Effect of timing of exposure to vasectomised rams and ewe lamb body condition score on the breeding performance of ewe lambs

2012 ◽  
Vol 52 (7) ◽  
pp. 471 ◽  
Author(s):  
L. M. Cave ◽  
P. R. Kenyon ◽  
S. T. Morris
Keyword(s):  
Body Condition ◽  
Reproductive Performance ◽  
Body Condition Score ◽  
Breeding Period ◽  
Breeding Performance ◽  
Ewe Lambs ◽  
Percentage Points ◽  
Condition Score ◽  
Ewe Lamb ◽  
Timing Of Exposure

The aims of this study were to examine the effects of exposing Romney ewe lambs (8–9 months of age) to vasectomised rams across three studies in the February–March period and to determine the influence of body condition score (CS) in two of the studies on their reproductive performance. In all studies, ewe lambs exposed to vasectomised rams had greater (P < 0.05) conception rates to the first 17 days of breeding by 6–12 percentage points. However, Studies 2 and 3 indicated that exposing ewe lambs to vasectomised rams did not increase (P > 0.05) the percentage of ewe lambs conceiving over a 34-day breeding period, nor did it increase the number of fetuses per ewe lamb presented for breeding. The results of Study 1 suggest that there is a limit to how early in the year ewe lambs can be exposed to vasectomised rams. In Study 2, a greater (P < 0.05) percentage of Teased CS 2.0 or 2.5+ ewe lambs conceived during the first 17 days of breeding than those which were Unteased. This effect was not observed (P > 0.05) in CS 1.5 ewe lambs. In Study 3, a greater (P < 0.05) percentage of CS 2.5+ ewe lambs conceived over the 34-day breeding period than ewe lambs of lower CS. In Studies 2 and 3, ewe lambs with a CS of 2.5+ had a greater (P < 0.05) number of fetuses per ewe lamb presented for breeding than CS 1.5 ewe lambs. In conclusion, exposing ewe lambs to vasectomised rams in the late February or March period increased the proportion of ewe lambs successfully bred in the first 17 days of breeding. Further achieving higher CS and heavier liveweights of ewe lambs at breeding should result in improved reproductive performance.

Proportion of rams and the condition of ewe lambs at joining influences their breeding performance

2010 ◽  
Vol 50 (6) ◽  
pp. 454 ◽  
Author(s):  
P. R. Kenyon ◽  
S. T. Morris ◽  
D. M. West
Keyword(s):  
Reproductive Performance ◽  
Pregnancy Rates ◽  
Breeding Period ◽  
Breeding Performance ◽  
Ewe Lambs ◽  
Condition Score ◽  
Ewe Lamb ◽  
In Pregnancy

The aim of the present study was to examine the effects of ram : ewe lamb ratio and condition score on the reproductive performance of ewe lambs. In the 2007 study, ewe lambs were bred with rams, at ram : ewe lamb ratios of 1 : 30, 1 : 50, 1 : 75 or 1 : 100. In the 2008 study, ewe lambs were bred at ratios of 1 : 31, 1 : 50, 1 : 75 or 1 : 100. Ewe lambs were bred over two 17-day periods. In both studies, ewe lambs bred in the first 17 days of breeding only were heavier (P < 0.05) than those bred in the second 17-day period only, and those ewe lambs diagnosed as twin-bearing were heavier (P < 0.05) than their single-bearing counterparts. Ewe lambs with a condition score of 2.5 or greater were more likely (P < 0.05) to be bred, and be pregnant, in the first 17 days of breeding than those of condition score 1.5 or 2.0. Over the entire 34-day breeding period, ewe lambs with a condition score of 2.5 or greater had higher (P < 0.05) pregnancy rates than those with a condition score of 2.0, which in turn had higher rates than those of 1.5. In the 2007 study, after 34 days of breeding, there were no differences (P > 0.05) in pregnancy rates among the different ram : ewe lamb ratios. While in the 2008 study, pregnancy rates after 34 days were greater (P < 0.05) in the 1 : 50 compared with both the 1 : 75 and 1 : 100 treatments. Pregnancy rates of 1 : 31 ewe lambs were greater (P < 0.05) than those of 1 : 75 ewe lambs. In the 2007 study, pregnancy rates of ewe lambs to the first 17 days of breeding were greater (P < 0.05) for those bred at a ratio of 1 : 75 than for those bred at 1 : 50, and tended to be greater (P = 0.08) than for those bred at 1 : 100. In addition, those bred at a ratio of 1 : 30 tended to have higher pregnancy rates (P = 0.07) than those bred at 1 : 50. While in the 2008 study, pregnancy rates to the first 17 days of breeding were greatest (P < 0.05) in the 1 : 31 and 1 : 50 treatments groups. In conclusion, the results of the present study indicate that achieving greater liveweights and higher condition scores of ewe lambs at breeding will increase the proportion pregnant, especially early in the breeding period. The data also suggest, in combination with the results of previous research, that farmers should consider utilising ram : ewe lamb ratios lower than 1 : 100, although further studies are warranted.

