Derivation of economic values for veal, beef and milk production traits using profit equations

Livestock Production Science, 34 ( 1993 ) 35-56 35 Elsevier Science Publishers B.V., Amsterdam

Derivation of economic values for veal, beef and milk production traits using profit equations

Henk Bekman ~ and Johan A.M. van Arendonk Department of Anirnal Breeding, Wageningen Agricultural University, Wageningen, Netherlands

(Accepted 29 July 1992)

ABSTRACT

Bekman, H., and J.A.M. van Arendonk, 1993. Derivation of economic values for veal, beef and milk production traits using profit equations. Livest. Prod. Sci., 34: 35-56.

In this study profit equations for milk, veal and beef bull production were developed to obtain economic values for different traits. Veal and beef production were described in terms of fat and protein daily gain. For categorical traits, dystocia and carcass quality traits, economic values were derived using an underlying continuous scale. Parameters in the profit equations were chosen to reflect the Dutch situation for Black and White cows, but they can be changed to fit other breeds and production circumstances. The consequences of altering beef production characteristics on growth and mature weight in dairy cows are discussed in the paper but not included in the economic weights.

Without product output restrictions, economic values for milk carrier, fat and protein yield were Dfl -0 .082, 5.70 and 12.85 per kg, respectively. Under a multiple restriction of milk yield and fat content on herd level, economic weigths were Dfl -0.328, 1.04 and 12.60 per kg, respectively. The economic weight of calf mortality was Dfl -3 .83 per % and the marginal costs of dystocia were Dfl 59.75 per cow per unit on the underlying liability scale. The economic value for birth weight was Dfl 5.40 per kg for dairy farmers, Dfl -4 .59 per kg for veal producers and Dfl -6 .91 per kg for beef producers. For veal calf producers, economic weights were Dfl 0.45 for daily gain (g/day), 25.67 for dressing percentage (%), - 14.22 for mortality (%), 26.48 for fleshiness, 0.06 for fat covering and 37.44 for meat colour in veal calves. For beef bull producers, economic values were: Dfl 0.59 for daily gain, 37.35 for dressing percentage, - 18.20 for mortality, 81.07 for fleshiness and 7.39 for fat covering.

Sensitivity analysis of economic weights to changes in price and production circumstances showed that future economic values might change dependent on level of output and prices.

Keywords: economic values, beef production, milk production.

I N T R O D U C T I O N

In the Netherlands, the dairy cattle population is used for the production of milk, veal and beef. Gross income of the dairy farmer originates 85% from

Correspondence to: Johan van Arendonk, Department of Animal Breeding, Wageningen Agri- cultural University, P.O. Box 338, 6700 AH Wageningen, The Netherlands. ~Present address: Product Board Livestock and Meat, P.O. Box 5805, 2280 HV Rijswijk, the Netherlands.

0301-6226/93/$06.00 © 1993 Elsevier Science Publishers B.V. All rights reserved.

36 H. BEKMAN AND J.A.M. VAN ARENDONK

the sale of milk and 15% from beef production, i.e. the sale of calves and culled cows (IKC, 1991 ). Calves not used for dairy purposes are used for either veal or beef production. The current breeding goal only contains milk production traits, despite considerable variation in veal and beef production traits (e.g. Van Veldhuizen et al., 1991 ). Beef production potential of young calves is hard to measure at the time when they are sold from the dairy herd. Currently, no information is available to estimate breeding values for beef (veal and beef bull) production traits in the Netherlands. This will change with implementation of an identification and registration system for cattle, which will allow combination of individual slaughter data with pedigree information. To maximize economic merit for dairy and beef producers, milk, veal and beef traits should be included in the breeding goal. Economic values are important factors in establishing such a breeding goal. Traits of interest for dairy farmers are milk, fat and protein yield, birth weight, mature weight and dystocia. For veal and beef producers, however, birth weight, daily gain, mortality, dressing% and carcass quality traits are of interest. The economic importance of the latter traits for the dairy farmer depends on their relationship with the value of the calf. Economic values for milk production have been widely discussed in the literature (Niebel, 1986; Gibson, 1989; Groen, 1989a), but those for veal, and beef production have received little attention (Niebel, 1986).

The aims of this study were ( 1 ) to derive profit equations for milk, beef bull and veal producers and (2) to obtain economic values for traits. The parameters in the profit equations reflect the Dutch situation for Black and White cows but they can be changed to fit other breeds and production circumstances. Sensitivity of economic values to changes in price and production circumstances were also studied.

MATERIAL AND METHODS

General concepts In selection-index theory, the aggregate genotype is usually defined as a lin-

ear function of traits to be improved, each multiplied by its economic weight. The economic value expresses the value of a unit change in the trait while keeping the other traits in the aggregate genotype constant. Several methods can be used to calculate economic values (Groen, 1989a). In this study profit or efficiency equations were used to derive economic values for continuous traits by partial differentiation to these traits. For categorical traits, such as dystocia and carcass quality traits, economic values were derived by partial differentiation to the underlying continuous scale for the trait assuming a normal distribution (Danell and Ronningen, 1981 ).

In the Netherlands, bull and surplus heifer calves are sold from the dairy herd when one week old. Fattening of bulls and veal calves is carried out at

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specialized farms. Separate profit equations were established for dairy farmers, veal and beef producers. This allowed for the calculation of economic values for each of these three categories of producers, as well as for the entire sector. For milk production traits the concept of Van Arendonk and Bras- camp (1990) was applied. For beef production, the feed costs were based on energy requirements for maintenance, fat, and protein production. Figure 1 is a schematic overview of milk and beef production showing the major components of their profit functions.

