275 Access to Shade Mitigate Heat Stress and Improves Growth Performance in Lambs During Summer

2021 ◽  
Vol 99 (Supplement_3) ◽  
pp. 143-144
Author(s):  
Aleena Joy ◽  
Frank R Dunshea ◽  
Brian J Leury ◽  
Iain J Clarke ◽  
Kristy DiGiacomo ◽  
...  

Abstract The objective of the present study was to investigate the effects of provision of shade on behavior, physiology, and growth of Merino lambs exposed to natural Australian summer conditions. Sixty Merino lambs were randomly allocated to either pasture with shade (n = 30;paddock with trees) or a pasture without shade (n = 30;paddock without any trees) for one month during southern-Australian summer (February-2021). Sheep were grazing on the pastures as per standard protocols followed on the farm with ad libitum access to water. Lambs were monitored twice daily between 0900-1000h and 1400-1600h to record their behavior, and physiological parameters were recorded on hot days (environmental temperature (T) >30°C). Behavioral patterns were represented as the proportion of animals doing specific activities in each treatment group. Grazing was the most frequent activity observed in animals during morning measurement (> 60% in both groups). However, high temperature (T > 30°C) decreased grazing behavior in sheep to < 5% in both treatments. Standing behavior was significantly greater (65.2 vs 21.6%; P < 0.05) for animals under non-shade treatment, while lying behavior was more frequent (17.3 vs 76.3%; P < 0.01) in animals having access to shade. Significantly more animals were seeking water troughs (P < 0.05) in the non-shade group (33.2%) compared to the shade group (10.3%). On an average hot day (T >28°C), most lambs in the shade group were seeking shade (P < 0.01), and when the temperature exceeded >32°C, 90% of the lambs were seeking tree shade. Sheep with access to shade exhibited lower (P < 0.01) respiration rate (117breaths/min) and rectal temperature (39.7°C) than non-shade group (151breaths/min;40.2°C). Overall, access to shade improved (P < 0.001) average daily gain (+0.047kg/day) in sheep compared to the non-shade group (-0.028kg/day). In conclusion, our research confirms that providing access to shade is an effective ameliorative strategy to mitigate heat-stress in sheep during summer heatwaves.

2020 ◽  
Vol 98 (5) ◽  
Author(s):  
Morgan E Biggs ◽  
Kellie A Kroscher ◽  
Lidan D Zhao ◽  
Zhenhe Zhang ◽  
Emma H Wall ◽  
...  

Abstract Pigs exposed to elevated ambient temperatures exhibit reduced daily gain, alterations in muscle and fat deposition, and decreased health. Negative aspects of gastrointestinal (GI) function, integrity, and permeability also occur. High-intensity sweeteners can ameliorate the negative effects of heat stress (HS) by increasing GI glucagon-like peptide-2 production while capsicum oleoresin has been shown to reduce inflammatory response. The effects of an artificial high-intensity sweetener and capsicum oleoresin (CAPS-SUC; TakTik X-Hit, Pancosma, Switzerland) on growth performance of pigs were examined. Forty-eight pigs (12 wk of age, 43.2 ± 4.3 kg) were assigned to six treatments: thermoneutral conditions (21 ± 1.1 °C; 40% to 70% relative humidity) fed ad libitum with (TN+) or without supplement (TN−), heat stress (35 ± 1 °C; 20% to 40% relative humidity) fed ad libitum with (HS+) or without supplement (HS−), and thermoneutral conditions pair-fed to HS intake with (PFTN+) or without supplement (PFTN−). Supplementation (0.1 g/kg feed) began 2 d prior to the 3-d environmental treatment period. Body weights (BWs) and blood samples were collected on days −1 and 3. Rectal temperature (RT) and respiration rate (RR) were measured thrice daily and the feed intake (FI) was recorded daily. Intestinal sections were collected for histology. Pigs in HS conditions exhibited increased RT (~1.2 °C) and RR (~2.7-fold) compared with TN and PFTN groups (P < 0.01). HS+ animals had increased RR when compared with HS− animals (P < 0.02). Heat stress decreased FI compared with TN. HS and PFTN decreased (P < 0.05) average daily gain compared with TN. Supplement did not alter the BW gain. HS and PFTN decreased (P < 0.05) Gain:Feed compared with TN during environmental treatment. Supplementation with CAPS–SUC increased Gain:Feed by 0.12 (P < 0.05). Circulating glucose concentrations tended to decrease in CAPS–SUC vs. non-supplemented HS and PFTN animals (P ≤ 0.1). Circulating insulin concentrations as well as monocyte count increased in HS compared with PFTN (P < 0.04) but did not differ from TN and likely linked to altered FI. CAPS–SUC increased basophil count (P < 0.02), irrespective of environment. Ileal villus height tended to decrease during HS and PFTN compared with TN (P < 0.08), indicating an effect of intake. Overall, CAPS–SUC supplementation increased pig feed efficiency and may improve immune response.