Effect of body condition and breeding history on the reproductive performance of twenty month old female breeding sheep

1993 ◽  
Vol 1993 ◽  
pp. 92-92
Author(s):  
Linda M Mitchell ◽  
Margaret E King
Keyword(s):  
Body Condition ◽  
Reproductive Performance ◽  
Body Condition Score ◽  
Combined Effect ◽  
Embryo Mortality ◽  
Optimum Performance ◽  
Ewe Lambs ◽  
Agricultural College ◽  
Condition Score ◽  
Breeding History

Ovulation rate in the ewe is positively related to body condition score (Gunn, Doney and Smith, 1979). For optimum performance it has been recommended that ewes should be in body condition score 3.5 at mating (MLC. 1981). However excessive fatness (body condition score 3.5 and above) has been associated with a reduction in lambing performance as a consequence of increased embryo mortality (Rhind, Gunn, Doney and Leslie. 1984).Previous studies at the Scottish Agricultural College-Aberdeen (King and Mitchell. 1990) have demonstrated superior reproductive performance for twenty month old female breeding sheep (gimmers) which have bred successfully as ewe lambs. The objective of the present study was to investigate the combined effect of body condition and breeding history (bred or unbred at eight months of age) on fecundity.

Relationship between genetic merit, milk production, body condition, blood parameters and reproductive performance of dairy cows

2001 ◽  
Vol 26 (2) ◽  
pp. 499-502
Author(s):  
S.E.M. Snijders ◽  
P.G. Dillon ◽  
K.J. O'Farrell ◽  
M. Diskin ◽  
D. O'Callaghan ◽  
...  
Keyword(s):  
Milk Production ◽  
Body Condition ◽  
Reproductive Performance ◽  
Body Condition Score ◽  
Plasma Concentrations ◽  
Breeding Period ◽  
Production Traits ◽  
Genetic Merit ◽  
Condition Score ◽  
Production Body

AbstractBased on their pedigree indices for milk production traits, 48 high (HM) and 48 medium (MM) genetic merit cows were studied in each of two years to determine the possible relationships between genetic merit, milk production, body condition, metabolite and hormone concentrations, feed intake and reproductive performance. The high genetic merit cows had higher milk production, greater body condition loss between calving and first service, lower plasma glucose and insulin-like growth factor-1 (IGF-1) and lower first and second service conception rates than the medium genetic merit cows. Furthermore, more high genetic merit cows were not pregnant at the end of the breeding period compared with medium genetic merit cows. Cows that did not conceive to first service were retrospectively compared to those that conceived to first service within each genetic merit category. Within the high and medium genetic merit category there were no significant differences between the cows that did not conceive and those that conceived to first service in terms of milk production, or plasma concentrations of glucose, non-esterified fatty acids (NEFA). Although medium genetic merit cows that did not conceive to first service lost more body condition score between calving and first service than those that conceived to first service, there was no difference in body condition score (BCS) change between calving and first service between high genetic merit cows that did not conceive and those that conceived to first service. In the present study, high genetic merit cows had higher milk production and reduced reproductive performance in comparison with medium genetic merit cows. However, reproductive performance was not associated with milk production, energy balance or plasma concentrations of glucose, NEFA or IGF-1 between calving and insemination

