Muhammad Khalid Qadeer, Shaukat Ali Bhatti*,
Haq Nawaz and Muhammad Sajjad Khan
Institute of Animal and Dairy Sciences, University of
Agriculture, Faisalabad, Pakistan
Received
27 August 2020; Accepted 10 October 2020; Published 10 December 2020
Abstract
The purpose of current experiment was to evaluate the effect of feeding
either milk or milk replacer (MR) offered at the rate of (@) 10% vs. 15% of body weight (BW) on growth
performance, post-weaning nutrient apparent digestibility and economics of
rearing Nili-Ravi
buffalo veal calves. Thirty-two calves were equally allocated to four
treatments in 2 × 2 factorial arrangements. Calves were fed either milk or MR
and subdivided into two groups offering liquid diet @ 10 or 15% of BW, but not
exceeding 5 and 6 L/d, respectively until week 8 and weaned at 10 weeks of age.
Calves were also offered a calf starter (CS) ration from 2nd week to
final live BW of 120 kg. Calves fed milk showed higher (P < 0.05), overall average daily gain (ADG) and took less time (P < 0.05) to reach target weight (120
kg) than MR one’s. Calves fed liquid diet @ 10% during the pre-weaning phase
also presented higher (P < 0.05)
overall ADG and took less time (P
< 0.05) to reach target weight than those fed at 15% of BW. Cost per kg live
weight gain (LWG) was higher in calves raised on milk and those fed @ 15% of
BW. Feeding MR @ 10% of BW was cost effective; however, MR feeding delayed the
days to reach the target weight. Hence the decision of rearing buffalo calves
on milk or MR may depend on priorities of the farmers and depending on the price
of inputs. © 2021 Friends Science Publishers
Keywords: Milk; Milk replacer; Buffalo
calves; Performance; Economics
Buffalo
milk is preferred over cow milk by many local consumers of Pakistan due to
higher fat content and fetches higher prices (Sarwar et al. 2002). High price of milk results in a higher feeding cost
compared to the sale price of calves at weaning (Bhatti et al. 2012). Thus, many farmers are tempted to sell milk instead
of feeding to the calves. As a consequence, many male buffalo calves die due to
underfeeding (Ahmad et al. 2009). In
many western countries, surplus male dairy (cow) calves are raised as veal and
sold at premium prices (Mollenhorst et al.
2016). Male buffalo calves could also be raised for veal production (Banjade et al. 2017), if international quality
standards are met economically (Bhatti et
al. 2013). Previous research suggests that buffalo calves have a better
milk conversion ratio than Friesian calves (Bhatti et al. 2009). This advantage makes them a suitable candidate to
explore for their veal production potential, especially in Pakistan. However,
the veal production potential of this buffalo breed under local environmental
conditions is not well documented. For successful veal production, high growth rates
at an early age can be achieved by feeding ad
lib quantities of milk (Khan et al.
2011; Iqbal et al. 2014); however, it
also increases the pre-weaning
feeding cost (Bhatti et al. 2013). To
reduce the pre-weaning feeding cost milk replacer (MR) can be an alternative
liquid diet as it is cheaper than milk (Heinrich et al. 1995; Abdullah et al.
2013). The traditional recommendation for feeding milk (or MR) to calves is @
10% of the body weight (BW) (Ahmad and Rehman 1989). However, higher average
daily gain (ADG) was reported for buffalo calves offered milk @ 15% of BW
compared to conventional (10% of BW) quantities (Abbas et al. 2017). Increasing milk further to 20% of BW; however, has
been found to be uneconomical (Bhatti et
al. 2013). Provision of a calf starter (CS) ration in the pre-weaning
period is an economical means of increasing growth rates (Bhatti et al. 2012). The use of MR with the
provision of a CS ration may be a profitable means of producing high quality
Nili-Ravi buffalo calves for veal production.
The study was conducted to assess the effect of feeding
either milk or MR offered at either conventional (10% of BW) or enhanced (15%
of BW) levels on the growth performance, nutrient apparent digestibility at
weaning and economics of rearing of Nili-Ravi buffalo veal calves.
Animal’s management and
dietary treatments
The trial was conducted from August,
2017 to July, 2018 at the Livestock Experimental Station Bahadurnagar, Okara.
