Effects of early weaning on growth, feed efficiency and carcass traits in Shorthorn cattle

2010 ◽  
Vol 50 (4) ◽  
pp. 315 ◽  
Author(s):  
M. L. Wolcott ◽  
H.-U. Graser ◽  
D. J. Johnston

This study aimed to examine the impact of early weaning on residual feed intake, and other production and carcass traits, in a group of cattle subjected to early or conventional weaning treatments, but otherwise managed as contemporaries. Shorthorn (n = 140) calves were randomly allocated by sex and sire to early and conventional weaning treatments. Early weaned animals (n = 69) were weaned at an average of 123 days of age and 145 kg liveweight, while conventionally weaned steers and heifers (n = 71) were 259 days old at weaning and 273 kg. Following conventional weaning, animals were managed as contemporaries through backgrounding, and entered feedlot finishing at a mean age of 353 and 408 days for heifers and steers, respectively, for finishing and feed intake testing. At the conclusion of feed intake testing hip height was measured, and animals were ultrasound scanned to assess fat depth, eye muscle area and percent intramuscular fat. Early weaned animals were significantly lighter (P < 0.001) than their conventionally weaned contemporaries, when weighed at conventional weaning. The weight difference observed at conventional weaning of 19.4 kg between treatment groups persisted throughout the experiment, with significant (P < 0.05) differences of 17.1, 15.6 and 15.8 kg at feedlot entry, and the start and end of the feed intake test period, respectively. Weaning treatment also approached significance for daily feed intake (P = 0.06), with early weaned animals tending to eat less than their conventionally weaned contemporaries (daily feed intake = 11.6 and 12.0 kg, respectively). Weaning treat\ment did not significantly affect feed efficiency whether measured as residual feed intake (P = 0.64) or feed conversion ratio (P = 0.27). None of the other traits measured were significantly affected by weaning treatment. These data showed that early weaning, as implemented for this experiment, resulted in animals that were lighter than their conventionally weaned contemporaries through backgrounding and finishing. Weaning treatment did not, however, influence feed efficiency or the post-weaning growth and carcass composition traits measured for this experiment.

2014 ◽  
Vol 54 (5) ◽  
pp. 550 ◽  
Author(s):  
W. Al-Husseini ◽  
C. Gondro ◽  
K. Quinn ◽  
L. M. Cafe ◽  
R. M. Herd ◽  
...  

Hormonal growth promotants (HGP) have been used to improve feed conversion ratio (FCR) and growth rates of cattle by modifying protein turnover rates. Residual feed intake (RFI) is correlated with FCR and has been adopted in Australia as a measure of feed efficiency in cattle for the purpose of genetic improvement. Eight genes (AHSG, GHR, GSTM1, INHBA, PCDH19, S100A10, SERPINI2 and SOD3) have been previously reported to be highly associated with RFI and could potentially be used to predict RFI in bulls and steers. In this study, expression levels of these genes in liver tissue of 46 cattle were measured by quantitative real-time PCR. These cattle were part of a larger tenderness gene marker experiment consisting of two breeds (Angus and Brahman); two sexes (steers and heifers) and HGP treatments (implanted vs control). Cattle were measured for growth, feed efficiency, body composition and carcass traits. Results showed the expression of these eight genes was significantly correlated with RFI. However, HGP treatment did not affect RFI or the expression of the RFI-associated genes. HGP treatment increased average daily gain by 20%, improved FCR by 18%, and increased rib eye-muscle area by 7.5%. HGP treatment was effective in improving growth rate, presumably by its known action in the protein turnover mechanism. This mechanism has been hypothesised as one of the regulators of RFI. Lack of effect of HGP treatment on RFI does not support this hypothesis.


