Associations between age at puberty, growth traits, plasma IGF-I and leptin concentrations with reproductive performance of Rahmani and Barki male Lambs

The current study assessed the effect of the pattern of live weight change on the ovarian function of maiden Barbarine ewes at approximately 1 year of age. For this purpose, a total of 171 weaned ewe lambs (mean live weight ± s.d. 34.7±3.07 kg and mean age ± SD 196±10 days at weaning) were selected for the experiment. Adjustment of live weight variation was used. Based on the slope of the curve, animals were grouped into three classes LWCI (n=46), LWCII (n=91) and LWCIII (n=34) with live weight loss being highest in LWCI and lowest in LWCIII. Following laparoscopy at 13 months of age, the proportion of ewe lambs found cycling in LWCIII (85.3%) was higher in comparison to animals in LWCI (43.4%; P<0.001) and tended to be superior to those in LWCII (61.5%; P<0.05). Following synchronisation with progestagen of the females found cycling, levels of plasma IGF-I concentrations between 6 and 42 hrs after removal of sponges were not significantly different between the three classes of live weight, and respectively averaged 94.2, 90.8 and 89.8 µg/l for LWCI, LWCII and LWCIII females. Levels of estradiol were also not significantly different between the three groups (0.73, 0.70 and 0.67 pg/ml for LWCI, LWCII and LWCIII ewe lambs, respectively). It was concluded that, in low input systems of semi-arid and arid Tunisia, mating ewe lambs at the approximate age of 1 year is likely to lead to depressed reproductive performance particularly when the summer live weight-loss is elevated.

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The effect of deworming naturally infected heifers on liveweight gain, reproductive performance and fecal egg counts

Canadian Journal of Animal Science ◽

10.4141/cjas93-031 ◽

1993 ◽

Vol 73 (2) ◽

pp. 287-293

Author(s):

S. L. Boyles ◽

L. J. Johnson ◽

W. D. Slanger ◽

B. J. Kreft ◽

J. D. Kirsch

Keyword(s):

Key Words ◽

Reproductive Performance ◽

Fecal Sample ◽

Average Daily Gain ◽

Treated Group ◽

The Other ◽

Control Group ◽

Age At Puberty ◽

Daily Gain

Twenty-six of 52 heifers with an average liveweight of 318 kg were dewormed by intraruminal injection of oxfendazole and placed in drylot on 31 January. The other 26 animals served as controls. All heifers were pastured starting on 14 June and the treatment heifers were dewormed in the same manner as at the start of the experiment (31 January) on 1 July and 31 July. The groups started out with similar total worm eggs per gram of fecal sample, but the dewormed heifers had fewer counts each month thereafter. The drylot average daily gain of the treated heifers was higher (P = 0.01) and less variable (P = 0.12) and by 29 May these animals were heavier by 11.7 kg (P = 0.10). The treated animals did not gain as fast on pasture (P = 0.20), but the gain continued to be less variable (P = 0.09). Age at puberty was not different. Number of open heifers in the treated group was 4 vs. 15% for the control group (P = 0.18). Deworming by intraruminal injection resulted in faster feedlot gains, more uniform gains during both drylot and pasture, reduced parasites and no abscess at injection sites. Key words: Anthelmintics, oxfendazole, cattle, heifers

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Insulin-like growth factor-I measured in juvenile pigs is genetically correlated with economically important performance traits

Australian Journal of Experimental Agriculture ◽

10.1071/ea05048 ◽

2005 ◽

Vol 45 (8) ◽

pp. 783 ◽

Cited By ~ 21

Author(s):

K. L. Bunter ◽

S. Hermesch ◽

B. G. Luxford ◽

H-U. Graser ◽

R. E. Crump

Keyword(s):

Growth Factor ◽

Growth Traits ◽

Genetic Correlations ◽

Selection Criterion ◽

Insulin Like Growth Factor ◽

Factor I ◽

Igf I ◽

Performance Traits ◽

Growth Factor I ◽

Daily Gain

Insulin-like growth factor-I (IGF-I) is a naturally occurring polypeptide produced in the liver, muscle and fat tissues. It is known to be associated with growth and development during the postnatal growth period. Evidence for strong genetic correlations between juvenile IGF-I and performance traits would suggest this physiological measure would be useful as an early selection criterion. This paper reports estimates of genetic parameters from 9 trials where IGF-I was measured in juvenile pigs. All trials involved populations undergoing active selection for improved performance (e.g. efficient lean meat growth). Juvenile IGF-I was moderately heritable (average h2: 0.31) and influenced by common litter effects (average c2: 0.15). Genetic correlations (rg) between juvenile IGF-I and backfat (BF), feed intake (FI) or feed conversion ratio (FCR) traits were generally large and positive: rg averaged 0.57, 0.41 and 0.65, respectively. Phenotypic correlations (rp) between juvenile IGF-I and BF, FI or FCR were much lower (rp averaged 0.21, 0.09, and 0.15, respectively) as residual correlations between IGF-I and these performance traits were low, consistent with being measured at very different times. Correlations (genetic or phenotypic) between juvenile IGF-I and growth traits (e.g. lifetime daily gain or test daily gain) were relatively low, with average values within ± 0.09 of zero. Results from the trials reported here, and several physiological studies, indicate that information on juvenile IGF-I concentration can be used as an early physiological indicator of performance traits traditionally measured later in life. There is a clear role for juvenile IGF-I to facilitate pre-selection and more accurate selection of livestock for hard to measure traits, such as FCR, in pig breeding programs.