MODEL DESCRIPTION

Milk production Total annual profitability of a dairy herd (Td) was described by the follow-

ing equation:

Td=--CF:d +Nc(Ro--Cd) (1)

where: CF:d = fixed costs of total dairy herd; Nc = average number of lactating cows in the herd; Rd = average revenue per cow per year (Dfl); Cd = average cost per cow per year, excluding CF:d (Dfl);

Average revenue (R) per cow per year was written as:

Ro =Pm xM+pfXF+pp x P + (CV/L) q-BWXPnX ( 1 -mortd) Xfns (2)

where M,F,P = annual production of milk carrier, fat and protein (kg); Pro, Pf, Pp = prices per unit of milk carrier, fat and protein (Dfl); CV = carcass value of culled cow (Dfl); L = average herdlife (year); BW = birth weight of calf (kg); p, = price per kg calf (Dfl); mortd = mortality of calves at the dairy herd (first week); fns=number of calves sold for beef production from the dairy farm (cow- lyear- 1 ).

Calf mortality (morto), which includes stillbirth and death within one week of age, was calculated as the weighted sum over different dystocia classes as:

mortd = mc + ~i fdyci X pmorti (3)

where mc = calf mortality for normal and easy calving; fdyci = frequency of ith dystocia class; pmorti = calf mortality in ith dystocia class (deviation from normal calving).

DERIVATION OF ECONOMIC VALUES USING PROFIT EQUATIONS 3 9

The average cost per cow per year was described by:

Cd =Cm ×M+cf ×F+cp × P + CM+CF:a + ( CH/L ) + Cdys (4)

where Cm, cf and Cp are the feed costs per unit of milk, fat and protein, respectively. The average cost further included annual maintenance costs (CM), fixed costs per animal (CF:a), rearing costs per heifer (CH) and costs for dystocia (Coys).

Costs associated with calving difficulties (Cdys) were based on Meijering ( 1986 ). Six categories for calving difficulties were distinguished, i.e. easy and normal calving, hard pull, veterinary aid, caesarean, and fetotomy. Easy and normal calving did not incur costs. Cost of dystocia (Coys) was calculated from:

Cdys = [ ~l~(t2 - - / . / ) - - q~(t 1 - /~) ] × Chp + [ q ) ( t 3 - - / / ) - - q ) ( t 2 - - / / ) ] × Cva

[~( t4--#)--q~(t3 - #)]XCca+ [1--q)(t4--/t) ]×Cfe (5)

where q~(/t) = cumulative normal density function; t i - # = distance between mean liability (/t) and fixed threshold ti in units of the standard normal liability scale; Chp, Cva, Cca, Cfe=cost of hard pull, vet. aid, caesarean and fetotomy, respectively;

The incidence of categories is given by q ) ( t i - / t ) -q~ ( t i _~ - / t ) , which is equal to the area between thresholds ti and ti_ ~ under the standard normal density function. Cost of hard pull, veterinary aid, caesarean and fetotomy are linear functions of fixed costs for veterinary fee, increased culling, and reduced milk production and fertility. Calf mortality is included in equation (3).

Partial differentiation of ( 1 ) with respect to a trait x gives the economic value of trait x, when expressed per cow:

1 6"I'd (o~d c~Co~ 1 oNe(_ Nc c~x = ~ x ~x ]+N--~-~-x ILa-Co) (6)

In case of restrictions on input or output at the herd level, one additional unit of trait x might influence Nc. Partial derivatives for milk and fat yield of ( 1 ) under restriction circumstances were given by Van Arendonk and Brascamp (1990). Partial derivatives for protein yield are of similar form as those for milk yield. The equation for multiple restriction on milk yield and fat content (fc) was given by:

Qmf = ( M + F + P) × ( 1 +qfc(fC- fCr) ) for fcr < fc (7)

where Qmf= quota under multiple restriction of milk yield and fat content;


qfc = penalty factor in milk output ( = 18); fc r = reference fat content. If fc r > fc , only a restriction on milk yield was applied. Exceeding the reference level for fat content introduces a scaling of the milk volume (Gibson, 1989) which affects the number of cows in the herd and profit per cow. In case of the multiple restriction it was assumed that fcr < fc.

Partial derivatives for birth weight and mortality expressed per cow are given by (8) and (9):

1 61" Nc ocBW --pn X ( 1 --mortd) Xfns (8)

1 6T Nc 0"BW- - Pn X mortd (9)

Change in birth weight only affects the calves which are sold for beef production while changes in mortality affects all calves born.

The marginal cost of a dystocia liability unit can be calculated as (Meijer- ing, 1986):

(~Cdys c~/t =Chp × ~O(h --/t) -- (Chp --Cva) × ~0(t2 --/~) - (ev a - Cca )

X {0(t3 - - • ) - - (Cca - -Cfe) )< ~0(t4 - - f l ) ( 1 0 )

where {o(/t) is the standard normal density function with mean/t. Equation (10) depends on the dystocia incidence.

Beef production Equations which were used for both veal and beef production are pre-

sented. In this section both veal and beef production will be referred to as beef production. However, as it will be shown later, these two categories differ in the parameter values used.

Total annual profitability of a beef herd (Tb) was described by the following equation:

Tb = --CF:b + Nb X (Rb --Cb ) ( 11 )

where CF:b = fixed costs of total beef herd (Dfl) Nb = number of animals entering per year; Rb = average revenue per animal (Dfl); Cb = average cost per animal (Dfl). The average revenue per animal (Rb) was a function of: mortality during the

DERIVATION OF ECONOMIC VALUES USING PROFIT EQUATIONS 41

fattening period (mortb), dressing percentage (DPb), fixed final weight at slaughter (FWb in kg), and the price of beef (Pb in Dfl/kg):

DPb Rb = ( 1 -- m o r t b ) X ~0-~- X F I~ b XPb ( 12 )

The price of beef (pb) wa s influenced by carcass quality characteristics as will be shown later.