2004 ◽  
Vol 44 (5) ◽  
pp. 483 ◽  
Author(s):  
D. W. Hennessy ◽  
P. F. Arthur

Records on 78 steers and heifers were used to determine relationships among different measures of growth, feed efficiency and carcass traits, and to evaluate the effects of 2 preweaning growth rates on growth and efficiency in a feedlot. The preweaning growth rates [g/day; 871 (high) or 466 (low)] were imposed on the steers and heifers for 115 days before they were weaned at a mean age of 220 days. They were 'backgrounded' for 7 months on high quality pastures before finishing on grain-based diets in a feedlot for 85 days. The cattle were then slaughtered and carcass measurements recorded. Estimates were made on 10 growth and feed efficiency indices during the feedlot, and 5 carcass traits were assessed at slaughter. Of the indices, the Kleiber ratio which does not require measurement of feed intake (r = 0.98), was highly correlated with relative growth rate (RGR), as was feed conversion ratio (FCR, r = –0.82), which includes feed intake in the calculation. Residual feed intake, calculated using the expected feed intake estimated from the dataset (RFIREG), was correlated (r = 0.62) with RFI calculated from Australian feeding standards (RFISCA), and with FCR (r = 0.45). FCR was not correlated with either carcass rib or hot P8 fat depths but was significantly correlated with carcass weight (0.39), dressing percentage (0.41) and eye muscle area (0.33). RFIREG was not correlated with any of the 5 carcass traits. Whilst the average daily gain in the feedlot was similar between the 2 preweaning groups (1.544 kg/day), the low group was significantly (P<0.05) lighter at feedlot entry (323 v. 376 kg). Daily feed intake was lower (P<0.01) in the low group (10.9 v. 11.8 kg) such that the FCR tended to be lower (P<0.10) relative to the high group. Differences between the preweaning treatment groups were not significant for the other measures of feed efficiency. The results indicate that early life nutritional restriction has some influence on FCR in the feedlot, but little effect on those feed efficiency measures, such as RFI, that account for energy required for both maintenance of liveweight and growth.


2018 ◽  
Vol 58 (1) ◽  
pp. 164 ◽  
Author(s):  
R. M. Herd ◽  
P. F. Arthur ◽  
C. D. K. Bottema ◽  
A. R. Egarr ◽  
G. H. Geesink ◽  
...  

Growth, feed intake, feed efficiency, and carcass and meat quality characteristics of 136 Angus steers differing in genetic merit for post-weaning residual feed intake (RFIp) were measured over 251 days in a large commercial feedlot. The steers were evaluated in two groups, low (Low-RFI) and high (High-RFI) genetic RFIp, measured by estimated breeding values for RFIp (RFIp-EBV). The difference in RFIp-EBV between the Low- and High-RFI groups was 1.05 kg/day (–0.44 vs 0.61 kg/day; P < 0.05). The Low- and High-RFI steers were similar (P > 0.05) in age (445 vs 444 days) and weight (435 vs 429 kg) at induction, and at the end of the feeding period (705 vs 691 kg). Average daily gain (ADG) over 251 days had a small negative association with variation in RFIp-EBV (P < 0.05), reflecting a 3.6% greater ADG accompanying a difference of 1 kg/day in RFIp-EBV. Pen feed intake and feed conversion by the Low-RFI group were 10.4 kg/day and 9.3 kg/kg, and for the High-RFI group were 11.1 kg/day and 10.4 kg/kg, but without availability of individual animal feed-intake data it was not possible to test for significant differences. Carcass weight and dressing-percentage was similar for the Low- and High-RFI steers. High-RFI steers had a significantly (P < 0.05) greater depth of subcutaneous rib fat at induction and finished with 5 mm more (P < 0.05) fat at the 10/11th ribs on the carcass than the Low-RFI steers. Cross-sectional area of the eye-muscle and three measures of intramuscular or marbling fat did not differ (P > 0.05) between the Low- and High-RFI steers. Shear force was higher (P < 0.05) in meat samples aged for 1 day from the Low-RFI steers, but there was no difference (P > 0.05) from the High-RFI steers after 7 days of ageing. Compression values for meat samples aged for 1 day did not differ between the RFI groups but were higher in meat samples aged for 7 days from the Low-RFI steers. For these Angus steers, genetic superiority in RFI was associated phenotypically with superior weight gain, decreased rib fat depth, slightly less tender meat, and no compromise in marbling fat or other carcass and meat quality traits.


