noite. No experimento para avaliar desempenho animal foi usado delineamento blocos casualizados com 4 tratamentos (0, 11, 33 e 60 dias de diferimento) e seis repetições. Para determinação produção de massa seca e composição florística foi usado a adubação fosfatada nas dosagens de x P₂O₅ em um delineamento em blocos casualizados com cinco tratamentos, 0, 30, 60, 90 e 120 kg de P₂O₅ com 4 repetições. A adubação fosfatada promoveu efeito para a composição florística de dicotiledôneas e U. trichopus (P<0,05). Houve efeito do diferimento de pastagem para o peso final dos caprinos, com o menor peso (20,40 kg) observado aos 60 dias de diferimento (P<0,05). A adubação fosfatada não aumentou a produtividade de matéria seca. O diferimento não é indicado para uma área de vegetação da caatinga, pois mesmo com a vedação, no período seco ocorreu uma diminuição na disponibilidade e na qualidade da forragem, acarretando um menor aporte dos animais.

Palavras-chave:
Disponibilidade de forragem; Ganho de peso; Pastagem nativa; Semiárido

Introduction

The Caatinga Biome in the semiarid region of northeastern Brazil is strongly influenced by the hot, dry climate (BSh’w), characterized by high temperatures (over 30ºC), average relative humidity of 61% and average rainfall of 500 mm/year, distributed in the short rainy season(¹1 Marengo JA, Alves LM, Alvala RCS, Cunha AP, Brito S, Moraes OLL. Climatic characteristics of the 2010-2016 drought in the semiarid Northeast Brazil region. An. Acad. Bras. Ci. 2018; 90(2):1973-1985. Disponível em: https://doi.org/10.1590/0001-3765201720170206
https://doi.org/10.1590/0001-37652017201... ,²2 Castanho ADA, Coe M, Andrade EM, Walker W, Baccini A, Campos DA, Farina M. A close look at above ground biomass of a large and heterogeneous seasonally dry tropical forest - Caatinga in North East of Brazil. An. Acad. Bras. Ci. 2020; 92(1):1 - 18. Disponível em: https://doi.org/10.1590/0001-3765202020190282
https://doi.org/10.1590/0001-37652020201... ). The vegetation in this region is characterized by the predominance of a shrub-tree layer composed of plants with low carrying capacity, resulting in low animal yield(³3 Souza MA, Souto JS, Andrade AP, Araujo KD, Gomes DL. Contribution of litter and leaf decomposition of Byrsonima gardneriana. Floresta Amb. 2019; 26(1):1 - 10. Disponível em: https://doi.org/10.1590/2179-8087.037616
https://doi.org/10.1590/2179-8087.037616... ). Despite this, it constitutes the basic forage support of most properties dedicated to livestock production in this region.

Goat farming is a widespread activity throughout the Brazilian territory, but it has a greater concentration in the semiarid northeastern Brazil. The rusticity of goats in the face of climatic adversities is secular, due to the process of adaptation, natural selection and also the influence of man(⁴4 Ribeiro KA, Alencar CMM. Desenvolvimento territorial e a cadeia produtiva da caprinovinocultura no semiárido baiano: o caso do município de Juazeiro-BA. Rev. Bras. Ass. Reg. Urb. 2018; 4(1):144-179. Disponível em: https://doi.org/10.18224/baru.v4i1.6571
https://doi.org/10.18224/baru.v4i1.6571... ). In Brazil, about 90% goat herds are located in the Northeast region, which has 92.5% semiarid region of the country(⁵5 Embrapa Caprinos e Ovinos. Pesquisa Pecuária Municipal 2017: efetivo dos rebanhos caprinos e ovinos. Boletim do centro de inteligência e mercado de caprinos e ovinos n. 5, 1st ed. Sobral: Embrapa; 2018. 13p.). Thus, in an attempt to improve production systems and consolidate this activity in the region, the aim is to introduce innovative pasture management techniques, with the aim of making them viable and improving this important source of income.

