This page has only limited features, please log in for full access.
New Mexico (NM) has been identified as the state in the US that will be most adversely impacted by climate change and associated water stress. Roughly 92% of NM is rangeland, most of which is grazed by beef cattle. We calculated the blue (surface and ground) and green (precipitation) water footprints (WF) of NM beef cattle industry (cow-calf, backgrounding, and feedlot). This analysis indicated that the weighted average WF of NM beef cattle was 28,203 L/kgmeat. The majority of the WF was accounted for green water (82%; 23,063 L/kgmeat) used by rangeland forages. Blue water accounted for only 18% (5140 L/kgmeat) of the total beef WF estimate. The relative contribution of green vs. blue water varied significantly among the different phases of beef production. In cow-calf, green water accounted for 99.5% of the WF whereas blue water, accounted for 100% of beef WF during backgrounding and feedlot. Based on our estimate, NM cow-calf operations is about a third or a quarter of the blue water (m3/year) used to produce corn or wheat, and only 5% or less of the water used to produce cotton or hay. In NM, irrigation accounts for about 84% of freshwater use followed by public/domestic use of 10%. Mining, thermo-electric, livestock production, aquaculture, and industrial uses collectively account for the other 6%.
Mohammed Sawalhah; Hatim Geli; Jerry Holechek; Andres Cibils; Sheri Spiegal; Craig Gifford. Water Footprint of Rangeland Beef Production in New Mexico. Water 2021, 13, 1950 .
AMA StyleMohammed Sawalhah, Hatim Geli, Jerry Holechek, Andres Cibils, Sheri Spiegal, Craig Gifford. Water Footprint of Rangeland Beef Production in New Mexico. Water. 2021; 13 (14):1950.
Chicago/Turabian StyleMohammed Sawalhah; Hatim Geli; Jerry Holechek; Andres Cibils; Sheri Spiegal; Craig Gifford. 2021. "Water Footprint of Rangeland Beef Production in New Mexico." Water 13, no. 14: 1950.
To explore the effect of COVID-19 pandemic lockdown on vegetation cover changes in Northern, Middle, and Eastern Jordan Badia rangelands, Landsat-8 (Operational Land Imager [OLI]) images were downloaded and processed to attain surface reflectance data for March and July 2018–2020. Normalized difference vegetation index (NDVI) was then derived from OLI-images, where the total area covered with water, bare soil, scattered vegetation, dense grasses and shrubs, and dense forests were estimated. Across the study period, 2019 had the highest rainfall (195 mm) and temperature (21.7 °C), while the lowest rainfall was recorded in 2018 (154 mm). The Northern Badia showed a consistently larger area of dense vegetation on average (407.4 km2) compared to the Eastern (149.3km2), and Middle (55.2 km2) Badia. The total area covered with scattered vegetation in 2020 was higher than in 2019 and 2018 across the years and studied area, except in Middle Badia. Vegetation cover classes were inconsistent for Middle Badia in March, scattered vegetation was higher in 2019 compared to 2020. However, the total area covered with vegetation in July was lower than in March across the years and studied area. The curfew allowed the regeneration of shrubs and grasses in the study area, which helped in restoring the rangeland vegetation. COVID-19 lockdown served as a conservation grazing technique and provided a real case of restoring the degraded rangeland cover through managed grazing.
Mohammed N. Sawalhah; Yahia A. Othman; Anas Abu Yahya; Salman D. Al-Kofahi; Fatima A. Al-Lataifeh; Andres F. Cibils. Evaluating the influence of COVID-19 pandemic lockdown on Jordan Badia rangelands. Arid Land Research and Management 2021, 1 -13.
AMA StyleMohammed N. Sawalhah, Yahia A. Othman, Anas Abu Yahya, Salman D. Al-Kofahi, Fatima A. Al-Lataifeh, Andres F. Cibils. Evaluating the influence of COVID-19 pandemic lockdown on Jordan Badia rangelands. Arid Land Research and Management. 2021; ():1-13.