1992 ◽  
Vol 54 (2) ◽  
pp. 191-195 ◽  
Author(s):  
H. Khalili ◽  
S. Crosse ◽  
T. Varvikko

AbstractForty-five Friesian × zebu crossbred calves (4 days old) were used to evaluate the effect of feeding different levels of whole milk and weaning at different ages. A total of 252 I whole milk offered over 12 weeks was compared with a feeding level of 134 I milk offered over 8 weeks. Water given ad libitum was also compared with allowing access to water once daily. The calves were penned and fed individually. The average daily gain of the calves weaned at 12 weeks was 464 g compared with 378 g for the calves weaned at 8 weeks of age and allowed access to water once daily and 422 g for the calves weaned at 8 weeks and given water a d libitum. Feeding extra milk and weaning at 12 weeks decreased the intake of concentrates and significantly (P < 0·05) increased live-weight gain. Allowing ad libitum access to water was associated with an increase in concentrate intake but this was not reflected in a significant increase in animal performance.


2021 ◽  
Vol 99 (Supplement_3) ◽  
pp. 495-496
Author(s):  
Abner A Rodriguez ◽  
Aixa Rivera ◽  
Alana Bayne ◽  
Susan K Duckett

Abstract Lamb production in tropical areas is conducted under heat stress in extensive grazing conditions of naturalized pastures (NP). The average daily gain (ADG) and yields of hot (HCY) and cold (CCY) carcass, wholesale cuts (WSC); neck (N), shoulder (SL), ribs 5–12 (RIB), loin (LN) and leg (LG), and detail cuts (DTC); shoulder chops (SCH), french chops (FCH), ribs (RS), back leg (BL) and shanks (SH) of 12 lambs (X = 19.4 kg) rotationally grazed (3 d occupation and 24 d resting period) for 154 or 238 d were determined. The Lambs grazed &gt;8 h NP, grass hay and water were offered ad libitum, 150 g/d of a supplement (12% CP), and mineral blocks. Weekly weights were used to determine ADG. Lambs were slaughtered at 22 (SW1) or 35 kg (SM2) to determine HCY and CCY, and WSC and DTC yield as % of cold carcass weight. Performance data was analyzed as a randomized experimental (CRD) design over time. Carcass and cut yields data were analyzed as a CRD with 6 replicates per treatment. Lambs fed during 238-d had similar ADG than those fed 154-d (68.14 vs.47.74 g/d). SW1 and SW2 had similar percentages of HCY (35.21 vs. 38.14) and CCY (34.48 vs. 37.40). The WSC as % of cold carcass weight, N (6.43 vs. 7.06), SL (29.95 vs. 30.20), RIB (16.10 vs. 16.95), LN (10.84 vs. 11.33) and LG (36.51 vs. 34.44) were similar for SW1 and SW2. Yield of SCH and SH was lower (P &lt; 0.05) for SW1 (15.80 and 8.11) than SW2 (23.00 and 9.11), but FCH (8.49 vs. 8.57), RS (6.89 vs. 7.00) and BL (36.52 vs 34.45) were similar. In summary, lambs slaughtered at 35 kg improved the retail cut yield, but did not influence ADG, HCY, CCY, and WCY compared to lighter lambs.


1967 ◽  
Vol 9 (2) ◽  
pp. 209-218 ◽  
Author(s):  
D. W. Holme ◽  
W. E. Coey

A trial designed to investigate the effects of two environmental temperatures, three feeding regimes and the interactions between them is described. A temperature of 72° F. was better than one of 54° F. for bacon pigs between 40 lb. and 200 lb. weight. The higher temperature resulted in faster growth, more efficient feed conversion and increased length of carcass. Other carcass characteristics were not significantly altered. Ad libitum feeding resulted in faster growth and fatter carcasses than restricted feeding, but did not have a significant effect on efficiency of feed conversion. When feed intake was restricted, feeding pigs once daily or twice daily resulted in similar performance and carcass composition.There was a significant interaction between environmental temperature and feeding method for average daily gain in that pigs fed ad libitum grew faster at the low temperature and pigs fed restricted amounts of feed grew faster at the high temperature. No other interaction reached significant levels.