2004 ◽  
Vol 84 (2) ◽  
pp. 177-185 ◽  
Author(s):  
F. S. Schenkel ◽  
S. P. Miller ◽  
J. W. Wilton

Genetic associations between feed efficiency, growth, and live ultrasound measured body composition traits were studied in purebred beef bulls of six breeds in Ontario bull test stations from 1991 to 2000. Feed traits included average daily feed intake (FI), feed conversion ratio (FCR), and residual feed intake [feed intake adjusted for production alone (RFIp) or production and backfat thickness (RFIb)]. Growth traits were average daily weight gain (ADG), mid-test metabolic weight (MW), hip height (HH), and scrotal circumference (SC). Body composition traits included ultrasound backfat thickness (BF), longissimus muscle area (LMA), and predicted percentage of intramuscular fat (IFAT). Bulls were measured every 28 d for weight and individual feed intake, and at the end of test for ultrasound body composition traits. Number of records per trait ranged from 2284 (FI) to 13 319 (ADG). Fixed effects of test group, breed and end of test age (within breed), and random effects of animal and herd of origin were modeled using REML bivariate analyses for all traits. Heritability estimates were moderate for all traits (0.30 to 0.55), except for IFAT (0.14). The genetic correlation between RFIp and RFIb was high (0.99) within breeds, but breeds ranked differently with respect to RFIp and RFIb. Genetic correlations of RFIb with ADG and backfat thickness were essentially zero, which indicate that selection on residual feed intake could be implemented to reduce feed intake and improve feed conversion without compromising growth or changing levels of subcutaneous fat. Key words: Central test, genetic correlation, heritability, residual feed intake


2018 ◽  
Vol 63 (No. 10) ◽  
pp. 408-418 ◽  
Author(s):  
Z. Krupová ◽  
M. Wolfová ◽  
E. Krupa ◽  
J. Přibyl ◽  
L. Zavadilová

The objective of this study was to calculate economic weights for ten current breeding objective traits and for four new traits characterising claw health and feed efficiency in Czech Holstein cattle and to investigate the impact of different selection indices on the genetic responses for these traits. Economic weights were estimated using a bio-economic model, while applying actual (2017) and predicted (2025) production and economic circumstances. For the actual situation, the economic weights of claw disease incidence were –100.1 € per case, and those of daily residual feed intake in cows, breeding heifers, and fattened animals were –79.37, –37.16, and –6.33 €/kg dry matter intake per day, respectively. In the predicted situation, the marginal economic weights for claw disease and feed efficiency traits increased on average by 38% and 20%, respectively. The new traits, claw disease incidence and daily residual feed intake, were gradually added to the 17 current Holstein selection index traits to improve the new traits. Constructing a comprehensive index with 21 traits and applying the general principles of the selection index theory, a favourable annual genetic selection response was obtained for the new traits (–0.008 cases of claw disease incidence and –0.006 kg of daily residual feed intake across all cattle categories), keeping the annual selection response of the most important current breeding objective traits at a satisfactory level (e.g., 73 kg of milk yield per lactation, 0.016% of milk fat). Claw health and feed efficiency should be defined as new breeding objectives and new selection index traits of local dairy population.


Animals ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 954 ◽  
Author(s):  
Safa’ M. Hatamleh ◽  
Belal S. Obeidat

This study considers the impact of dried distillers’ grain with solubles (DDGS) in diets of lambs. Randomly; 27 lambs were distributed to one of three diets. Diets were: a control diet (CON; n = 9), a 125 (DDGS125; n = 9) or a 250 g/kg DDGS (DDGS250; n = 9) of dietary dry matter (DM). The lambs were fed using these diets for 91 days. To assess carcass traits; five lambs were randomly selected at the end of the study. No significant differences were detected in intake and digestibility of DM; crude protein and fiber. Average daily gain did not differ among diets. Carcass characteristics did not differ among diets. With the exception of shear force and redness, which were greater in DDGS250 than in DDGS125 and CON diets, meat quality parameters were unaffected. Eye muscle area decreased in DDGS125 than in DDGS250 and CON diet. These results demonstrate that the feeding of lambs on DDGS at 125 or 250 g/kg DM did not have any impact on growth. These diets only had a simple effect on the characteristics of carcass and meat quality. These results suggest that it would be suitable to introduce these feeds into sheep nutrition in the future.