The effect of level of nutrition prior to mating on the reproductive performance of ewes of two welsh breeds in different levels of body condition

1991 ◽  
Vol 52 (1) ◽  
pp. 157-163 ◽  
Author(s):  
R. G. Gunn ◽  
T. J. Maxwell ◽  
D. A. Sim ◽  
J. R. Jones ◽  
M. E. James
Keyword(s):  
Body Condition ◽  
Reproductive Performance ◽  
Body Condition Score ◽  
High Surface ◽  
Live Weight ◽  
Corpora Lutea ◽  
Stocking Rate ◽  
Treatment Groups ◽  
Condition Score ◽  
Body Condition Scores

ABSTRACTThe effects of high-low (HL) and low-high (LH) patterns of nutrition during the 5 weeks prior to a synchronized mating were studied on the reproductive performance of 115 Welsh Mountain and 114 Brecknock Cheviot ewes in a range of body condition at the start of treatment. For 2 months prior to treatment imposition, ewes were grazed in a systematic way at different stocking rates on different sward heights to obtain a range of body condition scores. Target score groupings were 2·00 to 2·25, 2·50 to 2·75 and 3·00 to 3·25 and although scores of 1·50 to 3·25 were obtained, most lay in the 2·00 to 2·75 range. Two treatment groups, balanced for live weight and body condition score, received high and low levels of nutrition for 16 days from mid October, achieved, respectively, by a low stocking rate on a sward with a high surface height plus ad libitum concentrate and a high stocking rate on a sward with a low surface height plus 200 g hay per head per day. Treatments were then reversed for the 17 days prior to mating. Live-weight and body condition-score changes were recorded and reproductive performance at first mating was measured from counts of corpora lutea and viable embryos at slaughter either at return to service or at 4 weeks after first mating. There were no differences due to nutritional pattern in live weight or body condition score at mating. The LH treatment significantly increased the rates of ovulation, conception, multiple ova survival and potential lambing per ewe pregnant and per ewe mated in the Welsh Mountain breed but significantly increased only the rates of ovulation and potential lambing per ewe pregnant in the Brecknock Cheviot breed compared with the HL treatment. The relatively poorer response in the latter breed was partially due to a lower ovulation rate potential coupled with non-significantly lower rates of conception and survival of single-shed ova associated with the LH treatment. Much of this relatively poorer reproductive performance in the Brecknock Cheviot breed was in ewes with body condition scores 3= 2·75. Reproductive performance increased with increasing body condition at the start of treatment over the range of scores =≤ 2·25 to 2·50 in both breeds and, while continuing to improve in scores above 2·50 in the Welsh Mountain breed, in the Brecknock Cheviot breed it started to decline. Ewes with a body condition score of 2·50 in both breeds showed the greatest response in potential lambing rate to the LH treatment.

13 THE RELATIONSHIP BETWEEN EARLIER POSTPARTUM CYCLICITY AND SUBSEQUENT REPRODUCTIVE PERFORMANCE IN DAIRY COWS: A FIELD TRIAL

2011 ◽  
Vol 23 (1) ◽  
pp. 113
Author(s):  
I. H. Kim ◽  
H. C. Lee ◽  
H. G. Kang
Keyword(s):  
Dairy Cows ◽  
Body Condition ◽  
Reproductive Performance ◽  
Body Condition Score ◽  
Post Partum ◽  
Management Program ◽  
Breeding Period ◽  
Chi Square ◽  
Logistic Analysis ◽  
The Relationship

