Livestock Production Science 62 1999 29–41 www.elsevier.com locate livprodsci
Feeding intensity of pregnant heifers Effect of feeding intensity during gestation on performance and
plasma parameters of primiparous Ayrshire cows
a , b
a
¨ P. Mantysaari
, K.L. Ingvartsen , V. Toivonen
a
Agricultural Research Centre , Animal Production Research, FIN-31600 Jokioinen, Finland
b
Danish Institute of Agricultural Sciences , Department of Animal Health and Welfare, Research Centre Foulum, P.O. Box 50,
DK- 8830 Tjele, Denmark
Received 3 September 1998; received in revised form 22 February 1999; accepted 15 March 1999
Abstract
The effect of different feeding intensity at two stages of gestation on performance of primiparous cows was studied in 40 pregnant Ayrshire cows. The feeding intensity was either medium M or high H in period 1 2–6 months of pregnancy or
period 2 7–9 months of pregnancy resulting in treatments MM, MH, HM and HH. Before pregnancy all heifers were reared to gain 650 g day. In period 1, heifers on H feeding intensity, grew significantly faster than heifers on M 844 vs. 638
g day; SEM 5 18.9. Daily gains in period 2 were affected by feeding intensity in period 1 and were 710, 1042, 636 and 874 g on MM, MH, HM, and HH diets, respectively. The body weights at calving were 462, 498, 480 and 499 kg on MM, MH,
HM and HH diet, respectively. Feeding intensity in period 1 had no effect on milk production, but H plane of nutrition in period 2 increased milk yield by approximately 11 22.6 vs. 20.3 kg day, P , 0.004. Medium feeding intensity in period
1 increased postpartum DMI, and decreased postpartum mobilization of body reserves. Mobilization was positively correlated with BCS at calving r 5 0.48; P , 0.003 and with plasma free fatty acid r 5 0.73; P , 0.0001 and
b-hydroxybutyrate concentrations r 5 0.69; P , 0.0001. Prepartum treatments had no effect on postpartum plasma growth hormone GH or prolactin concentration, but high feeding intensity in period 2 decreased insulin INS concentration
postpartum. No relationships were found across treatments between milk yield and prepartum plasma hormone con- centrations, but a positive correlation was found between milk yield and postpartum GH and GH INS. The results show that
high compared with medium feeding intensity during the first two trimesters of gestation does not improve milk production of primiparous cows. Instead, during the last trimester a high feeding intensity is required for maximum milk yield.
1999 Elsevier Science B.V. All rights reserved.
Keywords : Feeding during gestation; Feeding intensity; Milk yield; Plasma parameters; Primiparous cows
1. Introduction
Feeding intensity during gestation can influence
Corresponding author. Tel.: 1358-3-41881; fax.: 1358-3-
milk producing ability of primiparous cows by
4188-3661. ¨
E-mail address : paivi.mantysaarimtt.fi P. Mantysaari
affecting calving body weight BW, mobilizable
0301-6226 99 – see front matter
1999 Elsevier Science B.V. All rights reserved. P I I : S 0 3 0 1 - 6 2 2 6 9 9 0 0 0 5 5 - X
¨ 30
P . Mantysaari et al. Livestock Production Science 62 1999 29 –41
body reserves MBR, and mammary growth and The purpose of the present experiment was to
development. Many studies have shown that the first study the effect of high prepartum feeding intensity
lactation milk yield correlates positively with BW at at different stages of pregnancy on milk production,
calving Clark and Touchberry, 1962; Ingvartsen et feed intake and plasma hormone concentrations and
al., 1988; Foldager and Sejrsen, 1991. However, a metabolites of primiparous Ayrshire cows.
high plane of nutrition during gestation has often failed to increase milk production of primiparous
cows Ducker et al., 1985; Valentine et al., 1987;
2. Material and methods
Lacasse et al., 1993; Grummer et al., 1995; Ingvar- tsen et al., 1995a. The degree and duration of high
2.1. Animals and diets feeding level and also the plane of nutrition before
gestation are likely to be important for these results. Forty pregnant Finnish Ayrshire heifers were
Foldager and Sejrsen 1991 reported an increase in blocked by due date three blocks and assigned
mammary development and milk production when randomly to one of four treatments on their fourth
prepartum 325 kg BW to calving daily gain week of gestation. The gestation was divided into
increased from 400 to 600 g. A further increase in two periods: months 2–6 period 1 and months 7–9
daily gain 800 g day did not improve milk pro- of pregnancy period 2; the last trimester. During
duction further. In other studies, a high feeding period 1, one half of the heifers had the medium M
intensity during the last 6, 12 or 24 weeks before and the other half high H plane of nutrition. In
calving had no effect on milk yield Foldager and period 2, half of the heifers on both planes of
Ingvartsen, 1995. A high feeding intensity for 24 nutrition were changed to the other plane of nutri-
weeks was, however, associated with decreased tion. Thus, the treatments were MM, MH, HM and
postpartum feed intake which is in accordance with HH.
