A E El-Tayeb and A G. Takla
Department of Animal Nutrition
Institute of Animal Production
University of Khartoum
PO Box 32, Khartoum North, Sudan
ABSTRACT
Holstein-Friesian heifers were used to study the effect of nutrition in late pregnancy on early lactation performance. Before calving heifers were fed 10 kg Sudan grass (Sorghum sudanense) per head per day, supplemented with 6 kg concentrate supplement for 43 days (treatment 1); 6 kg concentrate for 60 days (treatment 2); or 8 kg concentrate for 60 days (treatment 3). During the early lactation period all the animals were fed 10 kg Sudan grass per day plus concentrate ad libitum.
Average daily liveweight gains during the steaming-up period were not different (P>0.05) among treatments. The level of concentrate feeding affected (P<0.05) calf birth weight; calves born to heifers on treatments 2 and 3 were 7 and 8% heavier, respectively, than those born to heifers on treatment 1. No differences (P>0.05) were observed among the treatment groups in average daily gain after calving or in milk fat percentage. However, heifers on treatment 3 produced more milk than those on treatment 1.
RESUME
Performances post-partum de génisses croisées Holstein x race frisonne alimentées avant le vêlage avec du fourrage de sorgho fourrager (Sorghum sudanense) complémenté avec des concentrés
L'effet régime alimentaire vers la fin de la parturition a été étudié sur les performances de lactation post-partum de génisses métisses Holstein x race frisonne. Avant le vêlage, le régime alimentaire des animaux était composé de 10 kg de fourrage par jour complémenté soit avec 6 kg de concentrés par jour et par animal pendant 43 jours (traitement 1) ou 60 jours (traitement 2) soit avec 8 kg de concentrés pendant 60 jours (traitement 3). Au début Je la lactation, le régime alimentaire était constitué de 10 kg de sorgho fourrager par jour complémenté avec des concentrés ad libitum.
Les traitements n'avaient aucun effet significatif (P>0,05) sur les gains moyens quotidiens enregistrés avant la parturition. En revanche, ils avaient une influence significative (P<0,05) sur le poids des veaux à la naissance: ceux nés de femelles préalablement soumises aux traitements 2 et 3 pesaient respectivement 7 et 8% de plus que ceux dont la mère avait été soumise au traitement 1. Par ailleurs, le type de ration n'avait d'effet ni sur les gains moyens quotidiens post-partum, ni sur le taux butyreux du lait produit. Toutefois, la production de lait des animaux préalablement soumis au traitement 3 était supérieure à celle des autres génisses.
INTRODUCTION
Many tropical and subtropical countries are importing exotic breeds of dairy cattle or up-grading local types in an attempt to meet the local demand for milk and milk products. However, imported animals rarely achieve the levels of production that they show in their original habitats. Nutrition seems to be the major factor limiting the productive and reproductive performance of such animals.
Management practices in the tropics nominally emphasise nutrition of milking cows and neglect, to some extent, nutrition of heifers and dry cows. Therefore, the aim of this work was to study the effects of feeding period and level of concentrate supplements in late pregnancy on post-calving performance of Holstein-Friesian heifers.
MATERIALS AND METHODS
The study used 18 in-calf heifers (liveweight 320-420 kg: average 359 kg) born in Sudan to Holstein-Friesian cows imported as in-calf heifers in October 1984. Because the experimental animals were selected randomly from a large herd which was housed and managed as one group, they were given one week to adapt to the experimental handling. They were then blocked, according to liveweight, into three groups, of six animals each. All animals were fed a daily ration of 10 kg Sudan grass (Sorghum sudanense) and, in addition, the groups were randomly assigned to three dietary treatments:
· Group 1: 6 kg concentrates/head per day for 43 days pre-calving
· Group 2: 6 kg concentrates/head per day for 60 days pre-calving
· Group 3: 8 kg concentrates/head per day for 60 days pre-calving
All the animals were housed and fed individually.
The forage was offered in one meal at 1300 hours and concentrates were offered in two meals at 0800 and 1700 hours; the compositions of the feed ingredients are shown in Table 1.
After calving all animals were group fed 10 kg Sudan grass per head per day plus concentrates ad libitum.
Animals were machine-milked every 12 hours, at 0400 and 1600 hours; milk yield was recorded at each milking. Milk samples were collected once a week and tested for butter-fat content by the Gerber method.
Liveweight changes during the pre- and post-calving periods were assessed by weighing each animal once a week at 0700 hours, before the morning meal.
Calves were weighed immediately after calving. After calving, mastitis was kept at a minimum level by strict sanitary control (including good hygiene and teat dipping), and all carvers were tested for mastitis by rapid mastitis test at monthly intervals. Ticks were controlled by spraying with Gamatox.
Data were subjected to analysis of variance applicable to a randomised complete-block design (Steel and Torrie, 1980).
RESULTS
Animals in group 3 achieved higher liveweight gains than animals in the other two groups (Table 2), but the differences were not significant (P>0.05).
Calves born to heifers on treatment 2 (mean weight 34.6 kg) and 3 (34.8 kg) were heavier (P<0.05) than those born to heifers on treatment 1 (32.3 kg).