2021 ◽  
Vol 12 ◽  
Author(s):  
Hossein Mehrban ◽  
Masoumeh Naserkheil ◽  
Deukhwan Lee ◽  
Noelia Ibáñez-Escriche

There has been a growing interest in the genetic improvement of carcass traits as an important and primary breeding goal in the beef cattle industry over the last few decades. The use of correlated traits and molecular information can aid in obtaining more accurate estimates of breeding values. This study aimed to assess the improvement in the accuracy of genetic predictions for carcass traits by using ultrasound measurements and yearling weight along with genomic information in Hanwoo beef cattle by comparing four evaluation models using the estimators of the recently developed linear regression method. We compared the performance of single-trait pedigree best linear unbiased prediction [ST-BLUP and single-step genomic (ST-ssGBLUP)], as well as multi-trait (MT-BLUP and MT-ssGBLUP) models for the studied traits at birth and yearling date of steers. The data comprised of 15,796 phenotypic records for yearling weight and ultrasound traits as well as 5,622 records for carcass traits (backfat thickness, carcass weight, eye muscle area, and marbling score), resulting in 43,949 single-nucleotide polymorphisms from 4,284 steers and 2,332 bulls. Our results indicated that averaged across all traits, the accuracy of ssGBLUP models (0.52) was higher than that of pedigree-based BLUP (0.34), regardless of the use of single- or multi-trait models. On average, the accuracy of prediction can be further improved by implementing yearling weight and ultrasound data in the MT-ssGBLUP model (0.56) for the corresponding carcass traits compared to the ST-ssGBLUP model (0.49). Moreover, this study has shown the impact of genomic information and correlated traits on predictions at the yearling date (0.61) using MT-ssGBLUP models, which was advantageous compared to predictions at birth date (0.51) in terms of accuracy. Thus, using genomic information and high genetically correlated traits in the multi-trait model is a promising approach for practical genomic selection in Hanwoo cattle, especially for traits that are difficult to measure.


1977 ◽  
Vol 17 (85) ◽  
pp. 214 ◽  
Author(s):  
RJW Gartner ◽  
PK O'Rourke

A 23 factorial design was used to examine the effects of the following treatments on the productivity of steers fed in yards on an all-sorghum grain ration : nil vs. 70 mg chlortetracycline head-1 day-1; nil vs. 3 per cent dried molasses distillers solubles; nil vs. 36 mg implant of Zeranol. An additional treatment eompared zinc bacitracin with chlortetracycline. Eighteen groups each of five Hereford steers of a mean initial shrunk liveweight of 273.5 � SE 1.00 kg were used. They were slaughtered at a mean final shrunk liveweight of 399.8 � 2.97 kg. Mean results were: liveweight gain 1 .17 kg day-1, carcase weight gain 0.69 kg day-1, DM feed intake 6.91 kg day-1, feed conversion ratio 6.0. Feeding chlortetracycline resulted in increased carcase weight gain, an improved feed conversion ratio and a reduction in the number of liver abscesses. Regarding productivity, zinc bacitracin was not significantly different from chlortetracycline but it had no effect on reducing liver abscesses. Adding dried molasses distillers solubles caused a decrease in live- and carcase weight gain and an inferior feed conversion ratio. The anabolic implant Zeranol resulted in increased live- and carcase weight gain, increased DM feed intake but no significant differences in feed conversion ratio. The treatments had no effect on eye muscle area or muscle percentage of the carcases. Dried molasses distillers solubles was associated with a lower fat percentage (1 9.5 vs. 20.8 � 0.43; P <0.05). The rationsbsed resulted in an acetic to propionic ratio in ruminal fluid of 0.44 :1. There were no interactions and the usefulness of chlortetracycline and Zeranol and the poorer production using molasses distillers solubles in all-grain diets are discussed.


2001 ◽  
Vol 41 (7) ◽  
pp. 1013 ◽  
Author(s):  
M. B. McDonagh ◽  
R. M. Herd ◽  
E. C. Richardson ◽  
V. H. Oddy ◽  
J. A. Archer ◽  
...  

