Physiological and growth parameters of fattening lambs after shearing under heat-stress conditions

2017 ◽  
Vol 57 (3) ◽  
pp. 569 ◽  
Author(s):  
F. Moslemipur ◽  
S. Golzar-Adabi

Shearing is a common practice for lamb hygiene and health, which can also influence the animal survival and productivity in stressful environments. This study was conducted to investigate the effects of shearing on performance and some metabolic and physiological parameters of fattening lambs exposed to ambient heat stress. Thirty -two male Dalagh fattening lambs (32.4 ± 5.7 kg), 3.5 ± 0.5 months of age, were selected from a herd existing at the research station of the University of Gonbad Kavoos (temperate mild-latitude zone of Iran). Lambs were divided into two groups, maintained individually and fed with a mixture of alfalfa hay and concentrate with free access to drinking water. One group was completely shorn while the other group was left unshorn, and both groups were reared for 10 weeks (July–Sept.) with mean ambient temperature of 29.3°C. Feed intake and liveweight changes were recorded weekly whereas metabolic parameters were measured daily. Fasting blood samples were collected three times a week and used for blood metabolites and hormone assays. Results showed that shearing has no effects on feed intake and weight gain over the study. Feed conversion ratio was improved (P < 0.05) by shearing (10.70 vs 13.26 kg/kg). Shearing also caused a decline in lamb rectal temperature (P < 0.05), whereas heart rate remained unchanged. Respiratory rate was lower in shorn lambs (P < 0.001), whereas blood glucose, urea and total protein levels were not affected. Serum concentrations of thyroxine declined in shorn lambs compared with unshorn lambs (P < 0.05), but cortisol level was unchanged between groups. In conclusion, the study showed that when lambs are kept sheltered under heat stress conditions, shearing appears to induce energy retention via reducing some vital activities such as respiration and heat loss leading to enhanced feed efficiency. The decrease in thyroxine level can be considered as the possible underlying mechanism for the decline observed in rectal temperature.

1997 ◽  
Vol 1997 ◽  
pp. 187-187
Author(s):  
M. M. Muwalla ◽  
M. Y. Harb ◽  
T. F. Crosby

Lasalocid is a polyether antibiotic derived from the fermentation of streptomyces lasaliensis used as a coccidiostat in sheep. There are varying literature reports on lamb growth rate and feed intake when lasalocid is included in the diet of feedlot lambs. While some reports have shown that lasalocid enhances feed efficiency in ruminants by decreasing feed intake and either maintaining or improving rate of gain others indicate that lasalocid did not have any effect on lamb growth rates or feed efficiency (Stobart et al., 1987). Also, when lasalocid was fed to Chios lambs, growth rate was increased but there was no improvement in feed conversion efficiency (Hadjipanayiotou et al., 1988). There are no published data in the literature relating to the use of lasalocid as a growth promoter in the Awassi breed of sheep fed complete diets and the purpose of this study was to investigate the effect of lasalocid with two levels of protein on the growth rate and feed efficiency of weaned male and female Awassi lambs.


Agriculture ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1087
Author(s):  
Muhammad Israr ◽  
Naila Chand ◽  
Rifat Ullah Khan ◽  
Ibrahim A. Alhidary ◽  
Mutassim M. Abdelrahman ◽  
...  

A total of 300 day old broiler chicks (Hubbard) were assigned to 30 floor pens (10 birds per pen) under cyclic heat stress. Three diets including a control, as well as two levels of grape seed powder (GSP) and zinc (OZ) at the rates of 2.5 g/kg GSP + 50 mg/kg OZ and 5 g/kg GSP + 50 mg/kg OZ, were supplied to the broilers for 35 days. According to the results, broiler feed intake improved (p < 0.05) in GSP + OZ groups from 3–5 weeks and on an overall basis compared to the control diet. Body weight increased (p < 0.05) in GSP-5 + OZ-50 during weeks 2–5 and on an overall basis. The findings indicated that feed conversion ratio (FCR) decreased (p < 0.05) during week 5 in broilers supplemented with GSP-5 + OZ-50. The antibody titer (HI) against Newcastle disease (ND) was higher (p < 0.05) in GSP + OZ groups compared to control treatment. The value of malondialdehyde (MDA) decreased (p < 0.05) under GSP + OZ diets compared to control. Moreover, paraoxonase (PON1) was higher (p < 0.05) in GSP + OZ groups compared to untreated broilers. In conclusion, GSP + OZ positively supported growth traits, reduced MDA, and augmented PON1 and HI titer against ND in broilers exposed to heat stress.