Calves born at Bahadurnagar farm during August to December, 2017 were used in
this study. Newly born calves were artificially fed colostrum @ 10% of BW within 6 h of their
birth. The calves were kept in individual pens under a single
shed open from one side. Thirty-two calves were randomly assigned to one of the four
treatments, to give a total of eight calves per dietary treatment. The dietary
treatments were as follows: M10:
whole milk fed @ 10% of BW but not exceeding 5 L/d and weaned at the age of 10
weeks; M15: whole milk fed @ 15%
of BW but not exceeding 6 L/d and weaned at 10 weeks age; MR10: MR fed @ 10% of BW but not
exceeding 5 L/d and weaned at 10 weeks age; and MR15: MR fed @ 15% of BW but not exceeding 6 L/d and weaned
at 10 weeks age. The quantity of milk or MR given to the calves was adjusted
weekly (on calf BW basis) until week 8, and then steadily reduced to zero with
the calves weaned by the end of the 10th week. Calves were fed milk
or MR, in half equally divided proportions, twice a day in the morning and
evening.
Fresh buffalo milk (3.7% CP and 6.4% fat) was obtained from Nili-Ravi buffaloes at Bahadurnagar
dairy farms at the time of each feeding. Milk replacer Eurolac Green 20/18 (Schills Holland), containing 22% CP and 18% fat on DM basis, was prepared by thoroughly mixing 1 kg of the
powder in 7 L of warm water to attain temperature at the time of feeding
≥ 40°C, similar to freshly drawn milk. Reconstituted MR
contained 2.7% CP and 2.2% fat on as fed basis. The calves were fed milk or MR from nipple
fitted buckets to mimic natural suckling. The utensils
used for milk feeding were washed daily with detergent and then sun dried. In addition to their liquid diet
(fed for a total of 10 weeks), all the calves were offered a CS ration (19% CP
and 2.9 Mcal ME) from the second week until they reached the target weight of
120 kg. The daily intake of the CS ration was determined by offering
a weighed quantity once every day and weighing the refusal the next morning. Calves had free access to
clean, fresh water 24 h/d which was provided in a separate bowl located in
their pens.
The calves were weighed on an electronic scale
at the start of each week before their morning liquid feeding. This also
enabled calculation of the volume of liquid, given to each calf each week. All
the calves were observed every day, for any incidence of scour, based on
ranking of 1–4 as defined by Kertz and Chester-Jones (2004). Calves were
observed for other ailments and treated if required.
Post
weaning (week 10) apparent digestibly of dry matter (DM), ether extract (EE),
crude protein (CP) and crude fiber (CF) was performed by the total collection
method. Four, randomly selected animals from each treatment were used. The apparent digestibility of
nutrients was calculated on DM basis using equation.
Apparent digestibility (%) =
[Feed content (g) – fecal content (g)]/feed content (g) x 100
Chemical analysis to determine milk DM and CP
contents was undertaken using automatic milk analyser (Milkotester Ltd., Bulgaria). Feed and fecal samples were
analysed for DM, CP, EE and CF contents as described by AOAC (2006).
Record of expenditure on purchase of calves, feeding, medication, and
labour was maintained to calculate feeding and production costs of the buffalo
calves. However, expenditure on permanent equipment such as calf pens, feeding
buckets and managerial costs were not considered for production cost
calculations.
The data were analyzed using MIXED Procedures of SAS
(SAS 2011); for repeated measures, data were analyzed using an Auto Regressive
(1) covariance structure (Littell et al.
1998) taking calf effect as random and for non repeated measures, calf's birth
weight was taken as covariate. All results were presented as least
square means. Values were considered to differ significantly with P < 0.05.
Average daily liquid (milk or MR)
consumption of the Nili-Ravi buffalo calves is presented in Fig. 1. Intakes ranged from 2.8– 4.9
L/d and 3.4–5.3 L/d in the calves offered M10 and MR15, respectively. Total
liquid intake was higher (P <
0.05) in calves fed @ 15% of BW compared to those at the rate of 10% of BW;
however, it was not different (P >
0.05) in calves offered either milk or MR (Table 1). Nutrient intake (CP and
EE) was greater (P < 0 .05) among calves
given milk in comparison to those fed MR. Crude protein intake was higher (P < 0 .05) among calves fed liquid @
15% of BW compared to 10% of BW. The volume level of fed liquid had no effect (P > 0.05) on EE intake (Table 1).
