Experimental Lambs Research Articles

Economic analysis, performance, and feed efficiency in feedlot lambs

ABSTRACT The objective of this study was to evaluate residual feed intake (RFI), residual intake and body weight gain (RIG) and their relationship with other traits of efficiency, performance, and economic analysis of sheep. Lambs (n = 102) were evaluated during 56 days and a herd consisting of 500 ewes was simulated with the mean of dry matter intake (DMI) and final body weight of the lambs, the same as that of the experimental lambs. The lambs were fed hay-based [...]

Effect of dietary utilisation of sugarcane press mud on production performance of Muzaffarnagari lambs.

Sugarcane press mud (SPM) is one of the potential agro-industrial by-products available in India and research exploring its utilisation in small ruminant nutrition is scanty. In this direction, the present study evaluated the feasibility of dietary incorporation of SPM at different levels in a feeding trial lasting 180days. A total of 21 Muzaffarnagari ram lambs were randomly distributed into three groups of seven each based on comparable body weight (11.70±0.29kg) and age (3-5months) following a completely randomised design. The three dietary treatments were (1) SP0 (control), concentrate mixture without SPM; (2) SP10, concentrate mixture comprising 10% SPM and (3) SP20, concentrate mixture comprising 20% SPM on air-dry basis. The experimental lambs were offered weighed quantity of designated isonitrogenous (crude protein=20.6%) and isoenergetic (metabolisable energy=12.1MJ/kg) concentrate mixture (coarse mash) and along with ad libitum wheat straw (threshed to 1-2-cm length) and a 9-day metabolism trial was conducted. Results revealed no significant (P>0.05) differences in intake and digestibility of nutrients, nitrogen balance, nutritive value of diets, average daily gain, as well as feed conversion ratio among three groups. The serum concentration of triiodothyronine and tetraiodothyronine did not differ due to treatments. Likewise, wool yield and its quality, measured in terms of fibre diameter, medullation percentage and staple length were also comparable irrespective of dietary variation. Furthermore, the cost of concentrate mixture (Rs/day) was lower (P≤0.05) in SP20 followed by SP10 as compared to group SP0. These findings suggested that SPM could be safely fed up to 20% level in the concentrate mixture for lambs substituting expensive traditional feed ingredients without negatively inflicting the performance of growing lambs.

Study of guided wave propagation on a plate between two solid bodies with imperfect contact conditions

In this work, fundamental symmetric Lamb wave S0 mode is characterized in terms of its velocity variation as function of the interfacial conditions between solid bodies in contact. Imperfect contact conditions are numerically and experimentally determined by using ultrasonic Lamb wave propagation parameters. For the study, an experimental system was used, formed by two solid aluminum rods (25.4mm in diameter) axially loading a thin aluminum plate to control contact interfacial stiffness. The axially applied load on the aluminum plate was varied from 0MPa to 10MPa. Experimental Lamb wave signals were excited on the plate through two longitudinal contact transducers (1MHz of central frequency) using a pitch-catch configuration. Numerical simulations of contact conditions and Lamb wave propagation were performed through Finite Element Analysis (FEA) in commercial software, ANSYS 15®. Simulated Lamb wave signals were generated by means of a 5 cycles tone burst signals with different frequency values. Results indicate a velocity change in both, experimental and simulated Lamb wave signals as function of the applied load. Finally, a comparison between numerical results and experimental measurements was performed obtaining a good agreement.

Intake, nutrient utilization and growth performance of lambs fed detoxified Jatropha curcas meal

The study assessed the effect of dietary supplementation of detoxified Jatropha meal (DJM) on feed intake, nutrient utilization and growth performance of lambs. Growing lambs (24) of similar age and body weight (15.76±1.92kg) were selected for this study. The experimental lambs were allocated in four groups i.e. control group (CG) without DJM and replacing soybean meal (SBM) of CG with DJM on iso-nitrogenous basis in treatment groups (TG) by 12.5% (T1), 25% (T2) and 37.5% (T3). The feeding cum growth trial was conducted for a period of 180 days. The intake of dry matter (DM), organic matter (OM) and digestibility coefficients of DM, OM, CP, NDF and ADF were comparable between CG and TGs. Nutrient intake, DCP, TDN, Nitrogen (N) intake, excretion and retention were comparable between CG and TGs. Replacement of SBM with DJM even up to 37.5% did not show any significant impact on urinary excretion of total purine derivatives (PD), creatinine (C) and their ratio. Microbial N synthesis (g/d) and efficiency of microbial N synthesis of CG were comparable irrespective of DJM%. The initial and final body weights (BW) of lambs between CG and TGs were also comparable. Total BW gain (kg), average daily gain (ADG; g d-1) and feed conversion ratio (kg DM/kg gain) by lambs did not differ significantly between CG and TGs. The study concluded that SBM in the diet of lambs could be replaced by DJM up to 37.5% without any adverse impact on nutrient intake, digestibility, rumen microflora and growth of the lambs.

