Livestock Research for Rural Development 22 (3) 2010 Notes to Authors LRRD Newsletter

Citation of this paper

Performance of crossbred calves raised on different dietary treatments under smallholder dairy farm conditions

H L N Lyimo, G H Laswai*, L A Mtenga*, A E Kimambo*, D M Mgheni*, T Hvelplund**, M R Weisbjerg** and J Madsen***

Ministry of Livestock Development and Fisheries, P.O. Box 9152 Dar es Salaam, Tanzania
* Sokoine University of Agriculture, P O Box 3004, Morogoro, Tanzania
laswaig@suanet.ac.tz
** Aarhus University, Faculty of Agricultural Sciences, P.O. Box 50, 8830 Tjele, Denmark
*** University of Copenhagen, Faculty of Life Sciences, Denmark

Abstract

An on-farm study was carried out in Tanzania to assess the performance of crossbred (Frisian/Ayrshire x Tanzania Shorthorn Zebu) dairy calves fed on a concentrate, previously developed and tested on-station. The developed concentrate contained 189 g crude protein (CP) and 13 ME MJ per kg DM and was formulated using locally available feed resources. Twenty-seven (27) male calves, with birth weight 32 1.5 kg were randomly allocated to three treatments, whereby Treatment 1 (DC) calves were fed the developed concentrate, Treatment 2 (FC) calves were fed a common home made dairy cow concentrate (CP 130 g and ME 13 MJ per kg DM) used by farmers in the study area. Treatment 3 (FP) was a control, where farmers followed their normal calf rearing practice with no interference. Restricted suckling, ad libitum feeding of forages and up to 1 kg concentrate were used for the calves on DC and FC. Weaning was at 12 weeks. Feed intake and growth performance were recorded for 28 weeks.

 

Total dry matter intake was not different (P>0.05) between DC and FC. Mean growth rates (g/d) of calves under DC were higher (P<0.05) both pre (440) and post (460) weaning than those on FC (350) and FP (320 and 270), respectively.

 

It was concluded that feeding balanced calf concentrates formulated using locally available feed resources improves performance of calves under small holder dairy production systems.

Key words: calf concentrate, feed intake, on-farm study, weight gain


Introduction

Small scale dairying in Africa is recognised as an important instrument of social economic improvement and it is regarded as one of the strategies for poverty alleviation (Kurwijila et al 1995). Poor calf rearing practices including underfeeding result into high mortalities and poor growth rates (Moran 2002). The overall effect is lack of potential replacement heifers leading to low rate of herd growth and improvement (Kyambwa 1986; Kurwijila et al 1995). In the rural areas, use of concentrates to feed calves is not common due to high cost and erratic supply resulting into poor growth rate and late weaning of calves. The use of appropriate rearing practices including feeding balanced concentrates made from locally available feeds may increase calf growth and reduce mortality (Lyimo et al 2004).

 

Information on calf feeding in the smallholder farms in Tanzania and other African countries is scanty. Most technologies developed for calf rearing are based on on-station studies (Lyimo et al 2004) and may not be optimal under smallholder farm conditions. A review by Haverkont et al (1996) highlighted the need of farmer participation in the development of an appropriate innovative strategy for the smallholder farmers. The authors further emphasised that on-farm trials be conducted under the management system prevailing on the smallholder farms. Recently an on-station study in Tanzania (Lyimo 2006; Laswai et al 2007) revealed that calf performance is improved through feeding of balanced concentrate formulated using locally available feed resources. The concentrate was developed to contain (% DM) hominy feed (61), molasses (4), sunflower seed cake (14), Ipomoea species meal (14), fish meal (6), bone meal (0.5) and salt (0.5). The suitability of this concentrate under smallholder’s farm conditions, however, needs to be validated.

 

The objective of the present study was therefore to evaluate calf performance on the developed and tested on-station calf concentrate under farmer management conditions.

 

Materials and methods 

Study area

 

The study was conducted in Turiani district, located in the eastern part of Tanzania.  The area has an altitude range from 380 to 520 metres above sea level with annual rainfall of 1200–1500 mm and mean temperature range of 15–29 0C. The study was carried out during the rainy season, when the uncultivated lowlands were covered with grassland dominated with Panicum species, shrubs and some leguminous plants, while the swampy areas were mostly covered with Ipomoea aquatica plants.

