Determining the Ruminal Degradability of Sunflower Head Residues and the Effect of its Different Levels on Digestibility, Blood Parameters and Chewing Activity of Fattening Afshari Lambs

Sunflower is primarily an oil crop but the plant itself and its crop residues are used as animal feed. This study was to investigate the replacing of sunflower head wastes with wheat straw.

This research was conducted in the form of two experiments. In the first experiment, in order to determine the degradability of dry matter and neutral detergent fibre (NDF) of sunflower heads, three rams of Dalagh breed with rumen fistula were used and in the second experiment, 8 male Afshari lambs with an average live weight of 30±4.5 kg were tested in the change-over design with zero, 7, 14 and 21% in the diet. In this research, feed intake, digestibility, blood parameters, and chewing activity were measured.

The results showed that degradation percentage of DM and NDF was 20.41 and 25.59, respectively at time zero, and at 96 hour later it reached to the highest level of degradation equal to 73.47% and 46.40%, respectively. In this study dry matter intake (DM) was influenced by the experimental treatments (P=0.003). Replacing wheat straw with sunflower head improved digestibility of dry matter, organic matter and neutral detergent fiber but not significant. The feed conversion rate was improved with sunflower head treatments but not significant. Lambs that were used sunflower head residues, had more weight gain compared to the control group. None of the treatments containing sunflower head residues had a significant effect on blood parameters. Eating and chewing activity and whole chewing activity were influenced by the experimental treatments (p=0.01). The highest rumination activity per kg neutral detergent fiber, was related to the control treatment.

In general, replacing wheat straw with sunflower head residues up to 21 percent in the diet, can be done successfully. In general, according to daily weight gain, sunflower head residues can be replaced up to 21% levels in the diet by wheat straw.