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Nutritional Aspects of the Association of Spineless Cactus and Urea with Tifton-85 Hay in Wethers’ Diets
by
, , , , and
Robert Emilio Mora-Luna
1
,
Ana María Herrera
2,*,
Michelle Christina Bernardo de Siqueira
3,
Maria Gabriela da Conceição
4,
Juana Catarina Cariri Chagas
5,
Thayane Vitória Monteiro Santos
3,
José Augusto Bastos Afonso da Silva
3,
Francisco Fernando Ramos de Carvalho
3 and
Marcelo de Andrade Ferreira
3 1
Departamento de Ciencias Animales, Facultad de Agronomía y Sistemas Naturales, Pontificia Universidad Católica de Chile, Santiago 7820436, Chile
2
Facultad de Medicina Veterinaria, Universidad San Sebastián, Santiago 8420524, Chile
3
Departamento de Zootecnia, Universidade Federal Rural de Pernambuco (UFRPE), Recife 52171-900, Brazil
4
Centro de Ciências Agrárias e da Biodiversidade, Universidade Federal do Cariri, Juazeiro do Norte 63133-610, Brazil
5
Faculty of Veterinary Medicine and Animal Science, Department of Applied Animal Science and Welfare, Swedish University of Agricultural Sciences, 907-36 Umeå, Sweden
*
Author to whom correspondence should be addressed.
Animals 2025, 15(19), 2865; https://doi.org/10.3390/ani15192865
Submission received: 11 August 2025
/
Revised: 22 September 2025
/
Accepted: 23 September 2025
/
Published: 30 September 2025
(This article belongs to the Collection Sustainable Animal Nutrition and Feeding)
Simple Summary
In semi-arid conditions, the spineless cactus is an excellent feed option because of its high water-use efficiency for dry matter production and its rich content of non-fibre carbohydrates. This study assessed the replacement of Tifton-85 hay with increasing levels of spineless cactus plus urea and ammonium sulphate in diets for rumen-fistulated wethers, using a roughage:concentrate ratio of 70:30. Replacing up to 44% of roughage with spineless cactus plus urea and ammonium sulphate improved organic matter and metabolisable energy intakes. Digestibility of dry matter, organic matter, and non-fibre carbohydrates increased linearly with the inclusion of spineless cactus plus urea and ammonium sulphate. It also reduced voluntary water intake and feeding time. On the other hand, spineless cactus inclusion increased water excretion in faeces and the degradation rate of dry matter. A combination of 41% spineless cactus plus urea and ammonium sulphate and 29% Tifton-85 hay in a 70:30 roughage:concentrate diet maximised metabolisable energy intake under these conditions. These findings highlight the potential of spineless cactus as a strategic feed component for small ruminants in water-limited environments.
Abstract
This study evaluated the effects of including 0, 150, 300, 450, and 600 g/kg of dry matter (DM) of spineless cactus (SC; Nopalea cochenillifera Salm-Dyck) plus urea and ammonium sulphate (UAS) (9:1), replacing Tifton-85 hay (Cynodon spp. cv. Tifton 85), on nutrient intake and digestibility, feeding behaviour, water intake, and rumen dynamics. Five rumen-fistulated and cannulated crossbred wethers were randomly assigned in a 5 × 5 Latin square design. A roughage:concentrate ratio of 70:30 was supplied. Organic matter (OM) and metabolisable energy (ME) intakes showed quadratic responses (p < 0.05), with maximum values of 1157 g/day and 14.50 MJ/day estimated at SC+UAS levels of 364 and 410 g/kg DM, respectively. Apparent digestibilities of DM, OM, and non-fibre carbohydrates, as well as water excretion in faeces and degradation rate of DM, increased with SC+UAS inclusion (p < 0.05). Indigestible neutral detergent fibre (NDF) intake, feeding and rumination times, voluntary water intake, NDF degradation and passage rates, as well as the indigestible NDF passage rate, decreased with SC+UAS inclusion (p < 0.05). In wethers’ diets with a roughage:concentrate ratio of 70:30, a roughage combination of SC+UAS and Tifton-85 hay in a 41:29 ratio is recommended to maximise ME intake.
Keywords:
Digestibility; feeding behaviour; roughage; sheep; semi-arid
