254
Proc. Aust. Soc. Anim. Prod. Vol. 17
GROWTH, CARCASS AND MEAT QUALITY IN VEAL CALVES FED
DIETS BASED ON WHOLEMILK OR MILK REPLACERS
J.B. MORAN*,
G. GAUNT** and A. J. SINCLAIR***
SUMMARY
Friesian bull calves were fed 8 l/day of wholemilk, wholemilk plus soyflour,
milk-protein-based replacer or replacer plus soyflour together with ad lib
concentrate pellets from 8 to 16 weeks or age. Calves were slaughtered at 12 or
16 weeks of age and carcass and meat quality was assessed.
The inclusion of soyflour in the liquid diet reduced growth rates of calves,
However, meat from calves fed soyflour
contained a higher proportion of polyunsaturated fatty acids while the highest
proportion of saturated fatty acids was found in meat from calves fed wholemilk.
It was concluded that at a substitution rate of 0.30 in milk replacer, soyflour
was likely to depress growth rates through poorer palatability of the liquid
diet.
Keywords: Veal, soyflour, wholemilk, meat, carcass
but had little effect on carcass quality.
INTRODUCTION
There is renewed interest in Victoria in establishing economical year-round
production systems for pink veal. This has arisen from the current shortage of
medium weight (51-70 kg) carcasses in the wholesale and retail meat trade in
Melbourne. Our previous trials (Moran et al. 1987) have shown that feeding
systems based on li) l/day wholemilk plus concentrates will produce carcasses with
acceptable degree of finish and meat colour by 16 weeks of age.
Farm-gate returns for wholemilk in Victoria can vary from less than 15 c/l
in spring to over 3ti c/l in winter whereas the equivalent price for milk replacer
at the same dry matter (DM) content as wholemilk is about ‘25 c/l. Therefore
wholemilk and/or milk replacer could be fed during year-round veal production
systems. The price of milk replacers can be reduced by substituting milk protein
with cheaper plant protein. Soyflour has been successfully incorporated into milk
replacers provided it is heat treated to remove antitrypsin activity and the
It also has an added advantage of
calves are at least five weeks old (Roy 1980).
containing higher proportions of polyunsaturated fatty acids (YUFA) than milkprotein-based replacers and this will reduce the levels of saturated fatty acids
(SPA) in tissues of veal calves fed such diets (Wrenn et al. 1913).
This trial compared four liquid diets fed to veal calves, namely wholemilk,
wholemilk plus soyflour, milk-protein-based replacer and replacer in which 0.41)
of the milk protein was substituted with soyflour protein.
MATERIALS AND METHODS
Purebred Friesian bull calves were reared on wholemilk plus ad lib
concentrate pellets until eight weeks of age. They were then selected on the
basis of liveweight (mean of 94.7 kg) and placed in four groups each of ten
animals.
Between eight and 16 weeks of age, they were given access to ad lib
concentrate pellets and trough-fed one of the four diets described in Table 1.
The wholemilk contained 42 g/l milk fat, 30 g/l milk protein, t37 g/l solidsThe
not-fat and of the total fatty acids, 0.719 were SFA and 0.039 PUFA.
yc
Tc*
***
Kya br
Research Insti tute, Kya br am, Vic. 3620
Ruthe rgl en Resea rch In stitut e, Rutherglen, Vic. 3685
Royal Me 1 bourne Ins tit ute of Technology, Melbourne, Vic. 3001
Proc. Aust. Soc. Anim. Prod. Vol. 17
255
commercial milk-protein-based replacer (Veanavite: Bonlac food Ltd.) consisted of
810 g/kg skim milk powder, 170 g/kg tallow and 2c) g/kg vitamins and minerals
containing 45.8 g/kg nitrogen (N), 155 g/kg ether extract (EE) and of the total
fatty acids, 0.554 were SFA and’ 0.023 PUFA. The commercial soyflour (Soyolk:
Riverland Vegetable Oils Pty Ltd) was heat treated and contained 70.6 g/kg N, 237
g/kg EE and of the total fatty acids, 0.171 were SFA and 0.602 PUPA. The
concentrate consisted of barley (848 g/kg>, full fat soyflour (150 g/kg) plus
vitamins and minerals and contained 22.7 g/kg N, 43 g/kg EE, 42 g/kg crude fibre
and of the total fatty acids, 0.201 were SFA and 0.587 PUFA. The wholemilk was
offered warm each morning and the milk replacers were mixed using warm water.
