Genetic resources to increase the profitability of crossbred lamb production

2006 ◽  
Vol 46 (7) ◽  
pp. 799 ◽  
Author(s):  
N. M. Fogarty ◽  
V. M. Ingham ◽  
L. McLeod ◽  
G. M. Gaunt ◽  
L. J. Cummins
Keyword(s):  
Growth Rate ◽  
Genetic Resources ◽  
Carrying Capacity ◽  
Genetic Improvement ◽  
Annual Production ◽  
Production Cycle ◽  
Gross Margin ◽  
Terminal Sire ◽  
Lamb Growth ◽  
Sire Breed

The gross margin returns of first cross ewes by different sires have been evaluated on an equivalent carrying capacity basis by taking account of the feed requirements for the ewes and lambs and their varying performance and requirements throughout the annual production cycle. The study involved 2846 crossbred ewe progeny generated by 91 maternal sires from several breeds at 3 sites over 3 years including genetic links. The ewes were joined to terminal sire rams for 3 years and 8878 of their second cross lamb carcasses were included in the evaluation. The annual gross margin (A$GM) for individual ewes included income from lamb carcasses (with fat and weight discounts), lamb skins and ewe wool production, and costs for management and marketing. Individual feed requirements were calculated for ewe maintenance, gestation, lactation and lamb growth (pre- and post-weaning) and $GM was expressed on a dry sheep equivalent (dse) basis. Sire breed was not significant with a range of $5.28 GM/dse between sire breed means. There was a considerably greater range of up to $15 GM/dse among most of the sire ewe progeny groups within breeds and overlap among all sire breeds. Lamb turnoff rate was the major profit driver with lamb growth rate and carcass fat levels also contributing. The opportunities for genetic improvement in profitability of lamb enterprises are discussed.

Physiological responses to selection for carcass lean content in a terminal sire breed of sheep

1991 ◽  
Vol 1991 ◽  
pp. 25-25
Author(s):  
N.D. Cameron
Keyword(s):  
Lipid Metabolism ◽  
Genetic Improvement ◽  
Selection Index ◽  
Carcass Composition ◽  
Physiological Traits ◽  
Esterified Fatty Acids ◽  
Breeding Programmes ◽  
Selection For ◽  
Terminal Sire ◽  
Sire Breed

Sheep breeding programmes for genetic improvement in carcass composition of terminal sires measure livewelght and ultrasonic backfat and muscle depths for inclusion in a selection index to predict genetic merit. Physiological traits which were genetically correlated with carcass traits could be incorporated into the selection index to increase the accuracy of selection and the rate of genetic improvement.This study examined differences in physiological traits between lines selected for high or low carcass lean content. The measured physiological traits were chosen according to their role in protein and lipid metabolism : b-hydroxybutyrate (BHB) and glucose (GLUC) : indicators of energy balance; triglyceride (TRIG) and non-esterified fatty acids (NEFA) : intermediaries of lipid metabolism; UREA and creatinine (CREA) : indicators of nitrogen / amino acid metabolism and insulin-like growth factor-1 (IGF-1): an Indicator of growth hormone status.

Effects of crossbred ewe genotype and ram genotype on ewe prolificacy, lamb viability and lamb output in the lowland sector

2002 ◽  
Vol 139 (2) ◽  
pp. 169-181 ◽  
Author(s):  
L. E. R. DAWSON ◽  
A. F. CARSON
Keyword(s):  
Growth Rate ◽  
Northern Ireland ◽  
Growth Rates ◽  
Genetic Improvement ◽  
Live Weight ◽  
Growth Index ◽  
The Other ◽  
Lean Growth ◽  
And Control ◽  
Lamb Growth

