Effects of Limited Suckling and Varying Prepartum Nutrition on by nyb13813


									Effects of Limited Suckling and Varying Prepartum Nutrition
on Postpartum Reproductive Traits of Milked Buffaloes
                                                   R. H. USMANI, R. A. DAILEY, and E. K. INSKEEP
                                                           Division of Animal and Veterinary Sciences
                                                                              West Virginia University
                                                                              Morgantown 26506-6108

                      ABSTRACT                                     INTRODUCTION

      Effects of supplemental prepartum               Nili-Ravi water buffaloes (Bubalus bubalis)
  feeding and limited suckling on postpar-         contribute more than 75% of the national milk
  tum reproductive performance of milked           production in Pakistan (6) but are generally less
  Nili-Ravi water buffaloes were examined          efficient than dairy cattle (Bos rawus) in repro-
  in two 2 x 2 factorial experiments.              ductive performance (8). Lifetime production of
  Prepartum feeding was either moderate            dairy buffaloes is limited by the long calving
  (metabolizable energy = 32 Mcal/d) or            interval of 18 to 20 mo (24). A 5-mo reduction
  high (46 McaVd) in Experiment 1 and              in calving interval could add about 37 billion
  high (46 Mcal/d) or very high (51 Mcal/          rupees to the annual gross national product of
  d) in Experiment 2. Nutritional treatment        Pakistan (22). Common practice is to allow
  was initiated about 75 d prior to calving        buffalo calves to suckle for a limited time
  and stopped at parturition. Half of the          before each milking to initiate milk ejection.
  buffaloes were suckled by their calves           Knowledge of the effects of limited suckling on
  twice daily (2 rnin at each milking) until       postpartum reproductive efficiency of dajr
  second estrus. Prepartum feeding did not         buffaloes is limited (10, 19). Suckling length-
  influence any trait measured in either ex-       ens postpartum intervals to estrus and concep-
  periment. Postpartum intervals to uterine        tion in cattle, sheep, and several other mamma-
  involution, resumption of follicular devel-      lian species (14).
  opment, first rise in milk progesterone,            In beef and dairy cows, relationships have
  first palpable corpus luteum, and first es-      been shown between nutritional status prepar-
  trus were longer for limited-suckled buf-        tum and postpartum repmductive efficiency (9,
  faloes than for those that were only             12). Generally, farmers in Pakistan do not feed
  milked. Most buffaloes (86%) showed at           dry buffalo in later stages of pregnancy in
  least one short luteal phase (8 to 13 d)         relation to needs for body maintenance and
  before first estrus. Number o rises of
                                   f               fetal growth. Effects of prepartum feeding on
  progesterone before first estrus was             the performance of postpartum buffaloes have
  greater for limited- suckled buffaloes in        not been documented. Objectives of the present
  Experiment 2 but not in Experiment 1.            study were: 1) to examine the effect of limited
  Luteal activity after first estrus (15 to 19     suckling on uterine involution, postpartum
  d) and pregnancy rate to insemination at         ovarian function, estrous activity, and fertility
  second estrus (average 50%) did not dif-         of milked buffaloes maintained under routine or
  fer with limited suckling. In conclusion,        improved conditions of prepartum feeding, and
  postpartum anestrus of water buffaloes           2) to evaluate the value of energy supplementa-
  can be shortened by weaning calves at            tion prepartum in reducing postpartum intervals
  birth, regardless of supplemental feeding        to return of reproductive functions in such buf-
  prep-.                                           faloes when milked only o milked and limited
  (Key words: water buffalo, limited suck-         suckled.
  ling, postpamm intervals)
                                                             MATERIALS AND METHODS

  Received July 17,1989.                             Two experiments using Nili-Ravi buffalo
  Accepted January 4,1990.                         were conducted, each using a 2 x 2 factorial

1590   J Dairy Sci 73:1564-1570                  1564
                                 SUCKLING AND REPRODUCTION IN BUFFALOES                                          1565
TABLE 1. B s s of estimating onset and end points of several reproductive functions in postpartum buffaloes.
