Does dam parity affect the performance of ewe progeny born to 2-year-old ewes?

2008 ◽  
Vol 48 (7) ◽  
pp. 979 ◽  
Author(s):  
P. R. Kenyon ◽  
S. T. Morris ◽  
H. T. Blair ◽  
K. J. Stafford
Keyword(s):  
Production Systems ◽  
First Year ◽  
Productive Performance ◽  
Breeding Performance ◽  
Female Progeny ◽  
Ewe Lambs ◽  
Birth Rank ◽  
Condition Score ◽  
Ewe Lamb ◽  
Puberty Onset

An increasing number of ewe lambs are being presented for breeding in New Zealand, resulting in more two-tooth ewes of second parity compared with the more normal first parity. The effect of this on the resulting ewe progeny is unknown but is of interest as they are potential replacement ewes. This study was designed to determine if parity of Romney two-tooth ewes had any effect on their ewe lamb progeny to 20 months of age. Two-hundred and fifty female progeny born to two-tooth dams, which had lambed as a ewe lamb (n = 97), failed to conceive at ewe lamb breeding (n = 79), or had not been presented for breeding as a ewe lamb (n = 74), were weighed at regular intervals. The progeny also had onset of puberty and two-tooth breeding and pregnancy scanning performance measured. There were no effects of dam group on liveweight, condition score, 18-month breeding performance or pregnancy diagnosis. However, ewe lambs born to dams which failed to conceive as ewe lambs themselves were less likely (P < 0.05) to achieve puberty. In comparison with single-born lambs, twin-born ewes were lighter (P < 0.05) during their first year of age only. Birth rank had no effect on puberty onset or 18-month breeding performance. These findings indicate that ewe progeny born to second parity two-tooths or two-tooths, which were not presented for breeding as a ewe lamb, do not differ in their productive performance and that either group are suitable as replacement ewes. However, progeny born to two-tooth dams, which failed to conceive as a ewe lamb, would be less suitable as replacement ewes in production systems where ewe lamb breeding is an integral component of the system. Further studies are required to determine if similar relationships would be observed under differing environmental conditions and with different breeds.

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.

Single female offspring born to primiparous ewe-lambs are lighter than those born to adult multiparous ewes but their reproduction and milk production are unaffected

2012 ◽  
Vol 52 (7) ◽  
pp. 552 ◽  
Author(s):  
M. F. P. Loureiro ◽  
S. J. Pain ◽  
P. R. Kenyon ◽  
S. W. Peterson ◽  
H. T. Blair
Keyword(s):  
Milk Production ◽  
Reproductive Performance ◽  
Crude Protein ◽  
Female Offspring ◽  
Productive Performance ◽  
Single Female ◽  
Ewe Lambs ◽  
Ewe Lamb ◽  
Generation Offspring

Little is known about the long-term impacts of selecting progeny born to ewe-lambs (EL) as replacements. This study investigated whether being born to a ewe-lamb affected the liveweight, milk production and reproductive performance of the offspring to 3 years of age in comparison with those born to adult multiparous ewes. Twenty-seven and 28 single-born Romney ewe progeny (G1) were born to either EL or to adult ewes (AE), respectively. Offspring born to ewe-lambs (ELG1) were lighter (P < 0.001) at birth and up to 12 months of age compared with offspring born to adult ewes (AEG1). Reproductive performance of AEG1 and ELG1 did not differ in regards to puberty attainment, pregnancy rate and number of fetuses. First lactation milk production, fat, crude protein, total protein, casein, lactose and total solids yield did not differ (P > 0.05). The second generation offspring born to ELG1 and AEG1 did not differ in birthweight in the first parity, but it did differ in the second parity and those lambs born to ELG1 were heavier from birth to weaning compared with those lambs born to AEG1. Combined, these results indicate, in the animals used in our study that productive performance of ewes born to EL does not differ to 3 years of age to that of ewes born to AE.

scholarly journals Influence of feeding differentiation on the age at onset of puberty in Brazilian Bergamasca dairy ewe lambs

2016 ◽  
Vol 68 (1) ◽  
pp. 22-28 ◽  
Author(s):  
A. Dantas ◽  
E.R. Siqueira ◽  
S. Fernandes ◽  
E. Oba ◽  
A.M. Castilho ◽  
...  
Keyword(s):  
Body Condition Score ◽  
Phase 1 ◽  
Average Daily Gain ◽  
Age At Onset ◽  
Phase 2 ◽  
Plasma Growth Hormone ◽  
Ewe Lambs ◽  
Condition Score ◽  
Puberty Onset ◽  
Daily Gain

