Body condition scoring of local Ossimi ewes at mating and its impact on fertility and prolificacy

Abstract

The aim of this work was to study how body condition score (BCS) of Ossimi ewes (no.=362) at mating could be reflected on fertility, fecundity and prolificacy traits. Ewes were scored for body condition which employs a 1 to 5 score scale with an interval range of 0.5 point. Ewes were synchronized for estrus with PGF 2α and were introduced to fertile rams to be hand-mated. Breeding season of ewes extended from the 1 st of September to the end of December 2007. BCS of Ossimi ewes at mating was significantly (P < 0.05) affected both fertility and fecundity measurements. Half of ewes that scored very low (1.5) and quarter of those scored high (3.5-4) did not show estrus. Through 2 estrous cycles, 82 – 84 % of moderate BCS (2.5-3) ewes were conceived, while only 17% of very low BCS ewes were conceived. Also, the estimates of lambs born per ewes joined (LB/EJ) and kilograms born per ewes joined (KgB/EJ) were the highest in ewes that had moderate BCS (2.5 – 3) at mating. BCS did not affect both lambs born per ewe lambing (LB/EL) and pregnancy period. Therefore, its recommended to maintain the body score of ewes at mating in a moderate condition (2.5 or 3 BCS) to optimize profitability of commercial sheep flocks.

Full text

Egyptian Journal of Sheep & Goat Sciences, Vol. 4 (1), 2009: 37 - 44
37
BODY CONDITION SCORING OF LOCAL OSSIMI EWES AT
MATING AND ITS IMPACT ON FERTILITY AND PROLIFICACY
Abdel-Mageed, I.
Animal Production Department, Faculty of Agriculture, Cairo University, Giza, Egypt.
ABSTRACT
The aim of this work was to study how body condition score (BCS) of Ossimi ewes
(no.=362) at mating could be reflected on fertility, fecundity and prolificacy traits. Ewes were
scored for body condition which employs a 1 to 5 score scale with an interval range of 0.5 point.
Ewes were synchronized for estrus with PGF2αand were introduced to fertile rams to be hand-
mated. Breeding season of ewes extended from the 1st of September to the end of December
2007. BCS of Ossimi ewes at mating was significantly (P < 0.05) affected both fertility and
fecundity measurements. Half of ewes that scored very low (1.5) and quarter of those scored
high (3.5-4) did not show estrus. Through 2 estrous cycles, 82 –84 % of moderate BCS (2.5 - 3)
ewes were conceived, while only 17% of very low BCS ewes were conceived. Also, the
estimates of lambs born per ewes joined (LB/EJ) and kilograms born per ewes joined (KgB/EJ)
were the highest in ewes that had moderate BCS (2.5 –3) at mating. BCS did not affect both
lambs born per ewe lambing (LB/EL) and pregnancy period. Therefore, its recommended to
maintain the body score of ewes at mating in a moderate condition (2.5 or 3 BCS) to optimize
profitability of commercial sheep flocks.
Key words: sheep –body condition –fertility –prolificacy - profitability
INTRODUCTION
Body weight of the ewe at mating has been shown to influence subsequent litter
size (Gordan, 1997). The body weight of the ewe has two components, basic skeletal
size of the sheep on one hand and the degree of fatness (body condition, BC) on the
other hand. Moreover, body condition score (BCS) is a better predictor than live weight
for the weight of both total body fat and the individual fat depots (Teixeira et al.,
1989). The concept of BCS has been described as the relationship between fat and non-
fat tissues in the living animal (Caldeira et al., 2007a).
Subjective estimates of body condition are used widely by farmers and
technicians for describing body condition in sheep, based on five-point scale assessed
by palpation of the lumbar region (Teixeira et al., 1989). This method assesses mainly
subcutaneous fat cover with some indications of muscle thickness.
A subjective body condition scoring system can be useful in assessing the
nutritional status of ewes (Thompson and Cheeke, 2005 and Naziha et al., 2001).
Also, the general metabolic status of ewes may be monitored by body condition on a