Earlier postpartum cyclicity based on hormonal analysis was related to the subsequent fertility, although it has not been clarified under field conditions. This field study examined the relationship between the detection of corpus luteum (CL) at the first post partum month and subsequent reproductive performance in dairy cows. Holstein dairy cows underwent ultrasonography (Sonoace 600 with 7.5 MHz linear-array transducer; Medison Co. Ltd., Korea) at 30 (±7) days postpartum to determine the existence of CL in ovaries and then divided into 2 groups based on the existence of CL; the CL group (n = 156) or the non-CL group (n = 281). At the same time of ultrasonography, all cows were scored for body condition. Cows received the normal herd reproductive management program including oestrous detection or synchronization, or synchronization of ovulation in the breeding period. Pregnancy was determined per rectum 60 days after artificial insemination by both ultrasonography and palpation. Reproductive performance data were collected for a minimum of 210 days postpartum. Reproduction data between the CL and non-CL groups were evaluated by t-test, chi-square test, or logistic regression using an SAS program (Version 9.1: SAS Institute, Inc., Cary, NC, USA). The proportion of cows with CL in ovaries at 30 (±7) days postpartum was 35.7% of all cows. The number of days to first insemination after calving was more delayed (P < 0.0001) in the non-CL group (100.1 ± 2.7 days) than in the CL group (80.9 ± 2.9 days), while the pregnancy rate to first insemination did not differ (P > 0.05) between the CL group (44.2%) and the non-CL group (45.9%). The CL group had higher pregnancy proportions (PP) within 60 (odds ratio, OR = 2.3; P = 0.0063), 90 (OR = 1.6; P = 0.04), and 120 days (OR = 1.5; P = 0.05) postpartum than the non-CL group; however, the PP within 150 or 210 days postpartum did not differ between the 2 groups (P > 0.05). Besides, logistic analysis revealed that cows with body condition score (BCS) ≥3.00 were more likely to have CL (OR = 1.8; P = 0.015) compared with cows with BCS ≤ 2.75, while primiparous cows were less likely to have CL (OR = 0.6; P = 0.0085) compared with multiparous cows. In addition, cows that underwent ultrasonography later than 30 days postpartum were more likely to have CL (OR = 1.6; P = 0.0192) compared with cows that underwent ultrasonography earlier. In conclusion, the earlier cyclicity based on the detection of CL using ultrasonography at the first postpartum month, which might be in part due to a higher BCS, predicts an enhanced reproductive performance in dairy cows, particularly during the early and early-mid lactations. This work was supported by the research grant of the Chungbuk National University in 2010.

Genetic aspects of body weight, body condition score, scrotal circumference and reproductive performance in Italian Holstein young bulls

2003 ◽  
Vol 2003 ◽  
pp. 53-53 ◽  
Author(s):  
S. Biffani ◽  
A.B. Samoré ◽  
F. Canavesi ◽  
E. Olzi ◽  
M. Cassandro
Keyword(s):  
Body Weight ◽  
Body Condition ◽  
Reproductive Performance ◽  
Body Condition Score ◽  
Point Of View ◽  
Progeny Testing ◽  
Scrotal Circumference ◽  
Good Physical Condition ◽  
Condition Score ◽  
Recessive Genes

Apart from all the issues regarding health and undesirable recessive genes, which are determining factors to identify bulls not suitable for AI, there are other aspects which can be considered. The principal aims of AI studs are the selection of the best animals from a genetic point of view and the production of semen in a very short time, in order to start progeny testing as soon as possible. In Italy progeny testing starts when 1200 straws for each young bull are available. This requirement implies that bulls should be in good physical condition. According to this, the genetic centre of the Italian Holstein Breeder Association (ANAFI) has been paying growing attention to animal welfare and fitness, recording routinely some biometrical indicators. Body weight (BW), scrotal circumference (SC), body condition score (BCS) are some examples of this policy and could be helpful and easy predictors of reproductive performance for a young progeny testing dairy bull. The objective of this report was to conduct a preliminary analysis on the genetic aspects of BW, BCS, SC, age at the 1st usable straw (AGE1) and age at the 1200th straw (AGE1200) in Italian Holstein young bulls.

Sign in / Sign up

Export Citation Format

Share Document