Selection of diet by sheep grazing semi-arid pastures on the Riverine Plain. 1. A bladder saltbush (Atriplex vesicaria)-cotton bush (Kochia aphylla) community

1966 ◽  
Vol 6 (23) ◽  
pp. 460 ◽  
Author(s):  
JH Leigh ◽  
WE Mulham

The diet selected by Merino sheep grazing a bladder saltbush (Atriplex vesicaria Hew. ex Benth.)- cottonbush (Kochia aphylla R.Br.) community was determined by analysing extrusa from wethers fitted with oesophageal fistulas. Visual assessments were combined with hand clipped samples to determine the amount of forage available. The results showed that the dominant constituent of the pasture, bladder saltbush, was sparingly grazed, whereas many of the associated species, which often constituted only a minor portion of the total available forage, were heavily grazed.

1966 ◽  
Vol 6 (23) ◽  
pp. 468 ◽  
Author(s):  
JH Leigh ◽  
WE Mulham

The diet selected by Merino sheep grazing a cotton bush (Kochia aphylla)-grassland community was determined by analysing extrusa from wethers fitted with oesophageal fistula. Visual assessments were combined with hand clipped samples to determine the amount of forage available. In winter and spring the major constituents of the diet were the grasses Danthonia caespitosa and Lolium rigidum Gaudich., and the herbs Hypochaeris spp. and Hedypnois cretica (L.) Willd. In summer the grasses Sporobolus caroli Mez and Chloris truncata R. Br. were selected. The various species of Chenopodiaceae were largely ignored. A practical application of this information is presented in which it is suggested that the more acceptable, but short-lived spring forage can be fully utilized and the relatively unacceptable, but drought resistant, species of Chenopodiaceae be conserved for use during stress periods.


1967 ◽  
Vol 7 (28) ◽  
pp. 426 ◽  
Author(s):  
GW Robards ◽  
JH Leigh ◽  
WE Mulham

The diet selected by Merino sheep grazing a Danthonia caespitosa Gaudich. grassland was determined by analysing extrusa from Merino wethers fitted with oesophageal fistulas. Visual assessments were combined with hand clipped samples to determine the amount of forage available. In spring a large proportion of the diet consisted of annual species. In summer, when the range of species present in the pasture was low, Danthonia caespitosa made up the bulk of the diet. Under heavy grazing the amount of dry material and burrs of Medicago polymorpha L. in the diet increased as the supply of Danthonia caespitosa decreased. Nitrogen content and in vitro digestibility, both of the pasture and of the forage eaten during spring, decreased as forage availability decreased under heavy grazing. These values were lower in summer than in spring, but showed little change under increasing grazing pressure. The quality of the pasture, as assessed by nitrogen content and digestibility, would have been sufficient, even in the dry summer experienced during this study, to enable sheep to increase in body weight. Because of the lack of drought-resistant species capable of producing appreciable amounts of forage in the summer-autumn period, it is improbable that any system of management based on deferred or rotational grazing can be devised that will increase animal production from this pasture type.


1987 ◽  
Vol 44 (1) ◽  
pp. 169-172 ◽  
Author(s):  
A. A. Degen ◽  
R. W. Benjamin ◽  
E. Eyal

The native fat-tailed Awassi and the imported German Mutton Merino (GMM) sheep are well adapted to semi-arid conditions (Degen, 1977; Degen and Shkolnik, 1978). This enables these sheep to graze large areas of the Negev Desert in Israel that is marginal for farming. However, under extensive conditions both these sheep breeds yield low lamb crops producing fewer than 1·0 lamb per ewe per year.


Author(s):  
B.R. Watkin

AN Aberystwyth selection of tall fescue (Festuca arundinacea Schreb.), known as S170, was sown with certified New Zealand white clover (Trifolium repens) and re' clover (T. pratense) and compared under sheep grazing with other grass/clover pastures at the Grasslands Division Regional Station at Lincoln (Watkin, 1975) .


Plants ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 500
Author(s):  
Eun Su Lee ◽  
Do-Sun Kim ◽  
Sang Gyu Kim ◽  
Yun-Chan Huh ◽  
Chang-Gi Back ◽  
...  

Watermelon (Citrulluslanatus) is an economically important fruit crop worldwide. Gummy stem blight (GSB) is one of the most damaging diseases encountered during watermelon cultivation. In the present study, we identified quantitative trait loci (QTLs) associated with GSB resistance in an F2 population derived from a cross between maternal-susceptible line ‘920533’ (C. lanatus) and the paternal-resistant line ‘PI 189225’ (C. amarus). The resistance of 178 F2 plants was assessed by two different evaluation methods, including leaf lesion (LL) and stem blight (SB). To analyze the QTLs associated with GSB resistance, a linkage map was constructed covering a total genetic distance of 1070.2 cM. QTL analysis detected three QTLs associated with GSB resistance on chromosome 8 and 6. Among them, two QTLs, qLL8.1 and qSB8.1 on chromosome 8 identified as major QTLs, explaining 10.5 and 10.0% of the phenotypic variations localizing at same area and sharing the same top markers for both LL and SB traits, respectively. A minor QTL, qSB6.1, explains 9.7% of phenotypic variations detected on chromosome 6 only for the SB trait. High-throughput markers were developed and validated for the selection of resistant QTLs using watermelon accessions, and commercial cultivars. Four potential candidate genes were predicted associated with GSB resistance based on the physical location of flanking markers on chromosome 8. These findings will be helpful for the development of watermelon cultivars resistant to GSB.