2021 ◽  
Vol 99 (Supplement_3) ◽  
pp. 94-95
Author(s):  
Kelsie Webb ◽  
Ronald J Trotta ◽  
Phillip Bridges ◽  
James Matthews

Abstract To test the hypothesis that average daily gain (ADG) and clinical parameters of steers grazing novel non-toxic (NTE) or toxic KY-31 (TE) endophyte-infected tall fescue would be improved by ad libitum intake of vitamin-mineral mixes (V-M) that contain 27 ppm Se as a 1:1 blend of SELPLEX:sodium selenite (MIX) vs sodium selenite (ISe), 32 TE-naïve beef steers depleted of Se were randomly assigned to ad libitum consumption ISe vs MIX for 35 d and fed enough of a NTE/alfalfa/grain diet to achieve 0.57 kg BW gain/d. Within Se-form treatments, 2 steers were randomly assigned to each of 4, 2-acre NTE (ISe = 316 ± 31 kg, MIX = 315 ± 22 kg) or TE (ISe = 316 ± 37 kg, MIX = 314 ± 39 kg) paddocks for 84 d and had ad libitum access to their respective V-M. The MIXED procedure of SAS was used to assess effects of day, Se-form (ISe, MIX) and endophyte (NTE, TE) treatments, and their interactions. Whole blood Se decreased (P &lt; 0.01) 31% from d 0 to 84 and was 6.2% greater (P &lt; 0.01) for MIX steers. Serum prolactin decreased (P &lt; 0.01) 18% for NTE and 48% for TE steers from d 0 to 84 and was 17% greater (P = 0.01) for MIX vs. ISe TE steers. Alkaline phosphatase activity (AP) decreased (P &lt; 0.02) 27% from d 0 to 84 and was 15% greater (P &lt; 0.02) for MIX steers. Serum urea nitrogen increased (P &lt; 0.02) 8.2% from d 0 to 84 for TE but not NTE steers. Average daily gain (kg/d) was less (P &lt; 0.01) in TE (-0.18) vs NTE (0.09) steers. We conclude that the ad libitum intake of MIX ameliorated the negative effects of consuming TE on serum prolactin and AP but not ADG.


Animals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 2830
Author(s):  
Kayla M. Lucas ◽  
Dawn A. Koltes ◽  
Laura R. Meyer ◽  
John D. Tucker ◽  
Donald S. Hubbell ◽  
...  

Beef cattle phenotypes are affected by the consumption of toxic fescue. Toxic fescue’s impact is dependent on heat stress and breed composition, with genetic variability for robustness to toxin exposure believed to exist within and across breeds. The study objective was to characterize the effect of fescue toxicosis across breeds for known and novel heat and fescue stress-associated phenotypes. One-hundred crossbred fall-calving Charolais- and Hereford-sired cows of parities 1–3 were allocated to graze either toxic fescue (n = 50), non-toxic fescue (n = 25), or a rotation between toxic and non-toxic fescue (n = 25) for 156 days. Phenotypes impacted by breed (genetics) included hair coat score (p < 0.0001), hair reduction/shedding rate (p < 0.05), rectal temperature (RT) (p < 0.0001), vaginal temperature (p < 0.05), serum phosphorus concentration (p < 0.02) and respiration rate (RR) (p < 0.003). Cows on toxic fescue experienced reduced hair shedding efficacy (p < 0.0001), higher vaginal temperatures (p < 0.0001), increased systolic blood pressure (p < 0.04), increased RR (p < 0.0001) and reduced average daily gain (p < 0.0001), compared to cows grazing non-toxic fescue. Calves born from cows with higher RT during the last third of gestation had higher RT at weaning (p < 0.02), indicating potential physiological effects of in utero heat stress. The study indicates that beef cows exhibit variable responses to toxic fescue within and across breeds which may impact future calf phenotypes.


2021 ◽  
Vol 5 (Supplement_S1) ◽  
pp. S46-S50
Author(s):  
Micah S Most ◽  
Pablo C Grijalva ◽  
Haley N Beer ◽  
Rachel L Gibbs ◽  
Zena M Hicks ◽  
...  

1976 ◽  
Vol 56 (3) ◽  
pp. 365-371 ◽  
Author(s):  
D. E. BROWN ◽  
R. R. HACKER ◽  
G. J. KING

Twenty-four 6-wk-old pigs were housed in individual metabolism cages and exposed for 6 wk to either 2 C or 20 C with ad libitum feed and water. The pigs at 20 C and 2 C had an average daily gain (ADG) of 544 g and 343 g (P < 0.01), respectively. Feed consumption was similar for both treatments, with feed:gain ratios being significantly lower in the 20 C group during the 1st and 3rd 2-wk periods. Spleen and kidney weights were a larger percent of ingesta-free body weight in pigs housed at 2 C. The percent body weight of livers, thyroids, testicles, seminal vesicles and bulbo-urethral glands were not statistically different between 20 C and 2 C housed pigs. Body protein and ash were 5 and 1.3% lower in the 2 C pigs. Differences in plasma ACTH between treatments within day were significant. Consistently lower levels of plasma ACTH were obtained from pigs housed at 2 C.


