Phenotypic relationships among methane production traits assessed under ad libitum feeding of beef cattle1,2

2017 ◽  
Vol 95 (10) ◽  
pp. 4391-4398 ◽  
Author(s):  
T. Bird-Gardiner ◽  
P. F. Arthur ◽  
I. M. Barchia ◽  
K. A. Donoghue ◽  
R. M. Herd
Keyword(s):  
Methane Production ◽  
Production Traits ◽  
Ad Libitum ◽  
Ad Libitum Feeding

Phenotypic relationships among methane production traits assessed under ad libitum feeding of beef cattle

2017 ◽  
Vol 0 (0) ◽  
pp. 0
Author(s):  
T. Bird-Gardiner ◽  
P. F. Arthur ◽  
I. M. Barchia ◽  
K. A. Donoghue ◽  
R. M. Herd
Keyword(s):  
Beef Cattle ◽  
Methane Production ◽  
Production Traits ◽  
Ad Libitum ◽  
Ad Libitum Feeding

Methane production from dairy and beef heifers fed forages differing in nutrient density using the sulphur hexafluoride (SF6) tracer gas technique

2002 ◽  
Vol 82 (2) ◽  
pp. 201-206 ◽  
Author(s):  
D. A. Boadi ◽  
K. M. Wittenberg
Keyword(s):  
Organic Matter ◽  
Methane Production ◽  
Forage Quality ◽  
Cattle Breed ◽  
Restricted Feeding ◽  
Tracer Technique ◽  
Beef Heifers ◽  
Breed Type ◽  
Ad Libitum ◽  
Ad Libitum Feeding

The effects of cattle breed type [dairy (Holstein) versus beef (Charolais × Simmental)] and forage quality (high, medium and low) on methane production were measured under ad-libitum and restricted feeding conditions. The in vitro organic matter digestibility (IVOMD) of the forage diets was high = 61.5%, medium = 50.7% and low = 38.5%. Each hay diet was fed to four animals (two dairy and two beef heifers) in three periods of four 3 × 3 Latin squares. Each period consisted of 23 d during which heifers were individually fed their assigned forage for 14 d on ad-ibitum feeding. Following this, intake was restricted to 2% of body weight (BW) for 9 d. Methane production was measured for five 24-h intervals in each period at both levels of intake using the SF6 gas technique. Methane production was not different (P > 0.05) between dairy (238.0 ± 6.9 L d-1) and beef cattle (228.6 ± 7.8 L d-1) under either level of feeding. Forage quality affected CH4 (L d-1) output, with high = medium > low during ad-libitum feeding. This effect of forage quality on CH4 production was absent during restricted feeding (P > 0.05). Day-to-day variation in CH4 production was 26.9 and 27.1% on ad-libitum and restricted feeding respectively (P < 0.05), whereas animal-to-animal variation (P < 0.05) was 26.6% (ad libitum) and 25.3% (restricted). On ad-libitum feeding, dry matter intake (DMI) was strongly correlated (P = 0.0001; r = 0.8) with CH4 production (L d-1), and accounted for 64% of daily variation in CH4 production. Methane [L kg-1 digestible organic matter intake (DOMI)] was highest (P < 0.05) on low-quality diets under both feeding regimes, and was not influenced (P > 0.05) by cattle type. Methane production as a percent of gross energy intake (GEI) was not influenced by diet. It can be concluded that the SF6 tracer technique provides a measure of enteric CH4 production directly from animals under production conditions. There were no differences in CH4 production between dairy and beef breeds, but the quality of forages affected CH4 production under both ad-libitum and restricted feeding. Key words: Methane, SF6 tracer technique, cattle breed type, forage quality, level of intake

scholarly journals The impact of sex on the economics of pig fattening

2012 ◽  
Vol 50 (No. 5) ◽  
pp. 217-222
Author(s):  
R. Stupka ◽  
M. Šprysl ◽  
M. Pour
Keyword(s):  
Feed Intake ◽  
Quantitative Aspect ◽  
Profit Function ◽  
Production Traits ◽  
Slaughter Weight ◽  
Ad Libitum ◽  
The Difference ◽  
The Impact ◽  
The Given ◽  
Ad Libitum Feeding

The test was focussed on the influence of sex on the production traits of the (LW&times;L) &times; OLW combination of hybrids. In the system of ad-libitum feeding, 72 pigs were divided into two identical groups of gilts and barrows and the fattening performance, i.e. the growth intensity, daily feed intake and the quantitative aspect of the carcass value were monitored. On the basis of the profit function, it was found out that in the ad-libitum feeding with the separate fattening of barrows and gilts with respect to the given genotype, it is possible to achieve with the same slaughter weight the difference in the profit per 1 fattened pig 111.06&nbsp;CZK, i.e. 5.86%.

