22 Effects of Housing Cow-calf Pairs on Drylots vs Pasture on Calf Performance and Behavior Through Weaning

The objectives were to analyze the effects of housing cow-calf pairs in drylots or pasture on calf performance and behavior through weaning. Simmental × Angus (2 yr; 108/yr; 81 ± 15.3 d postpartum) spring-calving cows were stratified by age, BW, BCS, and calf sex and allotted to six groups/yr. Groups were randomly allotted to 1 of 2 treatments: drylot (DL) or pasture (PAST). Calves in the drylot had ad libitum access to a diet consisting of corn silage, dried distillers grain, corn stalks, dry rolled corn, and soybean hulls. Calves on PAST received creep feed three weeks prior to weaning. Calf BW was measured on d 0, 55, and 110. Calves were fence-line weaned on d 110. Behavior was observed for two days after weaning. Data were analyzed using the MIXED procedure of SAS. Drylot calves had greater (P < 0.01) BW at d 55 and 110. There was treatment by time interactions (P < 0.01) for lying and eating on d 111. More PAST calves were lying at h 2 and 3 and eating at h 11 and 12. More DL calves were lying at h 9, 10, 11, and 12. More DL calves were eating at h 2 and tended to at h 3. There was also a treatment by time interaction (P < 0.01) for vocalizations on d 111. More PAST calves vocalized at h 1, however, DL calves vocalized more at h 4 and tended to at h 5. There was treatment by time interactions (P < 0.01) for eating and walking on d 112. More DL calves were eating at h 2, 3, 4, 7, and 9. More PAST calves were walking at h 1 and 2. There was also a treatment by time interaction (P < 0.01) for vocalizations on d 112. More PAST calves vocalized at h 1 and 10. In conclusion, housing cow-calf pairs in drylots improved preweaning performance and altered postweaning behavior.

Effect of Biostimulation on Some Behavioral Aspects and Energy Balance of Sahiwal Cows during Peri-estrual Period

Background: Energy is the major nutrient needed for dairy cattle and its insufficient intake has a detrimental effect on their reproductive activity. Methods: The aim of this study was to investigate the effect of biostimulation on behaviour and energy balance of Sahiwal cows during peri-estrus through 2 types of bull contact. For this, 24 postpartum cows were divided into 3 similar groups (T0, T1 and T2) of 8 cows each. In T0, cows were not exposed to bull; in T1 the cows were exposed to bull through a fence-line contact and in T2, the cows were in direct bull contact for 12 hours daily. Result: In first post-partum estrus, the feeding time was non-significant among 3 groups but in second estrus, mean time spent on feeding was significantly (p less than 0.05) lower in T0 than T1 and T2 groups. The mean rumination time on d-0 of first estrus was significantly (p less than 0.01) lower in T1 and T2 cows as compared to T0 cows. Mean rumination time on d-0 in second estrus was significantly (p less than 0.05) lower in T1 and T2 than in T0. Mean resting times in first estrus in T1 and T2 were significantly lower (p less than 0.05) than in T0. Mean resting time in d-0 of second estrus was significantly (p less than 0.05) lower in T1 and T2 than the T0. There was no significant difference in the mean dry matter intake and levels of BHBA and NEFA among 3 groups of cows. It was concluded that biostimulation of Sahiwal cows through direct or fence-line bull contact during peri-estrus period highly reduced their feeding, rumination and resting times without affecting their energy balance as compared to non-bull exposed cows.

Long-Term Downwind Exposure to Air Pollution from Power Plants and Adult Mortality: Evidence from COVID-19

We estimate the causal effects of long-term exposure to air pollution emitted from fossil fuel power plants on adult mortality. We leverage quasi-experimental variation in daily wind patterns, which is further instrumented by the county orientation from the nearest power plant. We find that the average county’s fraction of days spent downwind of plants within 20 miles in the last 10 years is associated with a 27.6 percent increase in mortality from COVID-19. This effect is more pronounced in fence line communities with high poverty rates and a large proportion of Black population.Yes, and how many times must a man look up Before he can see the sky?Yes, and how many ears must one man have Before he can hear people cry?Yes, and how many deaths will it take ‘til he knows That too many people have died?The answer, my friend, is blowin’ in the wind The answer is blowin’ in the wind–Bob Dylan

Serum Anti-Mullerian Hormone and Estradiol Concentrations in Gilts and Their Age at Puberty