Bentonite supplementation can improve performance and fermentation parameters of chronic lead-exposed lambs.

Two experiments were conducted to investigate the effect of supplemental bentonite on performance, blood, and fermentation characteristics in Zandi lambs. In experiment 1, 20 Zandi male lambs (initial BW, 17.5±1.6kg and 110±5days old) were randomly assigned into four groups of five animals in each. The experimental treatments were (1) control (no Pb and bentonite), (2) 15mg/kg DM Pb as Pb acetate and no bentonite, (3) 15mg/kg DM Pb as Pb acetate and 1.5% bentonite, and (4) 15mg/kg DM Pb as Pb acetate and 3% bentonite. The dietary treatments had no significant effect on dry matter intake of experimental lambs. Feed required per unit of weight gain was more (P<0.05) in lead-exposed lambs in group 2 compared to the control and bentonite supplemented groups. Serum glucose, urea nitrogen, cholesterol, HDL, and LDL concentrations was similar among the treatments. In experiment 2, an in vitro gas production technique was used to evaluate the effects of bentonite supplementation on the gas production parameters of lead-polluted diets. The rate and amount of gas production was higher for bentonite supplemented groups (P<0.01). Asymptotic gas production (b), metabolizable energy, and concentration of short chain fatty acids were lower (P<0.05) for lead-polluted non-supplemented diet (group 2) as compared to the bentonite supplemented and control groups. It was concluded that bentonite supplementation favorably modified ruminal fermentation pattern and improved feed conversion ratio in growing lead-exposed lambs.

The effect of ewe nutrition and body condition during late-pregnancy on the behaviour of twin-bearing ewes and their lambs

This study describes the effect of maternal nutrition and body condition score (BCS) during pregnancy on the behaviour of twin-bearing ewes and their lambs as assessed 3h to 18h after birth. Ewes (n=274) of BCS 2.0, 2.5 or 3.0 were offered either pregnancy maintenance requirements (fed to allow for foetal but not maternal weight gain; ‘medium’) or ad libitum feeding from day 112 until day 136 of pregnancy for experiment 1 and from day 128 until day 141 of pregnancy for experiment 2. Lamb vigour behaviours (time to stand, suck, make contact with and follow their dam) and bleating behaviour of ewes and lambs were recorded for 5min, following handling at 3–18h. A subgroup of lambs in experiment 1 was tested in a maternal-recognition test. A lesser percentage of ewes in the ad libitum treatment than in the medium treatment high-pitched bleated (86.9% [95% CI 77.4–92.8%] versus 80.0% [69.2–87.7%], and 95.4% [86.5–98.5%] versus 86.9% [70.0–90.5%], in experiments 1 and 2 respectively, P<0.05). Number of low pitched bleats per ewe was generally greater for ewes in the ad libitum than the medium treatment, although this effect was mediated by mid-pregnancy body condition in a different way for each experiment. Effects of maternal body condition and nutrition treatment on bleating behaviour of lambs were not repeatable across experiments, and the ewe nutrition treatments did not affect lamb vigour behaviours (P>0.05) in the 5-min observation period immediately following handling at 3–18h after birth. Behaviour of twin-bearing ewes of BCS2-3 in mid pregnancy, and their twin-born lambs, showed very few changes 3–18h after birth in response to ad libitum versus pregnancy-maintenance feeding during mid to late pregnancy.