The 7:3 proportion of milk replacer: soyflour was based on recommendations from
the manufacturer.
Each pen of calves was loose housed on rice hulls in roofed steel yards and
had access to water. Concentrate intakes and liveweights were monitored weekly.
Half the animals in each pen were slaughtered at 12 weeks and half at 16 weeks of
age. Measurements taken on the carcasses and on the 9-lc)-ll rib joints were
‘Ihe M longissimus dorsi (LD) was
described in detail by Moran et a1.(1987).
analysed for total lipid content and fatty acids composition using the methods
described by Sinclair et al (1982).
Data on liveweights and growth rates were analysed by two-way analyses of
variance with milk type (wholemilk v milk replacer) and soyflour as fixed
factors. Carcass quality and composition and meat quality data were subjected to
regression analyses using all values within each diet and adjusting to the mean
carcass weight (66.7 kg) along the common slope. Within-diet linear regression
coefficients were tested prior to these adjustments but in all cases they were
not statistically. different.
.
RESULTS
The cool, damp conditions during the trial led to a severe outbreak of
Despite regular vaccinations, there were four deaths from
enzootic pneumonia.
suspected Clostridia diseases. Any calves showing ill thrift were'removed from I
the trial between 8 and 12 weeks of age, leaving eight healthy animals per group
from which* reliable performance data could be obtained. The morbidity of these
disease conditions was high (ie 0.2c)). However, the significant effects of diet
on growth rate (see Table 1) confirmed that the remaining calves were unlikely to
I
be affected at a subclinical level.
Intake and performance data are presented. in Table 1 from which it is
apparent that calves fed diets including soyflour had th,e poorer growth rates
over both age ranges. Intakes of DM from the, soyflour diets were overestimated .
becausetherewere occasional residues of undissolved soyflour in the troughs
that could not be weighed. The calves fed Diet M had loweltr growth rates than
those fed Diet R between8 and 12 weeks (P<&lO).but both groups grew equally
well between 12 and 16 weeks of.age.
There were no dietary effects ondressing p.ercent which averaged 51.6. .
Dietary effects on carcass measurements were alsonon-significant and the
following average values were recorded: conformation score 1.6 ona. .point
scale, carcass length .1352mm, leg length -526mm,.forequarter 36.6 kg, .hindquarter
46.7kg, 5-13 ribset 14.7kg. . Other carca.ss and meat quality measures' are
presented in Table 2. Meat colour of the.LD is expressed in terms of L value with
lower values for darker coloured meat. ,For comparative purposes, L values for
meat\ from week old calves. and lot-fed beef steerswere 49.3 and 37.4 respectively
(RD. Warner, unpublished data).' Dietary effects on ,weight of kidney fat, retail
meat yield, LD area, meat colour *and tenderness 'were all non-significant, The
only significant effects. of diet on&b composition, were lower. subcutaneous and
intermuscular fat contents in calves fed Diet RS.
Proc. Aust. Soc. Anim. Prod. Vol. 17
256
Table 1.
Intake and performance oi calves fed wholemilk or milk replacer uiets.
Table 2. Dietary effects
w.ere large differences in
the most YUFA, the least
from wholemilk-fed calves
on total lipid contents were non-significant out there
EA composition. Calves fed Diet MS produced meat with
monounsaturated PA and the highest PUFA/SFA ratio. Meat
had the highest levels of WA.
Table 2. Carcass and meat quality in calves fed wholemilk or milk replacer diets
adjusted to 66.7 Kg carcass weight
Results on
same
line followed
Although calves
fed the
by different
letter differ (PW.i)5).