2011 ◽  
Vol 62 (1) ◽  
pp. 77-84 ◽  
Author(s):  
Sana Dhane Fitouri ◽  
Darine Trabelsi ◽  
Sabrine Saïdi ◽  
Kais Zribi ◽  
Fayçal Ben Jeddi ◽  
...  

2021 ◽  
Vol 99 (Supplement_3) ◽  
pp. 254-255
Author(s):  
Alexey V Shakhin ◽  
Arsen V Dotsev ◽  
Tatiana E Deniskova ◽  
Gottfried Brem ◽  
Natalia A Zinovieva

Abstract Prolificacy is a very important trait in sheep. Romanov sheep, the well-known Russian sheep breed, are characterized by very high prolificacy; however, the genetic basis of this unique property of Romanov sheep is still unknown. It was reported that Ovine BMPR1B gene, located on the OAR6, is associated with prolificacy in several sheep breeds. The aim of our study was to identify candidate SNPs within BMPR1B gene, related to prolificacy. To achieve this goal, using NGS technology, we sequenced ovine BMPR1B gene in Romanov sheep (n = 6), which are characterized by high prolificacy (about 270 lambs per 100 ewes). The sequences of BMPR1B gene of Noire du Velay, Tan, Southdown and Australian Horned Merino sheep breeds as well as Asiatic mouflon (n = 1), which are characterized by significantly lower prolificacy (from 110 to 180 lambs per 100 ewes) were derived from publicly available sources and used for comparison. FST analysis performed in PLINK 1.9 program revealed 10 SNPs with values higher than 0.8. The majority of candidate SNPs under putative selection were localized in the region from 29,382,098 to 29,430,387 on OAR6 of Ovine reference genome (Oar_v3.1 (Ensembl release 98). Thus, we can suggest, that this region of the BMPR1B gene can be considered as the putative region, associated with high prolificacy of Romanov sheep. Additional studies will be needed to confirm the effect of identified candidate SNPs on prolificacy traits. The research results will be useful for artificial selection of sheep with higher prolific capacity, including the introduction of desired alleles in sheep populations using genome editing technologies. This work was supported by the Russian Ministry of Science and Higher Education No. 0445-2019-0024 and RFBR No. 20-516-56002.


2015 ◽  
Vol 15 (5) ◽  
pp. 222 ◽  
Author(s):  
Ji-Min Ju ◽  
Min Bum Kim ◽  
Su Jeong Ryu ◽  
Joo Young Kim ◽  
Jun Chang ◽  
...  

Author(s):  
Pavel Veselý

The aim of the study was to evaluate the effect of sheep pasture on the content of minerals in growth of the Mohelenska Serpentine Steppe National Nature Reserve.Merino sheep pastured on the steppe in 1997–1998, electrical fencer was used. There were 6.8–9.4 sheep per 1 ha in 1997 and 6.7–8.7 sheep per 1 ha in 1998 on the pasture area 4.25 and 6 ha. Samples of steppe growth were taken from five locations with typical fytocenological composition for particular area of steppe. Samples were taken each two weeks during vegetative season from area 3x1 m2. The contents of Ca, P, Na, K, Mg, Mn, Zn, Cu and Fe in dry matter were evaluated. The changes in the content of the nutrients were evaluated depending on the location before, after and during pasture. The values of nutrients were compared with content of these nutrients in meadow and pasture growths (noted in European databases).The content of Ca was from 2.23 to 4.06 g/kg of dry matter. Pasture decreased the variability of location in Ca content and there were significant decreases of Ca content on two locations (P < 0.01). Low content of Ca in steppe growth due to pasture significantly decreased on these locations in comparison with Ca content in pasture growth on no-serpentine soil. The content of P was from 2.23 to 4.06 g/kg of dry matter. Pasture did not affect the variability of location and on one location pasture significantly increased its content (P < 0.01). Despite it the content of P in dry matter was markedly lower than in pasture growths.The content of Na was from 43.88 to 113.97 mg/kg of dry matter. Pasture did not affect the variability of location and its content. The content of Na was markedly lower in steppe growth in comparison with pasture growths. Pasture also did not affect the content of K, which was from 9.96 to 18.10 g/kg of dry matter. But pasture increased the variability of location. The content of K in steppe growth was low in comparison with pasture growths. The content of Mg was from 2.14 to 4.64 g/kg of dry matter. On two locations the content of Mg increased due to pasture (P < 0.05). The content of Mg in steppe growth was comparable with its content in pasture growths. The content of Mn was from 27.55 to 41.32 mg/kg of dry matter and the content of Zn from 12.05 to 26.64 mg/kg of dry matter. Pasture increased the variability of location in both these nutrients. The effect of the pasture on their contents was not (P < 0.05). In steppe growth the content of Mn was markedly lower in comparison with pasture growths and the content of Zn was lower in comparison with pasture growths. The contents of Cu and Fe were from 1.81 to 5.94 mg/kg of dry matter and from 76.1 to 263.2 mg/kg of dry matter. Pasture increased variability of location in the content of Cu and decreased its content in three locations (P < 0.05). The content of Fe was not affected by pasture (P < 0.05). The contents of Cu and Fe were lower in comparison with pasture growths on no-serpentine soils.


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