Free Standard AU & NZ Shipping For All Book Orders Over $80!
Register      Login
Animal Production Science Animal Production Science Society
Food, fibre and pharmaceuticals from animals
RESEARCH ARTICLE

Energy sources in diets for lambs in confinement

Taiala C. de J. Pereira https://orcid.org/0000-0002-1419-207X A , Mara L. A. Pereira https://orcid.org/0000-0001-9704-7064 B , Herymá G. de O. Silva B , Alana B. dos Santos B , Leandro S. O. Ribeiro B , Douglas dos S. Pina A , Leandro B. Sousa B and Gleidson G. P. de Carvalho https://orcid.org/0000-0002-4108-6782 A *
+ Author Affiliations
- Author Affiliations

A Department of Animal Science, Universidade Federal da Bahia, Avenida Adhemar de Barros, 500, Ondina, CEP 40170-110, Salvador, Bahia, Brazil.

B Universidade Estadual do Sudoeste da Bahia, Campus de Itapetinga, Praça Primavera, 40, CEP 45700-000, Itapetinga, Bahia, Brazil.

* Correspondence to: gleidsongiordano@yahoo.com.br

Handling Editor: Gordon Dryden

Animal Production Science 62(3) 263-273 https://doi.org/10.1071/AN21136
Submitted: 26 March 2020  Accepted: 13 October 2021   Published: 16 November 2021

© 2022 The Author(s) (or their employer(s)). Published by CSIRO Publishing

Abstract

Context: The use of alternative sources in ruminant feeding features advantages such as diminished dependence on traditional cereals that can be used for human consumption or monogastric animals.

Aims: This study was conducted to examine nutrient intake, apparent digestibility, mean growth rate, nitrogen balance, and microbial protein synthesis in lambs fed diets containing different energy sources in the concentrate.

Methods: The experiment involved five uncastrated Santa Inês lambs, with an initial BW of 22.85 ± 1.0 kg, which were allocated individual metabolic cages and randomly assigned to one of the following five experimental treatments: maize (MA), wheat bran (WB), sorghum (SO), mesquite pod meal (MP) and peach palm meal (PP) in a 5 × 5 Latin square design, with five replicates each. Diets were isoenergetic with a roughage:concentrate ratio of 60:40.

Key results: The energy sources in the concentrate influenced (P < 0.0001) the intakes of DM and nutritional components. The apparent digestibility coefficients of the ether extract and NDFap were significantly (P < 0.05) different between WB and the other diets. The different energy sources in the concentrate (MA, WB, SO and MP) increased (P < 0.0001) the mean growth rate of the lambs. The diet containing PP as an energy source provided a smaller (P = 0.0002) N intake than that from any other diet, and the PP diet resulted in a negative N balance (P = 0.0200). Lambs fed with diets containing MP (80.38 g day−1) as an energy source showed a larger (P = 0.0007) microbial protein synthesis than did those fed with PP (24.47 g day−1).

Conclusions: Wheat bran, sorghum, and mesquite pod meal can completely replace maize for lambs fed diets based on 270 g kg−1 of maize.

Implications: A variety of unusual feed ingredients facilitates the raising of lambs in various regions, with ingredients being local and of the lowest cost, promoting benefits to sheep producers.

Keywords: alternative feedstuffs, Bactris gasipaes, digestibility, maize replacing, microbial protein, nitrogen balance, Prosopis juliflora, sheep.


References

Adams GA (1955) Constitution of a hemicellulose from wheat bran. Canadian Journal of Chemistry 33, 56–67.
Constitution of a hemicellulose from wheat bran.Crossref | GoogleScholarGoogle Scholar |

Allen MS, Bradford BJ, Oba M (2009) Board-invited review: the hepatic oxidation theory of the control of feed intake and its application to ruminants. Journal of Animal Science 87, 3317–3334.
Board-invited review: the hepatic oxidation theory of the control of feed intake and its application to ruminants.Crossref | GoogleScholarGoogle Scholar | 19648500PubMed |