                    ~~                  ~         ~~        ~

Paloation fmdimcs
~~~                 ~        ~
                                       Milk mopesterone urofile
                                        ~         ~
                                                                                 Detection of estrus
Completion of uterine involution       Interval to first rise i progesterone
                                                              n                  IntavaI t first estrus
Regression of corpus albicans of       Duration of first rise in progesterone    Duation of first estrus
Resumption of follicular development Number of progesterone rises before         Lengtb of  first estrous cycle after
                                       first estrus                              calving
Resumption of follicular development Number of progesterone rises More           Interval from calving to second estrus
                                       first estrus
Pormation of first palpable corpns lu- Duration of progesterone rise after       Duration of second estrus
teum (a)                               tiRt C S t N S
Life spans of CL formed bcfore and Interval from end of first to begin-
after first estrus                     ning of next rise in progesterone
Preenancv diamsis

arrangement of treatments (two amounts of                   hand milking (0300 and 1400 h). Calves were
prepartum feeding and limited or no suckling).              raised separately in individual pens where they
Experiment 1 was completed in two replicates                were fed whole buffalo milk Suckling treat-
with buffaloes calving during autumn of 1985                ment was similar in both experiments. One-half
(n = 36) and 1986 (n = 22) at the Animal                    of the number of buffaloes in each nutritional
Sciences Institute of the National Agricultural             group were allowed to nurse their calves twice
Research Center (Islamabad, P k s a ) Lacta-
                                aitn.                       daily for 2 min before milking (limited suckled)
tion numbers and ages of buffaloes ranged from              from the day of calving until second estrus.
1 to 9 (mean 3.7) and 3 to 14 yr (mean 8.4),                Calves fiom the remaining buffaloes were
respectively. Experiment 2 utilized 43 buffaloes            weaned within 72 h after birth (nonsuckled).
that calved at the Livestock Experiment Station                Starting on d 14 postpartum, buffaloes were
(Bahadarnagar, Pakistan) during the summer                  palpated per rectum twice weekly until second
(May through August) of 1986. These buffaloes               estms. At each palpation, approximate lengths
were 5 to 13 yr of age (mean 8.8). and their                and diameters of the cervix and both uterine
lactation numbers ranged fiom 2 to 7 (mean                                                ih
                                                            horns were recorded along w t location and
4.0).                                                       tone of uterus (20). Uterine involution was
   Nutritional treatment was initiated approxi-             considered complete when the uterus returned
mately 75 d prior to calving in each experi-                to the pelvic cavity and had a fair tone, and
ment. Buffaloes were paired by age (k 1 yr),                both horns showed no further decrease in
BW (k 20 kg), and expected date of calving (k               length or diameter at subsequent palpations.
10 d) and were assigned randomly to a prepar-               Size and location of palpable ovarian structures
tum feeding regimen. Prepartum feeding was                  [corpora lutea (CL) or follicles 210 mm in
moderate metabolizable energy (ME) (32 McaV                 diameter] were recorded. Palpation data were
d) or high ME (46 McaVd) in Experiment 1 and                used to calculate several variables (Table 1).
high (46 McaVd) or very high (51 M W d ) in                 Milk samples were collected on each palpation
Experiment 2. Buffaloes on moderate feeding                 day at the evening milking and stored at -20°C
received weighed amounts of available green                 until concentrations of progesterone were mea-
fodder only, whereas those on high or very high                 SUIed.
feeding were supplemented with concentrates.
Availability, chemical composition, and daily                   Progesterone Assay
consumption of feed as well as details of man-
agement have been reported earlier (21).                       Concentrations of progesterone in milk were
   Beginning at parturition, each buffalo was               measured by the microtiter plate enzyme immu-
fed daily 50 to 60 kg of green fodder and 1.0               noassay as described by Van de Wiel and
kg of concentrates for each 2.5 kg of milk                  Koops (23). Antibodycoated microtiter plates,
produced above 3.0 kg. Concentrates were of-                chemicals and reagents were supplied by
fered to individual buffaloes twice daily before            D.F.M. Van de Wiel (Research Institute for
                                                                         J o d of Diy Science Vol. 73, NO. 6. 1990
1566                                           USMANI ET AL.

Animal Production, Schoonard, Netherlands).                  palpation o the uterus on d 45 to 50 postbreed-
Milk samples were thawed at room tempera-                    ing.
ture, mixed, and diluted (1:200) with assay
buffer. Additional milk samples were collected               Statlstlcal Analyses
from five estrous buffaloes and used as a low
progesterone pool. Two standard curves (at dif-                 Data were examined by analysis o variance
ferent locations of the assay plate) were run                using General Linear Models procedures of
with each set of 36 unknown samples. Sensitiv-               SAS (3). The model for Experiment 1 included
ity of the assay, defined as the amount of                   nutrition, suckling, month of calving, their in-
progesterone that caused a 50% reduction of                  teractions, and replicate as independent vari-
initial binding in the standard curve, was .62               ables; age and parity of buffaloes were
ng/ml. Intraassay and interassay coefficients of             covariates (21). Replicate was not a factor in
variation were 12.7% (n = 4) and 13.5% (n =                  the model for Experiment 2. When the F-test
3 3 , respectively. Repeatability of measurement             was sisnificant, means were compared by Dun-
of progesterone within duplicate milk samples                can's new multiple range test.