The effect of different forms of sunflower products in diets for lambs and storage time on meat quality

The aim of the study was to determine the effect of sunflower products addition to lamb diets on lipid metabolism indices in blood plasma, carcass characteristics and longissimus dorsi muscle fatty acid (FA) composition. The experiment was performed on 24 Corriedale lambs weighing 22.9±1.89kg, assigned into 4 blocks of 6 animals each (according to the initial body weight), as a randomized complete block design. The control diet (CON) consisted of (g/kg dry matter; DM): meadow hay (188), ground corn (399), barley meal (223), soybean meal (136), sunflower meal (38.0) and vitamin-mineral premix (16.0). The experimental lambs additionally received different forms of sunflower products (g/kg DM): calcium salts of sunflower oil (CAS; 37.9), sunflower seeds (SFS; 68.6) or sunflower oil (SFO; 41.7). Furthermore, samples of longissimus dorsi muscle were frozen at −30°C to study the stability of FA during short- (1 month) and long-term (3 or 6 months) storage. Different forms of sunflower products did not affect lamb growth, carcass traits and chemical composition of longissimus dorsi muscle. Supplementing lambs with SFS diets negatively influenced lipid metabolism indices by increasing total cholesterol (TC) and low density lipoprotein (LDL) in blood plasma, without affecting the TC concentration in meat. The inclusion of different forms of sunflower products decreased nutritive value of meat by lowering the concentration of n-3 polyunsaturated fatty acids (PUFA). For that reason, we do not recommend sunflower products for lamb nutrition.Short and long-term storage increased total FA, saturated (SFA), monounsaturated fatty acids (MUFA), and interestingly, PUFA concentrations in meat. Such modifications could be associated with hydrolytic changes occurring during refrigerated storage.

Growth performance and hormonal status during feed restriction and compensatory growth of Small-Tail Han sheep in China

Average daily gain (ADG), hormonal status and gain:feed intake ratio were determined in Small-Tail Han lambs (initially 24±1.8kg; 90±11days of age) during feed restriction and compensatory growth. An adaptation period of 14days was allowed during which time the sheep consumed feed (crude protein=148g/kg; metabolizable energy=15.9MJ/kg DM) ad libitum. This was followed by 30days of feed restriction in which three groups of lambs (n=10 per group) received approximately 85 (Tr1), 75 (Tr2) and 60% (Tr3) of ad libitum intake; a fourth group (control, CK; n=10) continued to receive ad libitum feed. After the restriction period, all lambs were fed with ad libitum intake for 60 days. During feed restriction, the control sheep had higher ADG than the other three groups (P<0.01). The gain:feed intake ratios of CK and Tr1 were higher than for Tr2 and Tr3 (P<0.01). But during re-alimentation, ADG of Tr2 and Tr3 were higher than control lambs (P<0.01) while final body weight (BW) was similar among groups. Gain:feed intake did not differ among the four groups. Following feed constriction, there was no difference in dry matter intake (DMI) among the four groups during the 60-days feed re-alimentation period. There was no difference in plasma concentrations of growth hormone, insulin and insulin-like growth factor 1, triiodothyronine, thyroxine or cortisol. Within restricted groups, GH generally decreased during the restricted feeding period and increased with ad libitum feed intake. In addition, plasma IGF-1 concentration of all experimental lambs generally increased in the latter stages of the ad libitum feed intake. These changes were most pronounced in the two most feed restricted groups. In conclusion, the lambs in the highest feed restriction group (60% of ad libitum intake) were able to compensate completely for the reduced BW. The total DMI over the whole period of the highest restricted feed intake group was 14.2% lower than the control group (P<0.05). Therefore, the strategy of restricted feed would be economical for fattening lambs in China.

The Simple Lamb Wave Analysis to Characterize Concrete Wide Beams by the Practical MASW Test.

In recent years, the Lamb wave analysis by the multi-channel analysis of surface waves (MASW) for concrete structures has been an effective nondestructive evaluation, such as the condition assessment and dimension identification by the elastic wave velocities and their reflections from boundaries. This study proposes an effective Lamb wave analysis by the practical application of MASW to concrete wide beams in an easy and simple manner in order to identify the dimension and elastic wave velocity (R-wave) for the condition assessment (e.g., the estimation of elastic properties). This is done by identifying the zero-order antisymmetric (A0) and first-order symmetric (S1) modes among multimodal Lamb waves. The MASW data were collected on eight concrete wide beams and compared to the actual depth and to the pressure (P-) wave velocities collected for the same specimen. Information is extracted from multimodal Lamb wave dispersion curves to obtain the elastic stiffness parameters and the thickness of the concrete structures. Due to the simple and cost-effective procedure associated with the MASW processing technique, the characteristics of several fundamental modes in the experimental Lamb wave dispersion curves could be measured. Available reference data are in good agreement with the parameters that were determined by our analysis scheme.