Almeida PJP, Pereira MLA, da Silva FF, dos Santos AB, Pereira TCJ, dos Santos EJS, Moreira JV (2012) Santa Inês sheep supplementation on urochloa grass pasture during the dry season: intake, nutrient digestibility and performance. Revista Brasileira de Zootecnia 41, 668–674.
Santa Inês sheep supplementation on urochloa grass pasture during the dry season: intake, nutrient digestibility and performance.Crossref | GoogleScholarGoogle Scholar |

AOAC International (2012) ‘Official method of analysis AOAC.’ 19th edn. (AOAC International: Gaithersburg, MD, USA)

Argôlo LS, Pereira MLA, Dias JCT, da Cruz JF, Del Rei AJ, de Oliveira CAS (2010) Farelo da vagem de algaroba em dietas para cabras lactantes: parâmetros ruminais e síntese de proteína microbiana. Revista Brasileira de Zootecnia 39, 541–548.
Farelo da vagem de algaroba em dietas para cabras lactantes: parâmetros ruminais e síntese de proteína microbiana.Crossref | GoogleScholarGoogle Scholar |

Berchielli TT, Vega-Garcia A, Oliveira SG (2011) Principais técnicas de avaliação aplicadas em estudo de nutrição. In ‘Nutrição de Ruminantes’, 2nd edn. (Eds TT Berchielli, AV Pires, SG Oliveira) pp. 565–600. (Funep: Jaboticabal, Brazil)

Bezerra LS, Barbosa AM, Carvalho GGP, Simionato JI, Freitas Jr JE, Araújo MLGML, Pereira L, Silva RR, Lacerda ECQ, Carvalho BMA (2016) Meat quality of lambs fed diets with peanut cake. Meat Science 121, 88–95.
Meat quality of lambs fed diets with peanut cake.Crossref | GoogleScholarGoogle Scholar | 27288901PubMed |

Cabral LS, Neves EMO, Zervoudakis JT, Abreu JG, Rodrigues RC, Souza AL, Oliveira IS (2008) Estimativas dos requisitos nutricionais de ovinos em condições brasileiras. Nutrients requirements estimative for sheep in conditions Brazilian. Revista Brasileira de Saúde e Produção Animal 9, 529–542. http://www.rbspa.ufba.br

Cabral LS, Valadares Filho SC, Detmann E, Malafaia PAM, Zervoudakis JT, de Souza AL, Veloso RG, Nunes PMM (2006) Consumo e digestibilidade dos nutrientes em bovinos alimentados com dietas à base de volumosos tropicais. Revista Brasileira de Zootecnia 35, 2406–2412.
Consumo e digestibilidade dos nutrientes em bovinos alimentados com dietas à base de volumosos tropicais.Crossref | GoogleScholarGoogle Scholar |

Chen XB, Gomes MJ (1992) ‘Estimation of microbial protein supply to sheep and cattle based on urinary excretion of purine derivatives – an overview of technical details.’ (International Feed Resources Unit, Rowett Research Institute: Aberdeen, UK)

Chen XB, Hovell FDDB, Ørskov ER, Brown DS (1990) Excretion of purine derivatives by ruminants: effect of exogenous nucleic acid supply on purine derivatives excretion by sheep. British Journal of Nutrition 63, 131–142.
Excretion of purine derivatives by ruminants: effect of exogenous nucleic acid supply on purine derivatives excretion by sheep.Crossref | GoogleScholarGoogle Scholar |

Chizzotti ML, Valadares Filho SC, Valadares RFD, Chizzotti FHM, Tedeschi LO (2008) Determination of creatinine excretion and evaluation of spot urine sampling in Holstein cattle. Livestock Science 113, 218–225.
Determination of creatinine excretion and evaluation of spot urine sampling in Holstein cattle.Crossref | GoogleScholarGoogle Scholar |

Cirne LGA, da Silva Sobrinho AG, Basso FC, Takahashi R, Borghi TH, Viegas CR, de Carvalho GGP, Zeola NMBL (2015) Intake, microbial protein synthesis, and nitrogen balance in lambs fed diets containing mulberry hay. Semina: Ciências Agràrias 36, 4413–4422.
Intake, microbial protein synthesis, and nitrogen balance in lambs fed diets containing mulberry hay.Crossref | GoogleScholarGoogle Scholar |