One of the alternatives is the fallowing of pasture, which is an easy-to-perform, low-cost management strategy that guarantees forage stock during the period of scarcity. The use of fallowing occurs at the time of year with greatest forage shortage in a region and will determine the duration of the pasture growth period(⁶6 Cardoso AS, Barbero RP, Romanzini EP, Teobaldo RW, Ongaratto F, Fernandes MHMR, Ruggieri AC, Reis RA. Intensification: A key strategy to achieve great animal and environmental beef cattle production sustainability in brachiaria grasslands. Sustain. 2020; 12(16):1 - 17. Disponível em: https://doi.org/10.3390/su12166656
https://doi.org/10.3390/su12166656... ,⁷7 Santos AD, Fonseca DM, Sousa BML, Santos MER, Carvalho AN. Pasture structure and production of supplemented cattle in deferred signalgrass pasture. Ci. Anim. Bras. 2020; 21(43578):1-13. Disponível em: https://doi.org/10.1590/1809-6891v21e-43578
https://doi.org/10.1590/1809-6891v21e-43... ). Another suggestion is phosphate fertilization, which allows for greater flexibility in the period of fallowing of pasture(⁸8 Sousa BML, Santos MER, Amorim PL, Silveira MCT, Rocha GO, Carvalho AN. Effect of nitrogen fertilization on structure and tillering dynamics of Piata palisade grass during the deferment period. Semina: Ci. Agr. 2019; 40(1):249-258. Disponível em: https://doi.org/10.5433/1679-0359.2019v40n1p249
https://doi.org/10.5433/1679-0359.2019v4... ), since phosphorus is crucial for plant metabolism, playing a key role in cell energy transfer, respiration and photosynthesis. It is also a structural component of the nucleic acids of genes and chromosomes, as well as of many coenzymes, phosphoproteins and phospholipids(⁹9 Coelho, VAT.; Souza, CG.; Nascimento, ES.; Lacerda, LG.; Cardoso, PA. Deficiências de macronutrientes em Abobrinha Italiana (Cucurbita pepo L.): caracterização de sintomas e crescimento. Res. Soc. Dev. 2020; 9(3):1-19. Disponível em: http://dx.doi.org/10.33448/rsd-v9i3.2269
http://dx.doi.org/10.33448/rsd-v9i3.2269... ).

The low availability of phosphorus for growing plants is a predominant characteristic in Brazilian soils. Thus, the application of nutrients in adequate amounts and proportions, such as P₂O₅, is a fundamental practice to increase forage production(¹⁰10 Bononi L, Chiaramonte JB, Pansa CC, Moitinho MA, Melo IS. Phosphorus-solubilizing Trichoderma spp. from Amazon soils improve soybean plant growth. Scient. Rep. 2020; 10(2858):1-13. Disponível em: https://doi.org/10.1038/s41598-020-59793-8
https://doi.org/10.1038/s41598-020-59793... ). Urochloa trichopus grass is well accepted by ruminants and supports grazing close to the ground(¹¹11 Mugabe W, Moatswi B, Nsinamwa M, Akanyang L, Dipheko K, Matthews N, Nazar M, Shah IA, Shuaib M and Shah AA. 2017. Dry Matter Biomass Productivity and Composition of Grasses along Grazing Gradient in Fenced and Unfenced Grazing Areas of the Gaborone North, Botswana. Journal of Animal Research and Nutrition 2 (2:11): 1-6. http://doi:10.21767/2572-5459.100031
http://doi:10.21767/2572-5459.100031... ) and, in recent years, it has been gaining ground with producers in the Northeast region(³²32 Pereira Filho JM, Silva, AMA and Cezar, MF. 2013. Manejo da Caatinga para produção de caprinos e ovinos. Revista Brasileira de Saúde e Produção Animal 14 (1): 77-90. https://doi.org/10.1590/S1519-99402013000100010
https://doi.org/10.1590/S1519-9940201300... ). Due to these aspects, it has been gaining the semiarid northeastern region, and it can be used in pasture fallowing, as it presents tender stems and abundant foliage, high production of dry matter in the rainy season, high protein content and digestibility(¹²12 Coêlho JJ, Mello ACL, Santos MVF, Dubeux Junior JCB, Cunha MV, Lira MA. Prediction of the nutritional value of grass species in the semiarid region by repeatability analysis. Pesq. Agropec. Bras. 2018; 53(3):378-385. Disponível em: https://doi.org/10.1590/S0100-204X2018000300013
https://doi.org/10.1590/S0100-204X201800... ).