The average costs per animal (Cb) were described by the following equation:

C b = BW X Pn + Cb:b "31- ( 1 - m o r t b ) X Ct:b "Jr ( 1 - a X mortu )

X (Co:b + FCb ) X N F D ( 13 )

where BW=bir th weight of the calf (kg); p ,=pr ice per kg calf (Dfl kg-1 ); %:b = Cost for trading and transport of the calf (Dfl); C,:b = cost for delivery to slaughter house (Dfl); Co:b = average non-feed costs per day per animal (Dfl day- 1 ); FCb = average feed costs per day per animal (Dfl day- l ); a = constant adjusting the average cost per day to account for mortality during the fattening period (0 < a < 1 ), where a = 1 - tm; tm is average time at mortality divided by the length of the fattening period. Assuming that the weight of the calf when it arrives at the beef producer is equal to its birth weight, the number of fattening days (NFD) equals:

N F D - F W b - BW DGb (14)

where DGb is the average daily gain (kg day- 1 ). Average feed costs per animal per day (FCb) were described by the follow-

ing equations:

FCb = ( E M b + E G b ) X Pfb

wxljo.75 -t- B W °'75 EMb = memf×" "" b

2

AFFb × DEWGb X39311 EGb -

kf

ebwfx FWb -- BW DEWGb -

NFD

(15)

(16)

APFb × DEWGb × 23628 ÷ (17)

kp

(18)

where

42 H. BEKMAN AND J.A,M. VAN ARENDONK

EMb=daily energy requirement for maintenance, based on average metabolic weight during the fattening period (kJ ME day- l ); EGD = daily energy requirements for growth (kJ ME day-1 ); pf:b=price of feed for beef production (Dfl kJ ME- l ) ; memf= daily energy requirement for maintenance ~l,~"-T ME kg-75); DEWGD= daily empty body weight gain (kg day-~ ); AFFD = average fat fraction of daily gain; APFD = average protein fraction of daily gain; kf=energy efficiency for fat deposition (MJ NE MJ ME-I) ; kp= energy efficiency for protein deposition (MJ NE MJ ME-1 ); ebwf= ratio of empty body weight over live weight.

Daily empty body weight gain was calculated from the final body weight using ebwf and empty body weight of a week old calf. The latter was assumed equal to its live weight. Relationships of fat or protein fraction and carcass quality traits were ignored.

Partial derivatives per animal for daily gain, mortality, dressing percentage and birth weight are given in the following equations:

1 o~F NFD - ( 1 - aX mortb) X - ~ - b × (Co:b +Pfb × EMdb) (19)

0"DG~ Nb

1 o~F - - - a × N F D × (Co:b + FCdb) +ct:b --FWb ×DPb ×PD (20)

Nb ¢~mortb

1 o~ - - = - ( 1 -mor tb ) ×FWD ×PD (21)

N b o~DPD

1 ~ _ _ p ~ + ( l_a×mor tb )×Co:b+FCdb (22) Nb oeBW DGD

The change in average maintenance requirement due to a change in birth weight is small and is therefore ignored in equation (22).

Price adjustments for carcass quality Beef and veal carcasses are graded for fleshiness and fat covering using the

EUROP-classification (EEC, 1981 ). In addition, veal carcasses are classified for meat colour. Fleshiness and fat covering are scored on a five point scale with 3 subclasses ( + ,0, - ) each. Meat colour is scored using a five point scale with 2 subclasses ( + , - ). For simplicity, only the 5 major classes were considered in this study.

It was assumed that the underlying traits of the EUROP classification scores are normally distributed. Similar to equation (10) the marginal increase in price per unit of a EUROP liability unit was calculated as:


®b 4 (pi -p~+l) ×~o(ti - / t ) (23)

o e E C - i

where Pi= beef price of the ith-category,

( t i - g ) = the height of the ordinate of the standard normal density function with mean g at the threshold point between ith and i+ 1 th category. Equation (23) depends on the distribution over categories and the price differences between categories.

The economic values of a EUROP liability (EC) unit expressed per calf was described as:

1 ORb DP ~Pb Nb oeEC-- ( 1 -- mOrtb) X FVCb X b X ~---- C (24)

The base market price of veal or beef is unrelated to the distribution, but is set for one category. Base beef prices refer to R for fleshiness and 3 for fat covering. Base veal prices refer to R for fleshiness, 3 for fat covering and 3 for meat colour.

PARAMETERS IN THE BASIC SITUATION

Production level parameters used were representative for Dutch Black and White cattle and prices were normalized to the Dutch 1990 price level (Boer- derij, 1990; IKC, 1991; NRS, 1990).

Milk production and dystocia Table 1 gives the parameters for the milk production model which were

used in the basic situation. It was assumed that all calves sold from the dairy herd were males. Table 2 gives frequencies for dystocia and death rates (pmorti, eqn. 3 ), and fixed costs per category. The dystocia category frequencies were calculated from current birth recording data (NRS, 1990). Still- birth frequencies are from Meijering and Van Eldik ( 1981 ).

Beef production Distributions for carcass quality traits are given in Table 3 (PVV, 1990).

Prices given for the categories refer to differences from base prices (R3). The other parameters for beef production are given in Table 4. Empty body weight was assumed to be 0.917 times live weight (Rohr and Daenicke, 1984). The energy requirement for maintenance (memf) was assumed equal to 485 kJ ME per day per kg of metabolic body weight (Korver et al., 1988 ). In a review, Geay (1984) calculated kr and kp values of 0.75 and 0.20, respectively, from 52 published studies, while ARC (1980) gives kp= 0.45. In this study, kp was set equal to 0.25, following Korver et al. ( 1988 ). The average fractions

44

TABLE 1

Levels of variables used in the milk production model

H. BEKMAN AND J.A.M. VAN ARENDONK

Production traits Carrier production (kg cow- l year- 1 ) 6450 Fat production (kg cow- ~ year- L ) 310 Protein production (kg cow- ~ year- 1 ) 240 Birth weight (kg) 42.5 Calf mortality after 24 hours (%) 5 Fraction of calves sold 0.65

