scholarly journals Effects of feed intake and genetics on tissue nitrogen-15 enrichment and feed conversion efficiency in sheep1

2015 ◽  
Vol 93 (12) ◽  
pp. 5849-5855 ◽  
Author(s):  
L. Cheng ◽  
C. M. Logan ◽  
R. J. Dewhurst ◽  
S. Hodge ◽  
H. Zhou ◽  
...  
Keyword(s):  
Conversion Efficiency ◽  
Feed Intake ◽  
Feed Conversion ◽  
Feed Conversion Efficiency ◽  
Tissue Nitrogen

Performance and Intestinal Coliform Counts in Weaned Piglets Fed a Probiotic Culture (Lactobacillus casei subsp. casei CECT 4043) or an Antibiotic

2008 ◽  
Vol 71 (9) ◽  
pp. 1797-1805 ◽  
Author(s):  
PAULA FAJARDO BERNÁRDEZ ◽  
CLARA FUCIÑOS GONZÁLEZ ◽  
JESÚSMÉNDEZ BATÁN ◽  
LORENZO PASTRANA CASTRO ◽  
NELSON PÉREZ GUERRA
Keyword(s):  
Body Weight ◽  
Weight Gain ◽  
Conversion Efficiency ◽  
Feed Intake ◽  
Fecal Coliform ◽  
Body Weight Gain ◽  
Control Group ◽  
Feed Conversion ◽  
Feed Conversion Efficiency ◽  
The Mean

The production of biomass and antibacterial extracellular products by Lactobacillus casei subsp. casei CECT 4043 was followed in both batch and in realkalized fed-batch cultures. Enhanced concentrations of biomass and antibacterial extracellular products were obtained with the use of the latter fermentation technique in comparison with the batch mode. The culture obtained by fed-batch fermentation was mixed with skim milk and used to prepare a probiotic feed for weaned piglets. To test the effect of the potentially probiotic culture of L. casei on body weight gain, feed intake, feed conversion efficiency, and on fecal coliform counts of piglets, two groups of animals received either feed supplemented with the probiotic preparation or avilamycin for 28 days. The control group was fed nonsupplemented feed. At the end of the administration period (day 28), the groups receiving probiotic and avilamycin exhibited the highest average body weight gain values, although the mean feed intake and feed conversion efficiency values were not different among the groups (P > 0.05). For the entire experimental period (42 days), the control group exhibited the lowest feed intake value, the probiotic group exhibited the highest feed conversion efficiency value, and the antibiotic group exhibited the highest body weight gain (P < 0.05). Interestingly, no significant difference in body weight gain was observed between the probiotic and the control groups by day 42 (P > 0.05). Fecal coliform values decreased (although not significantly) by day 28 in the three groups. However, the mean counts returned to pretreatment levels by day 42 in all groups.

Effects of early pregnancy on postnatal maternal performance of mice

1977 ◽  
Vol 25 (1) ◽  
pp. 1-10 ◽  
Author(s):  
E. J. Eisen ◽  
W. R. Williams ◽  
J. F. Hayes
Keyword(s):  
Mammary Gland ◽  
Weight Gain ◽  
Conversion Efficiency ◽  
Early Pregnancy ◽  
Feed Intake ◽  
Feed Conversion ◽  
Feed Conversion Efficiency ◽  
Maternal Performance ◽  
And Function ◽  
Pup Growth

SUMMARYThe influences of age at first pregnancy and number of suckling young on maternal performance of mice were studied. Mean mating ages for early-pregnant and normal-pregnant females were 27 and 52 days respectively. Litter size from parturition (day 0) to day 12 of lactation was standardized to either 8 or 12 pups. The more rapid (P<0·01) growth rate and feed conversion efficiency of early-pregnant dams from mating to parturition continued from 0 to 12 days of lactation but occurred primarily in the first 3 days of lactation, so that there were no differences in body weight or feed intake from days 3 to 12 of lactation. There were no age at pregnancy effects on total mammary gland DNA, RNA or RNA/DNA ratio at day 12 of lactation or on individual progeny weights or feed conversion efficiency of litter growth from 3 to 12 days of lactation. Dams suckling eight young had a lower (P<0·01) feed intake, gain and feed conversion efficiency from 0 to 3 days of lactation. From 0 to 12 days of lactation, these dams were smaller, consumed less feed and their individual progeny weights were larger (P<0·01). Dams suckling eight pups had smaller (P<O01) mammary glands, less (P < 0·05) mammary gland DNA and a higher (P<0·05) RNA/DNA ratio. Interactions between pregnancy age and number suckling were not significant. Feed intake of the dam from 0 to 12 days of lactation was influenced more by litter weight gain (34%) than either dam weight gain (5%) or metabolic body size (6%). Maternal performance of mice, based on pup growth and mammary gland growth and function, was not affected by early pregnancy.