Clark JH, Klusmeyer TH, Cameron MR (1992) Microbial protein synthesis and flows of nitrogen fractions to the duodenum of dairy cows. Journal of Dairy Science 75, 2304–2323.
Microbial protein synthesis and flows of nitrogen fractions to the duodenum of dairy cows.Crossref | GoogleScholarGoogle Scholar | 1401380PubMed |

Costa JB, Oliveira RL, Silva TM, Ribeiro RDX, Silva AM, Leão AG, Bezerra LR, Rocha TC (2016) Intake, digestibility, nitrogen balance, performance, and carcass yield of lambs fed licuri cake. Journal of Animal Science 94, 2973–2980.
Intake, digestibility, nitrogen balance, performance, and carcass yield of lambs fed licuri cake.Crossref | GoogleScholarGoogle Scholar | 27482684PubMed |

da Conceição MG, de Andrade Ferreira M, de Lima Silva J, Costa CTF, Chagas JCC, de Figueiredo Monteiro CC (2018) Can cactus (Opuntia stricta [Haw.] Haw) cladodes plus urea replace wheat bran in steers’ diet? Asian-Australasian Journal of Animal Sciences 31, 1627–1634.
Can cactus (Opuntia stricta [Haw.] Haw) cladodes plus urea replace wheat bran in steers’ diet?Crossref | GoogleScholarGoogle Scholar | 29807413PubMed |

de Jesus Pereira TC, Pereira MLA, Moreira JV, Azevedo JAG, Batista R, de Paula VF, Oliveira BS, de Jesus dos Santos E (2017) Effects of alkaloid extracts of mesquite pod on the products of in vitro rumen fermentation. Environmental Science and Pollution Research International 24, 4301–4311.
Effects of alkaloid extracts of mesquite pod on the products of in vitro rumen fermentation.Crossref | GoogleScholarGoogle Scholar | 27757749PubMed |

Detmann E, Souza MA, Valadares Filho SC, Queiroz AC, Berchielli TT, Saliba EOS, Azevedo JAG (2012) ‘Métodos para análise de alimentos.’ (Suprema: Visconde do Rio Branco, Brazil)

de Vasconcelos GA, Véras RML, Véras ASC, de Carvalho FFR, Lima JS, Cardoso DB, de Souza EJO, do Vale Maciel M (2019) Replacement of corn by cassava dregs in lambs’ diet. Small Ruminant Research 181, 1–15.
Replacement of corn by cassava dregs in lambs’ diet.Crossref | GoogleScholarGoogle Scholar |

dos Santos AB, Pereira MLA, Silva HGO, de Carvalho GGP, Pereira TCJ, Ribeiro LSO, Azevedo JAG, Silva MGCPC, Sousa LB, Sousa LB, Alencar DO (2016) Intake, digestibility and performance of lambs fed diets containing peach palm meal. Tropical Animal Health and Production 48, 509–515.
Intake, digestibility and performance of lambs fed diets containing peach palm meal.Crossref | GoogleScholarGoogle Scholar | 26781510PubMed |

dos Santos Filho HB, Véras RML, de Andrade Ferreira M, de Lima Silva J, de Vasconcelos GA, Soares LFP, Cardoso DB (2015) Liquid residue of cassava as a replacement for maize in the diets of sheep. Tropical Animal Health and Production 47, 1083–1088.
Liquid residue of cassava as a replacement for maize in the diets of sheep.Crossref | GoogleScholarGoogle Scholar | 25899663PubMed |

Ferraz LV, Guim A, Véras RML, de Carvalho FFR, de Freitas MTD (2018) Cassava dreg as replacement of corn in goat kid diets. Tropical Animal Health and Production 50, 309–315.
Cassava dreg as replacement of corn in goat kid diets.Crossref | GoogleScholarGoogle Scholar | 28963649PubMed |

Goes RHTB, de Souza KA, Patussi RA, Cornelio TC, de Oliveira ER, Brabes KCS (2010) In situ ruminal degradability of crambe, sunflower and soybean seeds and their by-products in sheep feeding. Acta Scientiarum. Animal Sciences 32, 271–277.
In situ ruminal degradability of crambe, sunflower and soybean seeds and their by-products in sheep feeding.Crossref | GoogleScholarGoogle Scholar |