Prices Milk carrier (Dfl kg- ~ ) - 0.04 Fat (Dfl kg -1 ) 8.00 Protein (Dfl kg- 1 ) 14.00 Calf (Dfl kg live weight- l ) 9.00 Concentrate (DflMJ N E - 1 ) 0.0555 Rearing cost per heifer (Dfl) 2400 Carcass value per disposed animal (Dfl) 1700 Fixed cost per cow (Dfl year- l ) 1) 1650

Energy requirements Maintenance (MJ NE year- ~ )2) Milk carrier (MJ NE kg- l ) Milk fat (MJ NE kg -1 ) Milk protein (MJ NE kg- 1 )

15695 0.759

41.42 20.71

Sundries Herdlife (year) 4.0 Fat reference level (%) 4.1

) fixed cost per cow were derived from total cost per cow minus feed and dystocia cost per cow in this model. 2) average maintenance, age dependent growth, development of foetus and body-fat mobilization- restorage requirements of a third parity cow, (Groen, 1988).

of fat and protein in empty body weight gain were taken from measurements in Simmental bulls (Ferrell and Jenkins, 1985 ).

Veal production Distributions of carcass quality traits in veal calves are given in Table 3.

Price differences for veal between the categories were not available and were assumed to equal half the differences for fleshiness and fat covering for beef production. Price differences for meat colour were assumed equal to those for fleshiness. Other parameters for veal production are given in Table 4. The ratio of empty body weight over live weight in veal calves was assumed to be 5% higher (0.967) than for beef bulls (0.917 ), since rumen development and tract fill are limited due to the feeding of milk replacer. Energy requirements


TABLE 2

Frequencies (%), calf mortality (%) for six different dystocia classes and costs ( Dfl ) per cow for each class ~

Easy Normal Hard pull Vet aid Caeserean Fetonomy

Frequency (%) 45.50 43.80 7.82 1.24 1.61 0.03 Calf mortality (%) 1.30 2.00 12.60 23.70 0.00 100.00 Cost (Dfl.)

veterinary fee 0 0 6.00 106.50 398.00 361.50 reduced milk 0 0 75.00 75.00 75.00 75.00

yield reduced fertility 0 0 25.00 25.00 25.00 25.00 increased culling 0 0 l 18.00 118.00 118.00 118.00

~) From Meijering (1986).

TABLE 3

Frequency and price levels of carcass quality categories in veal and beef production ( PVV, 1990 )

E/1 U / 2 R/3 0 / 4 P/5

Frequency in veal production (%)

Fleshiness 0.70 6.30 36.40 51.00 4.30 Fat covering 8.50 39.20 48.30 3.90 0.10 Meat colour 5.00 22.10 42.70 22.00 8.20

Frequency in beef production (%)

Fleshiness 2.00 26.00 58.00 14.00 0.00 Fat covering 2.00 38.00 57.00 2.90 0.00

Price difference ( D r kg- J ) in beef production ~'2

Fleshiness 1 . 0 0 0 . 5 0 - - 0 . 5 0 - 1 . 1 0

Fat covering - 0.30 0.05 - - 0.35 - 0.85

1Expressed as difference from price in class R3. 2Price differences for fleshiness and fat covering in veal production were 50% of those in beef production. Price differences for meat colour in veal production were equal to those for fleshiness in veal production.

for maintenance were assumed equal to 460 kJ ME per day per kg of metabolic body weight (Van Es and Van Weerden, 1970). ARC (1980) gives 0.45 as an average value for k o in growing animals. Since the contribution of the rumen in digesting milk replacer is negligible, veal calves can be considered as simple-stomached species. In a review, Webster (1989) summarized for simple-stomached species, a k f value equal to 0.75 and a kp equal to 0.45. Van


TABLE 4

Basic levels of variables used in the model for beef and veal production

Beef Veal

Production Fixed live weight at slaughter (kg) 510 Daily gain (g .day- ~ ) 1045 Dressing percentage (%) 55 Mortality during fattening period (%) 5.5 Av. fat fraction in daily gain (%) 24.0 Av. protein fraction in daily gain (%) 18.0 Average time of mortality ( a ) 0.33

Energy requirement and utilization Maintenance (kJ M E / k g LW °'75) Fat deposition, kf Protein deposition, kp

Prices Meat price (Dfl kg carcass- 1 ) Feed price (Dfl MJ M E - l ) Fixed non-feed cost (Dfl day - ~ ) Delivery cost (Dfl animal- ~ ) Trade cost (Dfl animal- 1 ) Sundry cost (Dfl animal- ~ )

250 1100

65 4.5

16.1 19.0 0.33

485 460 0.75 0.85 0.25 0.45

7.75 10.75 0.034 0.128 0.38 0.35

25.00 15.00 25.00 18.00

190.00 60.00

Es ( 1977 ) showed that kf for veal calves is between 0.75 and 1.0, depending on several factors. In this study, kfwas set at 0.85 and kp at 0.45. The average fractions of fat and protein in empty body weight gain were calculated from data of Haecker (1920) for steers up to 227 kg empty body weight. Jesse et al. (1976) reported similar values for protein and fat in Hereford calves 'in medium condition'.

R E S U L T S

Milk production Table 5 gives the economic values for milk production traits at current price

levels for a free market situation and under various quota systems. Under a milk volume quota system, economic values of milk production traits were Dfl 0.26 lower than in a situation without a quota. This difference is slightly higher than that found by Groen (1989b,c) due to different price and production levels. As expected, fat quota only affected the economic ,~alue for fat yield. In the case of a multiple quota the economic values for milk and fat production were reduced compared to a situation with no quota.