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Effect of Digestible Lysine/Metabolisable Energy Ratio in F1 (Landrace x Yorkshire) Gilt Diets on Growth, Age at Puberty and Reproductive Performance in Closed Housing Condition

Advances in Animal and Veterinary Sciences ◽

10.17582/journal.aavs/2021/9.9.1347.1354 ◽

2021 ◽

Vol 9 (9) ◽

Author(s):

Nguyen Dinh Tuong ◽

Tran Thi Bich Ngoc ◽

Tran Hiep ◽

Pham Kim Dang

Keyword(s):

Reproductive Performance ◽

Housing Condition ◽

Energy Ratio ◽

Metabolisable Energy ◽

Age At Puberty

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On-farm evaluation of growth and reproductive performances of Washera and Gumuz sheep in northwestern Ethiopia: Basics for setting up breeding objectives/goals

PLoS ONE ◽

10.1371/journal.pone.0254924 ◽

2021 ◽

Vol 16 (7) ◽

pp. e0254924

Author(s):

Sisay Asmare ◽

Kefyalew Alemayehu ◽

Solomon Abegaz ◽

Aynalem Haile

Keyword(s):

Weight Gain ◽

Reproductive Performance ◽

Interaction Effect ◽

Growth Traits ◽

Live Weight ◽

Daily Weight Gain ◽

Average Daily Weight Gain ◽

Breed Type ◽

Breeding Objectives ◽

Performance Traits

Growth and reproductive performance traits are traits of economic importance for sheep selection and productivity improvement interventions. This study aimed at comparative evaluation of growth and reproductive performance traits of sheep in the highland and lowland agro-ecologies of northwestern Ethiopia. Data on growth performance traits were collected from 144 Washera (78 males and 66 females) lambs and 72 Gumuz (37 males and 35 females) lambs. Data on reproductive performance traits were collected from 260 Washera (130 rams and 130 ewes) sheep and 150 Gumuz (75 rams and 75 ewes) sheep. General linear model univariate procedure was employed to analyze the collected data. Breed, the interaction effect between breed and season of birth as well as the interaction effect between breed and type of birth all exerted very high significant effect (P<0.001) on live weight at all age groups. Breed type affected pre-weaning average daily weight gain significantly (P<0.01). Pre-weaning average daily weight gain of Washera (70 g/day) was found much better performance than 60 g/day of Gumuz. Breed type exerts significant (P<0.05) effect on age at first lambing, lambing interval, annual reproductive rate and number of lambs born per ewe life time. Average age at first lambing and lambing interval of Washera sheep were 11.69 months and 9.27 months, respectively. The corresponding values for Gumuz sheep were 12.51 months and 10.43 months, respectively. Production and reproduction performance values of traits varied across the two breeds and sexes as well. These values can be used to set up breeding objectives or goals for selective breeding of sheep giving special emphasis to growth traits believed to have medium heritability values.

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Association of SNP Marker in IGF-I and MYF5 Candidate Genes with Growth Traits in Korean Cattle

Asian-Australasian Journal of Animal Sciences ◽

10.5713/ajas.2005.1061 ◽

2005 ◽

Vol 18 (8) ◽

pp. 1061-1065 ◽

Cited By ~ 22

Author(s):

E. R. Chung ◽

W. T. Kim

Keyword(s):

Candidate Genes ◽

Growth Traits ◽

Snp Marker ◽

Korean Cattle ◽

Igf I

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Identification of Genes Targeted in South African Merino and Afrino Sheep Populations Under Long-Term Selection for Reproduction and Body Weight

10.21203/rs.3.rs-128951/v1 ◽

2020 ◽

Author(s):

Margaretha Snyman ◽

Sunika Süllwald ◽

Willem Olivier ◽

Carina Visser

Keyword(s):

Body Weight ◽

South African ◽

Reproductive Performance ◽

Genome Wide Association Study ◽

Growth Traits ◽

Reproductive Traits ◽

Term Selection ◽

A Genome ◽

Selection For

Abstract Background: Reproductive performance and body weight are of the utmost economic importance in determining the efficiency of sheep production. Simultaneous selection for increased reproductive performance and early growth traits is a common strategy in many flocks, but ambiguous results regarding the relationship between reproduction and body weight have been reported. The objective of this study was to perform a genome-wide association study (GWAS) in two South African Merino flocks and an Afrino sheep flock that were selected for both reproduction and body weight over decades. The GWAS aimed to identify SNPs associated with genes affecting the traits number of lambs born (NLB), number of lambs weaned (NLW), total weight of lamb weaned (TWW) and body weight (BW) and thus to ascertain which genes were targeted through directional selection.Results: In the GWAS, 16 SNP markers associated with reproductive traits were identified among the three populations, while 15 SNPs were associated with body weight. These SNPs were linked respectively to 26 and 21 documented genes in the sheep genome. Most of these genes were previously associated in literature with reproduction related, as well as with growth related traits in various farm animal species. This study, supported by results from previous studies performed on sheep and cattle, identified the following genes that warrant further investigation as to their functions and processes relating to growth and reproduction in sheep: MAP7D1, TRAPPC3, THRAP3, TRMP8, SPP2, HDAC9, ZFHX3, SIX6, C14orf39, TAF4B, TRSP1 EYA2, RBMS3, STL38L, BSPH1, LIG1, CABP5 and ELSPBP1. Conclusions: Long-term selection in the flocks for both body weight and reproductive traits, and especially on the composite trait TWW, have favoured genes with pleiotropic effects influencing both groups of traits. SNPs associated with these pleiotropic genes were detected in the association analyses for the various traits.

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