Factors affecting pre-weaning growth and weaning conformation of Angus cattle

1978 ◽  
Vol 29 (2) ◽  
pp. 359
Author(s):  
R Barlow ◽  
EB Dettmann ◽  
LG Williams
Keyword(s):  
Least Squares ◽  
New South ◽  
Average Daily Gain ◽  
Factors Affecting ◽  
Angus Cattle ◽  
South Wales ◽  
Weaning Age ◽  
Males And Females ◽  
Main Effects ◽  
Daily Gain

Weaning weight (ww) and conformation score (cs) records from Angus calves in five New South Wales herds were analysed by least-squares procedures to assess the nature and magnitude of variation. Herd, year, age of dam and sex were considered as main effects. Covariates included in the models were weaning age (WA) for ww and average daily gain (ADG), and both WA and ww for cs. Male calves (steers and bulls) were 16.6 kg heavier at weaning than female calves. Dams that were 5-8 years of age weaned calves that were 30.1 kg, 15.4 kg and 6.7 kg heavier than 2-, 3- and 4-year-old dams respectively. When ww was not included as a covariate in the model, age of dam effects on cs reflected those on ww, and there was little difference in cs between males and females. When adjusted for differences in ww, males had poorer cs than females, and calves from 3-year-old dams, and from dams over 8 years old, had poorer cs than those from dams of all other ages. Partial regressions of ww and ADG on WA, and of cs on ww, varied considerably between herd/year/sex subgroups.

Genetic and phenotypic parameters for pre-weaning growth and weaning conformation of Angus cattle

1978 ◽  
Vol 29 (2) ◽  
pp. 373
Author(s):  
R Barlow ◽  
EB Dettmann
Keyword(s):  
Least Squares ◽  
New South ◽  
New South Wales ◽  
Genetic Correlations ◽  
Components Of Variance ◽  
Weaning Weight ◽  
Environmental Correlations ◽  
Angus Cattle ◽  
South Wales

Weaning weight (WW) and conformation score (CS) records on Angus calves from four New South Wales herds were analysed by least-squares procedures. Paternal half-sib components of variance and covariance were used to obtain estimates of heritabilities of various measures of growth and cs, as well as genetic, phenotypic and environmental correlations. Estimates of the heritabilities of measures of growth ranged from 0.20 (all data) to 0.24 when derived from heifer data only. The heritability of cs was 0.24 when the data were adjusted for ww, and 0.19 when no covariate was included in the analysis. All correlations among different measures of growth were positive and close to unity. There were small positive phenotypic and environmental correlations (0.19 to 0.36) and small negative genetic correlations between ww and cs (–0.02 to –0.41).

Growth and carcass characteristics of crossbred and straightbred Hereford steers. III. Post-weaning growth in seven environments in New South Wales

1987 ◽  
Vol 38 (5) ◽  
pp. 941 ◽  
Author(s):  
RE Darnell ◽  
H Hearnshaw ◽  
R Barlow
Keyword(s):  
Body Condition ◽  
Bos Taurus ◽  
New South ◽  
Average Daily Gain ◽  
New South Wales ◽  
Coastal Environments ◽  
South Wales ◽  
Similar Body ◽  
Daily Gain ◽  
Constant Growth

Post-weaning growth, liveweight and body condition at slaughter were examined in 289 steers comprised of straightbred Hereford and first cross Brahman x Hereford, Simmental x Hereford and Friesian x Hereford. The steers were grown from weaning in seven environments throughout New South Wales. All steers were slaughtered when the average fat cover of the Herefords was in the range of 6-10 mm at the 12/13th rib. Brahman crossbreds were in similar body condition to Herefords at slaughter, which in turn were generally in better condition than both Simmental and Friesian crossbreds. Crossbred steers were heavier than Herefords at slaughter. Simmental crosses and Friesian crosses were 53 kg (12%) heavier on average over all environments, and Brahman crosses 41 kg (10%) and 83 kg (16%) heavier in inland and coastal environments respectively. Mean average daily gain (ADG) of the crossbred steers was always greater than that of the Hereford steers. There was a trend for ADG to be greater among the Brahman crosses earlier in the post-weaning period, but for the Simmental and Friesian crosses to grow faster later in the post-weaning period. Simmental crosses maintained a constant ADG advantage relative to Friesian crosses throughout the post-weaning period in environments where growth was favoured. Significant genotype x environment interactions occurred. Relative to Herefords, Simmental and Friesian crossbreds responded more to improved conditions, while Brahman crossbreds maintained a constant growth advantage regardless of environmental conditions. Bos taurus crosses grew faster than Brahman crosses, and Simmental crosses faster than Friesian crosses, only when environments were highly favourable.