The intake
of the CS ration during the first 6 weeks was negligible (< 100 g/d);
however, onward CS intake increased among MR-fed calves (Fig. 2). By the time of weaning (10
weeks), the animals in all treatments were consuming ~1 kg/d and did not differ
(P > 0.05) for total CS intake during the pre-weaning period
(Table 1). Intake of CS during the post-weaning phase was increased among
calves fed MR and by the 25th week, the daily CS ration consumption reached up to
Fig. 1: Average daily liquid intake of Nili-Ravi buffalo calves
fed either milk (M) or milk replacer (MR) at the rate of either 10% (M10, MR10)
or 15% (M15, MR15) of body weight. The vertical bars are the standard error of
the means
Fig. 2: Intake of calf starter ration by
Nili-Ravi buffalo calves fed either milk (M) or milk replacer (MR) at the rate
of either 10% (M10, MR10) or 15% (M15, MR15) of body weight during the
pre-weaning phase. The vertical bars show the standard error of the means
Fig. 3: Calf scour score of Nili-Ravi buffalo
calves raised on either milk (M) or milk replacer (MR) fed at the rate of
either 10% (M10, MR10) or 15% (M15, MR15) of body weight
Total CS intake over the entire feeding trial
was greater (P < 0.05) among calves raised on MR (Table 1); however, was
not different (P > 0.05) due to feeding level.
During the pre-weaning phase, average
weekly scour score was higher (P <
0.05) among calves fed @ 15% than those fed10% of BW. The average weekly score
was higher during the pre-weaning period and was almost normal during the
post-weaning period (Fig. 3).
Pre-weaning ADG was not different (P > 0.05) across the dietary
treatments, thus resulted in similar (P
> 0.05) weaning weights among treatments (Table 1). However, overall ADG
(from birth to target weight) was better (P
< 0.05) for those raised on milk compared with MR and was also better (P < 0.05) for calves fed liquid @ 10%
of BW during the milk feeding phase. Calves raised on milk reached the target
weight (120 kg) earlier (P < 0.05)
than those given MR. Calves fed liquid @ 10% of BW during the pre-weaning phase
also reached target weight earlier (P
< 0.05) than those offered liquid at 15% of BW (Table 1). Furthermore,
highest (P < 0.05) ADG was
recorded in M10 calves and the lowest (P
< 0.05) in MR15 calves. Calves fed milk took lesser time (P < 0.05) to reach the target weight
than those fed MR.
Apparent digestibility of nutrients
The prices of milk, MR and starter ration were 80 PKR/L, 38 PKR/L and 32
PKR/kg, respectively. The total cost of liquid feed during the milk feeding
phase was higher (P < 0.001) among
calves fed milk; however, was not different (P > 0.05) due to feeding level (Table 3). During the pre-weaning
period, the intake and thus cost of feeding CS did not vary (P > 0.05) across the dietary
treatments. Total cost of CS was higher (P
< 0.01) among calves given MR and was also higher (P < 0.001) in calves were fed liquid diet at the rate of 15% of
BW (Table 3). Medication costs through the pre- and post-weaning phases were
not affected (P > 0.05) by either
the liquid diet sources or level of liquid feeding. Total feeding cost during
the milk feeding phase was higher (P
< 0.001) in calves fed milk; however, was not different (P > 0.05) due to liquid feeding
levels. The purchase cost of the buffalo calves was PKR 3500/hd and the labour cost associated with the rearing of
these calves was PKR 8500/hd. Total overall feeding and production costs were higher
(P < 0.001) in calves given milk
and was also higher with increased level of liquid feeding (Table 3).
Ultimately total cost per kg LWG over the entire feeding period was higher (P < 0.001) among calves given milk
and was also higher in those fed liquid feed @ 15% of BW during the liquid
feeding period.