TABLE 5

Economic values (Dfl kg-~ cow-~ year - l ) of milk production traits under free market conditions (Qo), with a herd production quota on milk production (Qm) and fat production (Qf) and with a multiple restriction on milk production and fat percentage (Qmf) 1

Production trait Qo Qm Qf Qmf

Carrier yield - 0.082 - 0.342 - 0.082 - 0.328 Fat yield 5.70 5.44 - 0.17 1.04 Protein yield 12.85 12.59 12.85 12.60

Qmf: multiple quota system (milk volume and fat content, fat ref. = 4.1%).

TABLE 6

Economic values (Dfl kg- ~ ) of carrier, fat and protein production and their sensitivity to changes in price of milk fat (pf) and protein (pp), feed price (Pf:d), herd level of production (milk) and birth weight of calves (BW) under free market conditions (Qo) and with a multiple quota system (Qmf) l)

alternative Carrier Fat Protein

Qo Qmf Q0 Qmf Qo Qmf

base 2 - 0.082 - 0.328 5.70 1.04 12.85 12.60 pf, pp+20% -0 .485 7.30 -0 .36 15.65 15.25

- 20% - 0.170 4.10 2.43 10.05 9.96 Pr:d +20% -0.091 -0 .336 5.24 0.58 12.62 12.38

- 2 0 % -0 .074 -0 .319 6.16 1.50 13.08 12.83 milk +20% -0 .412 -0 .57 12.52

- 20% - 0.201 3.45 12.73 BW + 20%

- 20% - 0.334 0.92 12.60 -0.321 1.16 12.61

t Qmf: multiple quota system (milk and fat content, fat ref. = 4.1% ). 2base = economic values using base parameters.

Table 6 shows the sensitivity of economic values for milk production traits under no quota and multiple quota systems to changes in prices and production levels. Economic values of milk production traits were sensitive to price levels of feed, fat, and protein under both systems. Milk production level had a modest, non-linear effect on the economic value of fat under the multiple quota system (Qmf).

Economic value for birth weight was Dfl 5.40 and was sensitive to calf prices. The value of higher birth weights of female calves kept for dairy replacements was ignored. The economic value of calf mortality at the dairy herd was Dfl - 3.83. The marginal cost of dystocia with the current population parameters for incidence level and calf price were Dfl 59.75. The marginal cost for dys-


tocia were sensitive to calf prices and the incidence level of dystocia, as also demonstrated by Meijering ( 1986 ).

Beef production

Energy requirements. Table 7 shows daily energy requirements for maintenance, and for fat and protein gain for beef and veal production. The beef production model for fattening bulls resulted in energy requirements of 58.2 MJ ME per day. If the energy efficiency for maintenance (km) is set to 0.75 (ARC, 1980), feed conversion (MJ ME/kg daily gain), is calculated to be 33.4. Ten Napel et al. (1987) have reported a similar feed conversion for fattening Black and White bulls, i.e. 32.8. The estimate from the model for the percentage of total ME intake required for maintenance, was 52%. This is similar to what has been reported in the literature (Rohr and Daenicke, 1974; Geay et al., 1974). It can be concluded that the profit equations result in energy requirements which agree closely with practice.

When the beef production equations were applied to veal production, the total energy requirement was 36.7 MJ ME per day of which 50% was used to meet maintenance requirements (Table 7). This total energy requirement agrees closely with current feeding schemes practiced in the veal production industry for the same fattening period and similar daily gain.

Economic values. Table 8 shows the economic values for beef production traits and their sensitivity to changes in production and price levels. The economic value of mortality was mainly influenced by final weight, dressing percentage and beef price. Calf price had a large influence on the economic value for birth weight while the effect of other factors was small. Final weight and av-

TABLE7

Energy requirements in the model for beef bull and veal production

Energy requirement (MJ ME day- t

Beef Veal

Total 58.2 36.7 Maintenance 30.1 18.3 Protein gain 16.2 10.6 Fat gain 12.0 7.9


T A B L E 8

Economic values ( D f l c a l f - 1 ) for beef production traits (unit given between brackets) and their sen-

s i t i v i t y to changes in production and price levels ~'2)

Alternative M O R T B W D P D G

( % ) ( k g ) ( % ) (g /day)

base a - 1 8 . 2 0 - 6 . 9 1 3 7 . 3 5 0 . 5 8 8

B W + 2 0 % - 18 .23 - 6 .89 0 . 5 8 8

- 2 0 % - 18 .17 - 6 . 9 2 0 . 5 8 8

F W + 2 0 % - 2 1 . 5 9 - 6 . 7 8 4 4 . 8 2 0 . 7 8 8

- 2 0 % - 14 .73 - 7 .04 2 9 . 8 8 0 . 4 1 1

D P + 2 0 % - 2 2 . 5 5

- 2 0 % - 13 .85

m o r t + 2 0 % - 6.91 3 6 . 9 2 0 . 5 8 6

- 2 0 % - 6 . 9 0 3 7 . 7 9 0 . 5 9 0

D G + 2 0 % - 18.51 - 7 . 1 1 0 . 4 0 8

- 2 0 - 17 .73 - 6 . 6 1 0 . 9 1 9

p , + 2 0 % - 8 . 7 1

- 2 0 % - 5 . 1 1

Pb + 2 0 % - 2 2 . 5 5 4 4 . 8 2

- 2 0 % - 13 .85 2 9 . 8 8

Pf:b + 2 0 % - 17.61 - 6 .53 0 . 6 8 2

- 2 0 % - 18 .78 - 7 . 2 8 0 . 4 9 4

1when no values are presented, the economic values did not differ from those in the base situation. 2 B W = birth weight; F W = final weight; D P = dressing percentage; mort = mortality; D G = daily gain; Pn = c a l f p r i ce ; l h , = p r i c e of beef; Pf:b = p r i c e of feed for beef production. abase = economic values using base parameters.

erage daily gain, and to a lesser extent feed price, had strong influences on the economic value for daily gain. The economic value of daily gain showed a non-linear change with changes in birth weight, final weight and average daily gain.