scholarly journals Relationship between weaning age and antibiotic usage on pig growth performance and mortality

2020 ◽  
Vol 98 (12) ◽  
Author(s):  
Jamil E G Faccin ◽  
Mike D Tokach ◽  
Matthew W Allerson ◽  
Jason C Woodworth ◽  
Joel M DeRouchey ◽  
...  
Keyword(s):  
Feed Efficiency ◽  
Average Daily Gain ◽  
Performance Criteria ◽  
Short Term ◽  
Weaning Age ◽  
Pig Performance ◽  
Experimental Treatments ◽  
Main Effects ◽  
Daily Gain ◽  
Porcine Respiratory

Abstract A total of 2,184 pigs (DNA 600 × PIC L42) were used to evaluate the effects of weaning age and antibiotic (AB) use on pig performance from weaning to marketing in a commercial production system. Experimental treatments were arranged in a 3 × 2 factorial with main effects of weaning age (18.5, 21.5, or 24.5 d of age) and with the use of ABs or an antibiotic-free (NAE) program. At birth, pigs were ear tagged, and the date of birth and sex recorded. Pigs were weaned from a 4,000-sow farm over four consecutive weeks. Four weaning batches (one per week) of 546 pigs were used. Each weaning batch had one-third of pigs of each weaning age. Pigs were placed in pens by weaning age and then randomly assigned to an AB or NAE program. There were 14 replicate pens per treatment and 26 pigs per pen (13 barrows and 13 gilts). Pigs allocated to the AB program were fed a diet containing 441 mg/kg chlortetracycline (CTC) from day 8 to 21 postweaning. They were also administered 22 mg/kg of body weight (BW) of CTC via drinking water for five consecutive days after a porcine respiratory and reproductive syndrome outbreak during week 7 after weaning. In the first 42 d postweaning, increasing weaning age improved (linear, P < 0.001) BW at day 42, average daily gain (ADG), and average daily feed intake (ADFI). From weaning to 197 d of age, increasing weaning age increased (linear, P < 0.001) ADG and ADFI. Pigs on the AB program had greater (P = 0.031) ADG and ADFI compared with NAE pigs. An interaction (linear, P = 0.005) was observed for feed efficiency (G:F). When ABs were provided, increasing weaning age did not result in any change in G:F; however, in the NAE program, increasing weaning age increased G:F. Pigs on the AB program had lower (P < 0.001) total losses (mortality and removals) than those on the NAE program. Increasing weaning age marginally (linear, P = 0.097) decreased total losses. Increasing weaning age decreased (quadratic, P < 0.001) the number of pigs treated with an injectable AB but the AB program did not (P = 0.238). The weight sold (at 197 d of age) per pig weaned was increased (linear, P = 0.050) by increasing weaning age and by using AB in feed and water (P = 0.019). In summary, increasing weaning age linearly improved most of the pig performance criteria and relatively the short-term use of ABs reduced mortality and removals with both factors contributing to increased weight sold per pig weaned.

The effect of stocking rate on the performance of steers in central coastal New South Wales

1977 ◽  
Vol 17 (89) ◽  
pp. 899 ◽  
Author(s):  
Davies H Lloyd
Keyword(s):  
New South ◽  
Average Daily Gain ◽  
New South Wales ◽  
First Year ◽  
Stocking Rate ◽  
Paspalum Dilatatum ◽  
Period Effects ◽  
South Wales ◽  
The University ◽  
Daily Gain

The effect of stocking rate and sowing one-eighth of the area to lucerne on the liveweight change and carcase characteristics of Hereford steers grazing pastures dominated by Paspalum dilatatum was studied at the Wolverton Farm of the University of Sydney, Bringelly, New South Wales from 1971 to 1974. Stocking rate (1.5, 2.0, 2.5 and 3.0 steers ha-1) had an effect upon mean daily liveweight gain in some periods and this was reflected in the number of days taken to achieve 450 kg. (1.5 ha-1 took 509 days, 2.0 took 595, 2.5 took 802 and 3.0 took 842 days). There were significant differences in average daily gain between replicates in most periods. The lucerne did not persist after the first year. Having one-eighth of the area sown to lucerne did not significantly affect daily liveweight gain. There were highly significant period effects with the highest daily gain occurring in spring and summer, the lowest in winter and gain in autumn being dependent upon rainfall and stocking rate. In many periods increasing stocking rate above 2.0 steers ha-1 did not increase the per hectare liveweight gain.

