Effects of dietary sunflower seeds on rumen protozoa and growth of lambs.
Linoleic acid-rich sunflower-seed supplements (SSS) were used in two experiments (experiment 1, high-concentrate diets; experiment 2, high-forage diets) to study effects on rumen protozoa and the growth of lambs. Both experiments consisted of four treatments, two with a low-protein diet (120 g/kg) and two with a high-protein diet (160 g/kg). For both diets, one treatment was without (control) and one with the SSS (140 g/kg dietary DM). The lambs were fed ad libitum for 70 and 140 d in experiments 1 and 2, respectively. Thereafter, the digestibility of organic matter (OM), acid-detergent fibre and neutral-detergent fibre were determined for each diet with four lambs, and then all lambs were slaughtered and rumen fluid samples were collected and analysed. The results showed substantial decreases (P < 0.001) or total elimination of protozoa in the rumen fluid of the SSS-receiving lambs. In the first experiment the SSS also decreased (P < 0.05) feed intake, but an increase in average daily gain (P < 0.06) resulted in an improved (P < 0.05) feed:gain ratio. Also, the SSS increased (P < 0.05) the digestibility of fibre. In the second experiment the SSS decreased (P < 0.05) the OM digestibility, feed intake and growth of lambs. It was concluded that the use of sunflower-seed supplementation in high-concentrate diets of ruminants reduces rumen fauna, resulting in savings on dietary protein supplements and an increased digestion of feed.
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Agriculture and Agri-Food Canada, P.O. Box 300, Lethbridge, Alberta, Canada T1J 4B1. ivanm@agr.gc.ca
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D000818:Animals; D018753:Diet, Protein-Restricted / Q000379:methods; D004044:Dietary Proteins / Q000008:administration & dosage* / Q000378:metabolism; D019587:Dietary Supplements; D004063:Digestion / Q000502:physiology; D004734:Energy Metabolism / Q000502:physiology; D056890:Eukaryota; D005232:Fatty Acids, Volatile / Q000378:metabolism; D005260:Female; D005285:Fermentation / Q000502:physiology; D006368:Helianthus; D008297:Male; D009751:Nutritional Requirements; D012417:Rumen / Q000469:parasitology*; D012639:Seeds; D012756:Sheep / Q000254:growth & development* / Q000469:parasitology
D004044:Dietary Proteins; D005232:Fatty Acids, Volatile