A study was carried out on five lowland farms in Northern Ireland over 3 years to investigate the effect of crossbred ewe and ram genotype on ewe prolificacy, lamb viability and weaned lamb output. Four crossbred ewe genotypes were sourced from six hill farms involved in a previous study – Bluefaced Leicester×Blackface (BLXB), Texel×Blackface (TXB), Suffolk×Cheviot (SXCH) and Texel×Cheviot (TXCH). On each farm, groups of 20–30 of each crossbred ewe genotype were mated with Suffolk or Texel rams. Throughout the 3 years of the study, the ewe genotypes lambed at 1, 2 and 3 years of age. Within each of the ram breeds, high lean growth index rams sourced from UK sire reference schemes were compared with rams sourced from flocks not involved in objective genetic improvement programmes (control). BLXB ewes were the most prolific of the four ewe genotypes producing 1.73 lambs per ewe lambed compared with 1.47 for TXB, 1.46 for SXCH and 1.41 for TXCH (P<0.001). Lamb mortality was similar for the four ewe genotypes, thus number of lambs weaned was greatest for the BLXB ewes (P<0.001) with the other three crosses producing similar numbers of lambs. A greater proportion (P<0.05) of SXCH ewes lambed without assistance compared with BLXB and TXB ewes and a greater proportion of TXCH ewes had abundant supplies of colostrum compared with the other crosses (P<0.10). Output of weaned lamb per ewe lambed and per ewe metabolic live weight (P<0.001) was greatest in the BLXB ewes. Ewe productivity, prolificacy, number of lambs weaned and the proportion of ewes lambing without assistance increased with ewe age (P<0.001). Lamb growth rate from birth to 6 weeks and from birth to weaning increased with ewe age (P<0.05). Crossbred ewes lambing at 3 years old had a greater output of weaned lamb compared with ewes lambing at 1 and 2 years old (P<0.001). Ram genotype had no effect on ewe prolificacy, lamb viability or pre-weaning growth rates, although Texel-sired lambs had lower birth weights than Suffolk-sired lambs and control-sired lambs had lower birth weights than high lean index-sired lambs (P<0.05).

An on-farm evaluation of the effects of season of shearing on ewe and subsequent lamb performance

2009 ◽  
Vol 2009 ◽  
pp. 165-165
Author(s):  
T W J Keady ◽  
J P Hanrahan
Keyword(s):  
Growth Rate ◽  
Birth Weight ◽  
Litter Size ◽  
Carrying Capacity ◽  
Early Summer ◽  
Factors Influencing ◽  
Major Factors ◽  
On Farm ◽  
Lamb Growth

The weight of lamb carcass produced per hectare is one of the major factors influencing the efficiency of lamb production and is influenced by the litter size and subsequent lamb growth rate (Keady and Hanrahan, 2006). On many sheep farms ewes are housed during the winter to facilitate increased stock carrying capacity. Ewes are normally shorn once yearly, usually in early summer. Previous studies at Athenry (Keady et al., 2007, Keady and Hanrahan, 2008, 2009) have shown that shearing ewes at housing increased subsequent lamb birth and weaning weights by up to 0.6 and 2.5 kg, respectively. Therefore as a consequence of reducing age at slaughter by approximately 2 weeks, whilst increasing price received per kg of carcass. However, shearing at housing may increase management inputs as ewes are normally housed in smaller groups and need to be dry prior to shearing. Shearing in the autumn, prior to mating, enables the flock to be assembled under more favourable conditions. A previous study at this centre (Keady and Hanrahan, 2008) showed that shearing prior to mating tended to increase subsequent lamb birth weight (+0.3 kg) but did not alter litter size or lamb viability relative to lambs born from ewes which were shorn in late May. The aim of this study was to further evaluate the effects of season of shearing on fertility of March -lambing ewes and on subsequent lamb performance.

scholarly journals Comparison of performance of F1 Romanov crossbred ewes with wool and hair breeds during spring lambing under intensive and extensive production systems

2020 ◽  
Author(s):  
Brad A Freking ◽  
Tom W Murphy
Keyword(s):  
Production System ◽  
First Generation ◽  
Production Systems ◽  
Supplemental Feed ◽  
Extensive System ◽  
Intensive Production ◽  
System P ◽  
Terminal Sire ◽  
Lamb Growth ◽  
Sire Breed

