Effects of restricted suckling on milk production and health of cows and on the performance of the calves on small dairy farms in Central Vietnam

Nguyen Xuan Ba, Nguyen Huu Van and Nguyen Kim Duong^* 

 Faculty of Animal Science, Hue University of Agriculture and Forestry, Vietnam
* Faculty of Agriculture-Forestry-Aquaculture, Vinh University, Vietnam
bao.nguyenxuan@gmail.com or vanobihiro@yahoo.com

Abstract

The project was carried out to understand fully the current situation of dairy production in Nghe An province and determine the effect of restricted suckling on milk production and health of cows and on the performance of the calves at small dairy farms. The number of dairy herd have been increasing sharply in the province during the period 2001-2005. Most of them were kept at small dairy farms. Calves were fed using artifical rearing (AR) system. However, it seemed that the restricted suckling (RS) practice may be better in the current situation.

Ten F1 (HF x Laisind) cows in 5 households (two per each hhs, of which one  practiced AR and other applied RS). These cows were in the 2-3 lactation, kept in individual pens, fed elephant grass ad libitum and concentrate depending on the milk  production (1kg/2.5 kg milk), and with free access to mineral block and water. Milking times were around 5:00 and 17:00h.  In the AR treatment, calves were separated from the mother right after delivering. Milk was put in a bucket for them to drink and available at 6, 10, 14, 17, and 20h during the first week. In the RS treatment, calves stayed with the mother during  the first 24 hours after delivering to have colostrum ad libitum. From day 2, they were separated from the mother, but about 10 minutes before milking they were brought in front of their mother, and after milking they were released to stay with their mother about 30 minutes for suckling to have the residual milk. They were weighed before and after suckling to determine the milk intake. They were offered compensation amounts of milk  at 10, 14, and 22h.  From the second week, in addition to milk the calves of both treatments were given some concentrate and wilted grasses.

Cows in the RS treatment had higher yield of milk and less incidence of mastitis than those in the AR treatment. Calves of the RS treatment had higher live weight gain than those of the AR treatment. The farmers’ evaluation indicated that the RS practice was applicable in their situation.

Key words: Artificial rearing, growth rate, management, mastitis,

Introduction

There are three common regimes of rearing calves: (1) Suckling ad libitum: calves stay with mother all day and night; (2) Restricted suckling (RS): calves are only allowed to stay with mother a short time before and/or after milking; (3) Artificial rearing (AR): calves are removed from their dams within a few days after birth and bucket-fed either with cows' milk or milk substitute.

The AR system is imported from industrialized countries, but it appears to be frequently inappropriate under the conditions of feeding and management in most developing countries (Preston 1984). After machine or hand milking, there is always residual milk left in the udder which cannot be utilized, about 15% to 25% of the total milk (Ugarte 1977). The incidence of mastitis and calf mortality is often higher under the AR system than under RS (Ugarte and Preston 1975; Knowles and Edwards 1983).

Making use of the calf to stimulate milking is a popular practice in tropical countries. In the usual practice, the calves are kept in or brought to a pen adjacent to the milking parlour and when a cow is about to be milked, her calf is brought to her, allowed to suckle a few milk jets and then tied up in front of her or to her front leg during milking, after which both dam and calf remain together in another pen/paddock until milking of the whole herd is completed, then cow and calf are separated. Tesorero et al (2001) have reported that calf stimulation before milking to stimulate “let-down” increases saleable milk yield and its fat content without affecting calf growth rate, provided a feed supplement is given. This practice is partly as a consequence of difficulties in milking cows with Bos indicus genes without the presence of the calf. Sanh et al (1997) considered that restricted suckling after milking was a more appropriate system than calf removal and artificial rearing for managing cows and calves and coul be recommended especially for small-scale farmers. Therefore, there is a need to promote research in the Central Vietnam situation where dairy cattle are mainly kept on small-holder farms. The impact of this research is expected to be a live demonstration that may help the small-scale dairy farmers in the region to improve sources of income from dairy production.

Objectives

·        To introduce the RS system to the small dairy farms in Central Vietnam.

·        To study effect of RS on milk production, incidence of mastitis in the cows, performance of the calf, and economical efficiency of dairy production in small dairy farms.

Materials and Methods

Location and duration

The study was carried out in Nghe An province which is about 250 km south of Hanoi city. The experiment on the effect of restricted suckling on milk production and health of cows and on the performance of the calves was conducted in Cua Lo town, Nghe An province, for 3 months from February to April 2006.

Farmer selection

Five farmers were selected to join in the study. The selection of the farmers was based on:

·        Having at least two dairy cows, F1 (Holstein-Friesian [HF] x Laisind) in 2nd or 3rd lactation

·        Availability of land for growing elephant grass

·        Willingness to participate in the research and strong commitment to the idea

·        Willingness to share technologies with neighbors on animal management

Experimental design and animal management

Ten F1 (HF x Laisind) cows in 5 households (two per household) were allocated to AR or the RS system). They were kept in individual pens and fed elephant grass ad libitum, and a commercial concentrate (BS18, Guyomarch company) at the rate of 1kg/2.5kg milk). They had frees access to a mineral block and water.  Milking times were around 5:00 and 17:00h

Artificial Rearing:  

 The calves were separated from the mother immediately after delivering. They were fed milk from a bucket at 6, 10, 14, 17 and 20h during the first week. From the second week they were also given some concentrate and wilted grasses.  