In this context, the objective was to evaluate forage availability and performance of goats in thinned Caatinga enriched with Urochloa trichopus subjected to fallowing and fertilized with phosphorus.

Material and Methods

The experiment was conducted between March and August 2014, at Lameirão Farm, experimental unit of the Center for Rural Health and Technology of the Universidade Federal de Campina Grande (UFCG), geographically located at coordinates 7°02'56.8” South and 37°29'36.2” West, in the municipality of Santa Teresinha, in the state of Paraíba.

According to the Köppen climate classification, the climate in the region is BSh’ hot and dry (semiarid), with a short summer-fall rainy season(¹³13 Alvares CA, Stape JL, Sentelhas PC, Gonçalves JLM, Sparovek G. 2013. Köppen’s climate classification map for Brazil. Meteorologische Zeitschrift 22 (6): 711-728. Disponível em: http://doi.org/10.1127/0941-2948/2013/0507
http://doi.org/10.1127/0941-2948/2013/05... ). The maximum average annual temperature is 32.9 °C, the minimum is 20.8 °C, and relative humidity is 61%(¹⁴14 Brasil. Ministério da Agricultura e Reforma Agrária. Secretaria nacional de irrigação. Departamento nacional de meteorologia. Normas Climatológicas, Brasília, 1961­1990. 84p. Portuguese.).

The experiment was carried out in an area of 2.4 hectares of caatinga enriched with bushveld signalgrass (Urochloa trichopus (Hochst.) Stapf), which was divided into four paddocks of 0.6 hectares each.

At the beginning of the rainy season, bushveld signalgrass was sown. For this purpose, seeds were sown by broadcasting in order to facilitate the contact of the seed with the soil and always seeking a distribution as uniform as possible in the area.

Soil samples from the experimental areas, in the 0-20 cm deep layer, were taken for physical and chemical analysis carried out at the Soil and Water Analysis Laboratory (LASAG/CSTR/UFCG)(¹⁶16 LASAG. Laboratório de Solos e Água. Universidade Federal de Campina Grande, Centro de Saúde e Tecnologia Rural (UFCG/CSTR). Patos. 2014.) (Table 1). The soil of the experimental area was classified as Litholic Neosol(¹⁵15 Santos HG, Jacomine PKT, Anjos LHC, Oliveira VA, Lumbreras JF, Coelho MR, Almeida JA, Cunha TJF, Oliveira JB. Sistema brasileiro de classificação de solos, 5th ed. Brasília: Embrapa; 2018. 356p. Disponível em: https://www.embrapa.br/busca-de-publicacoes/-/publicacao/1107206/sistema-brasileiro-de-classificacao-de-solos
https://www.embrapa.br/busca-de-publicac... ).

Twenty-four F1 crossbred goats (Boer x Non-descript breed), uncastrated, 15.0 ± 2.6 kg initial body weight were distributed into four paddocks (6 animals per paddock) according to body weight, age and physiological status. Animals grazed on thinned Caatinga enriched with Urochloa trichopus, under continuous stocking, from 8 to 16 hours and later gathered and housed in individual pens with a feeder and a drinking trough, overnight, where they received a concentrate supplementation (1% body weight).

Four treatments were used in the pasture fallowing management system:

Regarding the first rainfall events in the region, causing the regrowth of the Caatinga vegetation, the time in days (20 days after the first rainfall events) was considered for placing the animals in the first paddock, thus constituting the periods of fallowing, treatment 1 (fallowing O, zero), treatment 2 (11 days fallowing in relation to treatment 1); treatment 3 (33 days fallowing in relation to treatment 1); treatment 4 (60 days fallowing in relation to treatment 1).

In each paddock, animals had access to water and mineral salt ad libitum. The value, in mm, of rainfall during the experimental period is illustrated in Figure 1.

Figure 1
Rainfall (mm) in the municipality of Santa Teresinha, state of Paraíba, during the experimental period.

All procedures for the animal research were approved by the Internal Ethics Committee in Animal Experimentation of the Center for Rural Health and Technology: Protocol 029/2012.

The supplement offered to the animals was prepared with ground corn, soybean meal (Table 2) and mineral mixture for goats (Caprinofós, Tortuga, São Paulo, Brazil) (Table 3), and was used only for animal maintenance.