2020 ◽  
Vol 9 (8) ◽  
pp. e978986866
Author(s):  
Rafael Pereira Barros ◽  
Joaldo Rocha Luz ◽  
Ana Paula de Souza Ramos ◽  
Deise Silva Costa ◽  
Luís Gustavo Tavares Braga

The objective of this study was to determine the crude protein requirements for juvenile jundiara fish, a hybrid of Pseudoplatystoma fasciatum X Leiarius marmoratus. A total of 240 juveniles of the hybrid, with an initial mean weight of 8.4 ± 1.41 g, were distributed in 15 fiberglass tanks (170 L) in a closed water recirculation and constant aeration system, with a density of 16 fish/tank. The experimental design was completely randomized with five treatments and three replications. The treatments consisted of diets with 32, 34, 36, 38 and 40% crude protein. Seventy days into the experiment the final fish weight and feed intake were measured. Two specimens from each experimental unit were collected for evaluation of carcass chemical composition, nutritional efficiency and blood parameters. The increase in crude protein content promoted the significant, increasing linear effect for mean weight gain, mean feed intake and specific growth rate, and decreasing effect for feed conversion. Significant differences were also observed in carcass chemical composition, nutritional efficiency, total plasma protein, glucose, cholesterol, triglycerides and lipase enzymatic activity. Thus, the increase in crude protein levels of up to 40% in jundiara diets promotes improvement in the productive performance of juvenile jundiara.


2019 ◽  
Vol 97 (Supplement_3) ◽  
pp. 392-392
Author(s):  
Eduardo Colombo ◽  
Reinaldo F Cooke ◽  
Kelsey Schubach ◽  
Bruna Rett ◽  
Alice Brandão

Abstract This experiment compared physiological and productive parameters in finishing cattle managed under heat stress conditions, and supplemented or not with Omnigen-AF (Phibro Animal Health, Teaneck, NJ). Crossbred cattle (Bos taurus × B. indicus; 64 heifers and 64 steers) were ranked by initial body weight (BW; 440 ± 3 kg) and sex, and allocated to 1 of 16 pens (8 heifers or steers/pen). Pens within sex were randomly assigned to receive (OMN; n = 8) or not (CON; n = 8) Omnigen-AF at 56 g/cow daily (as-fed basis). Cattle received a total-mixed ration during the experimental period (d 0 to 107), and Omnigen-AF was offered daily as a top-dress to OMN. Cattle were shipped on d 107 to a commercial packing facility for slaughter. Cattle BW was recorded and samples of blood and tail-switch hair collected on d 0, 28, 56, 84, and 106. Feed intake was evaluated biweekly from each pen, and feed efficiency calculated according to total feed intake and BW gain of each pen. From d 0 to 7, 28 to 42, and 84 to 98, heifer intravaginal temperature was recorded hourly (iButton temperature loggers DS1922L, Maxim Integrated, San Jose, CA). Environmental temperature humidity index (THI) was also recorded hourly throughout the experiment, and averaged 79.8 ± 0.6. Heifers receiving OMN had less (P &lt; 0.05) vaginal temperature from 1500 to 1900h (39.05 vs. 39.19 °C), when THI ranged from 85.3 to 90.1. No treatment effects were detected (P &gt; 0.20) for BW gain, feed intake, feed efficiency, and carcass traits. No treatment effects were also detected (P &gt; 0.17) for plasma concentrations of cortisol and haptoglobin, and cortisol concentrations in tail-switch hair. Hence, OMN ameliorated hyperthermia in finishing cattle exposed to heat stress conditions, but such benefit was not sufficient to improve productive and physiological responses.


