scholarly journals 91 Growth performance of landrace hair sheep lambs under different forage environments

2020 ◽  
Vol 98 (Supplement_2) ◽  
pp. 72-73
Author(s):  
Stephan Wildeus ◽  
Dahlia O’Brien ◽  
Gabriel J Pent ◽  
Kathryn Payne

Abstract Lambs for the project were produced under semi-continuous lambing using accelerated mating in a dual flock system of landrace hair sheep (Barbados Blackbelly and St. Croix). Lamb cohorts were born every 4 mo. At 4 mo of age, lambs were rotationally stocked on pastures consisting of either tall fescue, summer and winter annual forage mixtures, or were provided bermudagrass hay in sacrifice pastures. Lambs were rotated based on forage availability, and forage was sampled for nutrient analysis at each rotation. Soyhull pellets were provided at 1–3% BW. Lambs were removed as they reached 36 kg. Weights were recorded (n = 1945) from 7 cohorts between December 2017 and September 2019 as lambs moved between forage environments (6 to 40 d). The grazing lamb flock was made up of two cohorts (initial size: 25–53 lambs) at any given time. The effect of breed, sex, cohort class (4–7 mo, and 8–11 mo), and forage environment (classified as cool and warm season annual, perennial pasture, and hay) on ADG was determined. Mean ADG was higher in St. Croix than Barbados Blackbelly (105 vs. 93 g/d; P< 0.05), and ram than ewe lambs (115 vs. 84 g/d; P < 0.001). Older cohorts in each grazing period had higher ADG than younger cohorts (105 vs. 94 g/d; P < 0.05). There was a wide range in ADG for individual weigh periods (16 to 310 g/d), but warm and cool season annuals and hay feeding forage environments produced similar ADG (110–117 g/d); while summer perennial forage grazing was lower (56 g/d; P < 0.001). Supplementing forage with soyhull may have masked differences in lamb growth between forage environments despite higher crude protein and TDN in the annual forages (11 to 20%; and 55 to 85%) than in hay and perennial summer grazing (8 to 10%; and 50 to 55%).

2019 ◽  
Vol 97 (Supplement_1) ◽  
pp. 77-78
Author(s):  
Stephan Wildeus ◽  
Dahlia O’Brien

Abstract Developing a system of year-round lamb production can address issues of continuous supply and product uniformity. In this project, Barbados Blackbelly (BB) and St. Croix (STX) Landrace hair sheep were used to produce cohorts of lambs in 4 mo intervals. Lambs were born on pasture, weaned at approximately 9 weeks, and returned to pasture after a period of post-weaning transition in pens. Ram lambs were rendered short-scrotum at weaning and grazed with ewe lambs as a single group in a rotational grazing system using cool season perennial grasses, warm and cool season annual forages, hay, and soy hull supplementation based on season and forage availability. Lambs were removed as they reached 35–40 kg or 12 mo of age. Data from two lamb cohorts born in April (n = 45) and August (n = 39), respectively, were analyzed for the effect of breed and sex on BW and ADG at different production stages. Birth weights of the April and August cohorts were similar (3.36 kg), but pre-weaning ADG and weaning weights were higher (P < 0.001) in the April (400 g/d and 15.6 kg) than August cohort (304 g/d and 12.1 kg). In contrast, pasture ADG (to 9 mo of age) was higher (P < 0.001) in the August (114 g/d) than April (73 g/d) cohort. Pasture ADG was higher (P < 0.05) in STX (100 g/d) than BB (88 g/d), and higher males (106 g/d) than females (81 g/d). During joint grazing of the two cohorts (December through March) ADG was initially higher (P < 0.001) in the older April (76 g/d) than August (16 g/d) lambs, but similar as they transitioned to annual forage (310 g/d). Pasture ADG fluctuated greatly in relation to forage quality, and to a lesser degree with breed and sex, and 79% of April and 84% of August cohort lambs reached target weights as yearlings.