Table 1: Least square means of growth
performance of Nili-Ravi buffalo calves given either milk (M) or milk replacer
(MR) fed at the rate of either 10% or 15% of body weight
Parameters |
Feeding source |
Feeding level |
SE |
P- values |
||||
M |
MR |
10% |
15% |
F1 |
F2 |
F1*F2 |
||
Total milk
intake (L) |
280.5 |
280.0 |
268.8 |
295.5 |
8.3 |
NS |
* |
NS |
Crude protein intake
(kg) |
10.4 |
7.7 |
8.7 |
10.0 |
0.3 |
*** |
* |
NS |
Ether extract
intake (kg) |
17.9 |
6.3 |
11.6 |
14.8 |
0.4 |
*** |
NS |
NS |
Calf starter ration intake (kg) |
||||||||
Pre-weaning |
11.9 |
14.3 |
13.8 |
11.8 |
1.0 |
NS |
NS |
NS |
Post-weaning |
122.8 |
147.2 |
126.4 |
142.4 |
9.2 |
* |
NS |
NS |
Total |
134.8 |
161.6 |
140.2 |
154.4 |
9.1 |
* |
NS |
NS |
Birth weight (kg) |
38.7 |
37.9 |
37.9 |
38.7 |
1.4 |
NS |
NS |
NS |
Weaning weight (kg) |
76.8 |
72.2 |
75.2 |
74.2 |
3.1 |
NS |
NS |
NS |
Weeks to reach
target weight |
19.8 |
21.5 |
19.7 |
21.7 |
0.8 |
* |
* |
* |
Weight gain (kg) |
||||||||
Pre-weaning |
38.1 |
34.4 |
37.4 |
35.3 |
2.3 |
NS |
NS |
NS |
Post-weaning |
45.2 |
49.4 |
46.5 |
47.6 |
3.1 |
NS |
NS |
NS |
Total |
83.3 |
83.8 |
83.9 |
82.9 |
1.3 |
NS |
NS |
NS |
Average daily gain (g/d) |
||||||||
Pre- weaning |
543 |
491 |
534 |
504 |
33 |
NS |
NS |
NS |
Post-weaning |
676 |
648 |
70 |
611 |
33 |
NS |
* |
* |
Overall |
612 |
568 |
615 |
563 |
19 |
* |
* |
* |
F1 = Feeding
source: M or MR; F2 = Feeding level: 10% or 15% of body weight; F1*F2 =
Interaction of F1 and F2; NS: non-significant P > 0.05; *: P <
0.05; ***: P < 0.001
Table 2: Least square means of post-weaning
nutrient digestibility of Nili-Ravi buffalo calves reared on either milk (M) or
milk replacer (MR) fed at the rate of either 10% or 15% of body weight
Apparent digestibility (%) |
Feeding source |
Feeding level |
SE |
P- values |
||||
M |
MR |
10% |
15% |
F1 |
F2 |
F1*F2 |
||
Dry matter |
72.9 |
73.2 |
74.0 |
72.2 |
0.8 |
NS |
NS |
NS |
Crude protein |
73.4 |
73.1 |
73.1 |
73.4 |
1.0 |
NS |
NS |
NS |
Ether extract |
88.0 |
89.8 |
90.0 |
87.8 |
0.8 |
NS |
NS |
NS |
Crude fiber |
44.4 |
41.4 |
44.5 |
41.3 |
2.1 |
NS |
NS |
NS |
F1 = Feeding
source: Milk or MR; F2 = Feeding level: 10 or 15% of body weight; F1*F2 =
Interaction of F1 and F2; NS: non-significant P > 0.05; *: P < 0.05
Table 3: Least square means of costs of
production of Nili-Ravi buffalo calves fed either milk (M) or milk replacer
(MR) fed at the rate of either 10% or 15% of body weight
Cost (PKR) |
Feeding source |
Feeding
level |
SE |
P- values |
||||
M |
MR |
10% |
15% |
F1 |
F2 |
F1*F2 |
||
Liquid feed |
22442 |
10641 |
15844 |
19439 |
571 |
*** |
NS |
NS |
Starter ration |
||||||||
Pre-weaning |
382 |
458 |
440 |
380 |
33 |
NS |
NS |
NS |
Post-weaning |
3932 |
4712 |
4046 |
4559 |
294 |
* |
NS |
NS |
Total |
4314 |
5170 |
4486 |
4939 |
285 |
** |
* |
NS |
Medication |
||||||||
Pre-weaning |
586 |
409 |
455 |
584 |
63 |
NS |
NS |
NS |
Post-weaning |
198 |
190 |
183 |
209 |
32 |
NS |
NS |
NS |
Total |
784 |
599 |
638 |
793 |
78 |
NS |
NS |
NS |
Feeding and medication |
||||||||
Pre-weaning |
23411 |
11507 |
16739 |
20403 |
564 |
*** |
NS |
NS |
Post-weaning |
4130 |
4902 |
4230 |
4768 |