Эффективность альбена и альбена в комбинации с Т- и В-активином при экспериментальном диктиокаулезе ягнят

Objective of research. The aim of the research was to investigate the anthelmintic efficiency&#x0D; of Albena and Albena in combination with T and b-activin a in experimental dictyocaulus lambs.&#x0D; Materials and methods. Test Albena with 20 % of albendazole and Albena in combination&#x0D; with T and b-a activin is carried out at the experimental dictyocaulus lambs in August – September&#x0D; 2013 on 18 crossbred lambs aged 4-5 months, free from infection, as confirmed by the results&#x0D; coprevalence studies by the method of Berman and flotation. Lambs infected with invasive&#x0D; larvae of Dictyocaulus filaria at a dose of 1000 copies/goal. by providing them with water for oral&#x0D; administration. In 30 days after infection the lambs were divided into 3 equal groups of 6 animals&#x0D; each and were kept in machines under conditions that prevent spontaneous infection of lambs.&#x0D; Lambs of the first group was administered individually orally Albin in the form of 20% of granulated&#x0D; powder in a dose of 5 mg/kg DW of 0.25 g of granules per 10 kg of body weight. Animals of the&#x0D; second group asked Albin the same dose and subcutaneously T-activin in a dose of 2 mg/kg&#x0D; once a day for 1, 3 and 7 days and b-activin in a dose of 5 μg/kg intramuscularly once a day for&#x0D; 5 days. The third group of lambs was used and served as control. The efficacy of the drug was&#x0D; determined by helminthological autopsy of the lungs of lambs 15 days after deworming.&#x0D; Results and discussion. Obtained a 100% efficacy of treatment of lambs with Albena in&#x0D; combination with T and b-activin. Albin at a dose of 5 mg/kg showed 92,3% effective against D.&#x0D; filaria imaginal. Interenvironment lambs of the control group was 23.5±2,4 EKZ/goal.

Fibrolytic Bacteria Isolated from the Rumen of North American Moose (Alces alces) and Their Use as a Probiotic in Neonatal Lambs.

Fibrolytic bacteria were isolated from the rumen of North American moose (Alces alces), which eat a high-fiber diet of woody browse. It was hypothesized that fibrolytic bacteria isolated from the moose rumen could be used as probiotics to improve fiber degradation and animal production. Thirty-one isolates (Bacillus, n = 26; Paenibacillus, n = 1; and Staphylococcus, n = 4) were cultured from moose rumen digesta samples collected in Vermont. Using Sanger sequencing of the 16S rRNA gene, culturing techniques, and optical densities, isolates were identified and screened for biochemical properties important to plant carbohydrate degradation. Five isolates were selected as candidates for use as a probiotic, which was administered daily to neonate lambs for 9 weeks. It was hypothesized that regular administration of a probiotic to improve fibrolysis to neonate animals through weaning would increase the developing rumen bacterial diversity, increase animal production, and allow for long-term colonization of the probiotic species. Neither weight gain nor wool quality was improved in lambs given a probiotic, however, dietary efficiency was increased as evidenced by the reduced feed intake (and rearing costs) without a loss to weight gain. Experimental lambs had a lower acetate to propionate ratio than control lambs, which was previously shown to indicate increased dietary efficiency. Fibrolytic bacteria made up the majority of sequences, mainly Prevotella, Butyrivibrio, and Ruminococcus. While protozoal densities increased over time and were stable, methanogen densities varied greatly in the first six months of life for lambs. This is likely due to the changing diet and bacterial populations in the developing rumen.

Partial substitution of barley for corn: effect on "Hamra" lamb growth performance, carcass and meat characteristics.