HortScience ◽  
2004 ◽  
Vol 39 (5) ◽  
pp. 955-958 ◽  
Author(s):  
H. Budak ◽  
R.C. Shearman ◽  
R.E. Gaussoin ◽  
I. Dweikat

A simple marker technique called sequence-related amplified polymorphism (SRAP) provides a useful tool for estimation of genetic diversity and phenetic relationships in natural and domesticated populations. Previous studies and our initial screen showed SRAP is highly polymorphic and more informative when compared to AFLP, RAPD and SSR markers. In this study, applicability of the SRAP markers to obtain an overview of genetic diversity and phenetic relationships present among cool-season (C3) and warm-season (C4) turfgrass species and their relationship with other Gramineae species were tested. Phenetic trees based on genetic similarities (UPGMA, N-J) were consistent with known taxonomic relationships. In some cases, well-supported relationships as well as evidence by genetic reticulation could be inferred. There was widespread genetic variation among C3 and C4 turfgrass species. In Dice based cophenetic matrix, genetic similarities among all species studied ranged from 0.08 to 0.94, whereas in Jaccard based cophenetic matrix, genetic similarities ranged from 0.05 to 0.85. C3 and C4 species were clearly distinguishable and a close relationship between italian ryegrass and tall fescue were obtained based on SRAP. Genome structures of turfgrasses are comparable to other Gramineae species. This research indicates that the SRAP markers are useful for estimating genetic relationships in a wide range of turfgrass species. The SRAP markers identified in this study can provide a useful reference for future turfgrass breeding efforts.


HortScience ◽  
1990 ◽  
Vol 25 (8) ◽  
pp. 856g-856
Author(s):  
J. Anderson ◽  
D. Creech

The population of U.S. Asians will increase by 41% and reach 12 million by the year 2000. Chinese cabbage, Pak Choi, Daikon, and Bitter melon have moved out of the ethnic market and are now in mainstream outlets. This study targeted a diverse range of cool and warm-season crops. Besides those listed above, this study evaluated varieties of Asian greens, Chinese brocolli, Allium, edible soybeam, melon, squash, cucumber, edible Chrysanthemum, amaranth, winged bean, yard-long bean, and edible soybean. A randomized complete block design was utilized, with three replications of row length, varying from 10 to 33 feet, depending on species tested. Direct seedlings of cool-season crops in February and September, 1989 resulted in good market quality and yield of many varieties. Work in 1990 will focus on width of the market window, market information, and grower access to markets.


EDIS ◽  
2018 ◽  
Vol 2018 (5) ◽  
Author(s):  
Jose C.B. Dubeux ◽  
Nicolas DiLorenzo ◽  
Kalyn Waters ◽  
Jane C. Griffin

Florida has 915,000 beef cows and 125,000 replacement heifers (USDA, 2016). Developing these heifers so that they can become productive females in the cow herd is a tremendous investment in a cow/calf operation, an investment that takes several years to make a return. The good news is that there are options to develop heifers on forage-based programs with the possibility of reducing costs while simultaneously meeting performance targets required by the beef industry. Mild winters in Florida allows utilization of cool-season forages that can significantly enhance the performance of grazing heifers. During the warm-season, integration of forage legumes into grazing systems will provide additional nutrients to meet the performance required to develop a replacement heifer to become pregnant and enter the mature cow herd. In this document, we will propose a model for replacement heifer development, based on forage research performed in trials at the NFREC Marianna.   


Animals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 264
Author(s):  
Kathryn E. Ritz ◽  
Bradley J. Heins ◽  
Roger D. Moon ◽  
Craig C. Sheaffer ◽  
Sharon L. Weyers

Organic dairy cows were used to evaluate the effect of two organic pasture production systems (temperate grass species and warm-season annual grasses and cool-season annuals compared with temperate grasses only) across two grazing seasons (May to October of 2014 and 2015) on milk production, milk components (fat, protein, milk urea nitrogen (MUN), somatic cell score (SCS)), body weight, body condition score (BCS), and activity and rumination (min/day). Cows were assigned to two pasture systems across the grazing season at an organic research dairy in Morris, Minnesota. Pasture System 1 was cool-season perennials (CSP) and Pasture System 2 was a combination of System 1 and warm-season grasses and cool-season annuals. System 1 and System 2 cows had similar milk production (14.7 and 14.8 kg d−1), fat percentage (3.92% vs. 3.80%), protein percentage (3.21% vs. 3.17%), MUN (12.5 and 11.5 mg dL−1), and SCS (4.05 and 4.07), respectively. Cows in System 1 had greater daily rumination (530 min/day) compared to cows in System 2 (470 min/day). In summary, warm-season annual grasses may be incorporated into grazing systems for pastured dairy cattle.