The objective of the study was to evaluate body growth and age at onset of puberty on lambs fed two specific diets for low and high growth rates. A herd of 20 Brazilian Bergamasca lambs was divided in two groups (n= 10) and kept confined throughout the experimental period, two animals of the same treatment/pen. Two phases were established: Phase 1, from 90 days of age until the onset of puberty; and Phase 2, from puberty onset up to 1 year old. For Phase 1, two distinct diets were formulated, being: Treatment A, which was formulated to obtain an average daily gain of approximately 150g; and Treatment B, for an average daily gain of about 250g. In Phase 2, a balanced, equal diet was provided to both groups. Every 14 days, the animals were weighed and given average daily gain, average daily dry matter intake and body condition score. From the 5th month of age on, in each group, a vasectomized male was used to detect estrus, establishing age at puberty onset and estrus interval for each lamb. Blood samples were collected every 28 days to determine plasma growth hormone concentration. Treatment B lambs gained more weight and had higher body condition score (P<0.05) and there was no difference for age at puberty onset and plasma growth hormone levels (P>0.05) between treatments. It was found that both treatments showed satisfactory performances. Thus, treatment A may be indicated as a reasonable feeding system to achieve positive responses on confined ewe lambs during growth phase.

Effect of nutrition pre-breeding and during pregnancy on breeding performance of ewe lambs

2010 ◽  
Vol 50 (10) ◽  
pp. 953 ◽  
Author(s):  
F. J. Mulvaney ◽  
S. T. Morris ◽  
P. R. Kenyon ◽  
P. C. H. Morel ◽  
D. M. West
Keyword(s):  
Pregnancy Rate ◽  
Breeding Period ◽  
Breeding Performance ◽  
Pregnancy Diagnosis ◽  
Breeding Group ◽  
Ewe Lambs ◽  
Ewe Lamb ◽  
Breeding Groups ◽  
Pregnant Ewe ◽  
Medium Group

The objective of the present studies was to investigate the effect of differing nutritional levels before breeding and during the pregnancy period on the breeding activity, conception rate (proportion pregnant/ewe lambs bred), pregnancy rate (proportion pregnant/ewe lambs joined with the ram) and the number of fetuses identified at pregnancy diagnosis. In Study 1, ewe lambs were allocated to either ‘medium’ or ‘ad lib’ levels of herbage from 4 days before the start of the breeding period (P –4) to P64. In Study 2, four different pre-breeding nutritional groups (‘maintenance’, ‘medium’, ‘medium/ad lib’ and ‘ad lib’) were utilised from P –17 until P5. The ‘medium/ad lib’ group involved a nutritional switch from the ‘medium’ to the ‘ad lib’ group at P –4 and remained in the ‘ad lib’ until P5. At P5, all ewe lambs that were identified as bred (crayon-marked by ram) were allocated to either ‘medium’ or ‘ad lib’ levels of nutrition until P122. In Study 1, more (P < 0.05) ewe lambs were bred, identified as pregnant at P64 and more fetuses identified at P64 in the ‘ad lib’ group compared with the ‘medium’ group. In Study 2, fewer (P < 0.05) ‘maintenance’ pre-breeding group ewe lambs were bred over the 5-day breeding period compared with the other pre-breeding groups but the proportion of the ewe lambs pregnant at P53 did not differ (P > 0.05). In addition, more (P < 0.05) fetuses were identified at pregnancy diagnosis in the ‘ad lib’ pre-breeding group compared with all other pre-breeding groups. Post-breeding nutrition did not affect (P > 0.05) the proportion of ewe lambs displaying oestrus post-breeding, pregnancy rate or the number of fetuses identified at pregnancy diagnosis per ewe lamb present. This indicates that New Zealand pastoral farmers should aim to allow ad libitum levels of nutrition immediately before the start of the breeding period to pregnancy diagnosis to maximise the number of fetuses at pregnancy diagnosis.

Effect of ram introduction upon the pulsatile release of LH and follicle development in pre-puberal ewe lambs

1988 ◽  
Vol 1988 ◽  
pp. 95-95
Author(s):  
N.Z. Al-Mauly ◽  
M.J. Bryant ◽  
F.J. Cunningham
Keyword(s):  
Late Summer ◽  
First Year ◽  
Follicle Development ◽  
Similar Action ◽  
Pulsatile Release ◽  
Ewe Lambs ◽  
Ewe Lamb ◽  
Transition Into Adulthood ◽  
First Year Of Life ◽  
Lh Secretion

The introduction of rams to seasonally-anovular ewes will, at certain times of the year, stimulate increased pulsatile release of LH, follicle development and ovulation (Martin et al., 1986). The neuroendocrine mechanism governing the transition into adulthood of ewe lambs is incompletely understood, but it is believed to be similar to that which controls the transition to the breeding season in the adult ewe (Foster, Yellon and Olster, 1985; Legan, Karsch and Foster, 1977). Thus the introduction of rams may have a similar action in the pre-puberal ewe lamb as in the seasonally-anovular adult ewe. This experiment investigated the effect of the introduction of rams on the pattern of LH secretion and follicle development in ewe lambs during the late summer/early autumn of their first year of life.