2018 ◽  
Vol 58 (11) ◽  
pp. 2100 ◽  
Author(s):  
Don V. Nguyen ◽  
Bunmi S. Malau-Aduli ◽  
Peter D. Nichols ◽  
Aduli E. O. Malau-Aduli

The objective of this study was to investigate the effects of enriched omega-3 oil supplemental pellets, breed and gender on lamb liveweight (LWT), body conformation and carcass characteristics, and to assess the relationships between body conformation and growth under an intensive finishing condition. Sixty ewe and wether prime lambs 7 months old were randomly allocated to one of five dietary treatments: no oil inclusion (Control); 2.5% canola oil; 5% canola oil; 2.5% flaxseed oil and 5% flaxseed oil, balanced by breed (purebred Merinos (M × M) and Corriedale × Merino (C × M) and White Suffolk × Corriedale (W × C) first crosses). Lambs were individually supplemented with 1 kg pellets per day and had free access to lucerne hay and water throughout the 7-week feeding trial, after a 3-week adaptation. Dietary oil inclusion did not cause significant differences in daily feed intake, growth performance and carcass characteristics (P > 0.05). However, first-cross W × C lambs had significantly higher feed intake, chest girth and body conformation score (P < 0.05) than M × M and C × M lambs. Carcass weight, dressing percentage and fat depth of crossbred lambs were significantly higher than those of M × M (P < 0.05). Significant interactions between oil inclusion and breed on average daily gain (ADG) and feed conversion ratio were observed. There were positive and highly significant correlations among LWT, ADG and body conformation measurements (P < 0.01). These findings suggest that prime lamb producers can better manage and match their breeding goals with feed resources by supplementing first-cross C × M lambs with pellets containing 5% canola oil or feeding first-cross W × C lambs with 5% flaxseed oil pellets during the 10-week intensive finishing period.


2016 ◽  
Vol 06 (01) ◽  
pp. 24-30 ◽  
Author(s):  
Meriem Rejeb ◽  
Raoudha Sadraoui ◽  
Taha Najar ◽  
Moncef Ben M’rad

Author(s):  
Abner A. Rodríguez-Carías ◽  
José Israel Suárez-Rodríguez ◽  
Jonathan Collazo ◽  
John Fernández-Van Cleve

The objective of this study was to determine physiological parameters (rectal temperature = RT, respiratory rate = RR, heart rate = HR) and production parameters (dry matter intake = DMI, water intake = WI, average daily weight gain = ADG, and feed conversion = FC) of crossbred and Katahdin lambs raised in rotational grazing of native pastures (NP) and in confinement under heat stress conditions. Nine crossbred lambs (average initial weight = 19.4 kg) were used and fed in a rotational grazing system for 70 days with occupation and rest periods of seven and 21 days, respectively. The lambs had daily access to the grazing area for four to six hours, grass hay and water ad libitum, a daily supplement of 100 g of commercial concentrate and a nutritional block. In the confined system, six lambs of the Katahdin breed (average initial weight = 27.3 kg) were used, and for 28 days these were fed total mixed rations (TMR) containing 30% grass hay, 15.4% soybean meal, 54.6% corn grain and a mineral block. The diet contained 14% Crude Protein (CP) and 66% Total Digestible Nutrients (TDN) and was formulated for an ADG of 200 g. The offered and rejected feed was quantified every day [4% body weight (BW)/dry matter basis (DMB)] to determine the DMI, and the volume of water offered and rejected to determine WI. To validate the stress conditions, the maximum environmental temperature and relative humidity were monitored to calculate the temperature and humidity index (THI), and the RT, HR and RR of the 15 lambs were determined. The lambs were weighed every seven days. In both experiments, the THI oscillated between 78 and 80. The lambs were under environmental heat stress conditions (THI x̅ = 79) during both studies. The averages of HR and RT in the grazing system were 118.0 beats per minute and 38.6° C, while the averages under the confinement system were 108.6 beats per minute and 39.4° C, respectively. The average RR (53.6 and 62.6 breaths per minute, in grazing and in confinement, respectively) was greater than the normal value considered for thermal comfort. Respiratory rate is the main mechanism used by lambs to dissipate heat. The heart rate also showed slightly higher values than those reported for animals in their comfort zone. However, the rectal temperature values were constant. As expected, crossbred lambs fed under grazing conditions with naturalized pastures (NP) had a low ADG (55.6 g). Nevertheless, Katahdin lambs fed in confinement with TMR had a DMI of 935.4 g/day (3.14% BW/DMB), a WI of 3.5 L/day, a FC of 4.74 and an ADG of 226.2 g. In conclusion, raising crossbred sheep in rotational grazing of NP without any type of agronomic management results in ADG that could not be considered viable in traditional production systems. The introduction of pure breeds and feeding them in confined systems with a TMR results in a pre-determined ADG (>200 g/day) and is an alternative that can be evaluated economically for its practical implementation.


