Rumen fermentation patterns and nutrient digestion in lambs fed cottonseed meal supplemental diets

• Published in: Animal feed science and technology Vol. 103; no. 1; pp. 1 - 14
• Main Authors: Nagalakshmi, D., Sastry, V.R.B., Pawde, A.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 31-01-2003; Elsevier
• Subjects: Animal productions; Biological and medical sciences; Cottonseed meal; Fundamental and applied biological sciences. Psychology; Lambs; Nutrient digestibilities; Processing; Rumen fermentation; Terrestrial animal productions; Vertebrates; Nutrient digestibilities; Rumen fermentation; Lambs; Cottonseed meal; Processing; Malvaceae; Microbial activity; Ruminant animal; Animal feeding; Fiber crop; Gossypol; Dicotyledones; Angiospermae; Ungulata; Farming animal; Rumen; Digestion; Experimental study; Fermentation; Vertebrata; Mammalia; Chemical treatment; Sheep; Nutrient; Spermatophyta; Gossypium hirsutum; Artiodactyla; Processed food; Calcium hydroxide
• ISSN: 0377-8401; 1873-2216
• DOI: 10.1016/S0377-8401(02)00140-2

Twenty crossbred 3–4-month-old male lambs of uniform body weight were used to assess the effect of raw and processed cottonseed (
Gossypium) meals (CSM) on nutrient utilisation and rumen fermentation patterns. Lambs were assigned to five dietary treatments in a completely randomised design and fed isonitrogenous and isocaloric concentrate mixtures containing 30% deoiled groundnut cake (DGNC) (control), 40% of either raw, 45
min cooked, 1% calcium hydroxide (Ca(OH)
2) or iron (1 part free gossypol (FG):0.3 parts iron) treated CSM. The concentrate mixtures were fed to meet 80% of crude protein requirements (
NRC, 1985) with ad libitum access to chopped maize hay (
Zea mays). A metabolic trial of 6 days duration was conducted after 135 days of feeding, and rumen liquor was collected for 2 days at its end. Incorporation of 40% raw CSM resulted in reductions (
P<0.01) in the digestibility of dry matter and organic matter in comparison to control fed lambs. Cooking and Ca(OH)
2 treatment of CSM improved digestibilities of these nutrients, to levels comparable to those in control fed lambs. The ether extract (
P<0.05) and energy (
P<0.01) digestibilities in lambs fed Ca(OH)
2 treated CSM were higher compared to those lambs fed raw CSM diets. Acid detergent fibre and cellulose digestibilities were lower (
P<0.05) on cooked and iron treated CSM fed lambs. Retention of nitrogen and energy did not differ among diets. The digestible and metabolisable energy content of the Ca(OH)
2 treated CSM incorporated diet was higher (
P<0.01) than the other CSM containing diets, but similar to DGNC containing ration. Rumen pH and total volatile fatty acid concentration was similar among diets, but NH
3–N was lower (
P<0.05) on the cooked CSM diets versus the control. Feeding of lambs with raw CSM amounting to 17.9% of total dry matter intake (i.e. 303
mg FG intake per day) adversely affected utilisation of nutrients and rumen fermentation. This depression was alleviated to the greatest extent by 45
min cooking and 1% calcium hydroxide treatment. Iron treatment of CSM had little overall benefit.