Chicago/Turabian StyleMohammed N. Sawalhah; Yahia A. Othman; Anas Abu Yahya; Salman D. Al-Kofahi; Fatima A. Al-Lataifeh; Andres F. Cibils. 2021. "Evaluating the influence of COVID-19 pandemic lockdown on Jordan Badia rangelands." Arid Land Research and Management , no. : 1-13.
Accelerated climate change is a global challenge that is increasingly putting pressure on the sustainability of livestock production systems that heavily depend on rangeland ecosystems. Rangeland management practices have low potential to sequester greenhouse gases. However, mismanagement of rangelands and their conversion into ex-urban, urban, and industrial landscapes can significantly exacerbate the climate change process. Under conditions of more droughts, heat waves, and other extreme weather events, management of risks (climate, biological, financial, political) will probably be more important to the sustainability of ranching than capability to expand output of livestock products in response to rising demand due to population growth. Replacing traditional domestic livestock with a combination of highly adapted livestock and game animals valued for both hunting and meat may be the best strategy on many arid rangelands. Eventually, traditional ranching could become financially unsound across large areas if climate change is not adequately addressed. Rangeland policy, management, and research will need to be heavily focused on the climate change problem.
Jerry L. Holechek; Hatim M. E. Geli; Andres F. Cibils; Mohammed N. Sawalhah. Climate Change, Rangelands, and Sustainability of Ranching in the Western United States. Sustainability 2020, 12, 4942 .
AMA StyleJerry L. Holechek, Hatim M. E. Geli, Andres F. Cibils, Mohammed N. Sawalhah. Climate Change, Rangelands, and Sustainability of Ranching in the Western United States. Sustainability. 2020; 12 (12):4942.
Chicago/Turabian StyleJerry L. Holechek; Hatim M. E. Geli; Andres F. Cibils; Mohammed N. Sawalhah. 2020. "Climate Change, Rangelands, and Sustainability of Ranching in the Western United States." Sustainability 12, no. 12: 4942.
This study was conducted within the context of providing an improved understanding of New Mexico’s food, energy, water systems (FEWS) and their behavior under variable climate and socioeconomic conditions. The goal of this paper was to characterize the relationships between production and prices of some forage crops (hay, grain sorghum, and corn) that can be used as feed supplements for beef cattle production and the potential impacts from a changing climate (precipitation, temperature) and energy inputs (crude oil production and prices). The analysis was based on 60 years of data (1958–2017) using generalized autoregressive conditional heteroscedasticity models. Hay production showed a declining trend since 2000 and in 2017, it dropped by ~33% compared to that of 2000. Crude oil production (R2 = 0.83) and beef cattle population (R2 = 0.85) were negatively correlated with hay production. A moderate declining trend in mean annual hay prices was also observed. Mean annual range conditions (R2 = 0.60) was negatively correlated with mean annual hay prices, whereas mean annual crude oil prices (R2 = 0.48) showed a positive relationship. Grain sorghum production showed a consistent declining trend since 1971 and in 2017, it dropped by ~91% compared to that of 1971. Mean annual temperature (R2 = 0.58) was negatively correlated with grain sorghum production, while beef cattle population (R2 = 0.61) and range conditions (R2 = 0.51) showed positive linear relationships. Mean annual grain sorghum prices decreased since the peak of 1974 and in 2017, they dropped by ~77% compared to those of 1974. Crude oil prices (R2 = 0.72) and beef cattle population (R2 = 0.73) were positively correlated with mean annual grain sorghum prices. Corn production in 2017 dropped by ~61% compared to the peak that occurred in 1999. Crude oil production (R2 = 0.85) and beef cattle population (R2 = 0.86) were negatively correlated with corn production. Mean annual corn prices showed a declining trend since 1974 and in 2017, they dropped by ~75% compared to those of 1974. Mean annual corn prices were positively correlated with mean annual precipitation (R2 = 0.83) and negatively correlated with crude oil production (R2 = 0.84). These finding can particularly help in developing a more holistic model that integrates FEWS components to explain their response to internal (i.e., management practices) and external (i.e., environmental) stressors. Such holistic modeling can further inform the development and adoption of more sustainable production and resource use practices.