Abstract Objective was to evaluate wool (Dorset and Rambouillet) and hair (Dorper, Katahdin, and White Dorper) breeds for their ability to complement Romanov germplasm in two distinct production systems by estimating direct sire and grandsire effects on lamb growth, survival, and ewe productivity traits. Rams of the five breeds (n=75) were mated to Romanov ewes (n=459) over a 3 yr period to produce five types of crossbred lambs (n=2739). Sire breed (P &gt; 0.06) did not impact body weight (BW) or survival traits of the first generation crossbred (F1) lambs. Productivity of retained crossbred ewes (n=830) mated to Suffolk and Texel terminal sires was evaluated at 1, 2 and 3 years of age in each production system. In the intensive production system, labor and harvested feed were provided for sheep that lambed in March in barns and ewes were limited to rearing two lambs with additional lambs reared artificially. Ewes in the extensive production system lambed in May on pasture and were responsible for rearing all lambs born with no labor or supplemental feed provided before weaning. A total of 1,962 litters and 4,171 lambs from 2,229 exposures to two terminal sire breeds (Suffolk, Texel) was produced in the experiment. Crossbred ewes in the intensive production system were mated in October, resulting in larger litter sizes than crossbred ewes mated in December for the extensive production system. However, single and twin born lamb mortality was similar between the two systems that differed greatly in labor, feed, and facilities. Lambs produced in the intensive system received concentrate feed from an early age and were heavier at 24 wk of age than lambs produced in the extensive system. These outcomes resulted in greater 24-wk litter weight in the intensive than in the extensive system (P &lt; 0.0001). Unexpectedly, the relative performance of crossbred types did not differ importantly between production systems. White Dorper x Romanov crossbred ewes had numerical advantages in productivity in each system, however differences between ewe types were not significant. In the extensive system, without labor and shelter at lambing or supplemental feed until weaning, 3-year-old crossbred ewes of all types averaged 1.78 lambs marketed per ewe lambing and 40% of the ewes that gave birth to triplets weaned their entire litters. These results document that prolific sheep and extensive systems can be successfully combined if appropriate crossbred types are used.

scholarly journals 133 Effect of terminal sire breed on grazing performance, parasitism and market grade of crossbred lambs

2019 ◽  
Vol 97 (Supplement_1) ◽  
pp. 73-74
Author(s):  
Camren l Maierle ◽  
Andrew R Weaver ◽  
Reese H Tuckwiller ◽  
Roger T Rohrbaugh ◽  
Javier Garza ◽  
...  
Keyword(s):  
Growth Rate ◽  
Soybean Meal ◽  
Sale Price ◽  
Weaning Weight ◽  
Organic Farm ◽  
Fecal Egg Count ◽  
Carcass Conformation ◽  
Terminal Sire ◽  
Sire Breed

Abstract Improvements in growth and carcass conformation through terminal sire crossbreeding systems may improve lamb value in a pasture-based system. Therefore, the aim of this study was to compare the effects of different terminal sires on parasitism, growth, composition, and marketability of grazing lambs. Suffolk (SU; n = 2) and Texel (TX; n = 2) sires were mated to commercial ewes at the WVU Organic Farm. April-born lambs were managed on pasture as one group until weaning in midJune, then were separated into 3 replicates per sire breed. Lambs were rotationally grazed for 93 d with paddock movement every 10 d. Lambs were supplemented at a rate of 2% of bodyweight with a 16% CP corn-soybean meal supplement. Weights were collected at weaning and then weekly for the duration of the study. Fecal egg counts (FEC) and FAMACHA scores were collected biweekly. Lambs were de-wormed when FAMACHA score was ≥ 3. Ultrasound measures of rib eye area (REA) were obtained at study conclusion and lambs were marketed at a graded auction. Sire breed did not impact weaning weight or growth rate throughout the test. Fecal egg count was slightly higher in TX vs. SU-sired lambs (257 vs 191 eggs/g; P < 0.05). FAMACHA scores were lower in TX vs. SU-sired lambs (1.58 vs. 1.96; P < 0.0001). Fewer deworming treatments were necessary in TX-sired lambs at 10% (4/39) whereas as SU-sired lambs required 55% (22/40) (P < 0.0001). TX-sired lambs had greater REA (11.57 vs 9.42 cm2; P < 0.0001) and graded better at the saleyard. Grading was set to a 6 pt scale with higher equating to higher sale price. Lambs sired by TX rams graded 5.2 and SU-sired lambs graded 3.6 (P < 0.0001). These data demonstrate that Texel-sired lambs required fewer dewormer treatments and were compositionally more desirable when marketed

ENVIRONMENTAL AND GENETIC EFFECTS ON PREWEANING PERFORMANCE OF CALVES FROM FIRST-CROSS COWS. II. GROWTH TRAITS

1982 ◽  
Vol 62 (1) ◽  
pp. 51-67 ◽  
Author(s):  
H. T. FREDEEN ◽  
G. M. WEISS ◽  
J. A. NEWMAN ◽  
G. W. RAHNEFELD ◽  
J. E. LAWSON
Keyword(s):  
Growth Rate ◽  
Sex Differences ◽  
Birth Weight ◽  
Beef Cattle ◽  
Key Words ◽  
Growth Traits ◽  
Genetic Effects ◽  
Genetic Interactions ◽  
Terminal Sire ◽  
Sire Breed