Preweaning growth of Brahman, Braford, and Africander first-cross calves in the subtropics of New South Wales

1995 ◽  
Vol 35 (1) ◽  
pp. 1
Author(s):  
H Hearnshaw ◽  
PF Arthur ◽  
R Barlow ◽  
W Hoffman
Keyword(s):  
Body Length ◽  
New South ◽  
Average Daily Gain ◽  
New South Wales ◽  
Coat Colour ◽  
The Other ◽  
Colour Pattern ◽  
South Wales ◽  
Daily Gain ◽  
Preweaning Period

Preweaning growth of 435 first-cross Brahman x Hereford (BH), Braford x Hereford (BM) and Africander x Hereford (AM) calves was evaluated at Ballina in the subtropics of New South Wales. Thirty-five Brahman, 32 Braford, and 23 Africander sires were mated to Hereford females over 3 years to produce the calves. Mean gestation of BH calves (290 days) was 4 and 6 days longer than BfH and AfH calves, respectively. BH and AfH calves had more eyelid pigmentation (88 and 98%, respectively) than BM calves (59%). For males, birth weights of BH calves were higher than BfH, which, in turn, were heavier than AfH calves (38.6 v. 34.8 v. 31.5 kg). For females, birth weights of BH and BfH calves were not significantly different but were higher than those of AfH calves (33.3 and 32.6 v. 30.4 kg). BH calves had higher average daily gain (ADG) than BfH and AfH calves during the second half of the preweaning period, resulting in 200-day liveweights of 175.4, 167.5, and 167.3 kg for BH, BfH, and AfH calves. BH calves were taller and had larger girths than the other crosses at birth, but AM calves exhibited the greatest increase in height and body length from birth to weaning. For BH, BMI, and AfH calves, 34,6, and 94% were predominantly red, whereas 6, 94, and 5% were also red but had a Hereford coat colour pattern.

Evaluation of Hereford and first-cross cows on three pasture systems. II. Growth of Hereford and Brahman sired calves out of mature cows

1994 ◽  
Vol 122 (1) ◽  
pp. 131-138 ◽  
Author(s):  
H. Hearnshaw ◽  
P. F. Arthur ◽  
P. J. Kohun ◽  
R. Barlow
Keyword(s):  
Average Daily Gain ◽  
The Other ◽  
Weaning Weight ◽  
South Wales ◽  
Medium Quality ◽  
The Mean ◽  
Main Effects ◽  
Calving Difficulty ◽  
Daily Gain ◽  
Sire Breed

SUMMARYThe preweaning growth of the progeny of mature cows grazing high, medium or low quality pasture was evaluated. The cows were 5–9 years of age at the beginning of the study and were either purebred Hereford (H x H), first-cross Brahman x Hereford (B x H), Simmental x Hereford (S x H) or Friesian x Hereford (F x H). Hereford and Brahman bulls were mated to these cows for three mating seasons commencing in 1982, at Grafton, New South Wales, Australia. Records on 634 calves born over three consecutive years were used.Most traits were subject to significant sire breed or dam breed effects or their interactions with one or more of the other main effects (pasture, year of birth of calf, cow age and sex of calf). The incidences of calving difficulty and stillbirths were exceptions. Stillbirths (mean of 3·8%) were not affected by any of the effects studied, while calving difficulty was affected only by sex of calf effect (males, 3·9%; females, 0·8%). The mean calving date of Brahman-sired calves was 11·4 days later (P < 0·05) than that of Hereford-sired calves. Differences between Brahman-sired and Hereford-sired calves for weaning weight were not significant for S x H (Brahman, 237 kg; Hereford, 232 kg) and FxH (Brahman, 238kg; Hereford, 238kg) dams. For HxH dams however, calves sired by Brahman were heavier at weaning (205 kg) than those sired by Hereford (193 kg) bulls, while for B x H dams the reverse was true (Brahman, 222 kg; Hereford, 231 kg). For calves with B x H dams average daily gain (ADG) was the same (957 g/day) for each sire breed, while for the other dam breeds, Brahman-sired calves had a higher ADG than Hereford-sired calves (862 v. 779, 1014 v. 946 and 1022 v. 950 g/day for H x H, S x H and FxH, respectively). Calves sired by Brahman bulls had > 90% eyelid pigmentation while Hereford-sired calves had 44–74%. On high quality pasture, the weaning weights and ADG of calves of F x H and S x H dams were higher than those of B x H and HxH dams. On medium quality pasture, weaning weight of calves of crossbred dams (B x H, S x H and FxH) were similar but higher than those of H x H dams. On low quality pasture, mean weaning weight of calves of B x H was higher than those of S x H and F x H dams, which in turn, were higher than that of H x H dams.