Weed Science ◽  
1989 ◽  
Vol 37 (3) ◽  
pp. 375-379 ◽  
Author(s):  
Thomas J. Peters ◽  
Russell S. Moomaw ◽  
Alex R. Martin

The control of three summer annual grass weeds with herbicides during establishment of forage grasses was studied near Concord and Mead, NE, in 1984, 1985, and 1986. Three cool-season forage grasses, intermediate wheatgrass, tall fescue, and smooth bromegrass, and two warm-season grasses, big bluestem and switchgrass, were included. The control of three major summer annual grasses, green foxtail, barnyardgrass, and large crabgrass, was excellent with fenoxaprop at 0.22 kg ai/ha. Slight to moderate injury to cool-season forage grasses and severe injury to warm-season grasses were evident. Sethoxydim at 0.22 kg ai/ha and haloxyfop at 0.11 kg ai/ha controlled green foxtail and large crabgrass, but not barnyardgrass. Sulfometuron-treated big bluestem and switchgrass plots had the best forage stand frequencies and yields and, at the rate used, sulfometuron satisfactorily controlled green foxtail but only marginally controlled barnyardgrass and large crabgrass.


1992 ◽  
Vol 70 (8) ◽  
pp. 1596-1602 ◽  
Author(s):  
S. P. Bentivenga ◽  
B. A. D. Hetrick

Previous research on North American tallgrass prairie grasses has shown that warm-season grasses rely heavily on vesicular–arbuscular mycorrhizal symbiosis, while cool-season grasses are less dependent on the symbiosis (i.e., receive less benefit). This led to the hypothesis that cool-season grasses are less dependent on the symbiosis, because the growth of these plants occurs when mycorrhizal fungi are inactive. Field studies were performed to assess the effect of phenology of cool- and warm-season grasses on mycorrhizal fungal activity and fungal species composition. Mycorrhizal fungal activity in field samples was assessed using the vital stain nitro blue tetrazolium in addition to traditional staining techniques. Mycorrhizal activity was greater in cool-season grasses than in warm-season grasses early (April and May) and late (December) in the growing season, while mycorrhizal activity in roots of the warm-season grasses was greater (compared with cool-season grasses) in midseason (July and August). Active mycorrhizal colonization was relatively high in both groups of grasses late in the growing season, suggesting that mycorrhizal fungi may proliferate internally or may be parasitic at this time. Total Glomales sporulation was generally greater in the rhizosphere of cool-season grasses in June and in the rhizosphere of the warm-season grasses in October. A growth chamber experiment was conducted to examine the effect of temperature on mycorrhizal dependence of cool- and warm-season grasses. For both groups of grasses, mycorrhizal dependence was greatest at the temperature that favored growth of the host. The results suggest that mycorrhizal fungi are active in roots when cool-season grasses are growing and that cool-season grasses may receive benefit from the symbiosis under relatively cool temperature regimes. Key words: cool-season grasses, tallgrass prairie, vesicular–arbuscular mycorrhizae, warm-season grasses.


Genome ◽  
2005 ◽  
Vol 48 (4) ◽  
pp. 637-647 ◽  
Author(s):  
M A. Rouf Mian ◽  
Malay C Saha ◽  
Andrew A Hopkins ◽  
Zeng-Yu Wang

Microsatellites or simple sequence repeats (SSRs) are highly useful molecular markers for plant improvement. Expressed sequence tag (EST)-SSR markers have a higher rate of transferability across species than genomic SSR markers and are thus well suited for application in cross-species phylogenetic studies. Our objectives were to examine the amplification of tall fescue EST-SSR markers in 12 grass species representing 8 genera of 4 tribes from 2 subfamilies of Poaceae and the applicability of these markers for phylogenetic analysis of grass species. About 43% of the 145 EST-SSR primer pairs produced PCR bands in all 12 grass species and had high levels of polymorphism in all forage grasses studied. Thus, these markers will be useful in a variety of forage grass species, including the ones tested in this study. SSR marker data were useful in grouping genotypes within each species. Lolium temulentum, a potential model species for cool-season forage grasses, showed a close relation with the major Festuca–Lolium species in the study. Tall wheatgrass was found to be closely related to hexaploid wheat, thereby confirming the known taxonomic relations between these species. While clustering of closely related species was found, the effectiveness of such data in evaluating distantly related species needs further investigations. The phylogenetic trees based on DNA sequences of selected SSR bands were in agreement with the phylogenetic relations based on length polymorphism of SSRs markers. Tall fescue EST-SSR markers depicted phylogenetic relations among a wide range of cool-season forage grass species and thus are an important resource for researchers working with such grass species.Key words: phylogeny, EST-SSR, forage grasses, tall fescue.


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