scholarly journals PSIV-18 Identification of genes expressed in the liver transcriptome of Holstein-Friesian and Charolais steers divergent in residual feed intake across three dietary phases.

2018 ◽  
Vol 96 (suppl_3) ◽  
pp. 131-131
Author(s):  
M Higgins ◽  
D Kenny ◽  
C Fitzsimons ◽  
G Blackshields ◽  
S Coyle ◽  
...  
2014 ◽  
Vol 54 (9) ◽  
pp. 1254 ◽  
Author(s):  
G. C. Waghorn ◽  
K. A. Macdonald ◽  
M. M. Verwoerd

Residual feed intake (RFI) is a measure of feed (energy) requirements of individuals, relative to the population mean. Two groups, of ~120 Holstein-Friesian heifer calves (aged 6–9 months), which differed in efficiency by ~20%, were reared and mated. Liveweight and body condition score (BCS) were measured from 1 week pre-calving, for 16 weeks. Measurements were undertaken in 221, 59 and 104 of these animals as they entered their first (aged 2 years), second or third calving, respectively. The cattle were managed under conditions typical of commercial pastoral farming, and the objective was to measure effects of divergence for RFI on post-calving liveweight and BCS change, to indicate tissue mobilisation. The measurements made showed no difference between RFI selections for liveweight before the first (466 kg), second (535 kg) or third (569 kg) calving. Selection for divergent RFI did not affect liveweight at nadir (2–6 weeks post-calving), weight loss to nadir, or BCS at any time. Tissue mobilisation and re-synthesis is energetically inefficient, and although a greater post-calving loss from inefficient cf. efficient cows may have been anticipated, this was not supported by the similarity in liveweights, liveweight and BCS change in the selection lines for RFI.


2014 ◽  
Vol 54 (10) ◽  
pp. 1877 ◽  
Author(s):  
K. DiGiacomo ◽  
L. C. Marett ◽  
W. J. Wales ◽  
B. J. Hayes ◽  
F. R. Dunshea ◽  
...  

It is suggested that one-third of the inter-animal differences in efficiency is explained by differences in digestion, heat production, body composition and activity; while the remaining variation is the result of energy expenditure due to biological processes such as ion pumps and mitochondrial function. Inefficient animals may be wasting energy on inefficient processes resulting in increased heat production that may be reflected by differences in skin and core temperature. While the association between heat production and residual feed intake (RFI) has been touched on, it is yet to be fully elucidated. It is hypothesised that more efficient animals will expend less energy as heat, which will be reflected by differences in core and skin temperature measures. Fifty-four primiparous, Holstein-Friesian cows previously assessed for RFI (26 inefficient/high RFI, 28 efficient/low RFI) were selected and drafted into outdoor holding yards for measurements on two occasions (once during lactation and once during the non-lactating ‘dry’ period). Measures of body temperature were obtained using an infrared (IR) camera to obtain skin (surface) temperatures at multiple locations [muzzle, eye, jaw, ear, leg (front and back), rump, shoulder, teat, udder, side and tail] and rectal temperatures were measured using a digital thermometer. Respiration rates (RR) were obtained by counting the number of flank movements in 1 min. A subset of 16 cows (8 efficient and 8 inefficient) were utilised for further IR imagery in an undercover environment (to eliminate the influences of external environments). Skin temperature measurement obtained using an IR camera during the outdoor period demonstrated that inefficient cows had higher (0.65°C) teat temperatures (P = 0.05). Rectal temperature and RR were not influenced by efficiency group. When IR images were obtained undercover inefficient cows tended to have higher shoulder (0.85°C) and neck (0.98°C) temperatures than efficient cows (P < 0.087); while udder temperature was significantly greater (1.61°C) for inefficient than efficient cows (P = 0.018). These data indicate that some of the differences in efficiency may be attributed to differences in thermoregulation, as reflected by differences in skin (but not core) temperature and that IR imagery is a suitable method for determining these differences in a non-invasive manner. Further research is required to further establish these relationships, and the measurement of skin temperatures should be undertaken indoors to eliminate external environmental influences.


2011 ◽  
Vol 94 (9) ◽  
pp. 4715-4725 ◽  
Author(s):  
Y.J. Williams ◽  
J.E. Pryce ◽  
C. Grainger ◽  
W.J. Wales ◽  
N. Linden ◽  
...  

2014 ◽  
Vol 54 (9) ◽  
pp. 1460 ◽  
Author(s):  
J. B. Thornhill ◽  
L. C. Marett ◽  
M. J. Auldist ◽  
J. S. Greenwood ◽  
J. E. Pryce ◽  
...  