DISCUSSION
wholemilk grew slower than those fed'the milk-
Proc. Aust. Soc. Anim. Prod. Vol. 17
257
protein-based replacer early in the trial, they were able to completely
compensate for their lower DM intakes from their liquid diet through greater
concentrate intakes between 12 and 16 weeks of age.
Subsequently they grew as
fast as calves fed the milk replacer. The growth rates of 00th these groups of
calves (ie 1.4 kg/day) was superior to those from previous trials (Moran et al.
19871, in which calves fed 10 l/day wholemilk only grew at 1.2 kg/day. The calves
fed the soyflour performed poorer than those fed milk-protein diets (Roy 1980)
but this may have been further accentuated by the high level of soyflour in their
liquid diet.
The residues of undissolved soyflour in their troughs are
indicative of the poor reconstitution of this particular soyflour in warm water
and its poor acceptance by the calves. When fed at 300 g/kg of a milk-proteinbased replacer, there appears to be little economic benefit from soyflour.
Including the cost of wholemilk fed to 8 weeks of age (at 15 c/l) and costing the
commercial milk replacer at $1.75/kg, the soyflour at 7c)c/kg and the concentrate
at ituc/kg, total feed costs to produce a 65 kg carcass were as follows: $79,
.$;113, $108 and $125 for Diets M, MS, R and RS respectively. With wholemilk
costed at 3&/l, corresponding total feed costs were $151, $198, $146 and $162.
Unless the price of milk replacer is markedly reduced, it is unlikely to be used
for veal production in Victoria.
Diet had little effect on carcass quality or composition. The slower
growing calves fed Diet RS had less rib fat and this has been noted in previous
trials. Retail yield of meat averaged 0.65 and this is also similar to previous
results (Moran et al. 1987). Minimum standards for pink veal carcasses are 2 out
of 5 points for carcass conformation and meat colour at 42 L value (R.D. Warner,
J.R. Currie and J.B. Moran, unpublished data) hence these carcasses would have
been rejected on conformation score and been marginal for meat colour.
Meat from ruminant animals is generally rich in SFA and low in PUFA because
of hydrogenation of FA by rumenmicro organisms (Sinclair etal. 1982). These
calves were still behaving as monogastrics, despite consuming Ox.50 of their
dietary DM in the form of concentrate*pellets, because the meat from the
soyflour-fed calves had high PUFA/SFA ratios which reflected their higher intakes
of PUFA. The inclusion of soyflour in the wholemilk doubled PUFA levels in the
meat from o.lC, to c).2& Sinclair et al. (1962) reported PUFA levels of 0.09 in
beef and 0.10 in sheep both of which are similar to those in the calves fed non.
soyflour diets. .
From these results, it then appears that the inclusion of 0.30 heat-treated
'soyflour in a milk replacer for group-fed calves could lead to palatability
problems and reduced growth rates. Commercial milk replacers based on skim milk
powder do not appear to be economically feasible with current Victorian wholemilk
prices.
ACKNWLEDGEMENTS
The authors are grateful to Ms. R. D. Warner for meat colour measurements
The
and to Mr. C. Connally for management and feeding of th.e calves.
contribution of feedstuffs by Bonlac Food Ltd and Riverland Vegetable Oils Pty
Ltd is also ac'knowledged.
REFERENCES
MCRAN,J.B., WARNER&D. and CURRIE,J.R. (1987). In "Recent Advances in Anima'l
Nutrition in Australia,l987" p.18, editor D.J.Farrell (UNE: Armidale).
% ROY, J.H.B. (lUSti).
"The Calf" 4th ed p.,339 (Butterworths : London).
SINCLAIR,A.J., SLATTERY,W.J. and O'DEA,K. (1982).J.Sci.Food Agric. 33 : 771.
.
WRENN, T.R., WEYANT, JR., GORDON, C.H, GOERING, H.K., DRYDEN, Lop., BITMAN, Jo, *
EDMONDSON, L,.F. and KING, RL. (1973); J. Anim. Sci. 37 : 1419.