Abdel-Mageed, I., 2009
38
regular basis (Caldeira et al., 2007b). BCS provides not only a reliable prediction of
the reserves available to comply with the animal’s need, but its way of changing can
also offer a broad picture of the predominant orientation of metabolism.
Merrell (1990) emphasized that, ewes should be scored 6-8 weeks prior to the
start of mating, so that appropriate action may be taken to get as many sheep as possible
to the optimum condition (scores 2.5-3) at the time rams are introduced. BCS should be
monitored on a quarterly basis by someone from outside the herd as recommended by
Mosenfechtel (2004).
Ova wastage rates are increased and reproductive performance is reduced in ewes
in very high levels of body condition (Gunn et al., 1983 and Rhind et al., 1984).
While Rhind et al. (1990) reported that thare are non significant effects of ewe BCS on
its ovulation rate, pregnancy rate and ova wastage. On the other hand, poor body
condition was associated with a suppression of estrus (Gunn and Doney, 1975).
Effect of body condition score on reproductive performance of local sheep was
not studied, so it is the aim of this work.
MATERIALS AND METHODS
The present study was carried out on a commercial sheep flock located in
Sharqia Governorate. Ossimi ewes (n = 362) of the age 1-5 years with average
body weight 40 kg were permitted to breed in Autumn 2007 to study the impact
of body condition score of ewes at mating on their fertility, fecundity and
prolificacy traits.
Management of the flock:-
A day before the onset of breeding season, ewes were weighed and scored
to BC. The BCS was measured by using the technique of Russel et al. (1969)
which employs a 1 to 5 score scale, in addition to an interval range of 0.5 point.
Ewes were kept loose in semi-shade pens, where drinking water was
available all day time. Egyptian clover (Trifolium Alexendrinum), clover hay,
concentrate mixture and wheat straw were used for ration formulation according
to season of the year.
During dry, early and mid pregnancy periods maintenance requirements
were offered to ewes, while through pre-mating season (2 weeks), late
pregnancy and lactation periods feed offered was increased by about 50%.
Estrus synchronization and mating:-
Ewes were estrus-synchronized with intramascular dose of 0.5 ml PGF2α
(Estrumate, 125µg Cloprostenol, Coopers Company, England). After 11 days of

BODY CONDITION SCORING OF LOCAL OSSIMI EWES AT MATING AND ITS
IMPACT ON FERTILITY AND PROLIFICACY
39
the 1st injection, ewes did not show estrus were injected with another 0.5 ml
dose. Simultaneously, with the 1st and the 2nd injections of Estrumate, ewes
came in heat were introduced to fertile rams to be hand-mated. Breeding season
extended from 1st October to the end of December. The production system of the
flock was based on three breeding seasons per 2 years.
Measured traits:
Fertility traits: ewes did not show estrus per ewes joined to rams (EDSE/EJ),
ewes conceived per ewes joined (EC/EJ), ewes aborted per ewes
joined (EA/EJ) and ewes lambed per ewes joined (EL/EJ).
Fecundity traits: lambs born per ewes joined (LB/EJ) and kilograms born per
ewes joined (KgB/EJ).
Prolificacy traits: lambs born per ewe lambing (LB/EL) and kilograms born per
ewe lambing (KgB/EL).
Other traits: birth weight of lambs and pregnancy period.
Statistical analysis:-
Data were subjected to one-way analysis of variance to determine
statistical significant differences among different body condition scores using
Duncan Multiple Range Test of SPSS (2007).
RESULTS AND DISCUSSIONS:
Fertility and fecundity traits:-
All fertility and fecundity traits were significantly (P < 0.05) affected by
BCS of ewes, as presented in tables 1 and 2.
Table 1 shows that half of ewes given very low BCS (1.5) and about
quarter of those given the highest BCS (3.5 –4) did not exhibit estrus despite
extending the breeding season for three months, which reinforces the importance
of BCS of ewes for their estrous activity as previously reported by Rhind et al.
(1984) and Gordon (1997). Where BCS of a ewe directly related to
hypothalamic activity and GnRH secretion and that affects the reproductive
performance (Gordon, 1997).