Growth, feed intake and maternal performance of Angus heifers from high and low feed efficiency selection lines

2014 ◽  
Vol 54 (9) ◽  
pp. 1428 ◽  
Author(s):  
S. T. Morris ◽  
F. Y. Chan ◽  
N. Lopez-Villalobos ◽  
P. R. Kenyon ◽  
D. J. Garrick ◽  
...  
Keyword(s):  
Conversion Efficiency ◽  
Feed Intake ◽  
Feed Efficiency ◽  
Production Systems ◽  
Feed Conversion ◽  
Feed Conversion Efficiency ◽  
Herbage Intake ◽  
High Feed ◽  
Maternal Performance ◽  
Angus Heifers

Feed conversion efficiency is an important factor affecting profitability for cow-calf production systems. One method of characterising feed conversion efficiency is by calculating residual feed intake (RFI), the difference between measured and expected feed intakes. A high RFI value indicates low feed efficiency while a low RFI value indicates high feed efficiency. The present experiment used 49 Angus heifers sired by Angus bulls selected for high or low RFI. The progeny were bred on commercial farms and then transferred to Massey University at weaning at ~200 days of age. The heifers were weighed at ~30-day intervals and were mated at 15 months, calved at 2 years old and reared their calf to ~160 days of age. Each heifer had recorded its own liveweight gain (from its weaning to weaning of its first calf), herbage intake at 350 and 450 days of age using the n-alkane technique and maternal performance (calf production). These records were analysed to estimate the RFI of each heifer, and to determine differences in RFI between selection lines. There were no significant differences (P > 0.05) in liveweight or dry matter requirements between selection lines at Day 350, but differences were significant (P < 0.05) at Day 450 such that the high feed efficiency line were 24.6 kg heavier and required an extra 0.32 kg/head.day of herbage. There were no significant differences (P > 0.05) between the two lines in herbage intake or RFI measured at either Days 350 or 450. There were no differences (P > 0.05) in pregnancy rates, calf birth dates or birthweights, estimated 24-h milk production or calf weaning weights between the two lines. This experiment shows that beef cattle selected for low RFI have higher growth rates and heavier liveweights than cattle selected for high RFI; both lines had similar calf production at first breeding.

scholarly journals Effect of chicken genotype on growth performance and feed consumption in the development of broiler lines

2020 ◽  
Vol 40 (2) ◽  
pp. 1-6
Author(s):  
S. A. Amusan ◽  
C. O. N. Ikeobi ◽  
A. O. Adebambo ◽  
B. O. Agaviezor ◽  
M. Wheto ◽  
...  
Keyword(s):  
Body Weight ◽  
Growth Performance ◽  
Conversion Efficiency ◽  
Feed Intake ◽  
Feed Efficiency ◽  
Growth Traits ◽  
Feed Consumption ◽  
Feed Conversion ◽  
Reciprocal Crosses ◽  
Feed Conversion Efficiency

This experiment was conducted to assess the effect of chicken genotype on the growth performance, feed intake and feed efficiency of the progenies resulting from pure, straight and reciprocal cross of Giriraja (Gr) and Alpha chickens. Data obtained on body weight, body length, breast girth, keel length, feed intake and feed efficiency were analyzed using general linear models analysis of variance. Generally, all growth traits and feed consumption characteristics were significantly affected (P < 0.05) by chicken genotype. Growth traits and feed intake increased as birds advanced in age. Giriraja X Giriraja purebred chickens had the highest body weight, breast girth, feed intake and feed conversion efficiency through out the experimental period. However, the progenies resulting from the reciprocal crosses of Alpha X Gr had significant higher body weight and keel. Also, the feed conversion efficiency of the reciprocal crosses were better than the dihybrid cross progenies. The results therefore suggest that the superiority exhibited by the Giriraja could be utilized to improve the growth performance of the indigenous chicken thereby speed up desirable progress in the improvement of the indigenous broiler line.

Feed intake.

2021 ◽  
pp. 82-94
Author(s):  
Gordon McL. Dryden
Keyword(s):  
Conversion Efficiency ◽  
Feed Intake ◽  
Residual Feed Intake ◽  
Feed Conversion ◽  
Feed Conversion Efficiency ◽  
And Performance ◽  
Practical Factors

Abstract In this chapter the processes involve in regulating feed intake in animals are discussed. Topics also include: predicting feed intake; practical factors which affects intake; and relationship between intake and performance: residual feed intake and feed conversion efficiency.

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