Ashraf J. Zaied; Hatim M. E. Geli; Mohammed N. Sawalhah; Jerry L. Holechek; Andres F. Cibils; Charlotte C. Gard. Historical Trends in New Mexico Forage Crop Production in Relation to Climate, Energy, and Rangelands. Sustainability 2020, 12, 2051 .
AMA StyleAshraf J. Zaied, Hatim M. E. Geli, Mohammed N. Sawalhah, Jerry L. Holechek, Andres F. Cibils, Charlotte C. Gard. Historical Trends in New Mexico Forage Crop Production in Relation to Climate, Energy, and Rangelands. Sustainability. 2020; 12 (5):2051.
Chicago/Turabian StyleAshraf J. Zaied; Hatim M. E. Geli; Mohammed N. Sawalhah; Jerry L. Holechek; Andres F. Cibils; Charlotte C. Gard. 2020. "Historical Trends in New Mexico Forage Crop Production in Relation to Climate, Energy, and Rangelands." Sustainability 12, no. 5: 2051.
In support of Food-Energy-Water Systems (FEWS) analysis to enhance its sustainability for New Mexico (NM), this study evaluated observed trends in beef cattle population in response to environmental and economic changes. The specific goal was to provide an improved understanding of the behavior of NM’s beef cattle production systems relative to precipitation, temperature, rangeland conditions, production of hay and crude oil, and prices of hay and crude oil. Historical data of all variables were available for the 1973–2017 period. The analysis was conducted using generalized autoregressive conditional heteroscedasticity models. The results indicated declining trends in beef cattle population and prices. The most important predictors of beef cattle population variation were hay production, mean annual hay prices, and mean annual temperature, whereas mean annual temperature, cattle feed sold, and crude oil production were the most important predictors for calf population that weigh under 500 lb. Prices of beef cattle showed a strong positive relationship with crude oil production, mean annual hay prices, rangeland conditions, and mean annual precipitation. However, mean annual temperature had a negative relationship with mean annual beef prices. Variation in mean annual calf prices was explained by hay production, mean annual temperature, and crude oil production. This analysis suggested that NM’s beef cattle production systems were affected mainly and directly by mean annual temperature and crude oil production, and to a lesser extent by other factors studied in this research.
Ashraf Zaied; Hatim Geli; Jerry Holechek; Andres Cibils; Mohammed Sawalhah; Charlotte Gard. An Evaluation of Historical Trends in New Mexico Beef Cattle Production in Relation to Climate and Energy. Sustainability 2019, 11, 6840 .
AMA StyleAshraf Zaied, Hatim Geli, Jerry Holechek, Andres Cibils, Mohammed Sawalhah, Charlotte Gard. An Evaluation of Historical Trends in New Mexico Beef Cattle Production in Relation to Climate and Energy. Sustainability. 2019; 11 (23):6840.
Chicago/Turabian StyleAshraf Zaied; Hatim Geli; Jerry Holechek; Andres Cibils; Mohammed Sawalhah; Charlotte Gard. 2019. "An Evaluation of Historical Trends in New Mexico Beef Cattle Production in Relation to Climate and Energy." Sustainability 11, no. 23: 6840.
