Effects of Different Levels of Alfalfa Meal on Layer and Broiler Performance and Cholesterol Content of the Products

Abstract

Two experiments were designed to evaluate the effects of different levels of sun-cured alfalfa meal on performance of starting layers (White Hisex), broiler chicks (Hubbard), egg quality and cholesterol levels of egg yolk and blood serum of broilers. Eight experimental diets with (0, 2, 4 and 6%) of alfalfa meal levels incorporated with sorghum and maize as the main sources of energy. They were formulated to meet the essential nutrients for layers and others for broiler chicks (starter and finisher) according to NRC, (1994). In the first experiment: 192 hen of starting layer, with 25 weeks of age were utilized for 16 weeks. The monthly average temperatures and relative humidity were 31oC and 40%. They were randomly distributed into eight groups. Each group contained 6 hens/replicate, 4 replicates/ treatment. No significant differences (P>0.05) were seen in hen-day egg production (%), egg weight and feed intake throughout the experimental periods among all treatments. The best results of hen-day and fed intake were obtained from the treatment of sorghum+2% alfalfa and the lower values from the control treatment (sorghum + zero alfalfa), while the treatment of maize and all levels of alfalfa showed higher values of egg weight compared to other treatments. There is significant differences observed in hen-housed egg production (%), FCR, shape index, egg specific gravity, egg shell thickness, yolk colour, albumen height, haugh unit, yolk index and egg yolk cholesterol. The treatments of maize or sorghum with lower or higher levels of alfalfa gave the best results than the control treatments. v The treatment of sorghum+2% alfalfa showed the highest value of hen- housed egg production% and lower value was obtained from the control diet of sorghum + zero% alfalfa. The treatment of maize+6% alfalfa gave the highest value of egg weight compared to the other treatments. No significant differences were observed among the treatments during the experimental periods in feed intake/bird/day (g), in spite of the higher feed intake obtained from the treatment from sorghum or maize with 2% or 4% alfalfa compared to other treatments. The treatment of maize or sorghum with 6% alfalfa shows better feed conversion rate in comparison to the rest of the treatments during the experimental period. There were significant differences in shape index from the effect of alfalfa during the rest of experimental period. Higher values were obtained from the treatment of maize+6% alfalfa. The effects of different treatments on egg specific gravity showed significant differences (P<0.05) during the experimental period among sorghum + zero% alfalfa and all the treatments including maize based diets. The effect of the experimental treatments on egg shell thickness showed significant differences for the different treatments, with inconsistency in the result obtained. Yolk colour scores revealed significant differences among all treatments with the increase of yolk colour as the level of alfalfa increases. Significant differences (P<0.05) in the albumen height were observed among the experimental treatments during the experimental periods. The effect of alfalfa meal with sorghum or maize basal diet sources of energy on Haugh units during experimental period revealed significant differences among the treatments. Significant differences (P<0.05) among the dietary treatments in their effect on yolk index were observed during all the experimental periods except during week 4th and 12th . vi The results showed that there is a significant difference (P<0.05) in egg yolk cholesterol (mg/100g) among the different experimental treatments, with less values obtained from the treatments of maize+2% alfafa, maize+4% alfalfa and maize+6% alfalfa. In the second experiment: Day-old (unsexed) broiler chicks (n=232) were utilized for six-week study to determine the effect of alfalfa meal on live body weight, body weight gain, feed intake, feed conversion ratio, carcass quality characteristics, serum cholesterol level and meat colour of broiler chicks. The chicks were randomly distributed into eight groups. Each group contains 8 chicks/pen and 4 replications/treatments using a completely randomized design. The weekly average temperature and relative humidity during the experiment period were 24.6oC and 31.55%. The results showed no significant differences (P<0.05) in live body weight within sorghum or maize basal diets, but significant differences (P<0.05) were observed among all treatments, where maize + zero% alfalfa showed the highest body weight or growth performance throughout the experimental periods, followed by maize +2% alfalfa and the lowest values were obtained from sorghum+4% alfalfa. There are significant differences (P<0.05) revealed in body gain among all treatments with best results obtained from maize based diets with or without alfalfa compared to sorghum based diets The effect of alfalfa meal on daily feed consumption during the experimental period showed significant differences with the control treatment of both sorghum and maize gave the highest feed intake and the lowest feed consumption during the experimental period was obtained from the treatments of based diets with alfalfa. The best results of FCR were obtained from maize based diets compared to sorghum based diets. Maize+2% alfalfa gave best FCR throughout the experimental period and the lowest FCR were obtained from sorghum based diets with or without alfalfa. vii There were no significant(P>0.05) differences in carcass characteristics (final live weight, hot and cold carcass weight) for the basal diet of sorghum or maize with or without alfalfa meal. While there are significant differences (p<0.05) observed among experimental diets with higher values obtained from maize+2% alfalfa and lowest values from sorghum + 2% alfalfa. There are significant (P<0.05) differences appeared from the effect of alfalfa meal in hot and cold dressing percent where the treatments of maize+6% alfalfa and sorghum+6% alfalfa. While the other experimental treatments showed no significant (P>0.05) differences in their effect on hot and cold dressing percent. Significant differences (P<0.05)were observed among the experimental diets with best values obtained from maize based diets in their effect on carcass cuts except for back weight, wing weight and legs weight. The results indicated significant differences among diets in their effect on the lengths of large intestine, small intestine and caecum (mm). Serum cholesterol of broiler chicks was not significantly affected by the experimental treatments of alfalfa meal, but numerically there were reduction in the cholesterol content (mg/dl) in treatments of both sorghum and maize basal diets with less numerical values obtained from the treatments of sorghum+4% alfalfa, sorghum+6% alfalfa and maize+2% alfalfa. The results obtained in the first experiment indicated that the utilization of alfalfa meal in layers ration is of beneficial for layers in terms of improving their performance, egg quality and at the same time increased the yolk colour and reduced the cholesterol content of egg yolk. The results obtained in the second experiment showed that inclusion of alfalfa meal adversely affected growth, body weight gain, feed intake, feed conversion rate and reduced serum cholesterol and thus it may be beneficial for human health to consume meat with low cholesterol content to avoid the risk of cardiovascular diseases.