Residual feed intake (RFI) is calculated as the difference between an animal’s actual feed intake and its expected feed intake based on its size and growth over a specified test period. Following a single generation of divergent selection for postweaning RFI, Angus steers and Angus × Hereford, Angus×Poll Hereford and Angus × Shorthorn crossbred steers born in 1996 and 1997 were fed in a feedlot. Cohorts of steers were slaughtered at the same age and had attained similar (P&gt;0.05) final liveweights: 467 kg for steers selected for low RFI (high efficiency; HE, n = 91) and 459 kg for steers selected for high RFI (low efficiency; LE, n = 98). The HE and LE steers had similar (P>0.05) carcass weight (247 and 244 kg), dressing percentage (53.1 and 53.2&percnt;) and eye-muscle area (58.9 and 60.3 cm 2 ). The HE steers had slightly less subcutaneous fat over the rib than the LE steers (9.2 v. 10.1 mm, P&lt;0.05), and there was a trend towards less fat over the rump of HE steers (11.5 v. 12.1 mm, P = 0.10). For meat samples taken from the M. longissimus dorsi (LD) there were no differences (P>0.05) between the HE and LE steers in content of intramuscular fat (5.4 and 5.3% fresh weight), marbling scores, meat colour and fat colour. There were also no differences (P>0.05) between HE and LE steers in shear force and compression values for samples of LD aged for 1 day (4.6 and 4.6 kg shear force, 1.45 and 1.44 kg compression), or for 14 days (3.8 and 3.5 kg, 1.36 and 1.32 kg). Myofibril fragmentation index (MFI) measures the breakdown of these structural elements which occurs as an initial step in the process of protein degradation and meat tenderisation. MFI was lower (i.e. less fragmentation; P<0.05) in LD samples from HE steers than from LE steers, both in samples aged for 1 day (67.7 v. 72.5 units) and in samples aged for 14 days (87.8 v. 91.1 units). The rate of decline in MFI between 1 and 14 days post slaughter was similar in the LD samples from both lines of steers. There were no differences (P>0.05) between HE and LE steers in the activity of m-calpain and &micro;-calpain in LD immediately after slaughter (HE steers: 1.9 and 2.3 units, LE steers: 1.8 and 2.1 units). The level of calpastatin in LD from the HE steers was 13% higher than in the LD from the LE steers (5.2 and 4.6 units respectively, P<0.05). Rate of myofibril fragmentation was positively correlated (P<0.01) with the ratios of both m-calpain and µ-calpain to calpastatin, but not (P>0.10) with levels of either calpain or calpastatin. A single generation of divergent selection for RFI produced differences in calpastatin and myofibril fragmentation that may, with on-going selection for low RFI, negatively affect meat tenderness.


2001 ◽  
Vol 52 (4) ◽  
pp. 471 ◽  
Author(s):  
P. F. Arthur ◽  
G. Renand ◽  
D. Krauss

Data on young Charolais bulls were used to evaluate the effect of age of dam, and provide genetic parameter estimates for growth and feed efficiency traits in weaners compared with yearlings. Records on 510 performance test bulls born from 1985 to 1989 and 792 progeny test bulls born from 1988 to 1997 were used, plus available pedigree information (total n = 5493). After weaning (approximately 225 days of age), progeny test bulls were housed in barns and tested until 15 months for all bulls and 19 months of age for half of the bulls. From the records, the test period was artificially partitioned into a weaner and a yearling test. Both tests were for 140 days, with the weaner test commencing at approximately 274 days of age (6–8 weeks after weaning), and the yearling test commencing at approximately 430 days of age. For each test (weaner or yearling), average daily gain, daily feed intake, feed conversion ratio (feed intake per unit weight gain), and residual feed intake (feed intake net of the expected requirements for growth and maintenance) were calculated. Liveweights at 12 and 18 months of age were also studied. Age of dam effect was significant (P < 0.05) for weight at 12 and 18 months of age, and for all weaner traits except residual feed intake. All the traits studied were moderately heritable (0.20–0.46) except for feed conversion ratio in yearlings (0.10). Genetic correlations for the same traits measured in weaners and later in yearlings were less than unity (0.42–0.95), with the 3 highest correlations obtained for weight (0.950.03), feed intake (0.900.07), and residual feed intake (0.750.12). Therefore, for genetic improvement purposes, traits measured in weaners should be considered different from those measured in yearlings, except for weight and feed intake. However, the medium to very high genetic correlations between weaner and yearling tests for most of the traits studied indicate that selection based on weaners will have a positive correlated response in yearlings and vice versa.


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