A large statewide historical database involving livestock numbers, vegetation cover, precipitation, air temperature, and drought frequency and severity allowed us to explore relationships between climate and rangeland livestock grazing levels and livestock productivity from 1920 to 2017. Trends in vegetation cover and livestock grazing levels from 1984 to 2017 were also explored. Our climate time series was divided into two periods, 1920 − 1975 and 1976 − 2017, based on an apparent accelerated increase in mean annual air temperatures that began in the mid-1970s. Both mean annual precipitation (MAP) and mean annual air temperature (MAT) differed (P ≤ 0.05) between the two periods. MAP and MAT were 9.6% and 3.4% higher in period 2 compared with period 1, respectively. From the 1920s to 2010s the livestock grazing level and weaned calf numbers fell 30% and 40%, respectively, despite a significant increase in MAP. Long-term declines in livestock grazing levels and in weaned calf numbers were significantly (P ≤ 0.05) correlated with increasing MAT (r = − 0.34 and r = − 0.43, respectively). No long-term trends (1984–2017) in woody or perennial herbaceous cover were detected at the level of the entire state of New Mexico. Woody plant cover dynamics for New Mexico were not related to livestock grazing levels. However, at the county level we detected a 2% increase in woody plant cover coupled with a 9% decrease in cattle animal units between 2000 and 2002 and 2015 and 2017 for 19 select counties well distributed across New Mexico. Increases in woody plant cover varied greatly among counties and were higher for eastern than western New Mexico. Both global and New Mexico data show the climate warming trend is accelerating. Our findings have relevance to several other parts of the world because New Mexico occurs at midlatitude, has varied topography and climatic conditions, and several different range vegetation types.
Mohammed N. Sawalhah; Jerry L. Holechek; Andres F. Cibils; Hatim M.E. Geli; Ashraf Zaied. Rangeland Livestock Production in Relation to Climate and Vegetation Trends in New Mexico. Rangeland Ecology & Management 2019, 72, 832 -845.
AMA StyleMohammed N. Sawalhah, Jerry L. Holechek, Andres F. Cibils, Hatim M.E. Geli, Ashraf Zaied. Rangeland Livestock Production in Relation to Climate and Vegetation Trends in New Mexico. Rangeland Ecology & Management. 2019; 72 (5):832-845.
Chicago/Turabian StyleMohammed N. Sawalhah; Jerry L. Holechek; Andres F. Cibils; Hatim M.E. Geli; Ashraf Zaied. 2019. "Rangeland Livestock Production in Relation to Climate and Vegetation Trends in New Mexico." Rangeland Ecology & Management 72, no. 5: 832-845.
The influence of population growth and Syrian refugee settlements on rangeland degradation in Jordan using remotely-sensed data was assessed. Eleven cloud-free Landsat 8 Operational Land Imager (OLI) Images that cover the study area were used. Maximum likelihood classifier was applied to estimate rangeland, cropland, urban, water and forest cover percentages over the study area for the period 2013–2015. Change detection analysis of both 2013 and 2015 images revealed a dramatic expansion of urban lands and a consequent reduction in rangelands, especially in north-western Jordan. Our analysis suggests that Jordanian rangeland area decreased by 9.6%, forests by 1.5% and water by 0.6% during the study period (2013–2015). Meanwhile, urban lands increased by 11.4% and croplands by 0.2%. We attributed this change mainly to Syrian civil war and refugee settlements. This settlement process increased the demand for food and water and accelerated desertification processes in Jordanian rangelands, especially those in the north-western region. Our study underscores the value of using remotely sensed data as a viable approach to quantify degradation in Middle Eastern rangelands. Overall, we suggest initiating rigorous urban settlement regulations and land conservation control programs to mitigate land degradation in Jordanian rangelands.
Mohammed N. Sawalhah; Salman D. Al-Kofahi; Yahia Othman; Andres F. Cibils. Assessing rangeland cover conversion in Jordan after the Arab spring using a remote sensing approach. Journal of Arid Environments 2018, 157, 97 -102.
AMA StyleMohammed N. Sawalhah, Salman D. Al-Kofahi, Yahia Othman, Andres F. Cibils. Assessing rangeland cover conversion in Jordan after the Arab spring using a remote sensing approach. Journal of Arid Environments. 2018; 157 ():97-102.
Chicago/Turabian StyleMohammed N. Sawalhah; Salman D. Al-Kofahi; Yahia Othman; Andres F. Cibils. 2018. "Assessing rangeland cover conversion in Jordan after the Arab spring using a remote sensing approach." Journal of Arid Environments 157, no. : 97-102.
