Register      Login
Animal Production Science Animal Production Science Society
Food, fibre and pharmaceuticals from animals
RESEARCH ARTICLE

Effects of feeding fresh citrus pulp to Merino wethers on wool growth and animal performance1

Y. T. E. Fung A , J. Sparkes A , I. Van Ekris A , A. V. Chaves A and R. D. Bush A B
+ Author Affiliations
- Author Affiliations

A Faculty of Veterinary Science, The University of Sydney, Camden, NSW 2570, Australia.

B Corresponding author. Email: r.bush@usyd.edu.au

Animal Production Science 50(1) 52-58 https://doi.org/10.1071/EA08304
Submitted: 16 December 2008  Accepted: 12 August 2009   Published: 17 December 2009

Abstract

Two studies were conducted to determine the effects of replacing lupins with fresh citrus pulp in Merino wethers diets: (i) an in vitro study, which measured ruminal fermentation; and (ii) an in vivo study in which 18 mature Merino wethers were fed dietary treatments (n = 3) over 56 days to evaluate effects on performance [i.e. DM intake, average daily gain and wool growth]. In both the in vitro and in vivo studies, the control treatment consisted (in diet DM) of lucerne chaff (69.9%), lupins (30.1%) and phosphate (0.3%), whereas the citrus pulp treatments (n = 2; replacing lupins on 20 and 30% DM basis, respectively) consisted of lucerne chaff (61.7 and 63.3%), lupins (18.5 and 6.3%), phosphate (0.34 and 0.33%) and fresh citrus pulp (19.5 and 30.1%). Data were analysed using the MIXED model of SAS and orthogonal polynomial contrasts were used to determine linear (L) and quadratic responses to the level of citrus pulp. In the in vitro study, gas production, net total volatile fatty acid production as well as in vitro DM digestibility were similar (P > 0.05) among the dietary treatments. Ammonia production in citrus pulp treatments were twofold lower compared with the control (L, P < 0.01). The addition of citrus pulp to the diet increased the molar proportions of acetic acid and decreased that of butyric, branched-chain volatile fatty acids, and valeric acids (all L, P < 0.01) compared with the control diet. In the in vivo study, DM intake, average daily gain and feed conversion were similar among treatments (P > 0.52). Wool production parameters including clean fleece weight, yield and staple length were not different between diets (P > 0.30). Hence, fresh citrus pulp can be included up to 30% on a DM basis replacing lupins without detrimental effects on wool production and animal performance.


Acknowledgements

This study was conducted with financial support of the Australian Wool Education Trust. The authors thank University of Sydney staff: David Palmer and Riley Neve for assistance in animal husbandry, and Ajantha Horadagoda, Karen Williams and Jane Bursill for laboratory support.


References


Ariza P, Bach A, Stern MD, Hall MB (2001) Effects of carbohydrates from citrus pulp and hominy feed on microbial fermentation in continuous culture. Journal of Animal Science 79, 2713–2718.
CAS | PubMed |
[Verified 10 November 2009]

Hutton K (1987) Citrus pulp in formulated diets. In ‘Recent advances in animal nutrition in Australia’. (Ed. D Farrell) pp. 297–316. (University of New England: Armidale, NSW)

Leiva E, Hall MB, Van Horn HH (2000) Performance of dairy cattle fed citrus pulp or corn products as sources of neutral detergent-soluble carbohydrates. Journal of Dairy Science 83, 2866–2875.
CAS | PubMed |
[Verified 10 November 2009]

Pizon FJ, Wing JM (1976) Effects of citrus pulp in high urea rations for steers. Journal of Dairy Science 59, 1100–1103. open url image1

Pomares CC, Galloway DB, Holmes JHG, Clarke IJ, Tilbrook AJ (1995) Lupin and cowpea supplements for growth, wool production, and reproduction in rams. Australian Journal of Experimental Agriculture 35, 447–452.
Crossref | GoogleScholarGoogle Scholar | open url image1

SAS Institute Incorporation (2009) ‘SAS OnlineDoc 9.1.3.’ (SAS Institute Incorporation: Cary, NC)

Satter LD, Slyter LL (1974) Effect of ammonia concentration on rumen microbial protein production in vitro. The British Journal of Nutrition 32, 199–208.
Crossref | GoogleScholarGoogle Scholar | CAS | PubMed | open url image1

Scerra V, Caparra P, Foti F, Lanza M, Priolo A (2001) Citrus pulp and wheat straw silage as an ingredient in lamb diets: effects of growth and carcass and meat quality. Small Ruminant Research 40, 51–56.
Crossref | GoogleScholarGoogle Scholar | PubMed | open url image1

Schalch FJ, Schalch E, Zanetti MA, Brisola ML (2001) Substitution of the corn grain ground by citric pulp in the early weaning of dairy calves. Revista Brasileria de Zootecnia 30, 280–285. open url image1

Subcommittee on Sheep Nutrition CoAN, Board on Agriculture, National Research Council (1985) ‘Nutrient requirements of sheep.’ (National Academies Press: Washington, DC)

Taniguchi L, Zhoa Y, Uchikawa H, Obituse T (1999) Digestion site and extent of carbohydrate fractions in steers offered by-product diets, as determined by detergent and enzymatic methods. Animal Science (Penicuik, Scotland) 38, 173–182. open url image1

Van Soest PJ, Robertson JB, Lewis BA (1991) Methods for dietary fiber, neutral detergent fiber and non-starch polysaccharides in relation to animal nutrition. Journal of Dairy Science 74, 3583–3597.
CAS | PubMed |
open url image1

Vijchulata P, Henry PR, Ammerman CB, Potter SG, Palmer AZ, Becker HN (1980) Effect of dried citrus pulp and cage layer manure in combination with monensin on performance and tissue mineral composition in finishing steers. Journal of Animal Science 50, 1022–1030.
CAS |
open url image1

Volanis M, Zoiopoulos P, Tzerakis K (2004) Effects of feeding ensiled sliced oranges to lactating dairy sheep. Small Ruminant Research 53, 15–21.
Crossref | GoogleScholarGoogle Scholar | open url image1

Weatherburn MW (1967) Phenol-hypochlorite reaction for determination of ammonia. Analytical Chemistry 39, 971–974.
Crossref | GoogleScholarGoogle Scholar | CAS | open url image1









1 Presented at the 2009 Joint Annual Meeting ADSA CSAS ASAS Montreal (QC, Canada), 12–16 July (http://adsa.asas.org/meetings/2009/).