Grummer et al. 1995 who also found negative Before breeding all heifers were treated the same
effect of high prepartum feeding intensity on dry and reared to gain 650 g day. During gestation the
matter intake DMI with no change in milk pro- heifers were fed grass silage, barley, and mineral and
duction. vitamin supplements to meet the requirements for
Stair-step feeding high feeding intensity follow- 650 and 850 g daily gain on M and H plane of
ing lower of pregnant heifers has been reported to nutrition, respectively. The amount of barley varied
increase milk yield postpartum Park et al., 1987, according to weight from 0.5–1.00 kg day on M and
1989; Choi et al., 1997. Furthermore, stair-step from 1.75 to 2.25 kg day on H plane of nutrition.
feeding increased the differentiation and functional All heifers received the same concentrate mix for the
activity of the mammary glands Park et al., 1989; last 2 weeks before due date. The concentrate mix
Choi et al., 1997 which, at least in part, may explain which included 318 g kg barley, 318 g kg oats, 180
differences in milk yield. A possible explanation for g kg rapeseed meal, 150 g kg molassed sugar beet
enhanced mammary differentiation and milk pro- pulp, and 34 g kg minerals and vitamins was given
duction measured in the compensatory growth pat- in an increasing amount and reached 5 kg day at
tern associated with stair-step rearing are the changes parturition. After parturition the amount of concen-
in hormone secretion and enzymatic activities Park trate mix was increased to 7.5 kg day over a period
et al., 1988, 1989. Furthermore, Stelwagen et al. of 1 week and was kept constant until 160 days of
1992 showed that bGH injection during the last lactation. From 2 weeks before parturition and for
trimester increases the milk production. This is the rest of the experimental period postpartum
supposed to be due to an increase in mammary heifers were offered grass silage ad libitum.
parenchymal cell number Stelwagen et al., 1992. However, the effect of changing feeding intensity
2.2. Measurements and sampling during gestation in heifers on plasma hormone
concentrations and
subsequent milk
yield of
During periods 1 and 2 live weight, heart girth, primiparous cows has not been thoroughly investi-
wither height, body length from the point of the gated.
shoulder to the pinbone, hip width, and body
¨ P
. Mantysaari et al. Livestock Production Science 62 1999 29 –41 31
condition score BCS; from 1 5 skinny to 5 5 very analysed with KONE Specific autoanalyser accord-
fat; Lowman et al., 1976 of the heifers were ing to Hansen and Freier 1978.
recorded every fourth week. The calving BW was Hormones were analysed with double antibody
measured on calving day or the day after. BW of radioimmunoassays. For the assays of GH and PRL
calves were measured on the day of birth. During bovine GH antigen AFP11182B and bovine PRL
lactation cows were weighed once a week and BCS antigen AFP4835B were separately iodinated with
were recorded at the end of the experiment day 160 the iodogen method Salacinsku et al., 1981. First
of lactation. antibodies
used were
NIDDK-anti-oGH-2 Individual feed intakes were recorded daily
AFPC0123080 and
NIDDK-anti-bPRL-2 through out gestation and lactation periods. Daily
AFP753180. Second antibody in both assays was samples of each feed were composited to give a
anti-rabbit IgG Sigma R-0881. As standards 4-week sample for proximate and NDF analysis. The
USDA-bGH-B-1 AFP-5200 and bPRL, BIO AFP- chemical composition of feeds is given in Table 1.
7170E were
used. INS
was measured
with Milk yields were recorded daily and milk protein,
Phaseseph Insulin RIA Pharmacia Diagnostics, fat, and lactose were analyzed once a week.
Uppsala, Sweden. The recommended procedures Blood samples were taken from each animal from
accompanying the above mentioned hormones, anti- the coccygeal vein at 35, 28, 21, 16, 12, 8 and 4 days
bodies and the insulin kit were followed. before due date and 0, 1, 3, 7, 14, 21, 28, 35, 42, 56,
Inter-assay variation for hormone measurements 84 and 112 days postpartum. Blood was collected in
was included in the block effect and, therefore, does heparinized tubes and stored on ice until centrifuged
not influence the comparisons. Intra-assay variation at 2 48C for 15 min at 2000 3 g. Blood for b-
for GH, PRL, and INS were 4.4, 5.6 and 5.8, hydroxybutyrate BHBA analysis was precipitated
respectively. Intra- and inter-assay variation were 6.0 with HClO
and centrifuged. Plasma and HClO and 9.1 for free fatty acids FFA, 2.3 and 3.8 for
4 4
precipitated blood samples were frozen and stored at BHBA and 2.0 and 3.9 for glucose, respectively.