Regarding the application of P₂O₅: In the 10 m x10 m plots, the phosphorus level (kg/ha) to be applied was randomly selected, the amount was broadcast throughout the plot, soon after the first rain at the experimental site.

The availability of dry matter of herbaceous components (dicots, bushveld signalgrass and other grasses) was evaluated according to the methodology recommended by Araújo Filho(¹⁷17 Araújo Filho JA. Manejo pastoril sustentável da Caatinga, 22th ed. Recife: Projeto Dom Helder Câmara; 2013. 200p. Disponível em: http://portalsemear.org.br/wp-content/uploads/2018/03/ManejoPastorilSustentavelCaatinga2.pdf
http://portalsemear.org.br/wp-content/up... ) (2013), which consists of a rectangular metal frame measuring 1.00 m in length and 0.25 m in width (0.25 m²), which was thrown from transects traced in the North, South, East and West directions from the center point of the paddock. Fifteen samples were taken per paddock at different evaluation times, corresponding to 40 samples/ha. In each paddock of 0.6 ha, five plots of 10 x 10 m were allocated, where levels of 0, 30, 60, 90 and 120 kg/ha phosphorus were applied and the availability of dry matter and the floristic composition of herbaceous components were determined. Three samples were collected from each plot using a 0.25m² square.

The cut for sample collection was carried out close to the ground. After cutting, samples were placed on a bench and separated into herbaceous dicots, Urochloa trichopus and other grasses. Afterwards, samples were stored in identified paper bags and weighed on a precision scale to compose the data related to the green mass. Soon after weighing, samples were dried in a forced air oven at 55 °C to constant weight, which occurred after 72 hours(¹⁸18 AOAC. Association of Official Analytical Chemists. Official methods of analysis, 20th ed. Washington, D.C.: Latimer Jr., G.W.; 2016. 3172p.). Then, samples were weighed again to obtain the dry mass.

To assess animal performance, animals were weighed at the beginning of the experiment and every 15 days, until the end of the experimental period, for later calculations of total weight gain (TWG), and average daily gain (ADG), using the equations:

In the experiment to evaluate animal performance, a randomized block design with 4 treatments (0, 11, 33 and 60 days of fallowing) and six replications was used.

For data on dry mass availability and floristic composition based on availability, a split plot randomized block design was used, with fallowing periods assigned to plots and the five levels of phosphorus to the subplots.

The analyzed variables were tested by analysis of variance (ANOVA). Data were analyzed using the Statistical Analysis System 9.2 (SAS 9.2), considering probability values lower than 5% as significant according to Tukey’s test.

Results and discussion

According to Bezerra et al.(¹⁹19 Bezerra RCA, Leite MLMV, Almeida MCR, Lucena LRR, Simões VJLP, Bezerra FJSM. Características agronômicas de Urochloa mosambicensis sob diferentes níveis de fósforo e nitrogênio. Mag. 2019; 30(1):268-276. Disponível em: https://magistraonline.ufrb.edu.br/index.php/magistra/article/view/738/393
https://magistraonline.ufrb.edu.br/index... ), phosphorus plays a key role in the life cycle of plants, being present in metabolic processes of plants directly or indirectly related to energy expenditure. Also, according to these authors, phosphorus fertilization is necessary to achieve high phytomass productivity, due to its important role in plant morphogenesis, promoting an increase in metabolism and rates of enzymatic reactions. In this study, there was no interaction effect (P>0.05) between phosphorus levels and fallowing for dry mass availability and floristic composition of dicots, bushveld signalgrass and other grasses. Phosphorus fertilization of the caatinga enriched with bushveld signalgrass did not influence (P>0.05) the dry mass availability of dicots, other grasses and bushveld signalgrass (Table 5).

Our results differ from those found by Araújo et al.(²⁰20 Araújo MM, Santos RV, Vital AFM, Araújo JL, Farias JA. Uso do fósforo em gramíneas e leguminosas cultivadas em neossolo do Semi-Árido. Agropec. Cient. Semi-Árido. 2010; 6(1):40-46. Disponível em: http://dx.doi.org/10.30969/acsa.v6i1.66
http://dx.doi.org/10.30969/acsa.v6i1.66... ), who evaluated the use of phosphorus in grasses and legumes grown in semiarid neosoil, in which phosphate fertilization increased the production of dry mass of grasses and legumes. They also described that the responses of forage species to phosphorus fertilization vary widely from place to place, depending on the cultivated species, the management level and especially the availability of phosphorus in the soil.