Abdel-Mageed, I., 2009
40
Table 1: Means ± SE for ewes did not show estrus per ewes joined (EDSE/EJ) and
ewes conceived per ewes joined (EC/EJ) according to body condition score
(BCS) of ewes at mating.
BCS
No.
EDSE/EJ
EC1/EJ
EC2/EJ
EC1+2/EJ
EC≥3/EJ
1.5
12
0.50d± 0.15
0.17b± 0.11
0.00b± 0.00
0.17d± 0.11
0.33ab ± 0.14
2
104
0.10ab ± 0.03
0.17b± 0.04
0.29a± 0.04
0.46c± 0.05
0.44a± 0.05
2.5
98
0.00a± 0.00
0.31ab ± 0.05
0.53a± 0.05
0.82ab ± 0.04
0.18b± 0.04
3
86
0.00a± 0.00
0.44a± 0.05
0.40a± 0.05
0.84a± 0.04
0.16b± 0.04
3.5
42
0.24c± 0.07
0.24ab ± 0.07
0.33a± 0.07
0.57c± 0.08
0.19b± 0.06
4
20
0.20bc± 0.09
0.10b± 0.07
0.50a± 0.11
0.60cd ± 0.11
0.20b± 0.09
Total
362
0.08 ± 0.01
0.28 ± 0.02
0.39 ± 0.02
0.66 ± 0.02
0.26 ± 0.02
Means within columns with different superscripts are significantly different at 5% level.
EC1: ewes conceived in the 1st estrus
EC2: ewes conceived in the 2nd estrus
EC1+2/EJ: ewes conceived in the 1st two estruses
EC≥3: ewes need 3 estruses or more to be conceived
Rhind et al. (1984) recorded 20% reduction in ewes showing estrus of
Greyface sheep had very fat BCS (3.5) compared to intermediate fat ones (BCS
= 2.75) which is consistent with the results of the present study, suggesting a
problem of ewes in very fat condition during the breeding season.
The highest estimate (0.44) for EC/EJ in the mating of the 1st estrus was
recorded by ewes that had BCS of 3, while lower estimates 0.17, 0.17 and 0.10
were recorded in ewes of BCS 1.5, 2 and 4, respectively. Which means that
ewes had very low or very high BCS were conceived in the 1st estrus, that led to
increase the lambing interval of sheep flock; particularly for ewes had very low
BCS where no ones of 1.5 BCS were conceived by mating of the 2nd estrus.
Anyway, ewes that had score below 2 may need to be drawn out of the flock and
given access to the best available grazing as recommended by Gordan (1997).
The succeeded commercial sheep flock depends on only 2 estrous cycles
(about 35 days) in its breeding season and culling individuals that are not
conceived. In this regard, 82 –84 % of ewes that had moderate BCS (2.5 and 3)
were conceived through 2 estrous cycles, while only 17 - 46 % of ewes that had
BCS of 1.5 - 2 and 57 –60 % of ewes that had BCS of 3.5 - 4 were conceived.
About two fifths of the low BCS ewes and fifth of the high BCS ones
needed more than 2 estruses to be conceived, and reached to five estruses in
some ewes. Any way, a BCS below 1.5 and above 3.5 must be avoided to
prevent metabolic disturbances and to save the cost of excessive fattening in
ewes (Caldeira et al., 2007b).