Environmental and genetic effects on preweaning growth traits were evaluated for 4034 calves born and 3732 calves weaned in second and later parities from contemporary populations of first-cross dams maintained at two locations, Brandon and Manyberries. The calves were sired by Chianina (Chi), Charolais (C), Limousin (L) and Simmental (S) bulls mated to 10 F1 dam crosses representing the Hereford × Angus (HA) and nine dam-cross combinations produced by matings of C, S and L sires with H, A and Shorthorn (N) females. Sex differences were important (P < 0.0001) with males averaging 7% heavier at birth and 5% higher in measures of postweaning growth than females. Location differences were negligible for birth weight (1.2%), but preweaning growth rate was 10–13% greater at Brandon (P < 0.0001) than at Manyberries. Year differences were large for all traits measured (P < 0.0001) and, with the exception of birth weight, were related to differences in annual weaning date. Progeny rankings by terminal sire breed were Chi > C (2.5%), Chi > S (4.2%), and Chi > L (11.4%) for birth weight (all P < 0.0001) and Chi = C = S > L by 6% (P < 0.0001) for all measures of preweaning growth. Ranking of the dam crosses by their breed of sire (DS) were C > S > L for birth weight (P < 0.0001) and S > C > L for preweaning growth (P < 0.0002). The paired DS comparisons indicated S > L by 9.1% and C > L by 2.7% for growth rate. Ranking of the dam crosses by their breed of dam (DD) were H = N > A (P < 0.0001) for birth weight and [Formula: see text] for preweaning growth traits. A location × dam cross interaction was evident for the Charolais × Shorthorn dam cross (P < 0.01). Progeny from all dam crosses except the LH and LA at Manyberries grew more rapidly than their contemporary controls (HA progeny) with the Simmental crosses averaging 11–14% higher than the HA. Genetic interactions involving breed of sire and breed of dam were absent. Key words: Beef cattle, crossbreeding, preweaning growth

scholarly journals The Consequences of Budding versus Binary Fission on Adaptation and Aging in Primitive Multicellularity

Genes ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 661
Author(s):  
Hanna Isaksson ◽  
Peter L. Conlin ◽  
Ben Kerr ◽  
William C. Ratcliff ◽  
Eric Libby
Keyword(s):  
Cell Cycle ◽  
Growth Rate ◽  
Cellular Senescence ◽  
Carrying Capacity ◽  
The Other ◽  
Binary Fission ◽  
Fundamental Aspect ◽  
Accumulated Damage ◽  
Cell Age ◽  
Multicellular Organisms

Early multicellular organisms must gain adaptations to outcompete their unicellular ancestors, as well as other multicellular lineages. The tempo and mode of multicellular adaptation is influenced by many factors including the traits of individual cells. We consider how a fundamental aspect of cells, whether they reproduce via binary fission or budding, can affect the rate of adaptation in primitive multicellularity. We use mathematical models to study the spread of beneficial, growth rate mutations in unicellular populations and populations of multicellular filaments reproducing via binary fission or budding. Comparing populations once they reach carrying capacity, we find that the spread of mutations in multicellular budding populations is qualitatively distinct from the other populations and in general slower. Since budding and binary fission distribute age-accumulated damage differently, we consider the effects of cellular senescence. When growth rate decreases with cell age, we find that beneficial mutations can spread significantly faster in a multicellular budding population than its corresponding unicellular population or a population reproducing via binary fission. Our results demonstrate that basic aspects of the cell cycle can give rise to different rates of adaptation in multicellular organisms.

scholarly journals Performance of Strawberry Varieties Developed for Perennial Matted-Row Production in Annual Plasticulture in a Cold Climate Region

Agronomy ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1407
Author(s):  
Courtney A. Weber
Keyword(s):  
Large Scale ◽  
Fruit Size ◽  
Weather Conditions ◽  
Cold Climate ◽  
Annual Production ◽  
High Yield ◽  
Production Cycle ◽  
Late Season ◽  
Berry Weight ◽  
High Yields