was 98.1%. M a +2 SD of the concentration
of progesterone in low pooled milk was used as                                        RESULTS
a cut-off point (2 ng/ml) between baseline and
higher values of progesterone. Variables calcu-      Supplementalprepartum nutrition had no ef-
lated using that criterion are shown in Table 1. fect on any variable of postpartum reproduction
                                                 in either experiment. Effects of prepartum nu-
                                                 trition on changes in body weights around calv-
Detection of Estrus
and Breedlng                                     ing, birth weight and p w t h rate of calves, and
                                                 7 5 d milk yield of the buffaloes in these experi-
   Starting on d 14 postpartum, buffalo were ments have been reported earlier (21). Briefly,
observed (30 min) for standing estrus four prepartum weight gain by buffaloes, birth
times a day (0200, 1o00, 1800, and 2200 h) weight of calf, and 7 5 d milk yield increased
with the help of penisdeviated teaser bulls. with inmasing amounts of prepartum feeding.
Data from detection of estrus were used to Limited suckling was associated with a small
calculate several variables (Table 1).           but significant increase in 7 5 d milk yield. Milk
   Frozen-thawed semen from known fertile yield increased linearly with body weights of
bulls was used to inseminate the buffaloes at 12 buffaloes at the time of initiation of supplemen-
and 18 h after the onset of second postpartum tal prepartum feeding and at parturition. In the
estrus. Pregnancy was diagnosed through rectal following text and tables, results are presented

TABLE 2. Uterine involution and early postpanum ovarian activity in buffaloes.
                                                                        ~                               ~~     ~~   ~~~

                                         Expaiment 11                                      Exptrimcnt 2
                                                Lhtcd-ded                                       Limited-sackled
Variable                    Milked              and milked                  Milked              admilked
Number                       29                 29                          21                  22
Postpartum intervals (d) to:       SEM          5?     SEM                  Tz    SEM                        SEM
 Involution of uterus        30.8' 1.0          23.7b 1.6                   2 4 9 1.0            19.ob        .7
 Regression of corpus
  albicans of pnlpufncy      16.9   5           16.3    .5                  15.8      .5         15.7         .7
 Resumption of fohcular
  develope&                 22.3c 2.2           30.2d 2.4                   25.3     1.8        27.0         1.9
             intervals (rt SEM) within same row and experiment with ditrerent aupermipt differ (P<.oooS).
   c k e a n intervals (* SEM) within same r w and e x p i m a t with different superscript mr (~c.001).
   'Data are conibinad for the two nplicatcs of Experiment 1.
   2Follicks 210 mm in diameter.

Journal of Diy Science Vol. 73. No. 6, 1990
                                 IN                                   1567
                         for effects of suckling regardless of prepartum
                            Involution of the uterus was completed con-
                         sistently about 1 wk earlier in limited-suckled
                         than in nonsuckled buffaloes (Table 2). Repli-
                         cate (Jbperiment l), month of calving, and age
                         and parity of buffaloes did not influence the
                         postpartum interval to uterine involution.
                            The corpus albicans (CA) of pregnancy was
                         not palpable in most buffaloes (64% in Experi-
                         ment 1,74%in Experiment 2) by d 14 postpar-
                         tum (first palpation). In these buffaloes, the
                         interval to regression of CA was considered as
                         14 d Overall interval to regression of CA of
                         pregnancy averaged 16 d in each experiment
                         and did not differ between limited-suckled and
                         nonsuckled buffaloes (Table 2). Resumption of
                         follicular development (palpable follicle 210
                         mm in diameter) occurred about 1 wk earlier in
                         nonsuckled buffaloes in Experiment 1 (Table
                         2), but limited suckling had no effect in Experi-
                         ment 2.
                            Postpartum intervals to first rise to proges-
                         terone and formation of fist palpable corpus
                         luteum (CL)were longer in limited-suckled
                         buffaloes (lk.01; Table 3). Duration of luteal
                         phases prior to estrus did not differ with suck-
                         ling in either experiment (Table 3). Efficiency
                         of ovarian palpation to detect early luteal activ-
                         ity was only 10 and 34% for nonsuckled and
                         limited-suckled buffaloes, respectively. Palpa-
                         ble life span of first CL was always about 2 to
                         3 d shorter than the corresponding periods of
                         high concentrations of progesterone (22.0 ng/
                            Overall patterns of resumption of luteal
                         function were similar in both experiments.