1986 ◽  
Vol 66 (3) ◽  
pp. 777-790 ◽  
Author(s):  
J. J. BRENNAN ◽  
F. X. AHERNE

Ninety-six crossbred gilts and 96 crossbred boars averaging 20 kg were assigned to a factorial arrangement of three dietary calcium-phosphorus (Ca-P) levels and two slaughter weights (100 or 130 kg). The Ca-P regimens were based on (1) National Academy of Sciences-National Research Council (NAS-NRC)(1979), (2) Agricultural Research Council (ARC) (1981) and (3) 130% of ARC (1981) recommendations for grower and finisher swine. All pigs were fed ad libitum grower diets (0.60–0.50, 0.81–0.63, 1.05–0.82% Ca-P) from 20 to 55 kg and finisher diets (0.50–0.40, 0.72–0.54, 0.94–0.70% Ca-P) to 100 kg or 130 kg liveweight. At 100 kg liveweight 16 boars and 16 gilts from each of the Ca-P treatment groups were selected at random and slaughtered. The remaining pigs within each Ca-P group were allowed feed ad libitum or at 70% of ad libitum from 100 kg until slaughter at 130 kg. There was no significant effect of the three respective dietary Ca-P regimens on average daily gain, average daily feed intake, or feed/gain ratio of pigs during the 20- to 100-kg growth period. Metacarpal bending moment and femoral ash content increased (P < 0.05) in response to the first dietary Ca-P increment. There was a significant (P < 0.05) positive response of femoral ash content but not of bone bending moment to the second Ca-P increment. The incidence and severity of osteochondrosis of the femur, humerus, radius and ulna and leg soundness scores were unimproved (P > 0.05) by feeding elevated dietary Ca-P levels. There was no significant effect of ad libitum vs. restricted feeding during the 100- to 130-kg growth period on bone ash, bone bending moment or cartilage condition scores. Boars had significantly (P < 0.01) greater average daily gain and lower feed/gain ratio during the 20- to 100-kg growth period but they had more severe (P < 0.01) osteochondrotic lesions of the elbow joint and a lower (P < 0.001) femoral ash content than gilts. Correlation coefficients between cartilage soundness scores and bone ash content or bending moment were nonsignificant (P > 0.05). The results suggest that while bone ash content and bending moment respond positively to elevated Ca-P levels in excess of NAS-NRC (1979) recommendations, the incidence and severity of joint lesions and leg soundness scores are not reduced by maximizing bone mineralization. Key words: Osteochondrosis, calcium, phosphorus, swine


2012 ◽  
Vol 92 (3) ◽  
pp. 327-341 ◽  
Author(s):  
E. M. McGregor ◽  
C. P. Campbell ◽  
S. P. Miller ◽  
P. P. Purslow ◽  
I. B. Mandell

McGregor, E M., Campbell, C. P., Miller, S. P., Purslow, P. P. and Mandell, I. B. 2012. Effect of nutritional regimen including limit feeding and breed on growth performance, carcass characteristics and meat quality in beef cattle. Can. J. Anim. Sci. 92: 327–341. The effects of nutritional management regimen and breed on growth performance, carcass attributes, and meat quality were evaluated in 68 British (BRIT) and Continental (CONT) crossbred steers, managed on one of three nutritional regimens: (1) ad libitum access to a 77% corn diet (ALGRAIN), (2) limit feeding initially of the 77% corn diet, followed by ad libitum access to the 77% corn diet (LFGRAIN), and (3) limit feeding initially of a 90% haylage diet, followed by ad libitum access to the 77% corn diet (LFHAYL). Nutritional regimen by breed interactions (P<0.02) were present for average daily gain, dry matter intake (DMI), gain to feed, and shear force. LFHAYL regimen decreased gains to a greater extent for BRIT steers than CONT steers managed on ALGRAIN or LFGRAIN. Feed intakes were similar across nutritional regimens for CONT steers, while DMI was depressed in BRIT on LFHAYL as compared with steers started on ALGRAIN or LFGRAIN. Gain to feed was greater in BRIT cattle on LFGRAIN vs. ALGRAIN, while gain to feed was similar in CONT started on grain (ALGRAIN, LFGRAIN). Shear force was lower for beef from LFHAYL BRIT vs. beef from BRIT on ALGRAIN or LFGRAIN, while the converse was true for CONT. Limit feeding of a high-energy diet may be appropriate for cattle of British background to reduce feed input costs, while ensuring tenderness.


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