Annual plasticulture production of strawberries promises superior weed control, fruit quality and yields. However, strawberry varieties adapted for perennial, matted-row production and local markets in cold climate regions have not been widely tested for adaptation to an annual production cycle. Productivity of seven short-day varieties developed for matted-row and/or annual production was examined in an annual plasticulture system in two consecutive trials in central NY (lat. 42.87° N, long. 76.99° W) harvested in 2013 and 2014. ‘Flavorfest’ demonstrated good performance in Trial 1 with high yield (390 g/plant) and large fruit size (13.9 g mean berry weight). ‘Jewel’ was shown to be well adapted to the annual plasticulture system with consistently high yields (330 and 390 g/plant) that equaled or surpassed other varieties and had moderate fruit size. ‘Chandler’ performed similarly to previous trials conducted in warmer regions with yield (340 g/plant) and fruit size (9.8 g mean berry weight) similar to ‘Jewel’. ‘Clancy’ yielded less but was consistent from year to year. The late season varieties Seneca and Ovation showed marked variability between years, possibly due to drastically different temperatures during flowering and fruit development in Trial 1 compared to Trial 2. High temperatures in Trial 1 likely caused higher early fruit yield, a compressed season and a precipitous decline in fruit size in the later season, thus reducing yield in the late season. Survival after a second dormant period was poor resulting in a small second harvest and reduced fruit size. Overall, the system demonstrated many of the expected benefits but may be more sensitive to weather conditions in the region. While many varieties developed for matted-row production may work well in an annual plasticulture system, not all varieties are equally adapted. Performance of each variety should be determined independently before large scale adoption by growers.

scholarly journals Mammary Gland Structures Are Not Affected by an Increased Growth Rate of Yearling Ewes Post-Weaning but Are Associated with Growth Rates of Singletons

Animals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 884
Author(s):  
Emmanuelle Haslin ◽  
Rene A. Corner-Thomas ◽  
Paul R. Kenyon ◽  
Adrian J. Molenaar ◽  
Stephen T. Morris ◽  
...  
Keyword(s):  
Growth Rate ◽  
Mammary Gland ◽  
Live Weight ◽  
Late Pregnancy ◽  
Control Group ◽  
Early Lactation ◽  
Fat Pad ◽  
Negative Effects ◽  
Lamb Growth ◽  
Heavy Group

The experiment aimed to examine the impacts of an increased growth rate of ewes between three and seven months of age on udder development using ultrasound and to establish whether ultrasonography could be used to identify ewe mammary structures that may be indirect indicators of singleton growth to weaning. Udder dimensions, depths of gland cistern (GC), parenchyma (PAR) and fat pad (FP) were measured in late pregnancy (P107), early lactation (L29), and at weaning (L100) in 59 single-bearing yearling ewes selected from two treatments. The ‘heavy’ group (n = 31) was preferentially fed prior to breeding achieving an average breeding live-weight of 47.9 ± 0.38 kg at seven months of age. The ‘control’ group (n = 28) had an average breeding live-weight of 44.9 ± 0.49 kg. Udder dimensions, GC, PAR and FP did not differ between treatments. Lamb growth to L100 was positively associated (p < 0.05) with PAR at P107 and GC at L29. There was no evidence of negative effects of the live-weight gain treatments on udder development of yearling ewes as measured by ultrasonography. The results suggest that this ultrasound method has the potential to identify pregnant yearling ewes which would wean heavier singletons.

Effects of lasalocid and protein levels on feed intake and growth rate of Awassi lambs

1997 ◽  
Vol 1997 ◽  
pp. 187-187
Author(s):  
M. M. Muwalla ◽  
M. Y. Harb ◽  
T. F. Crosby
Keyword(s):  
Growth Rate ◽  
Feed Intake ◽  
Feed Efficiency ◽  
Published Data ◽  
Growth Promoter ◽  
Feed Conversion ◽  
Protein Levels ◽  
Feedlot Lambs ◽  
Lamb Growth ◽  
Awassi Lambs

Lasalocid is a polyether antibiotic derived from the fermentation of streptomyces lasaliensis used as a coccidiostat in sheep. There are varying literature reports on lamb growth rate and feed intake when lasalocid is included in the diet of feedlot lambs. While some reports have shown that lasalocid enhances feed efficiency in ruminants by decreasing feed intake and either maintaining or improving rate of gain others indicate that lasalocid did not have any effect on lamb growth rates or feed efficiency (Stobart et al., 1987). Also, when lasalocid was fed to Chios lambs, growth rate was increased but there was no improvement in feed conversion efficiency (Hadjipanayiotou et al., 1988). There are no published data in the literature relating to the use of lasalocid as a growth promoter in the Awassi breed of sheep fed complete diets and the purpose of this study was to investigate the effect of lasalocid with two levels of protein on the growth rate and feed efficiency of weaned male and female Awassi lambs.

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