The aim of this study was to investigate the effect of two kinds of given diets on growth, on some carcass characteristics and on the major meat nutrients of local Algerian sheep breed. The investigated sheep breed called "Hamra" is one of the most famous breeds in Algeria. Among one 106 animals, 40 lambs were selected according to their age, similar livestock characteristics and body weight. The samples were divided into two equal groups: control and experimental lambs according to their live weight; 24.63 ± 0.47 and 24.35 ± 0.64kg, respectively. Both groups were fed with two varieties of concentrate diets: corn diet based for the first group of control lambs (n = 20) and corn substituted by barley (Variety Saïda 183) for the second experimental group lambs (n = 20). Both diets were supplemented with 200g straw of barley/animal/ration. The chemical analysis of diets showed an elevated crude fibre content in the commercial concentrate. However, the experimental concentrate contained higher amounts of calcium. After 59days of fattening, no significant difference was found among the two studied groups on the growth performance (p > 0.05), showing the same final body weight. In contrast, a significant difference was found (p ≤ 0.001) in relation to the cost of the given diet. This could affect the price of the produced meat. At 37.85 ± 0.78kg live weight, 10 lambs fed with experimental concentrate were slaughtered. The dressing percentage was 46.65%, with 2.49% of carcass shrink. Furthermore, an interesting percentage of total muscle was obtained (63.73%) with a good carcass conformation scoring 9.56. Compared to other breed sheep, Hamra carcass could be considered as the most valuable one economically.

The effects of barley replacement by dehydrated citrus pulp on feed intake, performance, feeding behaviour and serum metabolic indicators in lambs

The citrus industry produces a wide amount of citrus pulp which can represent an alternative feed resource for feeding ruminants. However, citrus pulp also contains chemicals such as polyphenols, which can cause toxicity, limiting its use. We investigated the potential of replacing barley by dehydrated citrus pulp (DCP), at two levels of inclusion (24% and 35% on an as-fed basis), in a lamb fattening diet and monitored the performance, feeding pattern and serum parameters of the experimental lambs. The consumption of a diet containing up to 35% of DCP resulted in equivalent performance, feed efficiency and carcass weight and yield as compared with animals ingesting a cereal-based diet (control). The daily feed consumption pattern was slightly affected by the inclusion of citrus pulp in the diet. In terms of serum haematochemical profile, DCP ingesting animals had similar levels to control lambs. Pertaining to the serum protein profile, DCP addition had minor effects. A significant increase in the albumin content and in the albumin to globulin ratio was observed in the animals ingesting 35% DCP compared with the control-fed ones; but the values were not at a level to cause metabolic distress. The use of high levels of DCP in small ruminant fattening can ensure equivalent animal performances and metabolic welfare while providing a value addition to a local by-product.

Nutrient intake, digestibility and growth performance of Washera lambs supplemented with graded levels of sweet blue lupin (Lupinus angustifolius L.) seed

The experiment was conducted to evaluate nutrient intake, digestibility and growth performance of Washera lambs fed natural pasture hay-based diet supplemented with graded levels of sweet blue lupin (Lupinus angustifolius L.) seed. Twenty male intact Washera lambs with average age of four months and initial body weight of 16.9±0.32kg (mean±SD) were used in 90 days feeding trial followed by 10 days digestibility trial. The design of the experiment was randomized complete block design (RCBD) with five replications. The four supplement feeds were;150g wheat bran (WB) (control-T1), 150g WB+195g sweet lupin seed (SLS) (T2), 150g WB+245g SLS (T3) and 150g WB and 295g SLS (T4). Natural pasture hay was offered ad libitum. Digestibility trial was conducted at the end of the growth trial. Data were analyzed using the General Linear Model (GLM) procedures of SAS (version 9.2). Means were separated using Duncan's Multiple Range test. Correlation between nutrient intake, digestibility of nutrients and weight gain were analyzed using Pearson correlation procedure. Results showed that supplementation of SLS significantly increased total dry matter, crude protein and organic matter intakes. Supplementation of SLS improved the digestibility of dry matter and organic matter (P<0.05) and crude protein (P<0.001). However, the digestibility of NDF and ADF were not affected by supplementation (P>0.05). Average daily gain (ADG) was higher (P<0.001) for the SLS supplemented groups (61.8–89.1g/day). It was concluded that sweet blue lupin seed could serve as alternative CP supplement in natural pasture hay-based feeding of Washera sheep. Based on the biological performance of the experimental lambs (ADG and FCE values), T3 could be recommended for practical feeding of lambs if optimum performance is targeted.