Evaluation of Hereford and first-cross cows on three pasture systems. III. Milk yield and its influence on calf performance

1997 ◽  
Vol 129 (1) ◽  
pp. 91-98 ◽  
Author(s):  
P. F. ARTHUR ◽  
H. HEARNSHAW ◽  
R. BARLOW ◽  
P. J. WILLIAMSON ◽  
P. D. STEPHENSON ◽  
...  
Keyword(s):  
Milk Yield ◽  
Body Condition Score ◽  
New South ◽  
Average Daily Gain ◽  
Detailed Data ◽  
Yield Data ◽  
South Wales ◽  
Condition Score ◽  
Calf Performance ◽  
Daily Gain

Milk yield was determined by the weigh-suckle-weigh method over 2 years (1983 and 1984 calvings), for a total of 305 purebred Hereford (H×H) and first-cross Brahman×Hereford (B×H), Simmental×Hereford (S×H) and Friesian×Hereford (F×H) cows grazing three pasture systems at Grafton, New South Wales, Australia. The age of the cows ranged from 6 to 11 years. The data were used to evaluate different estimates of milk yield and to examine the effects of milk yield on growth of calves up to weaning.Of all the cow traits studied, average lactation milk yield (average of early, mid and late-lactation milk yields) had the highest correlation coefficient with calf 210-day weight (r=0·73) and pre-weaning average daily gain (ADGtotal, r=0·73), and explained >50% of the variation in the calf traits. However, milk yield was also moderately correlated with other cow traits (liveweight and body condition score). Thus, to predict calf performance, milk yield data may not be required if detailed data on other cow traits are available. This is supported by the finding that differences in the coefficients of determination (R2) between models for calf 210-day weight and ADGtotal which included average lactation milk yield and other cow traits (highest R2=69%) and models which included other cow traits but no milk yield estimate (highest R2=57%) were <13%.Cow breed rankings for average lactation milk yield were similar to those for calf 210-day weight and ADGtotal. On high quality pasture, S×H and F×H cows produced the most milk (S×H, 7·5 kg/day; F×H, 8·3 kg/day; B×H, 5·7 kg/day; H×H, 5·5 kg/day) and weaned the heaviest calves (S×H, 255 kg; F×H, 252 kg; B×H, 215 kg; H×H, 217 kg), while on low quality pasture, B×H and F×H cows produced the most milk (B×H, 4·2 kg/day; F×H, 3·7 kg/day; S×H, 2·9 kg/day; H×H, 2·7 kg/day) but B×H cows weaned the heaviest calves (B×H, 180 kg; F×H, 168 kg; S×H, 159 kg; H×H, 124 kg).

An analysis of beef cattle growth records available in south-eastern Australia

1970 ◽  
Vol 10 (44) ◽  
pp. 262
Author(s):  
WE Mason ◽  
RG Beilharz ◽  
R Carraill
Keyword(s):  
Growth Rate ◽  
Environmental Factors ◽  
Beef Cattle ◽  
Degrees Of Freedom ◽  
New South ◽  
Average Daily Gain ◽  
South Wales ◽  
Bull Calves ◽  
Eastern Australia ◽  
Daily Gain

Records of growth to weaning of 1812 calves from seven herds in Victoria and one herd in New South Wales were analysed. The results of the analysis were : 1. Preweaning growth rate of heifers decreased significantly with age at weaning. That of bulls and steers did not. 2. Age of dam had a large effect in all three sexes. Environmental factors (properties, years) affected bull calves more than heifer calves. There were fewer degrees of freedom at these levels of the analysis for steers. 3. Adjustments for age of dam were calculated and are presented (table 3). 4. Heritability estimates were obtained from dam-progeny regressions and intra-class correlations. The heritability of adjusted preweaning average daily gain was about 0.25. Clearly many more records need to be analysed to provide further estimates of heritability.