Effect of birthweight and birth rank on the survival of single and twin lambs born to ewe lambs

2010 ◽  
Vol 50 (6) ◽  
pp. 460 ◽  
Author(s):  
N. M. Schreurs ◽  
P. R. Kenyon ◽  
F. J. Mulvaney ◽  
P. C. H. Morel ◽  
D. M. West ◽  
...  
Keyword(s):  
Logistic Regression ◽  
Relative Risk ◽  
Standard Deviation ◽  
Management Options ◽  
Ewe Lambs ◽  
Birth Rank ◽  
Ewe Lamb ◽  
The Mean ◽  
Risk Ratios ◽  
High Range

Benefits of ewe lamb mating include improved lifetime production, increased rates of genetic gain and higher net profits. These benefits are only achieved if the ewe lamb successfully rears its offspring to weaning. A meta-analytic approach was used to assess the effects of birthweight and the interacting effect of birth rank on the survival to weaning of lambs born to ewe lambs. The data were from eight studies where birthweight and weight at weaning had been recorded for lambs born from ewe lambs. Data were for single- (n = 1392) or twin-born lambs (n = 456). The twin lambs were further classified as the ‘heavier’ or ‘lighter’ of the pair to give three birth rank categories. To compare the probability of dying before weaning between birth ranks, but with lambs compared at a similar birthweight, lambs were categorised by their birthweight as heavy (>3.8 kg) or light (<3.8 kg) and also categorised within their birth rank on their placement around the mean birthweight (birthweight deviation). A mid-range birthweight deviation fell between one standard deviation above or below the mean for each birth rank, whereas a low- and high-range birthweight fell below and above the mid-range, respectively. Logistic regression was used to assess the effect of birth rank (single, heavier twin and lighter twin) and birthweight on lamb mortality up to weaning. To compare the probability of surviving up to weaning between the different birth ranks, relative risk ratios were calculated. Birth ranks were compared for lambs within the same birthweight group (heavy or light) and same birthweight deviation (low-, mid-, high-range). Decreasing birthweight increased mortality before weaning in twins and the change in mortality was greater for the lighter twin. Birthweight did not alter mortality before weaning in singles. Comparison of the birth ranks showed that there were differences (P < 0.05) in the probability of dying for lambs of different birth ranks but similar birthweight. The results suggest that management options for ewe lambs that increase the birthweight of the lighter twin could increase the weaning percentage.

scholarly journals Growing and finishing crossbred feedlot ewe lambs fed with increasing levels of concentrate in the diet

2016 ◽  
Vol 37 (6) ◽  
pp. 4243
Author(s):  
Caroline Bertholini Ribeiro ◽  
Maria Da Graça Morais ◽  
Andréa Roberto Duarte Lopes Souza ◽  
Henrique Jorge Fernandes ◽  
Camila Celeste Brandão Ferreira Ítavo ◽  
...  
Keyword(s):  
Dry Matter ◽  
Production Systems ◽  
Average Daily Gain ◽  
Linear Effect ◽  
Dry Matter Digestibility ◽  
Ewe Lambs ◽  
Ewe Lamb ◽  
Individual Evaluation ◽  
Sheep Production ◽  
Daily Gain

To maximize economic gain in sheep production systems it is critical to adjust feedlot diets to maximize performance while minimizing feed, and especially concentrate, waste. Little information is available on ideal diets for crossbred ewe lambs. Therefore, this study aimed to evaluate the performance of feedlot crossbred ewe lambs, and the digestibility of diets, with increasing levels of concentrate during the growing and finishing phases. Twenty-four crossbred Texel × Pantaneira Texel ewe lambs were confined and fed Tifton hay with increasing levels of concentrate in the diet (20, 40, 60 and 80%) for individual evaluation of dry matter intake (DMI), digestibility of diets, average daily gain (ADG) and feed efficiency (FE). Animals were slaughtered at 47 kg. In the growing phase, the inclusion of concentrate in the diets (1176 g.kg-1) did not change DMI (p > 0.05). Concentrate levels had a quadratic effect (p < 0.05) on the dry matter digestibility coefficient (DMDC) and on total digestible nutrients (TDN) during the growing phase. In the finishing phase, there was a negative linear effect of concentrate levels on DMI (p < 0.05), but TDN intake was similar among the experimental diets (p > 0.05). DMDC and TDN values displayed a quadratic behavior (p < 0.05), plateauing at 60% concentrate. ADG and FE increased as concentrate was added to the diet in the growing phase (p < 0.05). During the finishing phase, lamb performance was similar (p > 0.05) for different diets. Thus, the use of 60% concentrate in the confined crossbred ewe lamb diet during growing and 20% concentrate during finishing is recommended.