Gomes P (1961) ‘A algarobeira.’ Serie SIA, 865. (Ministério da Agricultura, Serviço de Informação Agrícola: Rio de Janeiro, Brazil)

Gómez G, Vargas R, Quesada S (1998) Crecimiento y conversión alimenticia de ratas Sprague Dawley sometidas a la ingesta de extractos acuosos de pejibaye (Bactris gasipaes. Agronomía Costarricense 22, 185–190.

Gonda HL, Lindberg JE (1994) Evaluation of dietary nitrogen utilization in dairy cows based on urea concentrations in blood, urine and milk, and on urinary concentration of purine derivatives. Acta Agriculturae Scandinavica, Section A – Animal Science 44, 236–245.
Evaluation of dietary nitrogen utilization in dairy cows based on urea concentrations in blood, urine and milk, and on urinary concentration of purine derivatives.Crossref | GoogleScholarGoogle Scholar |

Gregory A, Bolwell GP (1999) Hemicelluloses. Comprehensive Natural Products. Chemistry 3, 599–615.
Hemicelluloses. Comprehensive Natural Products.Crossref | GoogleScholarGoogle Scholar |

Hall MB, Hoover WH, Jennings JP, Webster TKM (1999) A method for partitioning neutral detergent-soluble carbohydrates. Journal of the Science of Food and Agriculture 79, 2079–2086.
A method for partitioning neutral detergent-soluble carbohydrates.Crossref | GoogleScholarGoogle Scholar |

Hill J (2007) Impacts of nutritional technology on feeds offered to horses: a review of effects of processing on voluntary intake, digesta characteristics and feed utilisation. Animal Feed Science and Technology 138, 92–117.
Impacts of nutritional technology on feeds offered to horses: a review of effects of processing on voluntary intake, digesta characteristics and feed utilisation.Crossref | GoogleScholarGoogle Scholar |

Hoover WH, Stokes SR (1991) Balancing carbohydrates and proteins for optimum rumen microbial yield. Journal of Dairy Science 74, 3630–3644.
Balancing carbohydrates and proteins for optimum rumen microbial yield.Crossref | GoogleScholarGoogle Scholar | 1744285PubMed |

Huntington GB, Archibeque SL (1999) Practical aspects of urea and ammonia metabolism in ruminants. In ‘Proceedings American Society of Animal Science’, 1999, Raleigh, NC, USA, pp. 1–11. (American Society of Animal Science: Raleigh, NC, USA)

Kozloski GV (2019) ‘Bioquímica dos ruminantes.’ 3rd edn. 212 pp. (Universidade Federal de Santa Maria: Santa Maria)

Leterme P, García MF, Londoño AM, Rojas MG, Buldgen A, Souffrant WB (2005) Chemical composition and nutritive value of peach palm (Bactris gasipaes Kunth) in rats. Journal of the Science of Food and Agriculture 85, 1505–1512.
Chemical composition and nutritive value of peach palm (Bactris gasipaes Kunth) in rats.Crossref | GoogleScholarGoogle Scholar |

Licitra G, Hernandez TM, Van Soest PJ (1996) Standardization of procedures for nitrogen fractionation of ruminant feeds. Animal Feed Science and Technology 57, 347–358.
Standardization of procedures for nitrogen fractionation of ruminant feeds.Crossref | GoogleScholarGoogle Scholar |

Lima AGVO, Silva TM, Bezerra LR, Pereira ES, Barbosa AM, Ribeiro RDX, Rocha TC, Trajano JS, de Oliveira RL (2018) Intake, digestibility, nitrogen balance, performance and carcass traits of Santa Ines lamb fed with sunflower cake from biodiesel production. Small Ruminant Research 168, 19–24.
Intake, digestibility, nitrogen balance, performance and carcass traits of Santa Ines lamb fed with sunflower cake from biodiesel production.Crossref | GoogleScholarGoogle Scholar |

Lizieire RS, Silva JFC, Leão MI, Valadares Filho SC, Campos OF (1990) Níveis crescentes de proteína degradada no rúmen de cabras. I. Efeitos sobre consumo, digestibilidade aparente e balanço de nitrogênio. Revista Brasileira de Zootecnia 9, 552–561.

