scholarly journals The ability of laying hens to regulate phosphorus intake when offered two feeds containing different levels of phosphorus

2004 ◽  
Vol 92 (2) ◽  
pp. 233-240 ◽  
Author(s):  
G. R. Barkley ◽  
H. M. Miller ◽  
J. M. Forbes

The ability of laying hens to adjust their intake of available P (AP) was investigated with a maize–soyabean diet fed to forty-eight individually caged birds in a 2×4 factorial experiment. From 19 to 25 weeks of age (phase 1) twenty-four birds were fed a normal-P (NP) diet (2·2 g AP/kg DM) and twenty-four were fed a low-P (LP) diet (1·1 g AP/kg). LP eggs were lighter (51 v. 54 (sem 1·0) g; P>0·05), providing evidence that the LP diet was deficient in AP. From 25 to 28 weeks of age six hens from each phase 1 treatment were fed either the NP or LP diet alone or a choice of the LP and NP feeds or a choice of the LP feed and a phytase-supplemented (PP) feed (LP diet with 400 microbial phytase units/kg). With a choice of the NP and LP feeds, the hens fed the LP diet in phase 1 ate a smaller proportion of the LP feed (34 (sem 12·0)%) than the hens fed the NP diet in phase 1 (72 (sem 12·0)%; P>0·05), showing that P deficiency influenced subsequent selection for AP, i.e. an appetite for P was demonstrated. In those birds offered the LP and PP feeds, the presence of phytase in one of the two feeds significantly alleviated the effect of P deficiency on egg and body weights. The proportion of the LP diet chosen was not significantly affected by phase 1 treatment; it was not necessary for the hens to eat more than 50% of PP feed.

2014 ◽  
Vol 30 (1) ◽  
pp. 115-123
Author(s):  
V. Petricevic ◽  
M. Lukic ◽  
Z. Pavlovski ◽  
Z. Skrbic ◽  
Z. Jokic ◽  
...  

The study was conducted on Isa Brown hybrid hens at the age of 49-57 weeks. The effect of using different levels of share of raw soybean of two varieties in mixtures for feeding hens on egg production, body weight, food consumption, the occurrence of defective eggs, mortality and the relative weight of the pancreas was studied. The possibility of replacing the heat-treated soybean grains, varieties Lana, with reduced trypsin inhibitor (TI) and Lydia with a standard level of TI, with raw soybean grains was examined. The research was conducted on the principle of two factorial experiment 2 x 4 (2 varieties x 4 levels of share of raw grain in the mixture) with a total of 8 diet treatments and 4 replicates per each treatment. In the first 5 weeks of the study, the differences in the number of eggs produced under the influence of tested factors were not significant. Under the influence of soybean varieties, the level of share of raw soybean and interaction of the studied factors showed significant differences (p<0.01) after 53 week of age. The use of soy with lower TI in the diet for laying hens resulted in a significantly greater capacity compared to standard variety. The share of raw soybean grains of 8 % in the mixtures significantly reduced the number of eggs laid. The differences in body weights, food consumption, occurrence of defective eggs and the relative weight of the pancreas were not significantly influenced by the studied factors or by their interaction effect.


1996 ◽  
Vol 37 (4) ◽  
pp. 757-763 ◽  
Author(s):  
K. Johansson ◽  
J. Örberg ◽  
A.‐B. Carlgren ◽  
M. Wilhelmson

2021 ◽  
Vol 99 (Supplement_1) ◽  
pp. 41-42
Author(s):  
Marion Lautrou ◽  
Candido Pomar ◽  
Philippe Schmidely ◽  
Marie-Pierre Létourneau-Montminy

Abstract To optimize the use of dietary P by pigs, 5 feeding strategies were studied in a 3-phase feeding trial on 240 pigs (initial bodyweight (BW) of 31 kg): 1) C-C-C providing 100% of digestible phosphorus (Pdig, 4.3 g/kg STTD) and calcium (Ca, 9.7 g/kg) requirement to maximize bone mineralization, 2) L-L-L 60% of the Pdig and Ca requirements of C-C-C, 3) Phyt-Phyt-Phyt (phosphate-free, with phytase, 750, 686, 390 FTU/kg), providing 60% of Pdig and Ca requirements in phase 1, then 100%, 4) and 5) C in phases 1 and 3, and 60% of the need for Pdig in phase 2, associated with 65% of the requirements for Ca (N) or 80% (H), namely C-N-C and C-H-C. The BW and bone mineral content (BMC) were measured at the beginning and end of each phase. The BMC gain (gBMC), average daily gain (ADG) and average daily feed intake (ADFI) were calculated by phase. In phase 1, ADG was lower in the Phyt group than the C group (1.05 vs 1.10 kg/d, P &lt; 0.01) and the BMC of group C and gBMC were higher than those of the Phyt and B groups (P &lt; 0.05). In phase 2, C-C and Phyt-Phyt groups had similar BMC due to higher gBMC in the Phyt-Phyt (27.1 vs 18.4 g/d, P &lt; 0.01). At the end of phases 2 and 3, C-C-C, C-N-C and C-H-C groups had similar BMC. The Phyt and B groups showed an increased phosphorus-use efficiency during phases 1 and 2 (+20% vs C). Phosphorus retention was also higher in the C-N-C and C-H-C groups, during the depletion in phase 2 (+24% vs C, P&lt; 0.05). These results showed the potential of a depletion-repletion strategy including free phosphate diet to reduce phosphorus intake and excretion without affecting final growth performance and bone mineralization because of increased minerals utilization efficacies.