The floristic composition in dicots and Urochloa trichopus (Table 5) was influenced by phosphorus fertilization, where the level of 90 kg/ha P₂O₅ favored the highest percentage of Urochloa trichopus and the smallest percentage of dicots. Considering that phosphorus plays an important role in root development and in grass tillering, its deficiency in the soil limits the productive capacity of pastures(²¹21 Hallama M, Pekrun C, Lambers H, Kandeler E. Hidden miners - the roles of cover crops and soil microorganisms in phosphorus cycling through agroecosystems. Plant Soil. 2019; 434(1):7-45. Disponível em: https://doi.org/10.1007/s11104-018-3810-7
https://doi.org/10.1007/s11104-018-3810-... ). In this situation, phosphate fertilization is essential so that this element does not limit the response of the forage plant, but with applications of low levels of phosphorus in the process of restoring a degraded pasture, the response of plants is very slow, resulting in low productivity(²²22 Weeks Jr. JJ, Hettiarachchi GM. A review of the latest in phosphorus fertilizer technology: possibilities and pragmatism. J. Env. Quality. 2019; 48(5):1300-1313. Disponível em: https://doi.org/10.2134/jeq2019.02.0067
https://doi.org/10.2134/jeq2019.02.0067... ).

In native Caatinga, the effect of grazing by any species should not have significant effects on the vegetation, as long as the relationship between supply and demand for pasture is respected. Under overgrazing conditions, goats and sheep can induce changes in the floristic composition of the Caatinga(²³23 Pereira Filho JMP, Silva AMA, Cézar MF. Manejo da Caatinga para produção de caprinos e ovinos. Ver. Bras. Saúde Prod. Anim. 2013; 14(1):77-90. Disponível em: https://www.scielo.br/j/rbspa/a/733ThmLwSpcP7B7vxVw6qMy/?format=pdf⟨=pt
https://www.scielo.br/j/rbspa/a/733ThmLw... ,²⁴24 Menezes T, Carmo R, Wirth R, Leal IR, Tabarelli M, Laurênio A, Melo FPL. Introduced goats reduce diversity and biomass of herbs in Caatinga dry forest. Land Degr. Dev. 2020; 31(16):1-40. Disponível em: https://doi.org/10.1002/ldr.3693
https://doi.org/10.1002/ldr.3693... ). Santos et al.(²⁵25 Santos JP, Araújo EL, Alburquerque UP. Richness and distribution of useful woody plants in the semi-arid region of northeastern Brazil. J. Arid Env. 2008; 72(5):652-663. Disponível em: https://doi.org/10.1016/j.jaridenv.2007.08.004
https://doi.org/10.1016/j.jaridenv.2007.... ), in studies carried out with species on native pasture and on diet, reported that it is important to determine the strategies for using the materials to increase the results of forage production and animal performance, thus improving the development of ruminant production in the semiarid region.

The availability of dicots and other grasses reduced as the days of fallowing increased (60 days), which is justified, considering that the herbaceous broad-leaved vegetation of the caatinga, in its phenology, depends on climatic variation, mainly rainfall, accelerating the senescence process, reducing their availability. Urochloa trichopus grass, on the other hand, showed no variation in availability, although at the beginning of the fallowing (day 0), the grass forage mass value of 18.59 kgDM/ha showed a tendency to increase with the progress in the fallowing period, with values above 58 kgDM/ha (Table 6). The low amount of forage mass is justified by the lower occurrence of grass in the experimental area (floristic composition), considering that, at the beginning of the experiment, the grass was under regrowth, with higher water content and lower dry matter content in its composition.

The total availability of kgDM/ha in the fallowing periods had a significant effect, with the lowest availability with 60 days of fallowing, as rainfall reduced from 243.3 to 9.1 mm, which may have resulted in lower growth and higher senescence of the vegetation, considering that the animals were placed in the area 60 days after the beginning of the fallowing and 80 days after the beginning of the rains.