The growing populations in urban areas are continuously changing the surrounding natural ecosystems. Jordan is a country with limited resources and witnessing rapid population growth rates and urban advancement towards their agricultural lands. The aim of this research is to investigate the spatial and temporal urban expansion on the agricultural lands of Greater Amman (GAM) and Greater Irbid (GIM) municipalities for the period 2003–2015. Geographic Information System and ENVI-supervised classification technique were used to classify Landsat images of municipalities’ lands into urban, agricultural, and undeveloped lands. In 2015, the urban area of GIM land increased by 70% of that in 2003. The newly urbanized area represented 12% (39km2) of the total GIM land. The GIM land’s conversion rate to urban area was 1% (3.24km2). In 2015, the urban area of GAM land represented 41% of the municipality’s land where 16% (128km2) is the newly urbanized land with an annual land conversion rate of 1.3% (10.7km2). This sprawl was mainly on agricultural lands where 18 and 50% of the 2003 agricultural lands of GIM and GAM, respectively, were eliminated by 2015. The existed agricultural lands in GIM by 2015 represented 38% of the total municipality lands while only 14% of the total GAM land is agricultural land. The annual agricultural land recession rates in GIM and GAM were 1 and 1.1%; therefore, their agricultural lands are expected to be eliminated by 2053 and 2028, respectively. These rates of losing agricultural lands are alarming and need to be regulated through sustainable and recent urban planning approaches.
Salman D. Al-Kofahi; Nezar Hammouri; Mohammed N. Sawalhah; Ahmed A. Al-Hammouri; Fakher Aukour. Assessment of the urban sprawl on agriculture lands of two major municipalities in Jordan using supervised classification techniques. Arabian Journal of Geosciences 2018, 11, 45 .
AMA StyleSalman D. Al-Kofahi, Nezar Hammouri, Mohammed N. Sawalhah, Ahmed A. Al-Hammouri, Fakher Aukour. Assessment of the urban sprawl on agriculture lands of two major municipalities in Jordan using supervised classification techniques. Arabian Journal of Geosciences. 2018; 11 (3):45.
Chicago/Turabian StyleSalman D. Al-Kofahi; Nezar Hammouri; Mohammed N. Sawalhah; Ahmed A. Al-Hammouri; Fakher Aukour. 2018. "Assessment of the urban sprawl on agriculture lands of two major municipalities in Jordan using supervised classification techniques." Arabian Journal of Geosciences 11, no. 3: 45.
We determined the effects of two forage allowance levels (LOW vs. HIGH) and weather conditions on daytime and nighttime movement patterns of young rangeland-raised cows. We also investigated whether calf weaning weights (n = 42) were significantly related to postcalving movement patterns of the dam. Global positioning system data were collected over 4 years by recording 5-min interval locations of 52 crossbred cows grazing a 146-ha woodland/grassland pasture for approximately 20 days. The pasture was stocked moderately in 2004 (73 AUMs) and 2005 (78 AUMs) and lightly in 2006 (34 AUMs) and 2007 (32 AUMs). Estimated forage allowance was low in 2004 and 2005 (347 and 438 kg herbage ∙ cow− 1, respectively) and high in 2006 and 2007 (1104 and 1884 kg herbage ∙ cow− 1, respectively). We calculated distance traveled, path sinuosity, woodland preference, and area explored for each cow during 24 h (D + N), daytime (DAY), and nighttime (PRE dawn and POST sunset) periods. Cows in LOW traveled farther than counterparts in HIGH during D + N and DAY (P < 0.01) periods but traveled shorter or similar distances during POST (P = 0.05) and PRE (P = 0.29) nighttime periods, respectively. Cows in LOW exhibited more sinuous movement paths than cows in HIGH during DAY, PRE, and POST periods (P ≤ 0.01). Cows in LOW explored larger areas and spent more time in woodlands than counterparts in HIGH (P < 0.01). Weather factors associated with thermal comfort affected daily variation in both daytime and nighttime movement patterns of cows. A dam’s movement patterns in the weeks immediately following calving were correlated (P ≤ 0.01) with steer but not heifer calf WW. Moderate stocking rates (LOW treatment) induced behaviors that resulted in higher woodland preference and heavier steer calf WW.