2 208C for later analysis of glucose, free fatty acids FFA, growth hormone GH, prolactin PRL, and
2.3. Calculations and statistical analyses insulin INS. Glucose was analysed using Peridoch-
rom GOD-PAP glucose kit Boehringer Mannheim, Metabolizable energy ME values of the feeds
Germany and FFA using an analytical kit Waco were calculated according to MAFF MAFF, 1975.
Pure Chemical Industries which was optimised to The digestibility coefficients of the feeds were from
TM
conditions for an Opera autoanalyser. BHBA was
the feed tables by Tuori et al. 1996. Every 4-week
Table 1 Chemical composition of the feeds fed during gestation and lactation
Gestation Lactation
a
Grass silage Barley
Grass silage Concentrate
n 18
12 22
10 DM g kg
228.5620.1 886.060.3
239.9631.3 886.963.2
In DM g kg Ash
6.760.5 2.660.2
7.760.9 7.760.2
Crude protein 14.061.5
13.260.9 13.961.2
16.560.5 Crude fibre
33.061.3 5.360.4
29.364.2 10.160.4
Ether extract 4.360.3
2.360.1 4.560.3
3.560.2 NDF
61.061.7 22.561.7
55.865.6 28.161.4
b
ME MJ 10.760.4
13.260.1 10.760.5
12.060.04
a
A mix of barley 318 g kg, oats 318 g kg, rapeseed meal 180 g kg, molassed sugar beet pulp 150 g kg and minerals and vitamins 34 g kg.
b
ME is calculated according to MAFF 1975.
¨ 32
P . Mantysaari et al. Livestock Production Science 62 1999 29 –41
weights before parturition and 1-week weights after y
5 m 1 P1 1 P2 1 P 3 P 1 B 1 Anr
ijklmn i
j 1
2 ij k
l
parturition were used to compute growth curves 1 S
1 T 1 T 3 P 1 T 3 P
ijklm n
1 ni 2 nj
using a cubic function on time for each animal. From 1 T 3 P 3 P
1 e ,
the individual growth curves, initial and final weights
1 2 nij
ijklmn
in periods 1, 2, and lactation were predicted and used where P1 , P2 , S
and T are as described in the
i j
ijklm n
in the statistical analyses. Energy value of weight previous models, Anr is the fixed effect of assay
l
gain during pregnancy EV , MJ kg was calculated
g
number. Anr was included in the analyses of
l
from the ME above maintenance and activity using hormones. For plasma data no interactions were
the efficiency of utilization of ME for growth k 5
f
found. Therefore, only the main effects P1 , P2 and
i j
0.78q 1 0.006. Requirement of ME for maintenance T were tested.
n
and activity was calculated using equations proposed The body weight change during lactation as well
by AFRC 1993. One heifer on HM and one on HH as energy and protein efficiency were analyzed from
treatment gave birth to a stillborn about 2.5 months the combined data of each cow. The following model
before due date. Data from these two heifers were was used:
excluded. Feed intake, growth, and body measure- y
5 m 1 P1 1 P2 1 P1 3 P2 1 b
BWI ment data of the heifers during gestation were
ijk i
j ij
BWI k
analyzed using the GLM procedure SAS , 1987. 1 e ,
ijk
The full model was: where P1 and P2 are as described in the previous
i j
y 5
m 1 P1 1 P2 1 P1 3 P2 1 B 1 e ,
ijk i
j ij
k ijk
model, b is the linear effect of the pedigree index
BWI
for BW BWI . The BWI was included only in the where P1 is the fixed effect of plane of nutrition in
k k
i
analysis of BW data. The relationship between period 1; P2 the fixed effect of plane of nutrition in
j
production measurements and circulating mean plas- period 2; B is the fixed effect of block; terms P2
k j
ma metabolite concentrations were described by and P1 3P2 were not included in the analyses of
i j
Pearsons correlations calculated across individuals data from period 1. In period 2 data no interaction
across treatments. between periods 1 and 2 was found, therefore, only
the main effects P1 and P2 were considered.
i j
Production and feed intake data during lactation
3. Results and discussion