2017 ◽  
Vol 1 (1) ◽  
pp. 116-125 ◽  
Author(s):  
F. Liu ◽  
J. J. Cottrell ◽  
U. Wijesiriwardana ◽  
F. W. Kelly ◽  
S. S. Chauhan ◽  
...  

Abstract Improving insulin sensitivity may reduce impacts of heat stress (HS) in pigs by facilitating heat dissipation. Chromium (Cr) has been reported to improve insulin sensitivity in pigs. Therefore, the aim of this experiment was to investigate whether Cr supplementation can mitigate HS in growing pigs. Thirty-six gilts were randomly assigned to 2 diets containing 0 (control) or 400 ppb Cr. After 14 d the supplemented pigs were allocated to either 8 d thermoneutral (20°C constant; TN) or cyclic HS (35°C, 0900 h to 1700 h) conditions and continued their respective diet (n = 9 per group). Growth performance was recorded during the 14-d supplementation period. The physiological responses to HS were monitored by measuring respiration rate, rectal temperature, blood gas chemistry, and feed intake during thermal exposure. Kinetics of plasma glucose, insulin and NEFA were studied by intravenous glucose tolerance test (IVGTT) on d 8 of thermal treatment. Results showed Cr alleviated the HS-increased rectal temperature (P &lt; 0.05) and respiration rate (P &lt; 0.01) at 1300 h and 1600 h during thermal exposure. However, Cr did not mitigate the reduction in average daily feed intake which was reduced by 35% during HS or the HS-induced respiratory alkalosis. Chromium tended to increase average daily gain (0.86 vs. 0.95 kg, P = 0.070) during the 14-d supplementation under TN conditions before thermal exposure, which might be associated with the potential of Cr in improving overall insulin sensitivity, as evidenced by a reduced insulin resistance index calculated by Homeostatic Model Assessment (HOMA-IR; 0.65 vs. 0.51, P = 0.013) and a tendency of reduced fasting plasma insulin concentration (1.97 vs. 1.67 μU/mL, P = 0.094). Heat stress decreased the acute insulin releasing rate (P = 0.012) and consequently slowed glucose clearance rate (P = 0.035) during IVGTT. Besides, HS enlarged the values of area under the curve of NEFA during IVGTT (P &lt; 0.01), indicating a reduced lipid mobilization. In conclusion, HS reduced insulin response to IVGTT. Chromium supplementation exhibited a potential in improving insulin sensitivity and mitigating HS symptoms in growing pigs.


2014 ◽  
Vol 43 (1) ◽  
pp. 45-51
Author(s):  
GB Das ◽  
ME Hossain ◽  
MA Akbar

Six hundred day-old unsexed broiler chicks were used in a 42-day trial to compare the effects of different levels of palm oil supplementation on feed intake, weight gain, feed conversion and carcass quality of broilers. The chicks were randomly distributed following a completely randomized design in four treatment groups having three replications per treatment. Each treatment had 150 broilers with 50 broilers per replicate. Four diets were formulated using locally available ingredients as diet without oil, diets containing 2.5%, 3.0% and 3.5% palm oil. All broilers had free access to ad libitum feeding. Results indicated that, supplementation of diets with different levels of palm oil significantly (p<0.05) influenced feed intake of broiler only at the age of 6th week. It was observed that as the level of supplementation increased, feed intake gradually decreased up to 6th week. Supplementation of diets with different levels of palm oil increased live weight gain of broilers. Differences (p<0.01) were observed at the end of 4th, 5th and 6th weeks of age only. Use of different levels of palm oil significantly (p<0.05) changed blood weight, heart weight and dressed weight. Survivability of broilers was higher in the supplemented group compared with without oil group. It was concluded that, supplementation of palm oil at 3.5% level in the diet of broilers resulted higher weight gain, better feed conversion and improved carcass characteristics comparing other levels. It may be concluded that supplementation of palm oil at 3.5% level in the diet of broilers resulted significantly (p>0.05) higher feed conversion ratio compared to 2.5% and 3.0% levels.DOI: http://dx.doi.org/10.3329/bjas.v43i1.19384 Bang. J. Anim. Sci. 2014. 43 (1): 45-51


2012 ◽  
Vol 147 (1-3) ◽  
pp. 148-153 ◽  
Author(s):  
R.C. Wolp ◽  
N.E.B. Rodrigues ◽  
M.G. Zangeronimo ◽  
V.S. Cantarelli ◽  
E.T. Fialho ◽  
...  

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