 

Experimental design

 

Twenty-seven male calves (one calf per farm), with birth weight 32 1.5 kg were randomly allocated to three treatments, that is 9 calves per treatment. Treatment 1 (DC) involved feeding of on-station developed concentrate, whereas Treatment 2 (FC) was feeding of home made concentrate mixture for lactating cows. Treatment 3 (FP) was a control, where farmers raised their calves on forages and erratically offered minimal cow concentrate pre weaning and without concentrate post weaning, a common practice followed by most of the farmers in the study area (Lyimo et al 2004).

 

Feeds and feeding

 

The on-station developed concentrate  (Lyimo 2006; Laswai et al 2007) was formulated using FeedLIVE 1.51 (2000) computer software. The nutrient concentration and prices of the individual ingredients available in the vicinity of Turiani district were set in the matrix. The developed concentrate contained hominy feed (67%), molasses (6%), sunflower seed cake (15%), ipomoea species meal (15%), fish meal (7%) and 0.5% of bone meal and mineral mix. The home made farmer concentrate mixture for cows used in treatment FC was composed of maize bran (83 % DM) and sunflower seed cake (17 % DM). The concentrates were offered liberally until the allowance reached 1 kg (as fed basis), where the level was maintained. Clean drinking water was given freely throughout the experimental period. Fresh forages fed ad libitum (20 % refusal) to the calves were a mixture of Panicum maximum, Peniseteum purperium and some legumes. Amounts of concentrate and forage offered to calves on treatments DC and FC together with refusals were weighed daily to calculate feed intake. Correction for dry matter content of the forages during feeding was done by putting a sample of fresh forage in an open air near the cow stall and measured evaporation losses between the times the feed was offered and when refusals were measured. Samples of forages fed to calves were sampled from the bundles collected by each farmer at two weeks interval and those of concentrates from each concentrate prepared batch.

 

Management of animals

 

Calves were reared in draught-free individual pens constructed either within or near to the cow shed. Grass hay/straws were used as bedding material and were changed daily. Calves on treatments DC and FC were reared under restricted suckling method, whereby the calves were let to suckle one of the hindquarter teats of their dams and the residual milk from other teats. The suckled teat was exchanged to the other every two weeks interval. Suckling was during milking time at 0600h and 1700h in which calves were allowed to suckle their dams for few minutes before hand milking, to let milk down and for 30 minutes after milking. In the control treatment (FP) farmers were left to manage their animals as they are used to do (Lyimo et al 2004). All calves were weaned at 12 weeks of age.

 

Data collection

 

All calves were weighed at birth and thereafter at an interval of two weeks for a period of 28 weeks. They were weighed in three consecutive days just before evening milking and the average of the three days weighing was taken as the weight of the calf at that particular period.

 

Data on milk yield from the dams on treatments DC and FC was obtained by milking the three teats. Milk from the fourth teat was milked out and measured once in two weeks interval, during the period when the teat was exchanged to the other for the calf to suckle. The sum of milk recorded from all teats was taken as the milk yield from the dam. The residual milk suckled by the calf after milking was assumed to be 20 % of the milk yield from the dam (Sanh et al 1994). Milk suckled by the calf was the sum of the full suckled teat and the residual milk. Milk recording was not taken for Treatment FP. Samples of milk were taken from each dam on DC and FC at two weeks interval up to weaning at 12 weeks. The milk samples were preserved in sodium dichromate and stored at –5 0C for subsequent analysis. Body condition of the dams was taken at 4 weeks interval using score values from 0 to 5 with intermediate points as described by Rodenburg (1996). The score values were used to find the association between performances of the dams and the calves. 

 

Chemical analysis and in vitro digestibility

 

The feed samples were analysed for dry matter (DM), crude protein (CP) and crude fibre (CF) according to AOAC (2000). Milk protein was determined following the standard procedures of nitrogen determination and nitrogen conversion factor of 6.38 was used. Milk fat was determined using Gerber’s milk fat test method. Solid not fat (SNF) was calculated as the difference between total solids and the fat content. The in vitro digestibility of the forages followed the procedure outlined by Tilley and Terry (1963).