315 |
* |
NS |
NS |
Total |
27541 |
16409 |
20969 |
25171 |
425 |
*** |
*** |
NS |
Feeding and medication cost per kg live
weight gain |
||||||||
Pre-weaning |
642 |
340 |
454 |
592 |
25 |
*** |
* |
NS |
Post-weaning |
|
|
|
|
|
|
|
|
Total |
331 |
197 |
251 |
304 |
6.5 |
*** |
** |
NS |
Total production cost1 |
39540 |
28409 |
32968 |
37171 |
425 |
*** |
*** |
NS |
Per kg live weight gain |
324 |
234 |
271 |
305 |
3.7 |
*** |
*** |
NS |
F1 = Feeding
source: M or MR; F2 = Feeding level: 10% or 15% of body weight; F1*F2 =
Interaction of F1 and F2; NS (non-significant) P > 0.05; *: P <
0.05; **: P < 0.01; ***: P < 0.001
1includes calf purchase price (PKR
3500/head) and labour cost (PKR 8500 per head) but not infrastructure cost
Discussion
The study was planned to compare the
effects of milk or MR on growth of buffalo calves. Calves at early age are just
like monogastrics and are solely dependent on milk diets for nutrient
requirements. Therefore, increasing the volume of liquid offered to the buffalo
calves resulted in higher intakes. Abbas et al.
(2017) also found that Nili-Ravi calves fed a high volume (15% BW) of fresh
milk had higher total milk intake than those fed low volumes (10% BW). In present study liquid intake was adjusted weekly depending on the BW
of calves, thus due to similar ADG, calves fed milk or MR also did not differ
for their liquid intake. All calves
were provided access to the CS ration from 2 weeks of age and intake of
the CS ration during the first 6 weeks was negligible (< 100 g/d). Calves
fed MR showed higher daily intake of
the CS after week 6 (Fig. 2); however, total intake of CS at the
time of weaning was similar across all the treatments (Table 1). Similar
outcomes were reported by Abdullah et al.
(2013) where Nili-Ravi heifer calves offered whole milk had similar DMI (which
included CS and green fodder) to those fed MR at 10% of BW. Early and enhanced dry feed ingesting
improves timely rumen microbial growth, and results in greater metabolic
activity of rumen (Anderson et al.
1987). Thus, intakes of the CS ration during overall trial were higher in calves raised on MR. The volume of
liquid feeding had no effect on post-weaning and overall intake of the CS
ration starter. Calves offered higher volumes did not consume the whole
allowance, thus resulting, similar hunger for solid feed. Results were
consistent with Abbas et al.
(2017) who found that buffalo calves fed milk @ 15% of BW had similar
post-weaning CS intake as that fed milk @ 10% of BW.
Increase in
weight in buffalo calves during growth phase is usually credited to levels or
balance of nutrition. Provision of feed to these calves according to their nutritional
(protein and energy) requirement offers a practical dietetic tool to improve
efficacy (Tauqir et al. 2011). The
ADG of the buffalo calves up until weaning ranged between 446 g/d (MR15) to 554
g/d (M10). However, weaning weights (at week 10) of calves were not affected by
liquid dietary treatment, ranging between 69.2 kg (MR15) and 76.8 kg (M10).
Bhatti et al. (2009) reported that buffalo
calves given milk @ 10% of BW attained 77.2 kg live weight in 12 weeks period.