BODY CONDITION SCORING OF LOCAL OSSIMI EWES AT MATING AND ITS
IMPACT ON FERTILITY AND PROLIFICACY
41
Ewes had the lowest and the highest BCS recorded (Table 2) considerable
estimates (10 –17 %) of abortion than moderate BCS ones (0 –2 %). Also, 98%
of 2.5 and 3 BCS ewes were lambed compared to only 17% among 1.5 BCS
ewes. It could be concluded that hormones and metabolite concentrations
during the chronology of changes in BCS clearly show that ewes easily
managed their body reserves when BCS was between2 and 3.5 (Caldeira et al.,
2007b).
Table 2: Means ± SE for ewes aborted per ewes joined (EA/EJ), ewes lambed
per ewes joined (EL/EJ), lambs born per ewes joined (LB/EJ) and kilograms born
per ewes joined (KgB/EJ) according to body condition score (BCS) of ewes at
mating.
BCS
No.
EA/EJ
EL/EJ
LB/EJ
KgB/EJ
1.5
12
0.17c± 0.11
0.17c± 0.11
0.17d± 0.11
1.07b± 0.46
2
104
0.02ab ± 0.01
0.75b± 0.04
0.82bc ± 0.05
2.76a± 0.21
2.5
98
0.02ab ± 0.01
0.98a± 0.01
1.06a± 0.03
3.38a± 0.15
3
86
0.02ab ± 0.02
0.98a± 0.02
1.12a± 0.03
3.30a± 0.15
3.5
42
0.00a± 0.00
0.76b± 0.07
0.95ab ± 0.10
2.39a± 0.33
4
20
0.10bc ± 0.07
0.60b± 0.11
0.70c± 0.15
2.63a± 0.52
Total
362
0.03 ± 0.01
0.84 ± 0.02
0.94 ± 0.03
2.95 ± 0.10
Means within columns with different superscripts are significantly different at 5% level.
The highest estimates for LB/EJ and KgB/EJ (Table 2) were attained with
moderate BCS ewes, that corresponds with that mentioned before by Caldeira
et al. (2007b). That evident metabolic welfare is observed for ewes between
BCS of 2.5 and 3. The results of LB/EJ confirm previous findings that variation
in BCS of ewes at mating reflected on lamb crop of sheep flocks. Rhind et al.
(1984) recorded about 23% increase for potential lambing rate (LB/EJ) for
moderate BCS ewes (2.75) than the very fat ones (BCS = 3.5).
An insignificant increase was attained in LB/EL of ewes concomitant with
increasing their BCS (Table 3), that agreed with the results of Naziha et al.
(2001) working on fat-tailed Barbarine ewes where the highest prolificacy was
attained between BCS of 3.5 and 4. Birth weight of lambs was significantly
affected by BCS of their dams, while pregnancy period was not affected by it.

Abdel-Mageed, I., 2009
42
Table 3: Means ± SE for lambs born per ewes lambing (LB/EL), kilograms born
per ewes lambing (KgB/EL), birth weight of lambs and pregnancy
period (PP) according to body condition score (BCS) of ewes at
mating.
BCS
LB/EL
KgB/EL
Birth weight (kg)
PP (d)
Singles
Twins
1.5
1.00 ± 0.00
(2)
3.10b± 0.00
(2)
1.07b± 0.46
(2)
-
(0)
152.00± 0.00
(2)
2
1.08 ± 0.03
(78)
3.86ab ± 0.17
(76)
3.43ab ± 0.08
(66)
3.80a± 0.19
(16)
152.00± 0.35
(52)
2.5
1.08 ± 0.03
(96)
3.68ab ± 0.12
(90)
3.41ab ± 0.08
(82)
3.18c± 0.09
(16)
151.14 ± 0.38
(72)
3
1.12± 0.04
(84)
3.64ab ± 0.11
(78)
3.47ab ± 0.07
(74)
3.40b± 0.04
(8)
151.39 ± 0.32
(66)
3.5
1.25 ± 0.08
(32)
3.87ab ± 0.23
(26)
3.31ab ± 0.14
(20)
2.87c± 0.07
(12)
151.00± 0.38
(26)
4
1.17 ± 0.11
(12)
4.38a± 0.31
(12)
4.00a± 0.20
(10)
3.40b± 0.03
(6)
152.00± 1.10
(6)
Total
1.11 ± 0.02
(304)
3.76 ± 0.07
(284)
3.44 ± 0.04
(254)
3.34 ± 0.08
(58)
151.30 ± 0.18
(224)
Means within columns with different superscripts are significantly different at 5% level.
Numbers between parentheses represent number of observations.
Therefore, it is recommended to maintain the body score of ewes at mating
in a moderate condition (2.5 or 3 BCS) to optimize profitability of commercial
sheep flocks.
REFERENCES
Caldeira, R. M., Belo, A. T., Santos, C. C., Vazques, M. I. and Portugal, A. V.
(2007 a). The effect of body condition score on blood metabolites and hormonal
profiles in ewes. Small Rum. Res., 68:233-241.