Restricted suckling:

After delivering, the calves stayed with the mother during the first 24 hours to have colostrum ad libitum.  From day 2, they were removed from the mother, but about 10 minutes before milking they were brought in front of their mother, and after milking they were released to stay with her for about 30 minutes for sucking the residual milk. The calves were weighed before and after suckling to determine the milk intake. Compensation amounts of milk were offered at 10, 14 and 22h.  From the second week, in addition to milk,  they were given some concentrate and wilted grasses.

Photo 1: Cow in individual pen	Photo 2:  Suckling after milking

Photo 3: Weighing the calf to estimate milk consumption

Chemical analyses

Dry matter (DM), density  and fat content of milk samples were determined using an Ultrasonic Milk Analyzer (Lactoscan S, MILKOTRONIC LTD, Bulgaria)

Statistical analysis

Collected data were calculated and statistically analysed using Microsoft Excel version 2003.

Results and discussion

Basic information on dairy production in Nghe An province

Change in number of dairy cow during period of 2001-2005 is shown in Table 2. The provincial program for dairy production development was started in 2001 with the initial herd of 14 cows imported from Ho Chi Minh city. During the period 2001-2003, 441 dairy cows (326 from other provinces and 115 from Australia) were imported to Nghe An. In the same period, 4,648 Laisind cows (Red Shindhi × Vietnamese Yellow Cattle) were  artificially inseminated by Holstein Friesian semen to create local F1. It can be said that the population of dairy cows in the province has sharply increased during the five years.

However, from 2005 to 2006 the dairy production in the whole country fell into crisis because of the very low price of fresh milk and the competition from imported products. In Nghe An, although there is a milk processing factory (Vinamilk), it was too difficult for dairy farmers to sell the fresh milk because they are living far away from the factory and the milk collection system was not running well. Therefore, not many dairy farmers paid attention to their milking cows during this time. The situation improved by the end of 2007 due to the higher fresh milk price and the improvement of the milk collection system.

The breed structure of the total dairy herd in the province and the herd size at household level is shown in Tables 3 and 4. The F1 was the major group accounting for three fourths of the total dairy cow population. There are no large farms in the province. Dairy cows are kept in small scale in individual households. Therefore, it is recommended that any technical and policy support should be suitable to this situation.  For instance, making use of the calf to stimulate milking is a popular practice in tropical countries. Tesorero et al (2001) have reported that calf stimulation before milking to stimulate “let-down” increases saleable milk yield and its fat content without affecting calf growth rate, provided a feed supplement is given. This practice is partly as a consequence of difficulties in milking cows with Bos indicus genes without the presence of the calf. In another study, restricted suckling after milking was considered to be a more appropriate system than calf removal and artificial rearing for managing cows and calves and can be recommended especially for small-scale farmers (Man Van Sanh et al 1997).

Results of the experiment

Calves in the RS treatment were allowed restricted suckling for only the first three months of the lactation. Monthly milk yield of the cows on the RS treatment tended to be always higher than those on AR.  However, the difference in milk quality was very small. The positive impacts were that the growth rate of RS calves was higher than calves in AR, and the incidence of mastitis in RS cows was less than that in AR cows. These results are in agreement with reports by Knowles and Edwards (1983),  Mai Van Sanh et al. (1997) and Ugarte and Preston (1975). For these reasons, the participating farmers highly appreciated the restricted suckling system.  

Conclusions

            Based on the results of this research it is concluded that:

·        Cows in the RS treatment had higher yield of milk and less incidence of mastitis than cows inthe AR treatment.

·        Calves of the RS treatment had higher LW gain than those on the AR treatment.

·        The farmers' evaluation indicated that the RS practice is profitable and applicable.

Acknowledgements

The authors are grateful to the MEKARN project, financed by the Sida-SAREC agency. Thanks are also due to 5 farmers in Cua Lo town and the  Centre for Animal Breeding of Nghe An, who shared their experiences and participated actively in this study. Special thanks to Dr. T R Preston for his invaluable contribution to the success of this project.

References

Knowles R T and Edwards M D 1983 A comparison of the effects of restricted suckling and artificial calf rearing systems on dam and calf performance. Malaysian Agricultural Journal. 54:1-9.

Preston T R 1984 Restricted suckling: effects on cow and calf performance. Maximum livestock from minimum land. Proceedings of the fourth seminar held from 2nd to 4th May 1983 at the Bangladesh Agricultural University, Mymensingh, 54-66. Townville, Australia; James Cook University of North Queensland.

Mai Van Sanh, Preston T R and Ly L V 1997 Effects of restricted suckling versus artificial rearing on performance and fertility of crossbred F1 (Holstein Frisian x Local) cows and calves in Vietnam. Livestock Research for Rural Development. 9. Available from: http://www.cipav.org.co/lrrd/lrrd9/4/sahn941.htm

Tesorero M, Combellas J, Uzcátegui W and Gabaldón L 2001 Influence of suckling before milking on yield and composition of milk from dual purpose cows with restricted suckling.  Livestock Research for Rural Development. 13. Available from: http://www.cipav.org.co/lrrd/lrrd13/1/teso131.htm

Ugarte J 1977 Rearing dairy calves by restricted suckling. 10. Residual milk in cows suckling or not their calves after milking. Cuban Journal of Agricultural Science 11:253-262.

Ugarte J and Preston T R 1975 Restricted suckling. 6. Effects on milk production, reproductive performance and incidence of clinical mastitis throughout the lactation. Cuban Journal of Agricultural Science 9:15-26

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