The lack of difference in the intake of the CS ration during the pre-weaning
period also contributed to no difference in weaning weights. Over the entire
feeding period, ADG varied, ranging from 478 g/d (MR15) to 618 g/d (M10). As a
consequence of these differences in overall ADG, the time to reach target
weight also varied, ranging from 19.6 weeks (M10) to 25 weeks (MR15). Despite
there being no difference in intake of the CS ration between dietary levels,
numerically, CS intake during the liquid feeding period was greater in calves
fed liquid at 10% of BW (13.8 kg) than at 15% of BW (11.8 kg). If the calves
fed @ 10% of BW started eating the CS earlier would have promoted earlier rumen
development, and resulted in better gain in later life.
The most common and frequently occurring disease in buffalo calves is
diarrhea. Major risk aspects related with increased occurrence of diarrhea in
newborn calves are inappropriate liquid feeding (Ollivett et al. 2012). During the liquid feeding phase, the average weekly
scour score was higher in calves fed @ 15% than those fed 10% of BW. Similar results
were reported by Abbas et al. (2017)
when buffalo calves fed higher volumes (15% of BW) of milk had a greater number of days in
scour compared to those fed lower volumes (10% of BW). Despite the effect of
feeding level on fecal score, it had no effect on ADG during the pre-weaning
period. Higher intake of liquid diets results in increased digesta flow rate; thus,
less retention time negatively affected efficiency. During the post-weaning
period the weekly scour score was almost normal. Apparent digestibility
measured post-weaning was similar for all dietary treatments. However,
numerically higher DM and CF digestibility can be attributed to higher intake
of CS among milk-fed and those fed @ 10% of BW and therefore in microbial
protein synthesis. Sultan et al.
(2009) found increasing dietary (rumen degradable) protein resulted in higher
DM and NDF digestibilities in Nili-Ravi calves.
Higher pre-weaning cost to feed calves on
milk, despite similar level of intake, was a consequence of the higher price of
milk compared to MR. Further pre-weaning cost of the CS ration did not vary due
to similar intake of the CS ration across dietary sources. Pre-weaning cost
associated with liquid feeding level was not different between feeding at 10
and 15% of BW. Numerically higher pre-weaning CS cost in low fed calves
neutralized the liquid diet cost differences during pre-weaning period. In
contrast, Abbas et al. (2017) found
that the cost of Nili-Ravi calves during milk feeding period increased as the
volume of milk fed increased (from 10 to 15% of BW). However, as consequence of
overall increased intake, the cost of the CS ration was higher in the calves
raised on MR (5170 PKR) than those on milk. Though not different, numerically
cost of the CS ration (post-) was higher in calves fed their liquid diet @ 15%
of BW, and resulted in higher overall CS ration cost. Medication costs during the pre- and overall did not vary between
dietary treatments. Combining all feeding and medication costs resulted in
increased production cost of for calves reared on milk and similarly those
offered liquid 15% of BW. The most effective costing to determine the most
economically efficient rearing method is the cost per kg LWG. When fed at 15% of
BW, MR-fed calves consumed an additional 56.3 kg of CS and reached target
weight 5 weeks later than those fed milk. When fed at 10% of BW, there was no
significant difference in terms of weeks to reach target weight (19.6 versus
19.8 weeks), although the MR fed calves consumed an additional 12.4 kg of CS.
The differences in ADG and CS intake resulted in differences in the cost per kg
LWG. On the basis of these results, feeding MR at the rate of 10% of BW is the
most appropriate (PKR 321per kg LWG) for the economical raising of buffalo
calves for veal production.
Acknowledgements
Financial support of the Higher Education Commission of Pakistan to
conduct this study is highly acknowledged by authors. The authors are also
obliged to the administration of the Livestock Experiment Station,
Bahadurnagar, Okara, Pakistan, for making calves as well as farm facilities
available for this trial.
Author Contributions
MK Qadeer conducted the study; SA Bhatti planned
the study and analyzed the data; H Nawaz and MS Khan helped in writing the
manuscript.