Table 9 gives the economic values for fleshiness and fat covering of beef bull carcasses. The economic value for fat covering was relatively low due to a close to optimum distribution of slaughter animals over EUROP fat categories (Table 3).

The economic values for veal production traits and their sensitivity to changes in production and price levels are given in Table 10. Compared to beef production traits, absolute economic values were lower for mortality, birth weight, dressing percentage and daily gain. Economic values in veal calves were sensitive to the same factors as those in beef but absolute differences were smaller in most cases. Table 11 gives the economic values for carcass quality traits in veal production. The economic value for fleshiness was lower than in beef production due to lower price differences between categories. Fat covering at final slaughter weight was almost optimum (Table 3 ).


TABLE 9

Economic values (Dfl ca l f - t ) for f leshiness and fat covering liabilities in beef product ion and their sensi t ivi ty to changes in pa ramete r s ~ )

F leshiness Fat covering

Base z 81.07 7.39 D P , F W + 2 0 % 97.28 8.86

- 2 0 % 64.86 5.91 M O R T + 2 0 % 80.12 7.30

- 2 0 % 82.01 7.47 Pi--Pi+l + 2 0 % 97.28 8.86

- 2 0 % 64.86 5.91 m e a n + 0 . 1 a 81.63 5.27 liab, - 0 . 1 a 60.51 9.51

D P = d r e s s i n g percentage; F W = f i n a l weight; M O R T = m o r t a l i t y Pi-Pi+~ = price difference for f leshiness and fat covering, respectively. 2 base = base p roduc t ion and price level.

dur ing fat tening period;

TABLE 10

Economic values (Dfl ca l f - ~ ) for veal p roduc t ion t rai ts and their sensi t ivi ty to changes in p roduc t ion and price levels t,2

Al ternat ive M O R T BW DP D G (%) (kg) (%) ( g / d a y )

base 3 - 14.22 - 4 . 5 9 25.67 0.452 BW + 2 0 % - 14.31 - 4 . 5 3 0.447

- 2 0 % - 14.14 - 4 . 6 5 0.456 F W + 20% - 16.76 - 4.34 30.80 0.620

- 2 0 % - 11.60 - 4 . 8 5 20.53 0.306 D P + 2 0 % - 17.72

- 2 0 % - 10.73 M O R T + 20% - 4.60 25.42 0.451

- 20% - 4.57 25.90 0.454 D G + 2 0 % - 14.49 - 4 . 9 7 0.314

- 2 0 % - 13.82 - 4 . 0 1 0.707 Pn + 2 0 % - 6 . 3 9

- 2 0 % - 2 . 7 9 Pb + 20% - 17.72 30.80

- 2 0 % - 10.73 20.53 Pf:b + 2 0 % -- 13.64 - -3 .75 0.535

-- 20% -- 14.81 -- 5.43 0.370

when no values are presented, no changes in economic values f rom the base s i tua t ion occurred. 2 BW = bir th weight; F W = final weight; D P = dress ing percentage; mor t = mortal i ty; D G = daily gain; Pn = calf price; Pb = price o f veal; Pr:b = price o f feed for veal product ion. 3 base = economic values us ing base parameters .


TABLE 11

Economic values (Dflcalf- ~ ) for fleshiness, fat covering and meat colour liabilities in veal production and their sensitivity to changes in parameters ~

Fleshiness Fat covering Meat colour

Base 2) 26.48 0.055 37.44 DP,FW + 20% 31.77 0.066 44.92

- 20% 21.18 0.044 29.95 MORT + 20% 26.23 0.055 37.08

- 20% 26.73 0.056 37.79 P i - Pi+ 1 + 20% 31.77 0.066 44.92

-- 20% 21.18 0.044 29.95 mean liab. +0.1tr 26.86 -0 .99 37.17

- 0 . 1 a 26.12 1.11 37.65

~DP=dressing percentage; FW=final weight; MORT=mortal i ty during fattening pi+ ~ = price difference for fleshiness and fat covering, respectively. 2base = base production and price level.

period; Pi-

The economic value for meat colour of veal calves was higher than the economic value for fleshiness.

DISCUSSION

Energy requirements Applying the present beef production model requires knowledge about av-

erage daily gain in protein and fat, and about energy efficiency rates for protein and fat gain (eqn. 17). Fat gain is the main source of variation in energy requirements between breeds and sexes (Robelin and Daenicke, 1980). Among others, Ferrell and Jenkins ( 1985 ) have found differences for energy utilisation in cattle between breeds and sexes. However, using the parameters for the Black and White breed (Table 4), the energy requirements (Table 7 ) showed close agreement with practise. Assuming all calves sold from the dairy herd are male affects economic values of beef production traits, because female animals have lower daily gain and final weight, but a higher proportion of fat. However, in an optimum production system, female calves are only produced for milk production and beef production is based on male calves only.

In the model different energy efficiency factors (kp and k f ) for veal and beef production were used. A difference in energy efficiency factor for maintenance (km) was not included. Ketelaars and Tolkamp (1991) suggested that an increase in the efficiency for growth (1%) is counteracted by a decrease in km. If this hypothesis is true, veal calves have lower net energy requirements for maintenance than beef bulls per kg metabolic weight. Andersen

5 2 H. BEKMAN AND J.A.M. VAN ARENDONK

( 1978 ) showed that km differed between breeds and accounts for part of the differences in feed utilization between breeds. Genetic variation exists within breed in feed conversion (Jensen et al., 1991; Van Veldhuizen et al., 1991 ). However, it is not clear to what extent this is caused by a reduction of the relative importance of energy requirement for maintenance at a higher daily gain or by difference in feed utilization for the different processes. In the current study the efficiency of feed utilization (km, kp and kf) was assumed constant for all animals. Economic weights for these factors can be derived from the equations given.