Probabilistic-based damage identification based on error functions with an autofocusing feature

This study presents probabilistic-based damage identification technique for highlighting damage in metallic structures. This technique utilizes distributed piezoelectric transducers to generate and monitor the ultrasonic Lamb wave with narrowband frequency. Diagnostic signals were used to define the scatter signals of different paths. The energy of scatter signals till different times were calculated by taking root mean square of the scatter signals. For each pair of parallel paths an error function based on the energy of scatter signals is introduced. The resultant error function then is used to estimate the probability of the presence of damage in the monitoring area. The presented method with an autofocusing feature is applied to aluminum plates for method verification. The results identified using both simulation and experimental Lamb wave signals at different central frequencies agreed well with the actual situations, demonstrating the potential of the presented algorithm for identification of damage in metallic structures. An obvious merit of the presented technique is that in addition to damages located inside the region between transducers; those who are outside this region can also be monitored without any interpretation of signals. This novelty qualifies this method for online structural health monitoring.

Ventilation before Umbilical Cord Clamping Improves Physiological Transition at Birth or "Umbilical Cord Clamping before Ventilation is Established Destabilizes Physiological Transition at Birth".

Ventilation before Umbilical Cord Clamping Improves Physiological Transition at Birth or "Umbilical Cord Clamping before Ventilation is Established Destabilizes Physiological Transition at Birth".

Relative resistance of Menz and Washera sheep breeds to artificial infection with Haemonchus contortus in the highlands of Ethiopia.

The aim of this study was to evaluate the relative resistance of Menz and Washera sheep breeds to artificial infection with Haemonchus contortus. The challenge trial was conducted at the Debre Berhan Agricultural Research Center in Ethiopia. A total of 39 (Menz = 21, Washera = 18) lambs of about 6months old were used for the trial. All lambs were initially treated against internal parasite using albendazole and Fasinex to free them from internal parasites and kept indoors. H. contortus third-stage larvae (L3) were prepared according to standard procedure from adult female parasite collected from abattoirs and recovered using the Baerman technique. Approximately 5000 infective larvae were inoculated to the experimental lambs at about 5weeks after deworming. Fecal egg count (FEC), packed cell volume (PCV), FAffa MAlan CHArt (FAMACHA) score, lamb body weight, and survival of lambs were recorded at 28, 35, and 42days after challenge. Breed effect was not significant (P > 0.05), whereas time of measurement and the interaction of breed and time had significant (P < 0.05) effects on FEC and PCV. At 28days after challenge, Menz sheep had lower FEC than Washera sheep, whereas at days 35 and 42, the Washera sheep had lower FEC than Menz lambs. The PCV decreased significantly throughout the post-challenge period. Despite their parasite burden, Menz sheep were able to maintain live weight during the 42days of challenge. Chi-square tests for breed differences in lamb survival were not significant at any time (28, 35, and 42days after challenge). Lower FEC at 28days and delayed rise in FEC after infection in Menz lamb would allow in delaying anthelmintic treatment. In addition to maintain body weights during the infection period, sheep of both breeds exhibited substantial variability in PCV and FEC, suggesting opportunity to consider parasite resistance in selection program.

Best basis compressive sensing of guided waves in structural health monitoring

A novel signal compression and reconstruction procedure suitable for guided wave based structural health monitoring (SHM) applications is presented. The proposed approach combines the wavelet packet transform and frequency warping to generate a sparse decomposition of the acquired dispersive signal. The sparsity of the signal in the considered representation is exploited to develop data compression strategy based on the Best-Basis Compressive sensing (CS) theory. The proposed data compression strategy has been compared with the transform encoder based on the Embedded Zerotree (EZT), a well known data compression algorithm. These approaches are tested on experimental Lamb wave signals obtained by acquiring acoustic emissions in a 1m2 aluminum plate with conventional piezoelectric sensors. The performances of the two methods are analyzed by varying the compression ratio in the range 40–80%, and measuring the discrepancy between the original and the reconstructed signal. Results show the improvement in signal reconstruction with the use of the modified CS framework with respect to transform-encoders such as the EZT algorithm with Huffman coding.