Evaluation of Bos indicus and Bos taurus straightbreds and crosses. I. Post-weaning growth of steers in different environments

1994 ◽  
Vol 45 (4) ◽  
pp. 783 ◽  
Author(s):  
PF Arthur ◽  
H Hearnshaw ◽  
PJ Kohun ◽  
R Barlow
Keyword(s):  
Growth Rate ◽  
Bos Taurus ◽  
New South ◽  
Average Daily Gain ◽  
Bos Indicus ◽  
Environment Interaction ◽  
Back Cross ◽  
South Wales ◽  
Medium Quality ◽  
Daily Gain

Post-weaning growth of 186 steers comprizing straightbred Hereford (H x H) and Brahman (B x B), first-cross (B x H) and back-cross (H x BH and B x BH) was evaluated. The steers had been raised to weaning (8 months of age) by dams which grazed either high, medium or low quality pasture (pre-weaning pasture system) at Grafton, N.S.W. The steers were grown on pasture from time of weaning in one of three locations in New South Wales representing subtropical, temperate-good, and temperate-good to poor environments, and slaughtered when the average fat cover of the back-cross steers in each environment was 4-10 mm at the 12113th rib. Pre-weaning pasture system had a significant effect on post-weaning growth, with mean post-weaning (8-48 months of age) average daily gain (ADG) of steers from low (327� 8 g/day) being higher than that of steers from medium (304�6 g/day), which in turn, was higher than that of steers from high (276�9 g/day) quality pre-weaning pasture, indicating that steers from low and medium quality pastures exhibited compensatory growth. From 8 to 24 months of age, first-cross BxH steers had the highest ADG in all environments. The ranking of the other genotypes differed across environments. In the environment where growth rate was lowest (178 g/day for B x H), B x B and B x BH steers grew faster than H x H and H x BH steers; where growth rate was highest (584 g/day for B x H), the order was reversed; and where growth rate was intermediate (323 g/day for B x H), there were no significant differences in ADG among H x H, H x BH, B x BH and B x B steers. Steers from only two environments were retained after 24 months of age. Mean ADG from 8 to 36 or 48 months of age was not significantly different among straightbred and back-cross steers, but was lower than that for the first-cross steers. Genotype x environment interaction for liveweight at slaughter was not significant. First-cross B x H steers were 56 kg (11%) heavier (P < 0.05) than back-cross steers, which in turn, were 37 kg (8%) heavier (P < 0.05) than straightbred steers at slaughter.

Adjustment factors for weaning weights of Mashona cattle in Zimbabwe

1990 ◽  
Vol 114 (1) ◽  
pp. 35-40
Author(s):  
V. Buvanendran
Keyword(s):  
Least Squares ◽  
Average Daily Gain ◽  
Month Of Birth ◽  
Average Production ◽  
Adjustment Factors ◽  
Weaning Age ◽  
Commercial Farms ◽  
Specific Factors ◽  
The Difference ◽  
Daily Gain

SUMMARYThe effects of year of birth, age of dam, sex of calf, month of birth and weaning age on weaning weights of Mashona calves on six commercial farms in Zimbabwe were estimated by least squares procedures from data of 6365 calves born 1977–85. The least squares mean weight at 205 days among farms ranged from 123 to 159 kg while the linear regression coefficients of weight on age ranged from 0·31 to 0·46 kg. Adjustment for weaning age by the average daily gain from birth to weaning failed to remove the dependence of adjusted weight on age. Sex was the most important source of variation and the mean difference between male and female calves was 12·9 kg. Sex difference was markedly influenced by herd production rate, being greater in herds of above average production.Weights of calves of 3-, 4- and > 11-year-old dams deviated from those of dams aged 5–10 years (mature) by 14·5, 8·5 and 2·9 kg, respectively. Herd mean influenced the difference between 3-year-old and mature dams, the difference increasing as herd mean declined. Herd-year specific factors seem more appropriate for sex and 3-year-old dams and an annual crop of > 50 calves would confer an advantage to herd-specific over general adjustment factors. On the basis of equality of variances within subclasses, multiplicative factors were superior to additive factors for sex of calf and month of birth; both types of adjustment were suitable for age of dam.

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