Table 1. Composition and analysis of feed ingredients used in the feeding trial
|
Ingredient |
Composition (%) |
||
|
Pre-calving concentrate |
Post calving concentrate |
Sudan grass |
|
|
Sorghum grain (aura) |
40 |
35 |
|
|
Cottonseed cake |
30 |
35 |
|
|
Wheat bran |
28 |
28 |
|
|
Salt (NaCl) |
1 |
1 |
|
|
Limestone |
1 |
1 |
|
|
Chemical composition a |
|||
|
Dry matter |
93.6 |
94.1 |
45.0 |
|
Ash |
5.8 |
5.9 |
12.3 |
|
Crude protein |
13.7 |
15.8 |
6.7 |
|
Crude fibre |
12.8 |
11.5 |
50.5 |
|
Ether extract |
3.8 |
5.1 |
1.2 |
|
Nitrogen-tree extract |
57.5 |
55.8 |
29.3 |
a Determined according to AOAC (1980)
Liveweight at calving did not did not (P>0.05) among the treatment groups (Table 3). There were also no significant differences in average daily gain and final body weight at the end of the early lactation period.
Milk yields and fat percentage in early lactation are shown in Table 4. Heifers in group 1 clearly produced more milk than those in group 1, but butter-fat percentage did not differ (P>0.05) among treatments.
DISCUSSION
Heifers on treatments 2 and 3 appeared to be superior to heifers on treatment 1 in final body weight and liveweight gain before calving, but the differences were not significant. The apparent comparative rapid increase in the rate of weight gain as calving approached, for heifers 2 and 3 compared with those on treatment 1, was probably due to availability of nutrients which catered for both dam and foetus growth. This agrees with previous work (Greenhalgh and Gardner, 1958) which showed that the increased weight of heifers in the later stages of pregnancy, as a result of an increase in concentrate feeding, was related to the increase in weight of mother and foetus and its membranes at this time.
Table 2. Effect of pre-calving nutrition on performance of heifers in the pre-calving period
|
Treatment group |
Steaming-up period (days) |
Average body weight (kg) |
Average daily gain |
|
|
Initial |
Final |
(kg) |
||
|
1 |
43 |
358.0 |
411.2 |
1.2 |
|
2 |
60 |
359.0 |
438.6 |
1.3 |
|
3 |
60 |
359.0 |
451.5 |
1.5 |
|
SE |
|
14.1 |
15.4 |
0.3 |
Table 3. Effect of pre calving nutrition on performance of heifers in the early lactation period
|
Treatment group |
Early lactation (days) |
Liveweight at calving (kg) |
Final body weight (kg) |
Average daily gain (kg) |
|
1 |
98 |
355.3 |
455.0 |
1.0 |
|
2 |
98 |
388.3 |
464.5 |
0.8 |
|
3 |
98 |
396.0 |
473.7 |
0.8 |
|
SE |
|
14.1 |
16.1 |
0.1 |
Table 4. Effect of pre-calving nutrition on milk yield and fat content in the early lactation period
|
Treatment group |
Milking period (days) |
Milk yield (kg) |
Fat content (%) |
|
|
Total |
Daily average |
|||
|
1 |
91 |
980.2 |
10.7 |
3.9 |
|
2 |
91 |
1030.1 |
11.3 |
4.1 |
|
3 |
91 |
1329.2 |
14.6 |
3.9 |
|
SE |
|
127.6 |
1.4 |
0.2 |
The observed improvement in milk yield of heifers on treatment 3 compared with that of those on treatments 1 and 2 indicates that supplementation with high levels of concentrates before calving tends to cause heifers to exhibit their potentials in milk production. This is in line with previous studies (Keys et al, 1984; Nocek et al, 1986) which showed that feeding cows and heifers at high levels before calving resulted in better body condition at calving and better production performance after calving. This may be attributed mainly to availability of enough nutrients during the later stages of gestation, which would enable the dam to meet the increased nutrient requirements of lactation.
Milk fat contents were not significantly different (P>0.05) among treatments. Gardner (1969) also showed that milk fat percentages were not influenced by prepartum plane of nutrition.
REFERENCES
AOAC (Association of Official Analytical Chemists). 1980. Official methods of analysis. 13th edition. AOAC, Washington, DC, USA. 1018 pp.
Gardner R W. 1969. Interactions of energy levels offered to Holstein cows prepartum and postpartum. Production responses and blood composition changes. Journal of Dairy Science 52:1973-1984.
Greenhalgh J F D and Gardner K E. 1958. Effect of heavy concentrate feeding before calving upon lactation and mammary gland oedema. Journal of Dairy Science 41:822-829.
Keys J E, Pearson R E and Miller R H. 1984. Effect of ratio of corn silage and gass-legume silage with high concentrate during dry period on milk production and health of dairy cows. Journal of Dairy Science 67:307-312.
Nocek J E, Steel R L and Baud D G. 1986. Prepartum grain feeding and subsequent lactation forage program effects on performance of dairy cows in early lactation. Journal of Dairy Science 69:734-744.
Steel R G D and Torrie J H. 1980. Principles and procedures of statistics A biometrical approach. 2nd edition. McGraw Hill, New York, USA. 633 pp.