Mohammed N. Sawalhah; Andrés F. Cibils; Aditya Maladi; Huiping Cao; Dawn M. Vanleeuwen; Jerry L. Holechek; Christina M. Black Rubio; Robert L. Wesley; Rachel L. Endecott; Travis J. Mulliniks; Mark K. Petersen. Forage and Weather Influence Day versus Nighttime Cow Behavior and Calf Weaning Weights on Rangeland. Rangeland Ecology & Management 2016, 69, 134 -143.
AMA StyleMohammed N. Sawalhah, Andrés F. Cibils, Aditya Maladi, Huiping Cao, Dawn M. Vanleeuwen, Jerry L. Holechek, Christina M. Black Rubio, Robert L. Wesley, Rachel L. Endecott, Travis J. Mulliniks, Mark K. Petersen. Forage and Weather Influence Day versus Nighttime Cow Behavior and Calf Weaning Weights on Rangeland. Rangeland Ecology & Management. 2016; 69 (2):134-143.
Chicago/Turabian StyleMohammed N. Sawalhah; Andrés F. Cibils; Aditya Maladi; Huiping Cao; Dawn M. Vanleeuwen; Jerry L. Holechek; Christina M. Black Rubio; Robert L. Wesley; Rachel L. Endecott; Travis J. Mulliniks; Mark K. Petersen. 2016. "Forage and Weather Influence Day versus Nighttime Cow Behavior and Calf Weaning Weights on Rangeland." Rangeland Ecology & Management 69, no. 2: 134-143.
Jerry L. Holechek; Mohammed N. Sawalhah; Andrés F. Cibils. Renewable Energy, Energy Conservation, and US Rangelands. Rangelands 2015, 37, 217 -225.
AMA StyleJerry L. Holechek, Mohammed N. Sawalhah, Andrés F. Cibils. Renewable Energy, Energy Conservation, and US Rangelands. Rangelands. 2015; 37 (6):217-225.
Chicago/Turabian StyleJerry L. Holechek; Mohammed N. Sawalhah; Andrés F. Cibils. 2015. "Renewable Energy, Energy Conservation, and US Rangelands." Rangelands 37, no. 6: 217-225.
Milton G. Thomas; Ahmed H. Mohamed; Mohammed N. Sawalhah; Jerry L. Holechek; Derek W. Bailey; Jerry M. Hawkes; Pablo Luna-Nevarez; Francisco Molinar; Godfrey Khumalo. Long-Term Forage and Cow-Calf Performance and Economic Considerations of Two Stocking Levels on Chihuahuan Desert Rangeland. Rangeland Ecology & Management 2015, 68, 158 -165.
AMA StyleMilton G. Thomas, Ahmed H. Mohamed, Mohammed N. Sawalhah, Jerry L. Holechek, Derek W. Bailey, Jerry M. Hawkes, Pablo Luna-Nevarez, Francisco Molinar, Godfrey Khumalo. Long-Term Forage and Cow-Calf Performance and Economic Considerations of Two Stocking Levels on Chihuahuan Desert Rangeland. Rangeland Ecology & Management. 2015; 68 (2):158-165.
Chicago/Turabian StyleMilton G. Thomas; Ahmed H. Mohamed; Mohammed N. Sawalhah; Jerry L. Holechek; Derek W. Bailey; Jerry M. Hawkes; Pablo Luna-Nevarez; Francisco Molinar; Godfrey Khumalo. 2015. "Long-Term Forage and Cow-Calf Performance and Economic Considerations of Two Stocking Levels on Chihuahuan Desert Rangeland." Rangeland Ecology & Management 68, no. 2: 158-165.
Jerry L. Holechek; Mohammed N. Sawalhah. Energy and Rangelands: A Perspective. Rangelands 2014, 36, 36 -43.