 

Derived parameters

 

The metabolisable energy (ME) content of the forages was calculated as:

ME (MJ/kg DM) = 0.016 DOM g/kg DM

Where DOM was the digestible organic matter content (McDonald et al 2002) 

 

Energy in the concentrates was calculated as:

ME (MJ/kg DM) = 0.012CP + 0.031EE + 0.005CF + 0.014NFE

where CP, EE, CF and NFE are (g/kg DM) crude protein, ether extract, crude fibre and nitrogen free extract, respectively (MAFF 1975)

 

The total milk solids (TS) was determined as: 

0.25 LR + 1.22 F + 0.72

Where LR was lactometer reading of milk and F was percent fat content of the milk (O’Mahony 1988). Solid not fat (SNF) was calculated as the difference between the total milk solids (TS) and fat content of the milk

 

Energy from the milk was estimated from the components as:

ME (MJ/kg milk) = 0.386 F + 0.206 SNF – 0.23

where F and SNF were in percent of fresh milk (Tyrrel and Reid 1965)

 

Statistical analysis

 

Data were analysed using the general linear model (GLM) according to SAS (2000). LS Means were compared using the probability of difference (pdiff) procedure. Simple correlations between the pre-weaning body weight gains of the calves and the dams body condition score (BCS), dams milk yield and amount of milk suckled by the calf per day in the corresponding period were evaluated using proc Reg. procedure of SAS (2000).

 

Results and discussion 

The chemical composition and energy contents of the two concentrates and forages used in the experiment are given in Table 1.


Table 1.  Nutritive values of the feeds fed to the experimental calves

Feed

DM, %

%  DM

ME,
MJ/kg DM

CP

CF

EE

NFE

IVDMD

Developed Concentrate

92.0

18.9

11.4

6.7

58.2

NA

13.1

Home made Concentrate

92.6

13.0

15.1

8.6

57.3

NA

13.0

Forage

28.8

10.3

32.4

NA

NA

58.0

9.3

NA = Not analysed


Home made concentrate had lower CP content than the developed one and below the recommended values (18 – 20 %) for calf concentrate (NRC 2001). It had relatively high levels of crude fibre (CF), which could possibly be due to the undecorticated sunflower seed cake used in the formulation. The limitation of high fibre in the calf concentrates is low digestibility of the diet and hence poor performance of the young calves (NRC 2001).  

 

Milk suckled in the first week had higher (P<0.001) values of total solids, protein, milk fat and solid not fat than the subsequent weeks (Table 2).


Table 2.  LS Means for composition of milk fed to calves during the twelve weeks of rearing

Week

1Components, % fresh milk

Energy,

MJ/kg milk

Total solids

Protein

(N x 6.38)

Milk fat

Solid not fat

1

20.5a

9.34a

6.24a

14.9a

5.24a

2

13.5b

3.92b

4.17b

9.35b

3.30b

4

13.5b

3.56b

4.11b

9.29b

3.26b

6

13.2b

3.12b

3.96b

9.23b

3.20b

8

13.4b

2.97b

3.99b

9.48b

3.26b

10

13.3b

3.13b

4.03b

9.18b

3.21b

12

13.9b

3.04b

3.86b

10.0b

3.34b

SEM2

0.58

0.36

0.28

0.49

0.17

Significance

***

***

***

***

***

1 LSMeans with different superscript letters down the column in this and subsequent tables are significantly different  * = P<0.05, ** =P<0.01,*** =P<001

 2SEM = Standard error of the mean


There was little change with advancement in lactation after the first up to the twelfth week. Such observations agree with those reported by Donald et al (1985). During the first week milk was essentially colostrum that has high nutrient concentrations.

 
Feed intake by the calves

 

There was no significant (P>0.05) difference between treatments on milk intake (Table 3).


Table 3.  Feed intake by calves on the two treatments at different ages

Intake

Age

DC

FC

SEM

Significance

Milk, l/day

8

5.1

4.9

0.4

NS

 

12

2.2

2.1

0.1

NS

Concentrate, g DM/day

8

177

159

21.7

NS

 

12

289

282

25.3

NS

 

28

926

920

NE1

NE1

Forage, g DM/day

8

255

285

10.9

NS

 

12

690

784

22.3

NS

 

28

2893

2947

46.4

NS

TDMI2

8

1068

1099

28.6

NS

 

12

1270

1405

53.7

NS

 

28

3674

3729

41.5

NS

Protein intake, g/day

8

220

207

NA

NA

 

12

190

178

NA

NA

 

28

473

423

NA

NA

Energy, MEI MJ/day

8

21.5

21.0

NA

NA

 

12

17.2

17.7

NA

NA

 

28

39.0

39.3

NA

NA

1NE = Not estimated- all calves had reached the limit of 1kg concentrate offer

 NA = Not applicable, SEM = Standard error of the mean difference

2TDMI = Total dry matter intake at 8 and 12 weeks included milk solids, concentrate and forage dry matter


The average milk intake observed in the present study was slightly above the recommended amount (4 l/day) for feeding calves during the first four weeks (Hopkins and Quigley 1997). There was no significant difference (P>0.05) between treatments on the dry matter intake of the forage or concentrate (Table 3).