BODY CONDITION SCORING OF LOCAL OSSIMI EWES AT MATING AND ITS
IMPACT ON FERTILITY AND PROLIFICACY
43
Caldeira, R. M., Belo, A. T., Santos, C. C., Vazques, M. I. and Portugal, A. V.
(2007 b). The effect of long-term feed restriction and over-nutrition on body
condition score, blood metabolites and hormonal profiles in ewes. Small Rum.
Res., 68:241-255.
Gordon, I. (1997). "Controlled Reproduction in Sheep and Goats". CAB
International Wallingford Oxon UK.
Gunn, R. G. and Doney, J. M. (1975). The interaction of nutrition and body condition
at mating on ovulation rate and early embryo mortality in Scottish Blackface
ewes. J. Agric. Sci., Camb., 79: 19-25.
Gunn, R. G., Smith, W. F., Senior, A. J., Barthram, E. and Sim, D. A. (1983).
Premating pasture intake and reproductive responses in North Country Cheviot
ewes in different body conditions. Anim. Prod., 36: 509 (abstract).
Merrel, B. G. (1990). The effect of duration of flushing period and stocking rate on
the reproductive performance of Scottish Blackface ewes. In: New
Developments in Sheep Production (BSAP Symposium, Malvern), pp. 138-141.
Mosenfechtel, S. (2004). Good fertiltiy with a good body condition. Milchpraxis,
42(1): 12-15.
Naziha, A., Michel T. and Latifa, A. (2001). Relationship between body condition at
mating and reproductive performance in the fat-tailed Barbarine breed. Anim.
Res., 50: 135-144.
Rhind, S. M., Gunn, R. G., Doney, J. M. and Leslie, I. D. (1984). A note on the
reproductive performance of Greyface ewes in moderately fat and very fat
condition at mating. Anim. Prod., 38: 305-307.
Rhind, S. M., Wetherill, G. Z. and Gunn, R. G. (1990). Diurnal profiles of LH,
prolactin and progesterone and their inter-relationships in ewews in high or
moderate levels of body condition. Anim. Reprod. Sci., 24: 119-126.
Russel, A. J. F., Doney, J. M. and Gunn, R. G. (1969). Subjective assessment of
body fat in live sheep. J. Agric. Sci., Camb., 72: 451-454.
SPSS Inc. (2007). SPSS production facility release 16.
Teixeira, A., Delfa, R. and Colomer-Rocher, F. (1989). Relationships between fat
depots and body condition score or tail fatness in the Rasa Aragonesa breed.
Anim. Prod., 49: 275-280.
Thompson, M. I. and Cheeke, P. R. (2005). ‘'Feeding and Nutrition of Small
Ruminants’': sheep, Goats and Lamas, Applied Animal Nutrition, 3rd Edition, by
Peter R. Cheeke, Pearson Prentic Hall, New Jersy, USA.