2008 ◽  
Vol 3 (5) ◽  
pp. 351-356 ◽  
Author(s):  
Yahya Ebrahim-Ne ◽  
Ghassem Habibi Bibalani ◽  
Ebrahim Jafari Helan ◽  
Keyvan Hatefi Nezhad ◽  
Jalil Dolgari Sharaf ◽  
...  

2014 ◽  
Vol 10 (1) ◽  
pp. 55-76 ◽  
Author(s):  
Mohammad Reza Keyvanpour ◽  
Somayyeh Seifi Moradi

In this study, a new model is provided for customized privacy in privacy preserving data mining in which the data owners define different levels for privacy for different features. Additionally, in order to improve perturbation methods, a method combined of singular value decomposition (SVD) and feature selection methods is defined so as to benefit from the advantages of both domains. Also, to assess the amount of distortion created by the proposed perturbation method, new distortion criteria are defined in which the amount of created distortion in the process of feature selection is considered based on the value of privacy in each feature. Different tests and results analysis show that offered method based on this model compared to previous approaches, caused the improved privacy, accuracy of mining results and efficiency of privacy preserving data mining systems.


2019 ◽  
Vol 3 (2) ◽  
Author(s):  
T. R. Krause ◽  
E. R. Moore ◽  
J. Duggin ◽  
J. R. Segers ◽  
T. D. Pringle

ObjectivesProfitability in the beef industry has narrow margins regulated by revenue from output traits like growth and carcass merit, but profitability is also largely impacted by input expenses like feed costs. Selecting for improvements in feed efficiency during the finishing phase, one of the most feed intensive segments of the industry, can help to mitigate those input costs. This study compared growth performance, feed efficiency, body composition, and carcass characteristics in Angus steers (n = 321) from bulls divergently selected for feed efficiency and marbling.Materials and MethodsAngus sires were selected based on high (10th percentile or better) and low (85th percentile or worse) residual average daily gain (RADG) EPD as well as high (fifth percentile or better) and average (near 50th percentile) marbling (MARB) EPD. These criteria resulted in a 2 × 2 factorial design with four breeding lines: high RADG/high MARB, high RADG/average MARB, low RADG/high MARB, low RADG/average MARB. Data were analyzed using MIXED procedures of SAS with RADG and MARB as main effects. Significance was set at α = 0.05. Generation was also analyzed, where generation one (GEN1) steers were from a selected sire while generation two (GEN2) steers were from a selected sire and a selected dam.ResultsUltrasound and carcass data revealed no differences (P ≥ 0.12) in 12th rib backfat thickness from weaning through slaughter for the RADG EPD groups. Yield grade and dressing percent did not differ (P ≥ 0.56) across RADG or MARB groups. At the beginning and end of the feeding trial, the high RADG (P ≤ 0.02) group had larger ultrasound ribeye area (REA) than the low RADG group. Carcass REA tended (P = 0.08) to be larger in the high versus low RADG steers. During the feedlot trial and through slaughter, body weight was heavier (P ≤ 0.006) for the high versus low RADG steers but did not differ (P ≥ 0.44) across MARB EPD. Feed efficiency measures did not differ (P ≥ 0.32) across RADG or MARB groups apart from the tendency (P = 0.08) for residual feed intake to be lower in the high versus low RADG steers. Marbling scores differed (P ≤ 0.04) across RADG and MARB groups with the low RADG steers and the high MARB steers having improved marbling. The quality grade distribution across MARB EPD revealed that the average MARB steers graded 73% Choice and 25% Prime while the high MARB steers graded 56% and 42%, respectively. Slice shear force did not differ (P ≥ 0.32) across RADG or MARB EPD. Body weights tended (P = 0.06) to be heavier at the start of the feeding trial for GEN1 versus GEN2 steers. Total gain, average daily gain, and feed to gain (F:G) differed by generation (P ≤ 0.007) with increased rates of gain and reduced F:G in the GEN2 versus GEN1 steers. Body weights did not differ (P = 0.72) across GEN at the end of the feeding trial. Backfat thickness at the start and end of the feedlot phase was less (P ≤ 0.03) and marbling score was improved (P = 0.02) in the GEN2 versus GEN1 steers, respectively.ConclusionThese results suggest that selection using RADG EPD has negligible impacts on meat quality; and that progress in selection for efficiency can be achieved while advancing carcass quality and value. Furthermore, continued divergent selection for feed efficiency and marbling has the potential to improve feed efficiency through advancements in the rate of gain, while enhancing carcass merit through marbling.


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