Showing 3 results for Egg Production
Javad Pour-Reza, Mehdi Mehrshad,
Volume 1, Issue 2 (10-1997)
Abstract
Two experiments were designed and conducted to evaluate the effect of tallow and the nutritional value of millet and the effect of substituting millet for corn on the performance of laying hens. In the first experiment, the nitrogen corrected true metabolizable energy (TMEn) of tallow and millet was determined. Also the digestibility of dry matter (DM), protein, fat and crude fiber of millet was determined using the Sibbald's method. In the second experiment, with a completely randomized design and in a factorial arrangement, the effect of different levels of substitution of corn (0.0, 25, 50 and 75%), introduction of tallow at various amounts of 0, 3 and 6 percent, and also the effect of processing millet (ground and unground) on the diet of HY-Line layers from 26 to 38 weeks of age were studied. The criteria used were egg production rate, egg weight, egg output, feed intake, and feed conversion ratio. The results from the first experiment showed that screening millet increased its true metabolizable energy. Furthermore, crude fiber digestibility increased as a result of introducing fat into the diet (p<0.05). The results from the second experiment revealed that grinding millet had no significant effect on the performance of laying hens, but feed conversion ratio tended to improve in diets containing ground millet. Substitution of any amount of millet for corn significantly improved egg weight, egg output, and feed intake (P<0.05). Introduction of tallow by 6% significantly increased feed intake (P<0.05) too.
ٍsayed Mohammad Hashemi, Javad Pourreza,
Volume 2, Issue 3 (10-1998)
Abstract
This experiment was carried out to study the effects of different levels of vitamin C (0, 150, 300 and 450 ppm) and cage density (3, 4 and 5 birds) on performance and egg shell quality of laying hens under high environmental temperature. In a completely randomized design with 3 × 4 factorial arrangement, one hundred and ninety two (192) 25 week white leghorn hens were divided into 48 replicates four hens per replicate. The experimental period lasted 90 days. The criteria measured were: percentage production, egg weight, egg output, feed conversion ratio, shell thickness, shell weight, shell calcium and albumin height. Daily egg production and biweekly egg weight, shell thickness, shell weight and albumin height were recorded. Shell c1acium was measured at the end of the experiment's period. The results indicate that, 150 ppm vitamin C significantly (P < 0.05) increased egg weight and shell calcium. Albumin height was significantly (P < 0.05) increased at 300 ppm vitamin C supplementation. Cage density had no effects on shell weight, thickness and calcium, and albumin height. Egg weight, egg production and egg output were reduced significantly (P < 0.05) due to increased cage density. Feed conversion ratio was also increased significantly (P < 0.05) as cage density was increased. Interactions between vitamin C and cage density on shell and egg weight were significant (P < 0.05).
Mohammad Ali Edriss, Javad Pourreza, Saeid Ansari,
Volume 3, Issue 1 (4-1999)
Abstract
This experiment was conducted to study egg production traits in a flock of native fowl from Isfahan region and their crosses with three improved exotic breeds. Sexual maturity (SM), weight of the first egg (WFE), number of eggs (EP), egg weight (EW), feed intake (FI), and feed conversion ratio (FCR) were recorded individually during laying period up to 52 weeks of age. There were no significant differences (P < 0.05) in WFE between the four groups, but the difference between the four genetic groups was highly significant (P < 0.01) for SM, EP, EW, FI and FCR. During laying period, pooled coefficients of heritability (sire component) for SM, WFE, EP, EW, FI and FCR were estimated to be 0.24 ± 0.10, 0.03 ± 0.08, 0.41 ± 0.12, 0.48 ± 0.12, 0.13 ± 0.09 and 0.18 ± 0.09, respectively. In combined analysis, part record egg production (SM to 34 weeks of age) was positively correlated (genetically and phenotypically) with EP up to 52 weeks of age (rg = 0.74 ± 0.11, rp = 0.71). The values suggested that there is a relatively appropriate relationship in the combined groups analysis. In addition, EP up to 34 weeks of age was negatively correlated with FCR during the same period (rg = -0.92 ± 0.53, rp = -0.81).The estimated genetic and phenotypic correlation in this study suggested that selection based on part record egg production can not only be used successfully to improve EP during full record, but may also cause a better laying performance during laying period.