In this period, there was low availability of dry mass of herbaceous vegetation (990.00 kgDM/ha), when compared to 0 days of fallowing (2533.30 kgDM/ha), which is expected since some species of herbaceous vegetation of the caatinga have a short life span, germination, emergence, growth, flowering and senescence, very fast after the onset of rains. Results superior to those found here were reported by Carvalho Júnior et al.(²⁶26 Carvalho Júnior AM, Pereira Filho JM, Silva RM, Cezar MF, Silva AMA, Silva ALN. Efeito da suplementação nas características de carcaça e dos componentes não-carcaça de caprinos F1 Boer x SRD terminados em pastagem nativa. Rev. Bras. Zootec. 2009; 38(7):1301-1308. Disponível em: https://doi.org/10.1590/S1516-35982009000700020
https://doi.org/10.1590/S1516-3598200900... ) working with the effect of supplementation on carcass traits and non-carcass components of F1 Boer x Non-descript breed goats finished on native pasture, when they obtained a total availability of 3347.9 kg DM/ha native Caatinga. In turn, Pereira Filho et al.(²⁷27 Pereira Filho JM, Vieira EL, Kamalak A, Silva AMA, Cezar MF, Beelen PMG. Ruminal disappearance of Mimosa tenuilfora hay treated with sodium hidroxide. Arch. Zootec. 2007; 56(216):959-962. Disponível em: https://www.redalyc.org/pdf/495/49521619.pdf
https://www.redalyc.org/pdf/495/49521619... ) analyzed alternate sheep-goat grazing in the region of Sobral, state of Ceará, and found a phytomass production of around 3,000 kg/ha for thinned native pasture in rainy seasons.

The fallowing affected the animal performance in the final weight, in which 60 days of fallowing reduced the final weight of the animals (Table 7). Probably what caused the reduction in final weight was the lower availability of dry mass (Table 6), in the treatment with 60 days of fallowing, even not reflecting in the other variables. It is important to highlight that up to 33 days of fallowing, the final weight was not altered, most likely due to the high forage supply that exceeded the minimum of 3.5 times the necessary(³³33 Neves FP, Carvalho PCF, Nabinger C, Jacques AVA, Carassai IJ, Tentardini F. Estratégias de manejo da oferta de forragem para recria de novilhas em pastagem natural. Revista Brasileira de Zootecnia, v. 38, n. 8, p. 1532-1542, 2009. Disponível em: https://doi.org/10.1590/S1516-35982009000800018
https://doi.org/10.1590/S1516-3598200900... ), allowing the animals to express all their ability to select species more palatable and of better nutritional value(³⁴34 Bartolomé J, Franch J, Plaixats J, Seligman N. G. Diet selection by sheep and goats on Mediterranean heath-woodland range. Journal of Range Management, v. 51, n. 4, p. 383-391, 1998. Disponível em: https://doi.org/10.2307/4003322
https://doi.org/10.2307/4003322... ).

Results similar to those observed in the study were reported by Santos et al.(²⁸28 Santos JPR, Fonseca DM, Balbino EM, Monnerat JPIS, Silva SP. Capim-braquiária diferido e adubado com nitrogênio: produção e características da forragem. Rev. Bras. Zootec. 2009; 38(4)650-656. Disponível em: https://doi.org/10.1590/S1516-35982009000400009
https://doi.org/10.1590/S1516-3598200900... ), who evaluated the effect of supplementation in Santa Inês lambs finished on native pasture, and found a final body weight of 23.63 kg in animals receiving 1% supplementation, and by Silva et al.(²⁹29 Silva PHF, Carvalho CAB, Malafaia P, Garcia FZ, Barbero RP, Ferreira RL. Morphological and structural characteristics of Urochloa decumbens Stapf. deferred pasture grazed by heifers under two periods of protein-energy supplementation. Acta Scient. Anim. Sci. 2019; 41(44425):1-9. Disponível em: https://doi.org/10.4025/actascianimsci.v41i1.44425
https://doi.org/10.4025/actascianimsci.v... ), who studied Urochloa decumbens and reported a forage reduction in the dry season, with seasonality in animal production and animal weight in the last evaluation period.