AMA StyleJerry L. Holechek, Mohammed N. Sawalhah. Energy and Rangelands: A Perspective. Rangelands. 2014; 36 (6):36-43.
Chicago/Turabian StyleJerry L. Holechek; Mohammed N. Sawalhah. 2014. "Energy and Rangelands: A Perspective." Rangelands 36, no. 6: 36-43.
Mohammed N. Sawalhah; Andres F. Cibils; Chuan. Hu; Huiping. Cao; Jerry L. Holechek. Animal-Driven Rotational Grazing Patterns on Seasonally Grazed New Mexico Rangeland. Rangeland Ecology & Management 2014, 67, 710 -714.
AMA StyleMohammed N. Sawalhah, Andres F. Cibils, Chuan. Hu, Huiping. Cao, Jerry L. Holechek. Animal-Driven Rotational Grazing Patterns on Seasonally Grazed New Mexico Rangeland. Rangeland Ecology & Management. 2014; 67 (6):710-714.
Chicago/Turabian StyleMohammed N. Sawalhah; Andres F. Cibils; Chuan. Hu; Huiping. Cao; Jerry L. Holechek. 2014. "Animal-Driven Rotational Grazing Patterns on Seasonally Grazed New Mexico Rangeland." Rangeland Ecology & Management 67, no. 6: 710-714.
This experiment was conducted to evaluate the effect of administering hormonal treatments (melatonin and progestagen/equine chronic gonadotropin (eCG)) on advancing puberty in Awassi ewe lambs. Fifty-one 6-month-old ewe lambs of similar body weights (around 28 kg) were randomly assigned into four treatment groups; control (CON; n = 14), melatonin (MEL; n = 13), melatonin plus progestagen–eCG (MELPP; n = 11), and progestagen–eCG (PP; n = 13). Ewe lambs in the PP and MELPP groups were fitted with intravaginal progestagen sponges containing 60 mg medroxyprogesterone acetate for 14 days; 400 IU eCG were administered to each of these ewe lambs on the day of sponge removal. Ewe lambs in the MEL and MELPP groups received subcutaneous melatonin implants (Regulin®, 18 mg melatonin) 36 days before sponge insertion. Hormonal treatment had no effect on ewe lamb body weight change. Estrous behavior was greater (p < 0.001) in the PP and MELPP groups than in the CON and MEL ewe lambs. The duration from ram introduction to onset of estrus was shorter (p < 0.05) in the CON, PP, and MELPP than in the MEL ewe lambs. The number of ewe lambs showing luteal activity was greater (p < 0.001) in the MELPP and PP than in the CON and MEL groups. Lambing rate from mating during the first cycle following ram introduction differed significantly (p < 0.01) among treatments being greater in the MELPP and PP than in the CON and MEL groups. Based on these results, it can be concluded that progestagen–eCG appears to be more effective than melatonin in inducing reproductive activity. However, the majority of ewe lambs in the current study either failed to cycle or stopped cycling following the induced estrus. Such failure in advancing puberty may be related to body weight of ewe lambs at the time of mating.
Mohammad N. Sawalha; Rami T. Kridli; Khalil I. Jawasreh; Cesar A. Meza-Herrera. The use of melatonin and progestagen–eCG to initiate reproductive activity in prepuberal Awassi ewe lambs. Tropical Animal Health and Production 2011, 43, 1345 -1350.
AMA StyleMohammad N. Sawalha, Rami T. Kridli, Khalil I. Jawasreh, Cesar A. Meza-Herrera. The use of melatonin and progestagen–eCG to initiate reproductive activity in prepuberal Awassi ewe lambs. Tropical Animal Health and Production. 2011; 43 (7):1345-1350.
Chicago/Turabian StyleMohammad N. Sawalha; Rami T. Kridli; Khalil I. Jawasreh; Cesar A. Meza-Herrera. 2011. "The use of melatonin and progestagen–eCG to initiate reproductive activity in prepuberal Awassi ewe lambs." Tropical Animal Health and Production 43, no. 7: 1345-1350.