To calculate the energy requirement for daily gain the average fat and protein fraction of daily gain have been used. As a result of this changes in daily gain could be related directly to changes in energy requirements. Little however is known about the relation between carcass quality traits and the composition of growth. The composition of growth has not been changed in this study and consequently changes in carcass quality are not related to differences in energy requirement.

Economic values The economic values for milk were different from those found by Groen

(1989b,c). Part but not all of the difference was due to differences in production levels and prices. In this study energy requirement increased linearly with production level and additional energy requirements were covered by concentrate intake. Groen (1989b,c) used a non-linear model for calculating the monthly energy requirements (Groen, 1988 ) and additional energy requirements were partly covered increased intake of roughage. These factors ex- plained the remaining difference in level of economic values. The effect of a milk volume quota (Qm) on economic values, however, was of nearly the same magnitude as that observed by Groen (1989b,c).

The multiple quota system behaved like a mixture of Qm and Qf as demonstrated by Gibson (1989) and Van Arendonk and Brascamp (1990). The economic value for carder tends towards the economic value for carrier under milk volume quota (Qm), when fc is near fCr. The economic value for fat yield is close to that under Qv when fc is above fCr, but increases when fc moves towards fCr.

Increased levels of dystocia decreased the income of dairymen. Although higher birth weight had direct positive effect on net revenue from the sale of the calf, it affects net revenue negatively by an increase in dystocia levels (Meijering, 1986). If only birth weight or only dystocia is included in the breeding goal, the economic consequences of changes in the other trait should be taken into account in calculating economic values.

The economic value of birth weight was positive for dairy farmers (Dfl 5.40.cow -~) and negative for veal (Dfl -4 .59.calf -~) and beef (Dfl


- 6.91 .calf- l ) producers. Besides breed and sex characteristics, the value of young calves is mainly based on weight. At a constant level of dystocia, higher birth weights were beneficial for the dairy farmer. However, the average price per kg of a calf was higher than the cost for producing a kg of weight gain in the fattening herd and this caused the negative values for birth weight for veal and beef producers. Future pricing systems for young calves should better reflect the interests of both dairy and beef producers.

In the models used, the economic values for milk production traits and dystocia are expressed per cow, while economic values for veal and beef production are expressed per calf entering the beef herd. For the breeding goal, economic values of beef and milk production traits have to be expresssed at the base. For the beef production traits the fraction of calves sold from the dairy herd (Table 1 ) needs to be separated in fraction of calves entering the veal and beef herd, respectively. In addition, beef and milk production traits can be weighted using discounted expressions calculated with the geneflow method (Brascamp, 1978). Beef crossing or the use of embryo sexing will influence the number of dairy calves sold for beef production. These aspects should be included in calculating the number of discounted expressions (Cunningham and McClintock, 1974 ).

In the current study economic weights for dairy cows have only been calculated for milk production traits, birth weight and dystocia. In addition the economic efficiency of the dairy cow depends on feed costs and carcass value of culled cows. Feed costs associated with differences in milk production traits have been accounted for in equation (4). Selection for milk and beef production is expected to result in a correlated response in body weight of the cows (Robertson, 1973; Andersen, 1978; Haapa and Syv~iv~irvi, 1987; Van Aren- donk et al., 1992 ). Groen (1989b) found a negative economic value for mature weight ( -0.92 Dfl kg-lcow-1year-1 ) which originated from increased energy requirement for raising female replacements, increased energy requirements for lactating cows and increased carcass value of culled cows. In determining the optimal strategy for selection on milk and beef production traits the consequences for body weight of lactating cows have to be accounted for.

ACKNOWLEDGEMENTS

The authors wish to thank Aalt Dijkhuizen, Kor Oldenbroek and Jack Dek- kers for their helpful suggestions and comments and the Dutch Product Board for Livestock and Meat for financial support.

REFERENCES

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ARC, 1980. The nutrient requirements of ruminant livestock. Commonwealth Agricultural Bureaux, Agricultural Research Council, Washington, DC.

Boerderij, 1990. Weekblad voor de landbouw. Jrg 77-78. Misset, Doetichem. Brascamp, E.W., 1978. Methods on economic optimization of animal breeding plans. Report

B - 134, Research Institute for Animal Production "Schoonoord", Zeist, The Netherlands, 117pp.

Cunningham, E.P. and A.E. McClintock, 1974. Selection in dual-purpose populations: effect of beef crosses and cow replacements rates. Ann. Genet. Sel. Anim., 6:227-239

Danell, O. and K. R~nningen, 1981. All-or-none traits in index selection. Z. Tierz. Tierzgsbiol., 98: 265-284.

EEC, 1981. Community scale for the classification of carcasses of adult bovine animals. Reg. (EEC) No 1208/81, Reg. (EEC) No 2930/81.

Ferrell, C.L. and T.G. Jenkins, 1985. Energy utilization by Hereford and Simmental males and females. Anim. Prod., 41: 53-61.

Geay, Y., J. Robelin and R. Jarrige, 1974. Variations des quantit6s d'energie, de prot6ines et de lipides flx6es dans la carcasse par les jeunes taureaux h l'engrais. Proc. 6th symposium on energy metabolism, EAAP-publ., 14:139-142.

Geay, Y., 1984. Energy and protein utilization in growing cattle. J. Anim. Sci., 58: 766-778. Gibson, J.P., 1989. Economic weights and index selection of milk production traits when mul-

tiple production quotas apply. Anim. Prod., 49:17 i - 181. Groen, A.F., 1988. Derivation of economic values in cattle breeding. A model at farm level.