 

Dry matter intake of both concentrates and forage increased with age (Figure 1).



Figure 1.  Forage and concentrate (conc.) dry matter intake by calves on the two treatments (DC and FC)


At 8 weeks of age the rumen of a calf is expected to have attained full maturity (Sehested et al 2003), hence the observed increase in intake. The increase in concentrate and forage intake could also be due to reduction of milk suckled as calves approached weaning. At 12 weeks of age, total dry matter intake (TDMI) ranged between 1200 –1400 g/day (Table 3), a level adequate to allow successful weaning as suggested by Quigley (2001).

 

The calculated values of energy and protein intake by calves in the different treatments are also presented in Table 3. Calves on DC consumed more protein per day at all three ages than those on FC despite their relatively lower TDMI. This was because the developed concentrate had higher CP content (189 v/s 130 g CP/kg DM) than the home made concentrate used in treatment FC. The amounts of daily energy and protein intake observed in this study were higher than the recommended values of 12 MJ ME and 151 g CP, 18 MJ ME and 217 g CP and 25 MJ ME and 309 g CP for calves gaining 400 - 500 g/day at 8, 12 and 28 weeks of age, respectively (NRC 2001). This suggests that in the study area, when calves are fed concentrate and good quality forages, the amount of milk offered could be reduced without affecting performance of the calves.

 

Growth performance

 

The overall birth weight was 32 kg (Table 4) and it was higher than the reported range of 22 – 28 kg for Bos Taurus x Bos indicus crosses (Udo 1993; Berhane et al 1998).


Table 4.  Body weight and growth rates of the calves in the three treatments at different stages of growth

Parameter

Treatment

SEM    

Sign.

DC

FC

FP

Body weight, kg

 

 

 

At birth

32.1

32.1

32.9

1.5         

NS

12 weeks

69.4

61.4

60.4

2.1         

**

28 weeks

121.4

100.1

90.5

3.5       

***

Growth rate, g/day

 

 

 

Pre-weaning

440

350

320

3            

*

Post weaning

460

350

270

3        

***

Overall

450

350

290

2        

***


The higher birth weight observed in this study compared with those reported in other studies could be due to nutritional differences. Calves in this study area were born with heavy body weights possibly because of good nutrition as a result of continuous availability of high quality forages to the cows throughout the year.

 

LSMean body weights of calves for treatment DC at weaning (12 weeks) and at 28 weeks were significantly higher (P<0.01) than those for treatments FC and FP despite the observed similar DMI (Table 3), suggesting that the diet used in DC was nutritionally better for raising the calves than those used in treatments FC and FP.

 

Besides calves on treatment FP been raised by the farmers themselves without changing the feeding practice, their mean body weights were higher compared with the previously reported calf performance from the survey done in the same study area (curve SR in Figure 2).



Figure 2.  Growth curves of the calves reared on-farm under the three treatments and from survey data (SR, Lyimo et al 2004)


This shows that through researching with farmers, some improvement was achieved, possibly farmers changed their attitude towards improved calf rearing. Other aspects that could have contributed to the improved performance during the on-farm study could be improved management particularly housing, factors which have been reported elsewhere to affect calf performance (Place et al 1998).

 

Calves on DC had higher growth rates in both pre- (P<0.05) and post weaning period (P<0.01) than those on FC and FP (Table 4). This improvement could be due to the higher protein content (189 g/kg) of the developed concentrate compared with the home made concentrate (130 g/kg) and hence higher protein intake by calves on DC than those on FC (Table 3). This finding is in agreement with those of Akayenzu et al (1994), who observed that calves offered diets with CP level between 180 – 200 g/kg DM had higher rate of gain than those offered diet with 130 g/kg DM. Furthermore, addition of fish meal in the concentrate fed to calves on DC could have supplied the needed bypass protein by the calves to supply more amino acids than the microbial protein, hence improved growth performance. Despite the relatively higher total DM intake by calves on FC than those on DC (Table 3), calves on FC had lower growth rate than those on DC, implying that the utilization of the home made concentrate mixture was relatively poor. The tendency of farmers to provide little or no concentrates to pre-weaned calves and none to post weaned calves could explain the inferior growth rates obtained by calves on FP against the other two treatments.