Lu Z, Xu Z, Shen Z, Tian Y, Shen H (2019) Dietary energy level promotes rumen microbial protein synthesis by improving the energy productivity of the ruminal microbiome. Frontiers in Microbiology 10, 1144
Dietary energy level promotes rumen microbial protein synthesis by improving the energy productivity of the ruminal microbiome.Crossref | GoogleScholarGoogle Scholar |

Maeng WJ, Van Nevel CJ, Baldwin RL, Morris JG (1976) Rumen microbial growth rates and yields: effect of amino acids and protein. Journal of Dairy Science 59, 68–79.
Rumen microbial growth rates and yields: effect of amino acids and protein.Crossref | GoogleScholarGoogle Scholar | 1249281PubMed |

Mertens DR (1994) Regulation of forage intake. In ‘Forage quality, evaluation and utilization’. (Ed. GC Fahey Jr) pp. 450–493. (American Society of Agronomy: Madison, WI, USA)

Mertens DR (2002) Gravimetric determination of amylase-treated neutral detergent fiber in feeds with refluxing in beakers or crucibles: collaborative study. Journal of AOAC International 85, 1217–1240.

Min BR, McNabb WC, Barry TN, Peters JS (2000) Solubilization and degradation of ribulose-1,5-bisphosphate carboxylase/oxygenase (EC 4.1.1.39; Rubisco) protein from white clover (Trifolium repens) and Lotus corniculatus by rumen microorganisms and the effect of condensed tannins on these processes. The Journal of Agricultural Science 134, 305–317.
Solubilization and degradation of ribulose-1,5-bisphosphate carboxylase/oxygenase (EC 4.1.1.39; Rubisco) protein from white clover (Trifolium repens) and Lotus corniculatus by rumen microorganisms and the effect of condensed tannins on these processes.Crossref | GoogleScholarGoogle Scholar |

Moore KJ, Jung H-JG (2001) Lignin and fiber digestion. Rangeland Ecology & Management/Journal of Range Management Archives 54, 420–430.
Lignin and fiber digestion.Crossref | GoogleScholarGoogle Scholar |

Mora-kopper S, Mora-Urpi JE, Mata-Segreda JF (1996) Lipolytic activity in meals of pejibaye palm fruit (Bactris gasipaes, Palmae). Revista de Biologia Tropical 44, 597–599.

Murillo M, Kroneberg A, Mata JF, Calzada JG, Castro V (1983) Estudio preliminar sobre factores inhibidores de enzimas proteolíticas en la harina de pejibaye (Bactris gasipaes. Revista de Biologia Tropical 31, 227–231.
Estudio preliminar sobre factores inhibidores de enzimas proteolíticas en la harina de pejibaye (Bactris gasipaes.Crossref | GoogleScholarGoogle Scholar |

Murillo MG, Zumbado M, Cooz AE, Espinoza A (1991) Evaluacíon de la harina de pejibaye (Bactris gasipaes) en dietas para pollas de reemplazo durante el periodo de iniciacíon y en gallinas ponedoras al inicio de postura. Agronomía Costarricense 15, 135–141.

National Research Council (2001) ‘Nutrient requirements of dairy cattle.’ 7th edn. 450 pp. (National Academy Press: Washington, DC, USA)

National Research Council (2007) ‘Nutrient requirements of small ruminants: sheep, goats, cervids and new world camelids.’ (The National Academies Press: Washington, DC, USA)
| Crossref |

Orlandi T, Pozo CA, Schiavo J, Oliveira L, Kozloski GV (2020) Effect of using Acacia mearnsii tannin extract as a feed additive on nutritional variables and productive performance in dairy cows grazing a temperate pasture. Animal Science Journal 91, e13407
Effect of using Acacia mearnsii tannin extract as a feed additive on nutritional variables and productive performance in dairy cows grazing a temperate pasture.Crossref | GoogleScholarGoogle Scholar | 32567213PubMed |

Ørskov ER (2000) New concepts of feed evaluation for ruminants with emphasis on roughages and feed intake. Asian-Australasian Journal of Animal Science 13, 128–136.