INFLUENCE OF DIFFERENT TREATMENTS OF GUAR KORMA MEAL ON SHEEP PERFORMANCE

The present study was conducted to study the effect of heat, soaking, chemical (ethanol) or biological (bacteria) treatments of Guar korma meal (GKM) on concentration of anti-nutritive compounds, rumen fermentation characteristics, microbial counts, degradability of tested TMR's, the blood picture and the consequently sheep performance was also studied. The total mixed rations (TMR's) were: 1- TMR without GKM (control); 2- TMR with 10% untreated GKM (TMRU), 3- TMR with 10% heated GKM (TMRH), 4- TMR with 10% soaking GKM (TMRS), 5- TMR with 10% GKM treated with ethanol (TMRE) and 6- TMR with 10% GKM treated with lactic acid bacteria (TMRB). Digestibility trials were conducted with Barki rams, while rumen fermentation trials were conducted with fistulated Barki ewes. Feeding trials were applied with thirty male growing lambs, whereas they were randomly divided into six similar groups according to their body weights for a feeding period of 120 days, where weight was recorded and blood samples were collected. All treatments, showed a positive effect in decreasing concentration of anti-nutritive compounds. TMRB had highest feeding values, nitrogen utilization, higher VFA's concentration and higher rates of ammonia-N and VFA's productions, while, lowest ammonia-N concentration was recorded with TMRH. Total bacteria count was increased with all treatments comparing with TMRU, while protozoa counts were decreased with incorporating untreated or treated GKM in TMR's comparing with control. Microbial protein was ranged between 54.16 and 100.62 (gm/day) for untreated GKM and LAB treated GKM containing TMR's with significant differences. Effective degradability ED (%) of DM were higher (P< 0.05) for TMR's containing biologically and chemically treated GKM. Highest effective degradability of CP was recorded with TMRB with significant differences with other TMR's. However, lower effective degradability of CP was recorded with TMR's containing GKMH and GKMU. Highest daily gain was recorded with LAB treated GKM containing TMR. The lowest daily gain was recorded by sheep fed ration contained untreated GKM. The economic cash return (L.E/head/d) was more profit for ration contained GKMB and GKME than other total mixed rations. Except for cholesterol, total protein, albumin, globulin and their ratio the other serum metabolites of the experimental lambs were not significantly influenced by the dietary treatments. It could be concluded that the lactic acid bacteria treated GKM could be used at 10% in TMR for sheep. Chemically treated GKM by ethanol could be also used at 10% without any adverse effects on sheep performance. However, it is important to carry out further research on long term feeding of sheep to follow metabolites compounds consequential in blood, milk and meat.

Persistent challenge with Trichostrongylus colubriformis and Haemonchus contortus larvae does not affect growth of meat-breed lambs suppressively treated with anthelmintics when grazing

This experiment tested the hypothesis that persistent challenge with anthelmintic susceptible Trichostrongylus colubriformis and Haemonchus contortus larvae would not affect growth of grazing, meat-breed lambs when suppressively treated with anthelmintics. The experiment was a 2×2 factorial design using 6–7 months old White Suffolk X Border Leicester/Merino (meat-breed) lambs which were either infected with 2000 T. colubriformis and 300 H. contortus L3/week (IF) or remained uninfected (UIF) for 9 weeks and were either treated (TX) with a combination of short and long-acting anthelmintics or remained untreated (UTX). Lambs grazed as one flock and were rotated between paddocks to avoid autoinfection from pasture. Lambs were humanely euthanised on day 63 and the abomasum and small intestine collected to determine total worm burdens and tissue antibody response specific to T. colubriformis. As expected, worm egg count (WEC) and worm burden were significantly higher in IF UTX lambs (p<0.001). WEC was dominated by H. contortus and peaked at 2325epg on day 63 but remained at zero for the other treatment groups for the duration of the experiment. Tissue antibody responses were evident in IF lambs (titres; 9982 vs 2767, p=0.012) but treatment had no effect (titres; 5912 vs 5349, p=0.829). Lambs grew an average of 2.6kg during the experiment with no difference between IF TX and UIF TX groups (p=0.432). Elevated tissue antibody responses were not associated with differences in growth. Results from this experiment support the hypothesis that persistent larval challenge with anthelmintic susceptible H. contortus and T. colubriformis will not affect growth of grazing, meat-breed lambs when suppressively treated with effective anthelmintics. Therefore the use of sheep suppressively treated with effective anthelmintics appears to be a valid substitute for gastrointestinal nematode-free lambs in field experiments.