281 Can We Developmentally Program the Epigenome to Improve Traits Relevant to Production in Cattle?

2021 ◽  
Vol 99 (Supplement_1) ◽  
pp. 20-20
Author(s):  
Robert A Cushman ◽  
Alexandria Snider ◽  
Matthew S Crouse
Keyword(s):  
Ovarian Reserve ◽  
Equal Opportunity ◽  
Production Systems ◽  
Pubertal Development ◽  
Transcript Abundance ◽  
Developmental Programming ◽  
Production Traits ◽  
Female Progeny ◽  
Primordial Follicles ◽  
Functional Changes

Abstract While sequence variation can be informative to associate regions of the genome with specific traits and improve genetic selection, the epigenome may provide a more powerful tool to manage cattle. Identifying practices that are producer friendly and effectively control epigenetic function within animals is crucial to translating developmental programming to a production setting. Initial studies of developmental programming investigated how environmental or nutritional stresses during fetal and peri-natal development impacted performance of animals later in life. These studies demonstrated changes in methylation, alterations in transcript abundance, and negative impacts on physiology, but they also suggested that we may be able to beneficially impact the epigenome and developmentally program animals to excel in their niche in the production system. Maternal nutritional status during the third trimester influenced date of conception of female progeny in several studies but failed to do so in other studies. Transcriptomic analyses provided evidence that nutritional treatments alter mRNA abundance in brain, liver, muscle, and ovary, but does not conclusively demonstrate that this is due to functional changes in the epigenome. If developmental programming is to be applied in production systems, responses must be consistent and beneficial. Reducing nutrient intake in heifers during peri-pubertal development increased number of primordial follicles in the ovaries and reproductive longevity. While nutritional programming of the ovarian reserve in peri-pubertal heifers appears to occur consistently across locations and studies, it does not ensure that subsequent environmental stressors will not induce changes in the ovarian reserve that will negate beneficial effects. These studies demonstrate that it is possible to developmentally program the epigenome in cattle in ways that will improve production traits; however, there remains a need for studies to improve the consistency of response and to determine best practices that fit into production systems. USDA is an equal opportunity provider and employer.

PSXIII-17 Supplementing organic-complexed or inorganic Co, Cu, Mn, and Zn to beef cows during gestation: post-weaning responses of offspring reared as replacement heifers or feeder cattle

2021 ◽  
Vol 99 (Supplement_3) ◽  
pp. 432-432
Author(s):  
Kelsey Harvey ◽  
Reinaldo F Cooke ◽  
Eduardo Colombo ◽  
Bruna Rett ◽  
Osvaldo Sousa ◽  
...  
Keyword(s):  
Treatment Effects ◽  
Body Condition Score ◽  
Average Daily Gain ◽  
Beef Cows ◽  
Female Progeny ◽  
Feeder Cattle ◽  
Condition Score ◽  
Haptoglobin Concentration ◽  
Eden Prairie ◽  
To Receive

Abstract Beef cows and their progeny were used to evaluate the effects of supplementing organic-complexed or inorganic Co, Cu, Mn, and Zn during gestation: on offspring reared as replacement heifers or feeder cattle. Non-lactating, pregnant beef cows (n = 190) were ranked by parity, pregnancy type, body weight (BW) and body condition score (BCS), at 117 ± 2.2 d of gestation (d 0) and assigned to receive a supplement containing: 1) sulfate sources of Cu, Co, Mn, and Zn (INR; n = 95) or 2) an organic complexed source of Cu, Mn, Co, and Zn (AAC; Availa®4; Zinpro Corporation, Eden Prairie, MN; n = 95). From d 0 to calving, cows were maintained in a single pasture and individually offered treatments three times a week. Calves were weaned at 6 mo of age (d 367) and preconditioned for 45-d. Heifer puberty status was verified weekly (d 437 to d 619) based on plasma progesterone concentrations. Steer calves were shipped to a commercial feedlot on d 493, where they were managed as a single group until slaughter (d 724). Plasma cortisol concentration was greater (P = 0.05) in AAC calves at weaning but tended to be less (P = 0.10) on d 370 compared with INR calves. Mean plasma haptoglobin concentration was greater (P = 0.03) in INR vs. AAC calves during preconditioning, and no treatment effects were noted (P = 0.76) for preconditioning average daily gain (ADG). Puberty attainment was hastened in AAC heifers during the experiment (treatment × day; P &lt; 0.01), despite similar (P = 0.39) ADG between treatments from d 412 to 620. No treatment effects were detected (P ≥ 0.24) for steer ADG from d 412 until slaughter, nor for carcass quality traits. Therefore, supplementing Co, Cu, Zn, and Mn as organic complexed instead of sulfate sources to beef cows during the last 5 mo of gestation did not improve performance of steer progeny until slaughter, but hastened puberty attainment in female progeny reared as replacement heifers.

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