Selection for components of efficient lean growth rate in pigs 2. Selection pressure applied and direct responses in a Landrace herd

1994 ◽  
Vol 59 (2) ◽  
pp. 263-269 ◽  
Author(s):  
N. D. Cameron ◽  
M. K. Curran
Keyword(s):  
Growth Rate ◽  
Genetic Correlations ◽  
Correlated Response ◽  
Selection Line ◽  
Control Line ◽  
Direct Response ◽  
Lean Growth ◽  
Ad Libitum ◽  
Selection For ◽  
Ad Libitum Feeding

AbstractResponses to divergent selection for lean growth rate with ad-libitum feeding (LGA), for lean food conversion (LFC) and for daily food intake (DFI) in Landrace pigs were studied. Selection was practised for four generations with a generation interval ofl year. A total of 2642 pigs were performance tested in the high, low and control lines, with an average of 37 boars and 39 gilts performance tested per selection line in each generation. The average within-line inbreeding coefficient at generation four was equal to 0·04. There was one control line for the DFI and LFC selection groups and another control line for the LGA selection group. Animals were performance tested in individual pens with mean starting and finishing weights of 30 kg and 85 kg respectively with ad-libitum feeding. The selection criteria had phenotypic s.d. of 32, 29 and 274 units, for LGA, LFC and DFI, respectively, and results are presented in phenotypic s.d.Cumulative selection differentials (CSD) were 5·1, 4·5 and 5·5 phenotypic s.d. for LGA, LFC and DFI, respectively. Direct responses to selection were 1·4,1·1 and 0·9 (s.e. 0·20) for LGA, LFC and DFI. In each of the three selection groups, the CSD and direct responses to selection were symmetric about the control lines. The correlated response in LFC (1·1, s.e. 0·19) with selection on LGA was equal to the direct response in LFC. In contrast, the direct response in LGA was greater than the correlated response (0·7, s.e. 0·18) with selection on LFC. There was a negative correlated response in DFI (-0·6, s.e. 0·18) with selection on LFC, but the response with selection on LGA was not significant (0·2, s.e. 0·16).Heritabilities for LGA, LFC and DFI ivere 0·25, 0·25 and 0·18 (s.e. 0·03), when estimated by residual maximum likelihood, with common environmental effects of 0·12 (s.e. 0·02). Genetic correlations for LFC with LGA and DFI were respectively positive (0·87, s.e. 0·02) and negative (-0·36, s.e. 0·09), while the genetic correlation between DFI and LGA was not statistically different from zero, 0·13 (s.e. 0·10). Selection on components of efficient lean growth has identified LGA as an effective selection objective for improving both LGA and LFC, without a reduction in DFI.

scholarly journals Short-term consequences of a sudden increase in feed allowance in broiler breeder hens

1993 ◽  
Vol 73 (1) ◽  
pp. 159-167 ◽  
Author(s):  
F. E. Robinson ◽  
M. W. Yu ◽  
M. E. Lupicki ◽  
R. T. Hardin
Keyword(s):  
Feed Intake ◽  
Egg Production ◽  
Liver Fat ◽  
Sudden Increase ◽  
Broiler Breeder ◽  
Breeder Hens ◽  
Preovulatory Follicles ◽  
Broiler Breeder Hens ◽  
Ad Libitum ◽  
Ad Libitum Feeding

The immediate effects of a sudden increase in feed allowance on selected morphological and reproductive traits were investigated in broiler breeder hens at 44 wk of age. Fifty Indian River hens were individually caged at 40 wk of age. Prior to 40 wk of age the birds had been feed restricted in accordance with the breeder's recommended feeding program. Five treatment groups (T1, T2, T3, T4 and T5) of 10 birds each were formed based on level of feeding and duration of exposure to such feeding. T1, T2 and T3 birds were feed restricted (128 g of daily feed bird−1) from 40 to 44, 40 to 45 and 40 to 46 wk of age, respectively. T4 and T5 birds were also feed restricted at the same level as the other groups to 44 wk of age and then were full fed from 44 to 45 and 44 to 46 wk of age, respectively. To facilitate study of follicular recruitment and yolk deposition, hens were fed 10 g of oil-soluble red and black dyes, daily, on alternate days, beginning at 42 wk of age. Birds were killed on day 0 (44 wk; T1), day 7 (45 wk; T2, T4), or day 14 (46 wk; T3, T5). Full-fed hens consumed approximately 100 g more feed per day than did feed-restricted hens, with marked increases in feed intake on the first day of full feeding. After 7 d of ad libitum feeding, significant increases were seen in body weight, liver weight, percent liver fat, plasma lipid concentration, ovary weight, and the incidence of a double hierarchy (simultaneous development) of large follicles. After 14 d of ad libitum feeding, significant increases were also observed in absolute fat-pad weight, individual weights of the four largest preovulatory follicles and number of large preovulatory follicles. The increased number of large follicles in the ovary was not associated with any change in egg production. It is apparent that the morphological disruptions associated with overfeeding broiler breeder hens can be identified within 7 d of full feeding, while any effects on egg production are not seen within the first 14 d of ad libitum feeding. Key words: Broiler breeder, feed intake, yolk deposition, ovarian morphology, egg production