Abbas W, SA Bhatti, MS Khan, N Saeed, HM Warriach, P
Wynn, DM Gill (2017). Effect of weaning age and milk feeding volume on growth
performance of Nili-Ravi buffalo calves. Ital
J Anim Sci 16:490‒499
Abdullah M, ZM Iqbal, M Saadullah, A Haq, K Javed, MA
Jabbar, A Tauseef (2013). Comparative performance of calves fed milk and/or
milk replacer supplemented with calf starter up to weaning age in Nili-Ravi buffaloes. Buff Bull 32:874‒877
Ahmad M, S Rehman (1989). Effect of feeding whole milk/
skim milk on the growth of male buffalo calves. In: Tenth Annual Report (1988–89), pp: 115‒118. Livestock
Production Research Institute, Bahadurnagar, Okara, Pakistan
Ahmad S, M Yaqoob, N Hashmi, MA Zaman, MS Amjad (2009).
Farmers’ attitude towards interventions regarding buffalo calf health care and
management practices under field conditions. Pak Vet J 29:125‒128
Anderson KL, TG Nagaraja, JL Morrill, TB Avery, SJ
Galitzer, JE Boyer (1987). Ruminal microbial development in conventionally or
early-weaned calves. J Anim Sci
64:1215‒1226
AOAC (2006). Official
Methods of Analysis, 15th Edition. Association of Official
Analytical Chemists; Arlington, Virginia, USA
Banjade J, NR Devkota, DK Yadav, NP Chaudhry (2017).
Commercial fattening of buffalo calves for economic meat production. Nepal Vet J 34:51‒59
Bhatti SA, K Nazir, MJ Basra, MS Khan, M Sarwar, MAI
Mughal (2013). Prospects of raising Sahiwal calves for veal production under
tropical environment. Trop Anim Health Prod
45:923‒930
Bhatti SA, MF Ahmed, PC Wynn, D McGill, M Sarwar, M
Afzal, E Ullah, MA Khan, M S Khan, R Bush, HM Warriach, A Khan (2012). Effect
of diet on pre-weaning performance of Sahiwal calves. Trop Anim Health Prod 44:819‒826
Bhatti SA, MS Khan, M Sarwar, E Ullah (2009).
Performance of buffalo and cow calves during pre-weaning period under same
managemental conditions at the University of Agriculture, Faisalabad. Pak J Zool Suppl Ser 9:623‒628
Heinrich AJ, SJ Wells, WC Losinger (1995). A study of
the use of milk replacer for dairy calves in the United States. J Dairy Sci 78:2831‒2837
Iqbal Z, Z Hayat, M Abdullah, K Javed, N Ahamd (2014).
Milk and milk replacer performance in dairy calves. J Anim Plant Sci 24:52‒54
Kertz AF, H Chester-Jones
(2004). Invited review:
Guidelines for measuring and reporting calf and heifer experimental data. J Dairy Sci 87:3577‒3580
Khan MA, DM
Weary, MAGV Keyserlingk (2011). Hay intake improves performance and rumen
development of calves fed higher quantities of milk. J Dairy Sci 94:3547‒3553
Littell RC, PR Henry, CB Ammerman (1998). Statistical
analysis of repeated measures data using SAS procedures. J Anim Sci 76:1216‒1231
Mollenhorst H, PBM Berentsen, H Berends, WJJ Gerrits,
IJMD Boer (2016). Economic and environmental effects of providing increased
amounts of solid feed to veal calves. J
Dairy Sci 99:2180‒2189
Ollivett TL, DV Nydam, TC Linden, DD Bowman, MEVan
Amburgh (2012). Effect of nutritional plane on health and performance in dairy
calves after experimental infection with Cryptosporidium
parvum. J Amer Vet Med Assoc
241:1514–1520.
Sarwar M, MA Khan, M Nisa, Z Iqbal (2002). Dairy industry in Pakistan:
A Scenario. Intl J Agric Biol 4:420‒428
SAS (2011). User’s
Guide: Statistics, 6th Edition, SAS Institute, Inc., Cary, North
Carolina, USA
Sultan JI, A Javaid, M Nadeem, MZ Akhtar, MI Mustafa
(2009). Effect of varying ruminally degradable to ruminally undegradable
protein ratio on nutrient intake, digestibility and N metabolism in Nili Ravi
buffalo calves (Bubalus bubalis). Livest Sci 122:130‒133
Tauqir NA, MA Shahzad, M Nisa, M Sarwar, M Fayyaz, MA
Tipu (2011). Response of growing buffalo calves to various energy and protein
concentrations. Livest Sci 137:66‒72