Abstract
A randomized design trial was used to evaluated effects of cottonseed hulls (CSH) and bermudagrass hay (BGH) particle size in feedlot diets fed to female Rambouillet lambs (n = 10/treatment) ...on dry matter intake (DMI), physiological parameters, and growth performance. After 14 days of adaptation, lambs were individually fed 80% concentrate diets during two distinct 21-d periods with either CSH or BGH as the roughage source, respectively. Diets were identical except for the roughage particle size (3/8, 1/4, or 3/16-inch hammermill screens); control diets contained unground CSH or course-ground BGH. Data were analyzed by period using a model including treatment as main effect and animal as repeated measure. No differences in initial and final BW were observed. Lamb DMI (g/d) did not vary (P > 0.10) among the different particle sizes. However, there was a linear decrease (P = 0.007) in DMI as a percentage of BW when CSH particle size increased, while no difference was observed for BGH (P > 0.55). Rumen fluid pH was not affected by roughage particle size (P > 0.19) in either Period. No differences (P > 0.10) in rumen fluid FAs concentration were observed related to CSH despite a quadratic trend (P = 0.07) in acetate concentration. Total VFA (P = 0.01), acetate (P = 0.008), and propionate (P = 0.04) concentrations in ruminal fluid from lambs fed diets containing BGH quadratically increased, while butyrate linearly decreased (P = 0.03). There was a trend for a quadratic increase (P = 0.09) in blood serum ammonia when CSH particle size increased. Blood serum urea during both periods and ammonia during Period 2, did not vary with roughage particle size. Results suggested that particle size is dependent upon type of roughage. Generally, in high concentrate lamb feedlot diets a course particle size (3/8” screen) is recommended.
A randomized design trial was used to evaluated effects of cottonseed hulls (CSH) and bermudagrass hay (BGH) particle size in feedlot diets fed to female Rambouillet lambs (n = 10/treatment) on dry ...matter intake (DMI), physiological parameters, and growth performance. After 14 days of adaptation, lambs were individually fed 80% concentrate diets during two distinct 21-d periods with either CSH or BGH as the roughage source, respectively. Diets were identical except for the roughage particle size (3/8, 1/4, or 3/16-inch hammermill screens); control diets contained unground CSH or course-ground BGH. Data were analyzed by period using a model including treatment as main effect and animal as repeated measure. No differences in initial and final BW were observed. Lamb DMI (g/d) did not vary (P > 0.10) among the different particle sizes. However, there was a linear decrease (P = 0.007) in DMI as a percentage of BW when CSH particle size increased, while no difference was observed for BGH (P > 0.55). Rumen fluid pH was not affected by roughage particle size (P > 0.19) in either Period. No differences (P > 0.10) in rumen fluid FAs concentration were observed related to CSH despite a quadratic trend (P = 0.07) in acetate concentration. Total VFA (P = 0.01), acetate (P = 0.008), and propionate (P = 0.04) concentrations in ruminal fluid from lambs fed diets containing BGH quadratically increased, while butyrate linearly decreased (P = 0.03). There was a trend for a quadratic increase (P = 0.09) in blood serum ammonia when CSH particle size increased. Blood serum urea during both periods and ammonia during Period 2, did not vary with roughage particle size. Results suggested that particle size is dependent upon type of roughage. Generally, in high concentrate lamb feedlot diets a course particle size (3/8" screen) is recommended.
Abstract
Hi-A™ corn is a unique type of lines and hybrids that were developed by the Texas A&M AgriLife Corn Breeding Program and have high anthocyanin and antioxidants. A completely randomized ...design trial was used to evaluated effects of Hi-A and low-A (regular) corn cobs and bermudagrass hay (BGH) in feedlot diets fed to female Rambouillet lambs (n = 10/treatment), with initial body weight (BW) of 30.7+1.2 kg, on dry matter intake (DMI), BW, average daily gain (ADG), and growth:feed ratio (G:F). After 14 days of adaptation, lambs were individually fed a total mixed ration with 80% concentrate and 20% of one of the roughages (Hi-A, low-A, or BGH) for 63 days. Hay was chopped, while cobs were ground using a hammermill with a 9.52-mm screen. Data were analyzed using repeated-measures ANOVA. The BW was not affected by the diet but increased (P < 0.001) during the trial. Diet did not influence the ADG. However, the ADG was lower (P < 0.001) in the d-42 (0.12 kg/d) than the rest of the trial (0.22 kg/d), after a period of constant high temperatures. The interaction diet vs. day affected (P < 0.05) DMI. In general, lambs increased (P < 0.05) DMI (g/d) and decreased (P < 0.05) relative DMI (%BW) in the final part of the trial, when the animals were getting closer to the harvesting date. Lambs had lower (P < 0.05) DMI of BGH diets than Hi-A diets from d-42 to d-63 and Low-A diets from d-49 to d-56. The G:F ratio was not affected by the diet but decreased (P < 0.05) from the middle to the end of the trial. Corn cobs are valuable as alternative roughage for feedlot lambs, with intake and growth performance comparable to BGH.
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