Beak trimming at two different ages, Week-1 and Week-8, under four dietary regimens, varying in percent crude protein (CP) and metabolizable energy (ME) were compared. The dietary regimens were conventional high energy (CHE), conventional medium energy (CME), conventional low energy (CLE) and step-up protein regimen (SUP). At 20 weeks of age, 192 birds from each beak-dietary treatment were housed in laying cages for 24 weeks of egg production. One-half of the birds were provided with high light intensity ranging from 20 to 70 lux and one-half with low intensity from 2.5 to 22 lux. Cumulative feed intake through 20 weeks of age for the CHE fed birds was significantly lower than that for the CLE fed birds but did not differ from that of the CME or the SUP fed birds. The feed intake of the CME and CLE groups did not differ from each other; however, both were significantly greater than that of the SUP fed birds. Birds reared on CME had the lowest protein consumption with no difference in protein consumption between CHE, CLE and SUP fed birds. Birds reared on the SUP regimen had the lowest ME intake followed by the CLE group with no significant difference between CHE and CME groups. By 20 weeks of age, there was no significant difference in body weight for CHE, CME and CLE birds with those on SUP being significantly lower than all other treatments. Livability for the 20-week growing phase did not differ among dietary treatments. The influence of age when beaks were trimmed (Week-1 or Week-8) on feed, protein, and energy intake, body weight or livability for the 20-week growing period did not differ between the two beak treatments. By 44 weeks of age, there were no significant body weight differences among any of the juvenile dietary treatments. Age at 50% production, hen-day and hen-housed egg production, egg weight, shell quality, feed per egg, livability and mortality due to prolapse per se did not differ significantly among juvenile dietary treatments for the six 28-day production period. Birds reared on SUP regimen laid a significantly higher number of pee-wee eggs (< 42.5 g) and a significantly lower number of extra-large eggs (63.8 - 70.8 g) than those fed the other diets. Age at beak trimming and level of light intensity did not influence any of the parameters evaluated during the laying period. / Master of Science

Day old Dekalb XL-link pullets were randomly assigned to eight dietary treatments of 100 birds each. The percent crude protein (CP) with the respective weeks fed in parentheses for each treatment (T) was as follows: T1. control 18(0-6), 15(6-14) and 12(14-20); T2. 18(0-1), 12(1-8), 15(8-14) and 18(14-20); T3. 18(0-1), 12(1-10), 15(10-16) and 18(16-20); T4. 18(0-1), 12(1-12), 15(12-16) and 18(16-20); T5. 16(0-1), 12(1-10), 15(10-16) and 18 ( 16- 20 ); T6 . 16 ( 0-1 ) , 12 ( 1-12 ) , 15 ( 12 -16 ) and 18 ( 16- 2 0); T7. 20(0-1), 12(1-10), 15(10-16) and 18(16-20); and T8. 20(0-1), 12(1-12), 15(12-16) and 18(16-20). All diets were fed ad lib. The control pullets were heavier for most of the 20-week growing period. Skeletal growth was highly correlated with body weight, however body size was not different at 20 weeks. Cumulative feed intake of the control fed birds was significantly greater than five of the reverse protein fed birds. Feed conversion and protein intake suggested a potential economic advantage in reverse protein feeding. At 20 weeks of age, 576 pullets were transferred to laying cages and fed a common diet. No differences in body weight were seen at 28 weeks of age. Livability was not affected by dietary treatment. Hen-day and hen-housed figures showed significant treatment effects during the first 28-day period only. No significant differences were seen in egg weight, % egg size, egg mass, egg specific gravity, shell deformation, Haugh units or any feed trait. Reverse protein feeding appeared to offer promise as a method of restricting growth in egg-type pullets. The significance of effects on egg production traits may have been masked by small sample size. / M.S.