 

Growth rates of 450 g/day obtained in the present study for DC (Table 4) was higher than 300 g/day obtained on-station (Lyimo 2006; Laswai et al 2007), where similar concentrate was used. This difference could be explained by better quality of forage and the milk quantity and quality fed to calves in the present study relative to those of on-station experiment. Energy and protein contents of the forages used in the present study were 9.3 ME MJ and 100 g CP per kg DM, which were higher than those of hay (8.7 ME MJ and 44.5 g CP per kg DM) used for on-station experiment.  Similarly, in the on-station experiment calves were offered 4.0 kg of milk reduced to 2.0 kg at weaning, amounts, which were smaller than the suckled milk in the present study (Table 2). Milk suckled by the calves during the present study had 3.5 ME (Table 2) compared to 3.3 ME MJ/kg in milk given to the on-station calves (Lyimo 2006). Moreover, the calves in the present study were suckling, hence having better chances of getting the residual milk that is reported to have higher fat content than milk from a bucket (Sanh et al 1999). The LSmean growth rate of the calves recorded on treatment DC was higher than those reported by Mchau (1991) and Mulangila et al (1997) in other parts of Tanzania, implying that the concentrate could be used by farmers elsewhere to improve calf performance.

 

Relationship between calf and dam performances

 

Average milk production from the cows during the first 28 weeks of lactation was 9.71.7 kg/day. Milk available for sale or home consumption was on average 8.81.7 kg/day. The available milk is 10% less than the total yield. The difference represents milk consumed by the calf. The observed available milk in the present study agrees with that reported by Temi (1999) and Lyimo et al (2004) in the same area. The values also agree with those reported by Mchau (1991) and Mulangila et al (1997) in other parts of Tanzania.

 

Correlation between calf body weight gain and milk intake, milk yield of the dam and dam’s body condition score (BCS) are shown in Table 5.


Table 5.  Correlation between the calf body weight gain and birth weight, body condition score (BCS) of the dam, milk yield and milk intake by calves

Age

Component

Correlation coefficient

Significance

1st month

Weight gain x Birth weight

0.52

**

 

Weight gain x BCS of dam

- 0.21

NS

 

Weight gain x milk yield

0.23

NS

 

Weight gain x milk intake

0.54

*

2nd month

Weight gain x Birth weight

0.64

**

 

Weight gain x BCS the dam

- 0.20

NS

 

Weight gain x milk yield

0.31

NS

 

Weight gain x milk intake

0.50

*

3rd month

Weight gain x Birth weight

0.39

*

 

Weight gain x BCS of dam

- 0.43

NS

 

Weight gain x milk yield

0.19

NS

 

Weight gain x milk intake

0.20

NS


The calf weight gain was positively correlated to its birth weight, milk intake and dams production and negatively correlated to BCS of the dam. The correlation coefficient was highest and significant (P<0.05) between body weight gain and birth weights during the pre-weaning period. The results agree with observations made by Athur et al (1996). Calf weight gain was significantly (P<0.05) correlated with milk intakes in the first and the second month when the calf depended mainly on milk. This implies that where the milk is less in the first two months of age the calf has low growth rate.

 

The negative correlation between dam’s BCS and calf’s weight gain was expected. Calves were growing while the dam being milked lost weight. The observed low and insignificant difference (P>0.05), however indicates that the dam was loosing weight not because it has been suckled more by the calf but because of some other reasons, such as more milk being milked out and/or inadequacies in nutrition (McDonald et al 2002). This implies that high milk yield does not mean high growth rate to the calf as milk produced could be used for home consumption and/or sold for cash rather than feeding the calf. In addition, variations in growth rate observed in the different treatments were less influenced by the milk yield of the dam.
 

Conclusion and recommendations 

A calf concentrate has been developed using locally available feeds and proved to improve calf performance under smallholder dairy farming systems in Tanzania. An appropriate calf feeding system to be recommended to the smallholder dairy farmers in the study area is a combination of restricted suckling, feeding selected forages ad libitum and the developed concentrate amounting to 1 kg/day starting from the second week of age and weaning calves at 12 weeks of age. Further research is needed to assess the short and long term social economic implications of the developed feeding system in relation to prices of feeds, milk and weight gain in calves. Studies on how best the existing local forages, and of particular interest in this study is Ipomoea aquatica could be selected and combined for optimal performance of calves.

 

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Received 23 April 2009; Accepted 9 February 2010; Published 1 March 2010

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