                         Most buffaloes (86%) showed at least one short
                         luteal phase prior to first estrus. Number of
U                        luteal phases before first estrus did not differ
                         with suckling in Experiment 1, but was greater
                         for limited-suckled buffaloes in Experiment 2
                         (Table 3). No buffaloes in Experiment 1 and
                         only 2 (10%)in Experiment 2 had more than
                         two short luteal phases.
                            Data regarding postpartum estrous activity
                         are summanzed in Table 4. Mean intervals
                         from calving to first and second estruses were
                         significantly longer in limited-suckled buffaloes
                         in each experiment. Interval between first and
                         second estrus was about 4 d shorter in limited-
                          suckled buffaloes in Experiment 1; such a dif-
                         ference was not observed in Experiment 2 (Ta-
                         ble 4).
                                Jonmal of Dairy Science Vol. 73, No. 6, 1990
1568                                                          I.
                                                    USMANI ET A.

TABLE 4. Postpartum estrous activity, luteal function after first observed estrus, and pregnancy raks in buffaloes.
                                                       Experiment 11                          Expe&nent 2
                                                             Limited-suckled                       Limited-suckled
Variable                                     Milked          andmillied         Milked             andmilked
                                             X        SEM           SEM                SEM         z        SEM
Interval to first eshus, d                   39.0   2.4"     60.7   3.3b        41.8   3.y         75.9     4 9
Duration of fmt estrus, h                    16.9   15       16.5   2.3         17.2   2.8         20.1     22
Length of luteal phase after first estrus:
 Based on progesterone, d                    17.1   .9       15.3    .8         14.3   1.6         17.0     1.4
 Based on palpable CL, d                     11.9   .7       12.0    .6         11.5   1.0         11.9     1.0
First estrous cycle, d                       24.6 1.p        21.0    .gf        22.8   1.8         22.7     1.3
Interval fiom calving to second estrus, d    63.6 2.2'       81.9   3.8b        64.5   3.3'        98.6     4.2b
Duration of second estrus. h                 30.6 2.4        29.5   2.9         30.8   2.7         31.3     3.2
presnan~yrate, d                             53              44                 50                 50
   + b * c l + , f ~ a n ~ SEM) within same r o w and experiment beanng a different superscript differ. + b ~ < . ~ l .
   'Buffaloes were inseminated at second estrus after calving. Pregnancy was diagnosed by utenhe palpation per rectum
on d 45 to 50 postbreeding.

    Duration of first or second observed estrusand magnitude of uterine contractions has been
was not a€fectedby suckling, but second estrus proposed (13) but was not supported in recent
was consistently longer than first estrus. In  studies in postpartum dairy cows where daily
Experiment 1, the duration of first estrus was injections of oxytocin from parturition to d 28
longer (k.01) for buffaloes that calved during postpartum did not alter the rate of uterine
November (24.0 f 3.3 h) than for buffaloes thatinvolution (18).
calved during August through October (15.0 f      The more rapid resumption of follicular de-
2.8 h).                                        velopment in nonsuckled buffaloes in the pre-
    Concentrations of progesterone were less   sent studies corroborates earlier reports on Nili-
than .8 n g / d on the day of first estrus, in-Ravi (20) and Murrah buffaloes (15). The inter-
creased to more than 2.0 ng/ml by d 4, and     vals were shorter when follicular development
remained high (6.8 f 1.5) for 14 to 17 d beforeresumed on the ovary contralateral to the previ-
returning to baseline at about 48 to 72 h priorously gravid uterine horn in nonsuckled buffa-
to second estrus. A developing C was palpa-
                                   L           loes (15) and cows (16).
ble by d 5 to 7 postestrus, and its palpable life The delayed onset of ovarian and estrous
span averaged 12 d. Functional and structural  activities after calving in limited-suckled com-
life spans of CL formed after first estrus werepared with nmsuckled buffaloes is in agree-
similar in all buffaloes. Regnancy rate to     ment with previous repom for dairy buffaloes
breeding at second postpartum estrus averaged  (10, 19), beef cows (1, 25) and dairy cows (5).
about 50% and w s not affected by any factor
                  a                            Intensity of suckling (27), number of calves
studied.                                       suckling per cow (26), and weaning age of
                                               calves (1) were correlated negatively with re-
                                               sumption of luteal activity in postpamun beef
                                               cows. The mechanism of depression in ovarian
   Enhancement of uterine involution by lim- activity due to suckling is not clearly under-
ited suckling is in agreement with our earlier stood. However, most workers agree that suck-
work with Nili-Ravi buffaloes (19) but was not ling decreases mean LH and frequency and
observed in Egyptian buffaloes (10). In dairy amplitude of LH pulses (25, 28).