The objective of this experiment was to compare the whole-tract digestibility of dry matter (DM) and nitrogen (N) in Holstein-Friesian dairy cows selected for divergent feed conversion efficiency. The experiment used 16 primiparous Holstein–Friesian dairy cows selected based on their residual feed intake (RFI) measured as growing calves. The cows were housed in individual metabolism stalls and fed lucerne cubes ad libitum plus 6 kg DM per day of crushed wheat grain. Feed intake, milk yield, faecal and urine output were measured for 5 days. Rumen fluid was collected per os from each cow on one occasion. Milk production parameters and intakes of DM, organic matter, neutral detergent fibre, acid detergent fibre and N did not differ between RFI groups. Apparent whole-tract DM digestibility and N digestibility did not differ between RFI treatment groups. Rumen metabolites were also unaffected by RFI. In conclusion, divergence in RFI as calves was not associated with differences in whole-tract DM or N digestibility in lactating cows. Therefore, emphasis on selection for phenotypic divergence in RFI may not contribute to improved utilisation of consumed nutrients in Australian Holstein-Friesian dairy cows.


2017 ◽  
Vol 57 (7) ◽  
pp. 1499 ◽  
Author(s):  
L. C. Marett ◽  
S. R. O. Williams ◽  
B. J. Hayes ◽  
J. E. Pryce ◽  
W. J. Wales

Residual feed intake (RFI) is the difference between an animal’s actual and expected feed intake. Two experiments were conducted comparing energy and nitrogen partitioning in mid-lactation, in Holstein–Friesian cows selected for high or low RFI measured previously as growing calves. Each experiment used 16 cows (8 high-RFI and 8 low-RFI); the first used primiparous (PP) cows and the second used multiparous (MP) cows. Cows were housed individually for 4 days in metabolism stalls, then open-circuit respiration chambers for 3 days. Each cow was offered ad libitum lucerne hay cubes plus 6 kg DM per day of crushed wheat grain. Individual feed intake, milk yield, milk composition and faecal and urine output were measured. Methane and carbon dioxide output and oxygen consumption were measured in the chambers. In MP cows, a greater proportion of energy intake was partitioned to milk and less to heat in low-RFI than high-RFI cows. The proportion of gross-energy intake per kilogram metabolic bodyweight partitioned to milk production was greater and the proportion partitioned to methane and heat production was lower in MP than in PP cows. Energy from tissue mobilisation was not affected by RFI or parity. The amount of nitrogen consumed from feed was greater in MP than PP cows. As a percentage of N intake, N partitioned to milk was greater in PP than in MP cows, but there were no overall effects of RFI on N partitioning. However, there was a trend towards a positive association between N excreted in the urine and RFI, which could have environmental implications. Both RFI and parity were associated with variation in energy and nitrogen partitioning and should be examined in a larger subset of animals in future.


2019 ◽  
Vol 97 (5) ◽  
pp. 2181-2187
Author(s):  
Ahmed A Elolimy ◽  
Emad Abdel-Hamied ◽  
Liangyu Hu ◽  
Joshua C McCann ◽  
Daniel W Shike ◽  
...  

Abstract Residual feed intake (RFI) is a widely used measure of feed efficiency in cattle. Although the precise biologic mechanisms associated with improved feed efficiency are not well-known, most-efficient steers (i.e., with low RFI coefficient) downregulate abundance of proteins controlling protein degradation in skeletal muscle. Whether cellular mechanisms controlling protein turnover in ruminal tissue differ by RFI classification is unknown. The aim was to investigate associations between RFI and signaling through the mechanistic target of rapamycin (MTOR) and ubiquitin-proteasome pathways in ruminal epithelium. One hundred and forty-nine Red Angus cattle were allocated to 3 contemporary groups according to sex and herd origin. Animals were offered a finishing diet for 70 d to calculate the RFI coefficient for each. Within each group, the 2 most-efficient (n = 6) and least-efficient animals (n = 6) were selected. Compared with least-efficient animals, the most-efficient animals consumed less feed (P &lt; 0.05; 18.36 vs. 23.39 kg/d DMI). At day 70, plasma samples were collected for insulin concentration analysis. Ruminal epithelium was collected immediately after slaughter to determine abundance and phosphorylation status of 29 proteins associated with MTOR, ubiquitin-proteasome, insulin signaling, and glucose and amino acid transport. Among the proteins involved in cellular protein synthesis, most-efficient animals had lower (P ≤ 0.05) abundance of MTOR, p-MTOR, RPS6KB1, EIF2A, EEF2K, AKT1, and RPS6KB1, whereas MAPK3 tended (P = 0.07) to be lower. In contrast, abundance of p-EEF2K, p-EEF2K:EEF2K, and p-EIF2A:EIF2A in most-efficient animals was greater (P ≤ 0.05). Among proteins catalyzing steps required for protein degradation, the abundance of UBA1, NEDD4, and STUB1 was lower (P ≤ 0.05) and MDM2 tended (P = 0.06) to be lower in most-efficient cattle. Plasma insulin and ruminal epithelium insulin signaling proteins did not differ (P &gt; 0.05) between RFI groups. However, abundance of the insulin-responsive glucose transporter SLC2A4 and the amino acid transporters SLC1A3 and SLC1A5 also was lower (P ≤ 0.05) in most-efficient cattle. Overall, the data indicate that differences in signaling mechanisms controlling protein turnover and nutrient transport in ruminal epithelium are components of feed efficiency in beef cattle.


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