Effect of Diets with Various Calcium and Boron Levels in Prelaying Period on Growth, Bone Ash and Subsequent Performance and Shell Quality of Laying Hens

Abstract

This experiment was conducted to determine the effects of diets with three different levels of calcium (% 0.8, 1.6, 3.2) and four different levels of boron (0, 75, 150, 300 mg kg-1) in prelaying period (14-20 weeks) on growth, bone ash and subsequent performance and egg shell quality of laying hens. A total 864 Super Nick pullets at 14 weeks of age were randomly allocated to twelve treatments arranged in a 3x4 factorial design with six replicates of 12 pullets each. Feed and water provided for ad-libitum access. The tibia samples were taken, three pullets and hens from every replicates at 20 and 42 weeks of age, respectively. Results of the present experiment showed that body weights and body weight gains were reduced in high prelay dietary Ca and B as the main factor. Feed intake of the pullets was not significantly influenced by the treatments. There were no detectable difference in feed intake, egg production, egg mass and feed conversion ratio (g, feed/ g, egg mass) and eggshell weight, but interactive effects of dietary Ca and B levels on eggshell thickness, egg specific gravity and shell breaking strength was significant. Shell thickness and breaking strength were significantly higher in hens fed pre-lay diet with 3.2 % Ca and no supplemental B than other treatments and egg specific gravity was significantly reduced by feeding 1.6 % Ca and 75 mg kg-1 B at 36 weeks of age. Bone ash (g or %) of hens at 20 and 42 weeks of age was not changed by Ca levels or interaction dietary Ca and B levels, but pullets receiving the 150 mg kg-1 B as the main factor had significantly higher in bone ash (g or %) values than other dietary B levels.

Effect of Different Nutrient Density Prelay Diets on Production Performance of White Leghorn Layers

“…Prelay CP effect corroborates with Keshavarz (1998) and Babiker et al (2010) findings. Different prelay Ca levels did not change pullet's FC corroborate with Kocbeker et al (2017). Different prelay diets did not change layer's FC.…”

“…The EP was numerically increased by 6.37% in T5 fed with high nutrient density prelay diet than control (T0) fed with low nutrient density prelay diet. Previous reports about using different levels of Ca (Kocbeker et al, 2017) in pullet's prelay diet did not show beneficial effect on EP. Low-prelay CP (14.0% and 15.4%) diets (Leeson and Summers, 1981) did not have a significant effect on EP, whereas higher prelay CP (18.1%) diet (Joseph et al, 2000) had higher EP.…”

“…Chauynarong et al (2007) concluded that low prelay CP might affect ovary weight and EP in Isa-Brown hens. Kocbeker et al (2017) reported no difference in the EP by using 0.8, 1.6 and 3.2% prelay Ca during 14-20 weeks.…”

Influence of the calcium and nutrient content of the prelay diet on egg production, egg quality, and tibiae mineralization of brown egg-laying hens from 16 to 63 wk of age

“…An increase in the Ca content of the prelay diet from 2.5 to 3.8% improved shell quality, in agreement with data of Hurwitz and Bar (1971) and Brooks (1986) in hens fed prelay diets containing 1.3 vs. 4.1% Ca and 1.0 vs. 3.0% Ca, respectively. Similarly, Koçbeker et al (2017) reported an improvement in shell thickness and breaking strength of the eggs from 20 to 42 wk of age, in hens fed from 14 to 20 wk of age a diet with 3.2 vs. 1.6% Ca.…”

Examining the effects of adding boric acid at different doses into mixed feed on fattening performance, carcass characteristics, and bone quality of Japanese quails

“…It increased egg weight but it decreased egg thickness compared to the Control group. In another study [25], it was determined that LW decreased in 150 and 300 mg/kg boron addition compared to those fed by the feed with 0 and 75 mg/kg boron in 20weeks old pullets. Similar findings were also found in the study by Waleed and Hayani [15].…”