and beef cows, most workers have reported         Frequent Occurrence of at least one short
more rapid uterine involution due to suckling luteal phase before first observed estrus (86%)
(13), but the mechanism is not understood An c o n f i i s results of our earlier studies with N l -
oxytocin-mediated increase in the frequency Ravi buffalo (20). Similar patterns of reestab-
Journal of Diy Science Vol. 73, No. 6, 1990
                           SUCKLING AND REF’RODUCIION IN BUFPALOES                                        1569
 lishment of cyclic activity after parturition have   ment and gained weight prepartum (21). Post:
 been documented for cows, ewes, and primates         partum feeding presumably supplied enough
 (14). Inadequate luteotropic support and hyper-      energy for maintenance of lactation so that
 sensitivity to uterine prostaglandin F , are not     buffaloes did not suffer the “lactational stress”
 responsible for the short-lived CL (7).              reported to reduce the return to reproductive
    The interval from end of first to beginning       competence in postpartum dairy cows (11, 17).
 of next rise in progesterone was longer (1 1 to         Net profitability of any dairy female is deter-
 16 d) than the 6 to 7 d reported for normally        mined by miUc producing ability and calving
 cycling buffaloes (8). Resumption of ovarian         frequency. Usmani and Inskeep (21) indicated
 activity in postpartum buffaloes appears to be       that better nutrition of buffaloes in advanced
 characterizedby the occurrence of a short luteal     pregnancy is likely to result in greater returns
 phase, which is followed by a long follicular        from milk production. Although limited-suck-
 phase before fist observed estrus; similar           led buffaloes had a small edge over nonsuckled
 events were seen earlier in postpartum buffa-        buffaloes in terms of 75-d yields of milk and
 loes (20).                                           milk fat, nonsuckled buffaloes are expected to
    Underestimation of early postpartum luteal        be more profitable due to their better reproduc-
 activity by rectal palpation of buffaloes is con-    tive efficiency after calving. Because pregnancy
 sistent with our earlier report in Niii-Ravi buf-    rate did not differ with suckling when buffaloes
 faloes (20). Changes in concentrations of pro-       were bred at second estrus after calving @re-
gesterone in plasma or milk should be used            sent studies), the calving interval of nonsuckled
 along with rectal palpation for accurate mea-        buffaloes would be about 1 mo shorter than that
surement of luteal activity.                          of limited-suckled buffaloes (10, 19).
    Normal length of the estrous cycle of buffalo
ranges from 19 to 24 d with an overall mean of                       ACKNOWLEDGMENTS
21 d (2, 8). No report could be found regarding
the effects of limited suckling on estrous               The authors thank Naeem Iqbal (Islamabad,
cyclicity of buffalaes. In Experiment 1, limited      Pakistan) for his help in feeding and palpations
suckling shortened the interval from first to         of experimental buffaloes; E. C.Townsend for
second observed estrus, whereas length of es-         his help in the statistical analyses of the data,
trous cycle was normal in both groups of buffa-       and Gretchen Riggs for typing the manuscript.
loes in Experiment 2. Neither functional nor                                       aitn
                                                      Financial support by the P k s a Agricultural
structural life spans of CL f m e d after first       Research Council and the Food and Agriculture
estrus differed with suckling in either experi-       Organization of the United Nations for the
ment. Combining the fact that herd location and       graduate study program of R.H. Usmani at
season of calving differed between these two          West Virginia University are highly appreciat-
experiments with previous results in buffaloes        ed. We acknowledge the cooperation of staffs
(8, 20), it appears that environmental and man-       of the Animal Sciences Institute (Islamabad)
agemental factors can alter the onset and inten-      and the Livestock Experiment Station
sity of estrous behavior in this species.             (Bahadamagar) during the study. This manu-
    Studies with beef cows indicate that prepar-      script is published with the approval of the
tum nutrition partially determines reproductive       director of the West Virginia Agricultural and
efficiency during the postpartum period (4, 11).      Forestry Experiment Station as Scientific Paper
Reproductive efficiency decreased only when           Number 2139 from the Division of Animal and
cows were restricted in energy intake prior to        Veterinary Science.
calving, and supplementation to moderate en-
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                                                            J o d of D i y Science Vol. 73, No. 6, 1990
1570                                              USMAM ET AL.

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Journal of Dairy Science Vol. 73, No. 6, 1990

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