Agric. Sys., 27: 195-213. Groen, A.F., 1989a. Cattle breeding goals and production circumstances. PhD-thesis, Wagen-

ingen Agricultural University, The Netherlands, 167 pp. Groen, A.F., 1989b. Economic values in cattle breeding. I. Influences of production circumstan-

ces in situations without output limitations. Livest. Prod. Sci., 22: 1-16. Groen, A.F., 1989c. Economic values in cattle breeding. II. Influences of production circum-

stances in situations with output limitations. Livest. Prod. Sci., 22:17-30. Haapa, M. and J. Syv~iv~irvi, 1987. Relationship for growth and intake between young bulls and

daughters. In: S. Korver, G. Averdunk and B.B. Andersen (Editors), Performance Testing of AI bulls for Efficiency and Beef Production in Dairy and Dual Purpose Breeds. EAAP Publication No. 34. Pudoc, Wageningen, The Netherlands, pp. 99-102.

Haecker, T.L., 1920. In: Berg, R.T. and R.M. Butterfield (eds.), 1976. New concepts of cattle growth. Sydney University Press, 240 pp.

IKC, 1991. Informatie en Kennis Centrum Veehouderij. Kwantitatieve informatie veehouderij 1991-1992. Publikatie nr 6. Lelystad.

Jensen, J., I.L. Mao, B.B. Andersen, and P. Madsen, 1991. Genetic parameters of growth, feed intake, feed conversion and carcass composition of dual-purpose bulls in performance testing. J. Anim. Sci., 69: 931-939.

Jesse, G.W., G.B. Thompson, J.L. Clark, H.B. Hedrick and K.G. Weimer, 1976. Effects of ration energy and slaughter weight on composition of empty body and carcass gain of beef cattle. J. Anim. Sci., 43: 418-425.

Ketelaars, J.J.M.H. and B.J. Tolkamp, 1991. Toward a new theory of feed intake regulation in ruminants. PhD-thesis, Wageningen Agricultural University, The Netherlands, 253 pp.

Korver, S., M.W. Tess and T. Johnson, 1988. A model of growth and growth composition for beef bulls and bulls of different breeds. Agric. Sys., 27: 279-294.

Meijering, A., 1986. Dystocia in dairy cattle breeding. With special attention to sire evaluation for categorical traits. PhD-thesis, Wageningen Agricultural University, The Netherlands, 179 pp.

Meijering A. and P. van Eldik, 1981. Proefprojekt geboorteregistratie. IVO-rapport B - 165. NRS, 1990. Personal communication.


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weight, liveweight gain, breed and sex. Ann. Zootech., 29, n ° h.s., 99-118. Robertson, A., 1973. Growth rate, appetite, body composition and efficiency. Proceeding of

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KURZFASSUNG

Bekman, H. und van Arendonk, J., 1993. Herleitung 6konomischer Gewichte fur Merkmale der Fleischproduktion beim Kalb und Rind sowie fiir die Milchleistungsmerkmale fiber Gewinn- funktionen. Livest. Prod. Sci.,34: 35-56, aufenglisch.

In dieser Untersuchung wurden Gewinnfunktionen fiir die Milch-, Mastk~ilber- und Mastbul- lenproduktion aufgestellt, um 6konomische Gewichte fiir verschiedene Merkmale zu erhalten. Ffir die K~ilber- und Mastbullenproduktion wurden dabei die t~iglichen Zunahmen in Fett- und Proteinzuwachs beschrieben. Bei kategorischen Merkmalen, der Schwerkalbigkeit und der Schlachtk6rperqualit~it, wurde bei der Herleitung der ~Skonomischen Gewichte eine kontinuier- liche Variable unterstellt. Die Parameter der Gewinnfunktionen wurden so gew~ihlt, dab sie die Situation der holl~indischen Schwarzbunten widerspiegeln; Sie k~Snnen j edoch ge~indert werden, um andere Rassen oder Produktionsverh~iltnisse zu berficksichtigen. Die Auswirkungen sich ~indernder Produktionsverh~iltnisse in der Rindfleischproduktion auf die Gr6Be und das aus- gewachsene Gewicht der Milchkfihe werden in dieser Arbeit diskutiert aber nicht in die tikon- omischen Gewichte einbezoqen.

Ohne Produktionseinschr~inkungen betrugen die 6konomischen Gewichte fiir Milch-, Fett- und Eiweil3menge -0 .082, 5.70 bzw. 12.85 Dfl. pro kg. Unter einer gemeinsamen Beschr/in- kung der Milchmenge und des Fettgehalts auf den Herdendurchschnitt ~inderten sich die 6kon- omischen Gewichte auf -0 .328. 1.04 bzw. 12.60 Dfl. pro kg. Der 6konomische Wert fiir die KWbersterblichkeit lag bei - 3.83 Dfl. j e% und die Kosten f'tir Schwerkalbigkeit betrugen 59.75 Dfl. pro Kuh und Einheit auf tier angenommenen Skala der Liabilit~it. Die 6konomischen Gew- ichte t'fir das Geburtsgewicht waren 5.40 Dfl. pro kg fiir Milchviehhalter, - 4 .59 Dfl. pro kg ftir Kalbfieischproduzenten und - 6.91 Dfl. pro kg ftir Bullenm~ister. Die iSkonomischen Gewichte in der Kalbfleischproduktion waren 0.45 Dfl f'fir t~igliche Zunahmen (g/Tag), 25.67 fiir die


Ausschlachtung (%), - 14.22 beim Verenden (%), 26.48 ftir die Fleischigkeit, 0.06 ftir die Fet- tabdeckung und 37.44 ftir die Fleischfarbe. In der Mastbullenproduktion wurden folgende Werte gefunden: 0.59 Dfl. fiir t~igliche Zunahmen, 37.35 ftir Ausschlachtung, - 18.20 ftir Sterblichkeit, 81.07 ftir die Fleischigkeit und 7.39 ftir die Fettabdeckung.

Untersuchungen fiber die Empfindlichkeit der 6konomischen Gewichte gegeniiber Anderun- gen von Preisen oder Produktionsbedingungen zeigten, dab sich zukfinftige ~Skonomische Werte mit dem Produktionsniveau oder den Preisen ~indern k6nnten.

Documents

Derivation of economic values for veal, beef and milk production traits using profit equations