Palmquist DL, Mattos WRS (2011) Metabolismo de lipídeos na alimentação de ruminantes. In ‘Nutrição de ruminantes’. 2nd edn. (Eds TT Berchielli, AV Pires, SG Oliveira) pp. 299–322. (Funep: Jaboticabal, Brazil)

Pereira L, Pires AJV, Carvalho GGP, Silva RVMM, Simionato JI, Lacerda ECQ, Bezerra LS, Eiras CE, Carvalho BMA (2016) Nutritional characteristics of lambs meat fed diets with cotton cake. Journal of Food Quality 39, 140–149.
Nutritional characteristics of lambs meat fed diets with cotton cake.Crossref | GoogleScholarGoogle Scholar |

Pereira TCJ, Pereira MLA, Almeida PJP, de Carvalho GGP, da Silva FF, Silva HGO, dos Santos AB (2014) Substitution of maize for mesquite pod meal in diets for lambs. Italian Journal of Animal Science 13, 3278
Substitution of maize for mesquite pod meal in diets for lambs.Crossref | GoogleScholarGoogle Scholar |

Pereira TCJ, Pereira MLA, Oliveira CAS, Argôlo LS, Silva HGO, Pedreira MS, Almeida PJP, dos Santos AB (2013) Mesquite pod meal in diets for lactating goats. Revista Brasileira de Zootecnia 42, 102–108.
Mesquite pod meal in diets for lactating goats.Crossref | GoogleScholarGoogle Scholar |

Pereira TCJ, Ribeiro LSO, Pereira MLA, Pires AJV, de Carvalho GGP, Pereira CAR (2019a) Feeding behavior of goat kids fed diets containing peach palm meal. Acta Scientiarum. Animal Sciences 42, e47088
Feeding behavior of goat kids fed diets containing peach palm meal.Crossref | GoogleScholarGoogle Scholar |

Pereira TCJ, Ribeiro LSO, Pires AJV, Pereira MLA, Santos AB, Silva HGO, de Carvalho GGP (2019b) Growth performance and apparent digestibility by goats fed diets with peach palm meal replacing maize. Applied Animal Science 35, 563–569.
Growth performance and apparent digestibility by goats fed diets with peach palm meal replacing maize.Crossref | GoogleScholarGoogle Scholar |

Powell JM, Gourley CJP, Rotz CA, Weaver DM (2010) Nitrogen use efficiency: a potential performance indicator and policy tool for dairy farms. Environmental Science & Policy 13, 217–228.
Nitrogen use efficiency: a potential performance indicator and policy tool for dairy farms.Crossref | GoogleScholarGoogle Scholar |

Quaranta A, D’Alessandro AG, Frate A, Colella GE, Martemucci G, Casamassina D (2006) Behavioural response towards twelve feedstuffs in lambs. Small Ruminant Research 64, 60–66.
Behavioural response towards twelve feedstuffs in lambs.Crossref | GoogleScholarGoogle Scholar |

Reynolds CK, Kristensen NB (2008) Nitrogen recycling through the gut and the nitrogen economy of ruminants: an asynchronous symbiosis. Journal of Animal Science 86, E293–305.
Nitrogen recycling through the gut and the nitrogen economy of ruminants: an asynchronous symbiosis.Crossref | GoogleScholarGoogle Scholar | 17940161PubMed |

Ribaski J, Drumond MA, Oliveira VR, Nascimento CES (2009) ‘Algaroba (Prosopis juliflora): Árvore de Uso Múltiplo para a Região Semiárida Brasileira.’ (Comunicado Técnico: Colombo, PR, Brazil)

Ribeiro LSO, Pereira MLA, Santos AB, Pires AJV, Carvalho GGP, Silva HGO, Pereira TCJ (2021) Nitrogen balance of goat kids fed diets containing peach palm meal. Arquivo Brasileiro de Medicina Veterinária e Zootecnia 73, 543–549.
Nitrogen balance of goat kids fed diets containing peach palm meal.Crossref | GoogleScholarGoogle Scholar |