For experiment one, blood samples were obtained from 200 gilts at 90, 120, 150, 180, and 200 days of age. Serum samples from the 30 youngest (166.1 ± 0.7 days) and 30 oldest (198.8 ± 0.6 days) gilts exhibiting estrus by 200 days, and a further 18 gilts that remained anestrus at 200 days, were assayed for serum concentrations of anti-Mullerian hormone (AMH) and estradiol (E2). Gilts younger at puberty had higher (p < 0.05) AMH levels than those older at puberty, and both groups had higher AMH levels than anestrus gilts (p < 0.05). Regardless of age, serum E2 was higher (p < 0.05) in gilts that achieved puberty than in gilts remaining anestrus. At spontaneous pubertal estrus detection, there was no effect of pubertal age on the number of preovulatory ovarian follicles. For experiment two, 152 prepubertal gilts received an intramuscular (IM) injection of 400 IU eCG plus 200 IU hCG and then received fence-line boar contact to detect estrus onset. Serum AMH concentrations were higher (p < 0.05) in the first 25 gilts to exhibit puberty than the last 28 gilts, with the first gilts also having more preovulatory follicles (p < 0.0001). Taken together, these data support an association between serum AMH concentrations and degree of physiological maturity and ovarian follicular development in gilts.

PSVIII-30 Reduced-lignin alfalfa digestibility and effects on performance of growing beef steers

Novel alfalfa varieties have been developed to have less lignin by genetic modification, (HarvXtra, Forage Genetics International) and by conventional breeding, (HiGest 360, Alforex Seeds). Second crop (d 29) of these alfalfas and a control, LegenDairy XHD (Winfield Solutions LLC), were harvested as high moisture wrapped bales (45.9–51.6 % DM) at the Arlington Agricultural Research Station (AARS) located near Arlington, WI, on July 5, 2017. The objectives of these experiments were to characterize novel reduced-lignin alfalfa varieties, assess their effects on growth of beef steers, and determine digestibilities using a total fecal collection trial. Treatments were fed ad libitum as alfalfa baleage to 300 kg (initial weight) black-hided beef steers, (n = 72, 4 pens/treatment, 83 d). Steers were fed solely alfalfa baleage and offered a trace mineral salt block by way of fence line feed bunks. Alfalfa lignin values were 7.56, 7.18, and 6.3% DM (P = 0.34) for LegenDairy, HiGest and HarvXtra, respectively. Steers gained 0.94, 1.00, and 1.07 kg hd-1 d-1 (P = 0.25) for LegenDairy, HiGest and HarvXtra, respectively. The same harvested alfalfa was used in a total collection fecal trial with fecal collection bags (Table 1). Numerical differences between alfalfa digestibilities were observed but no significant treatment effects were detected. Total tract NDF digestibilities (TTNDFD) for harvested alfalfas were 33.9, 35.0 and 40.3 % NDF (P = 0.079) for LegenDairy, HiGest and HarvXtra, respectively. Alfalfa lignin concentration differences were not detected through acid detergent-lignin analysis of harvested bales. While the ranking of lignin concentrations, digestibilities, and growth rates followed prevailing logic, alfalfa variety treatment effects were not detected. Experimental designs with greater sensitivity should be implemented in the future.

117 Organic and conventional pasture systems for lamb production in Southeastern U.S

Little is known about U.S. organic production of ruminant livestock. Objective was to examine growth, gastrointestinal nematode (GIN) infection, and eligibility of organic certification between conventional (CON) and organic (ORG) management (Mgt) up to 150 d of age. Katahdin lambs (ORG, n = 240; CON, n = 690) were born in fall (Oct–Dec) or winter (Jan–Mar) between 2014 and 2019 in Booneville, AR. Intact male and female lambs were fence line weaned ~90 d of age, grazed tall fescue and/or mixed forages and were supplemented (corn/soybean meal) when forage quality became limiting. Organic sheep and pastures were certified by NICS. Body weight was determined at birth and approximately 60, 90, 120, and 150 d of age. Blood and feces were collected for packed cell volume (PCV) and fecal egg counts (FEC) at 90, 105, 120, 135, and 150 d of age. Lambs were selectively dewormed based on Five Point Check and incidence recorded. Data were analyzed by Proc GLM or Mixed with repeated measures (SAS) and included Mgt, sex, season, yr, d of measurement and interactions; age of lamb was included as covariate if needed. Birth weight was usually greater in fall born ORG and less in winter born than CON (mgt x season x yr, P &lt; 0.001), and varied between ORG and CON over time (mgt x season x yr x d, P &lt; 0.001). A similar 4-way interaction occurred for FEC and PCV (P &lt; 0.001). Incidence of deworming was similar between ORG and CON (ranged between 0 and 3 times/lamb, and 3.2% to 151% over season and yr). Because copper oxide wire particles were used for most ORG deworming, between 50 and 92% of lambs were eligible for organic certification by 150 d of age (mgt x season x yr, P = 0.03). Comparisons between farming systems are complex and should consider factors such as varietal and seasonal changes in forages.