Food Drive and Satiety in Yellow Mice

1957 ◽  
Vol 189 (1) ◽  
pp. 36-38 ◽  
Author(s):  
Guy Hollifield ◽  
William Parson
Keyword(s):  
Yellow Gene ◽  
Running Activity ◽  
Fasting And Refeeding ◽  
Ad Libitum ◽  
Per Se ◽  
Relationship Of ◽  
The Relationship ◽  
Ad Libitum Feeding ◽  
Reduced Activity

Spontaneous running activity during ad libitum feeding, fasting and refeeding was studied in inbred yellow mice. These studies suggest that the yellow gene per se is not associated with reduced activity and that inbred yellow mice have intact hypothalamic feeding centers. The relationship of these findings to obesity in yellow mice is discussed.

Daily changes in food availability, but not long-term unpredictability, determine daily torpor-bout occurrences and frequency in stripe-faced dunnarts (Sminthopsis macroura)

2015 ◽  
Vol 63 (1) ◽  
pp. 12 ◽  
Author(s):  
Alexandra M. Leslie ◽  
Mathew Stewart ◽  
Elizabeth Price ◽  
Adam J. Munn
Keyword(s):  
Food Availability ◽  
Control Period ◽  
Daily Torpor ◽  
Torpor Bout ◽  
Effect Of Food ◽  
Rapid Adjustment ◽  
Sminthopsis Macroura ◽  
Ad Libitum ◽  
Ad Libitum Intake ◽  
Ad Libitum Feeding

Daily torpor, a short-term reduction in body temperature and metabolism, is an energy-saving strategy that has been interpreted as an adaptation to unpredictable resource availability. However, the effect of food-supply variability on torpor, separately from consistent food restriction, remains largely unexamined. In this study, we investigated the effect of unpredictable food availability on torpor in stripe-faced dunnarts (Sminthopsis macroura). After a control period of ad libitum feeding, dunnarts were offered 65% of their average daily ad libitum intake over 31 days, either as a constant restriction (i.e. as equal amount of food offered each day) or as an unpredictable schedule of feed offered, varied daily as 0%, 30%, 60%, 100% or 130% of ad libitum. Both feeding groups had increased torpor-bout occurrences (as a proportion of all dunnarts on a given day) and torpor-bout frequency (average number of bouts each day) when on a restricted diet compared with ad libitum feeding, but torpor frequency did not differ between the consistently restricted and unpredictably restricted groups. Most importantly, torpor occurrence and daily bout frequency by the unpredictably restricted group appeared to change in direct association with the amount of food offered on each day; torpor frequency was higher on days of low food availability. Our data do not support the interpretation that torpor is a response to unpredictable food availability per se, but rather that torpor allowed a rapid adjustment of energy expenditure to manage daily fluctuations in food availability.

ACETATE AND FREE FATTY ACID METABOLISM IN THE FAT-TAILLED SHEEP

1984 ◽  
Vol 64 (5) ◽  
pp. 244-245 ◽  
Author(s):  
J. G. VAN DER WALT ◽  
A. MARAIS ◽  
S. CAMPBELL ◽  
J. M. GOODEN
Keyword(s):  
Fatty Acid ◽  
Free Fatty Acid ◽  
Key Words ◽  
Fatty Acid Metabolism ◽  
Acid Metabolism ◽  
Carbon Flow ◽  
Whole Body ◽  
Free Fatty Acid Metabolism ◽  
Ad Libitum ◽  
Ad Libitum Feeding

Two-thirds of all acetate to FFA conversion takes place in the hindquarter of Karakul lambs fed ad libitum. An amount equivalent to two-thirds of this net FFA production is taken up by the hind-quarter. Half ad libitum feeding resulted in halving the whole-body acteate turnover, reversing the direction of carbon flow from FFA to acetate and doubling the FFA turnover, chiefly by mobilizing tail fat. Resumption of ad libitum feeding reversed the process, without synthesizing FFA from acetate. Key words: Sheep, growth, fat-tail, FFA, acetate, turnover

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