Russell JB, O’Connor JD, Fox DG, Van Soest PJ, Sniffen CJ (1992) A net carbohydrate and protein system for evaluating cattle diets: I. Ruminal fermentation. Journal of Animal Science 70, 3551–3561.
A net carbohydrate and protein system for evaluating cattle diets: I. Ruminal fermentation.Crossref | GoogleScholarGoogle Scholar | 1459918PubMed |

Salazar PC, Navarro-Cerrillo RM, Grados N, Cruz G, Barrón V, Villar R (2019) Tree size and leaf traits determine the fertility island effect in Prosopis pallida dryland forest in Northern Peru. Plant and Soil 437, 117–135.
Tree size and leaf traits determine the fertility island effect in Prosopis pallida dryland forest in Northern Peru.Crossref | GoogleScholarGoogle Scholar |

Santos AB, Pereira MLA, Silva HGO, Pedreira MS, Carvalho GGP, Ribeiro LSO, Almeida PJP, Pereira TCJ, Moreira JV (2014) Nitrogem metabolism in lactating goats fed with diets containing different protein sources. Asian Australasian Journal Animal Sciences 27, 658–666.
Nitrogem metabolism in lactating goats fed with diets containing different protein sources.Crossref | GoogleScholarGoogle Scholar |

Santos ET, Pereira MLA, Silva CF, Souza-Neta LC, Geris R, Martins D, Batista R (2013) Antibacterial activity of the alkaloid-enriched extract from Prosopis juliflora pods and its influence on in vitro ruminal digestion. International Journal of Molecular Sciences 14, 8496–516.
Antibacterial activity of the alkaloid-enriched extract from Prosopis juliflora pods and its influence on in vitro ruminal digestion.Crossref | GoogleScholarGoogle Scholar | 23595000PubMed |

Santos FAP, Pedroso AM (2011) Metabolismo de proteínas. In ‘Nutrição de Ruminantes’. 2nd edn. (Eds TT Berchielli, AV Pires, SG Oliveira) pp. 265–292. (Funep: Jaboticabal, SP, Brazil)

Silva JFC (2011) Mecanismos reguladores de consumo. In ‘Nutrição de ruminantes’. (Eds TT Berchielli, AV Pires, SG Oliveira) pp. 61–114. (Funep: Jaboticabal, SP, Brazil)

Silva LFP, Dixon RM, Costa DFA (2019) Nitrogen recycling and feed efficiency of cattle fed protein-restricted diets. Animal Production Science 59, 2093–2107.
Nitrogen recycling and feed efficiency of cattle fed protein-restricted diets.Crossref | GoogleScholarGoogle Scholar |

Statistical Analysis System – SAS Institute (2014) ‘SAS systems for windows user’s guide.’ (SAS Institute Inc.: Cary, NC, USA)

Van Soest PJ (1994) ‘Nutritional ecology of the ruminant.’ 2nd edn. (Cornell University Press: Ithaca, NY, USA)

Van Soest PJ, Robertson JD, Lewis BA (1991) Methods for dietary fiber, neutral detergent fiber, nonstarch polysaccharides in relation to animal nutrition. Journal of Dairy Science 74, 3583–3597.

Weiss WP (1999) Energy prediction equations for ruminant feeds. In ‘Proceedings of the 61st Cornell nutrition conference for feed manufacturers, Rochester, NY’. pp. 176–185. (New York State College of Agriculture and Life Sciences: Ithaca, NY)

Yáñez-Ruiz DR, Moumen A, Martin Garcia AI, Molina Alcaide E (2004) Ruminal fermentation and degradation patterns protozoa population, and urinary purine derivatives excretion in goats and wethers fed diets based on two-stage olive cake: effect of PEG supply. Journal Animal Science 82, 2023–2032.
Ruminal fermentation and degradation patterns protozoa population, and urinary purine derivatives excretion in goats and wethers fed diets based on two-stage olive cake: effect of PEG supply.Crossref | GoogleScholarGoogle Scholar |