Santos et al.(⁷7 Santos AD, Fonseca DM, Sousa BML, Santos MER, Carvalho AN. Pasture structure and production of supplemented cattle in deferred signalgrass pasture. Ci. Anim. Bras. 2020; 21(43578):1-13. Disponível em: https://doi.org/10.1590/1809-6891v21e-43578
https://doi.org/10.1590/1809-6891v21e-43... ) argued that the fallowing leads to the accumulation of mature stems and dead material and a decrease in the availability of leaves, with a consequent reduction in animal consumption and performance. Pastures managed at different heights provide different forage masses, interfering with the availability and accessibility of pastures to animals, affecting intake by grazing animals and the animal(³⁰30 Janusckiewicz ER, Casagrande DR, Raposo E, Bremm C, Reis RA, Ruggieri AC. Sward structure and ingestive behavior of cows in tropical pastures managed under different forage allowances. Arq. Bras. Med. Vet. Zootec. 2019; 71(6):2009-2016. Disponível em: https://doi.org/10.1590/1678-4162-10913
https://doi.org/10.1590/1678-4162-10913... ,³¹31 Rocha GO, Santos MER, Vilela HH, Carvalho BHR, Sousa BML, Fagundes JL, Backes AA, Fontes PTN. Structure of piatã palisadegrass deferred for two periods and fertilised with nitrogen. Semina: Ci. Agr. 2020; 41(3):995-1006. Disponível em: http://dx.doi.org/10.5433/1679-0359.2020v41n3p995
http://dx.doi.org/10.5433/1679-0359.2020... ). On the other hand, the botanical composition of the diet for goats, sheep and cattle in the caatinga tends to adjust to the frequency, availability and supply of dry matter(³⁵35 Formiga LDAS, Pereira Filho JM, Silva AMA, Oliveira NS, Soares DC, Bakke OA. Forage supply in thinned Caatinga enriched with buffel grass (Cenchrus ciliaris L.) grazed by goats and sheep. Acta Scientiarum. Animal Sciences., v.34, p.189 - 195, 2012. Disponível em: https://doi.org/10.4025/actascianimsci.v34i2.12548
https://doi.org/10.4025/actascianimsci.v... ), with emphasis on species with better nutritional value(³⁶36 Formiga LDAS, Pereira Filho JM, Oliveira NS, Silva AMA, Cézar MF, Soares DC. Valor nutritivo da vegetação herbácea de caatinga enriquecida e pastejada por ovinos e caprinos. Revista Brasileira de Saúde e Produção Animal., v.12, p.403 - 415, 2011. Disponível em: https://www.bvs-vet.org.br/vetindex/periodicos/revista-brasileira-de-saude-e-producao-animal/12-(2011)-2/valor-nutritivo-da-vegetacao-herbacea-de-caatinga-enriquecida-e-pastej/
https://www.bvs-vet.org.br/vetindex/peri... ,³⁷37 Leite ER, Cezar MF, Araújo Filho JA. Efeitos do melhoramento da Caatinga sobre os balanços protéico e energético na dieta de ovinos. Ciência Animal, 12(1)67-73, 2002. Disponível em: https://ainfo.cnptia.embrapa.br/digital/bitstream/item/35689/1/API-Estudo-do-melhoramento-da-caatinga.pdf
https://ainfo.cnptia.embrapa.br/digital/... ), especially in protein(³⁸38 Araújo Filho JA, Gadelha JA, Leite ER. et al. Composição botânica e dieta de ovinos e caprinos em pastoreio combinado na região dos Inhamuns, Ceará. Revista Brasileira. de Zootecnia, v.25, n.3, p.383-395, 1996. Disponível em: https://ainfo.cnptia.embrapa.br/digital/bitstream/item/53756/1/API-Composicao-botanica.pdf
https://ainfo.cnptia.embrapa.br/digital/... ).

Conclusion

Fallowing is not indicated for an area of caatinga vegetation, because even with the closure of the pasture, in the dry period, there was a decrease in forage availability and quality, resulting in a lower performance of animals, since the areas were in a rest period until their entry.

Acknowledgements

The present study was carried out with the support of the Coordination for the Improvement of Higher Education Personnel - Brazil (CAPES) - Financing Code 001.

References

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