Feeding behavior of feedlot lambs fed with high levels of crude glycerin
The objective of this trial was to evaluate the effect of crude glycerin (CG) inclusion on feeding behavior of feedlot lambs. Forty Santa Ines intact males lambs were used with initial BW of 22.9 ± 4.10 kg, assigned in a completely randomized block. Diets consisted of Tifton-85 hay (Cynodon dactylon), corn, crude glycerin (83 % glycerol), corn gluten meal, corn oil, urea, sunflower meal, soybean hulls and mineral. The diets presented 18 % of roughage and 82 % of concentrate. The CG used is a byproduct from biodiesel originated from vegetable oils of soybean and sunflower. Five treatments were used: 0 % CG, 7.5 % CG, 15 % CG, 22.5 % CG and 30 % inclusion of CG on dry matter basis, whereas, the diet with 30% of CG promoted a total replacement of corn. The animals were housed in individual pens with free access to water. The feed intake was adjusted to ensuring 10 % of orts (ad libitum). The diets were offered twice daily at 0700 and 1600 h with 50 % of total in each meal. Feeding behavior was performed during 48 h by 2 trained observers that made visual observations every 5 min of feeding, drinking, ruminating, resting and other activities. Further, the ruminating efficiency was determined. The means of 2 d were calculated expressed in 24 h. The data were analyzed using the MIXED procedure of SAS and the treatments were compared using orthogonal contrasts (linear and quadratic) considering 5 % of significance level. There was no difference treatments among the variables measured (P > 0.05). The exception was drinking activity that showed a quadratic response (P = 0.04). On average, the animals presented 16.6 minutes drinking, 234.4 minutes eating, 428 minutes ruminating, 535 minutes resting and 226.8 in other activities. The ruminating efficiency was 325 (min of ruminating / kg DMI). In conclusion, crude glycerin in feedlot lambs influences only time spent drinking.
Keywords: animal nutrition, biodiesel, feed intake