Young Sheep Research Articles

Gastrointestinal parasites of bile and faeces of slaughtered cattle and sheep from Maiduguri Municipal Abattoir, North Eastern Nigeria

The occurrence and types of gastrointestinal parasites of bile and faeces of cattle and sheep from the semi-arid region of Maiduguri, North-Eastern Nigeria were determined using standard parasitological techniques. Samples of bile and faeces collected from three hundred and eighty seven (387) cattle and 389 sheep were analysed using bile sedimentation, faecal sedimentation and faecal floatation. An overall prevalence of 42.63% was found in cattle, while 49.36% was in sheep. Results from both species did not vary significantly (p>0.05) based on the sexes, ages and breeds except in sheep, where adult animals were significantly (p˂0.05) infected than the young sheep. Furthermore, 91(23.51%), 13(3.35%) and 84(21.70%) cattle and 15(3.85%), 22(5.65%) and 183(47.04) sheep were positive for one parasite or the other using the bile sedimentation, faecal sedimentation and faecal floatation techniques respectively. In cattle, Fasciola spp was the most predominant parasite recovered with 75(39.89%), followed by strongyle 66(35.11%), Dicrocoelium hospes 23(12.23%) and coccidia 21(11.17%). One animal in each case was infected with Paramphistomum spp. 1(0.53%), and Toxocara vitulorum 1(0.53%). In sheep, Fasciola spp. 24(9.44%), Dicrocoelium hospes 4(1.57%), Paramphistomum spp. 5(1.97), strongyle 75(29.53%), coccidia 140(55.12%), mite egg 1(0.39%), Strongyloides papillosus 2(0.79%) and Moniezia expansa 3(1.18%) were found. Co-infection of two or three parasites in both cattle and sheep was observed with strongyle/coccidia combination being the most frequent. The recovery of parasites of economic and public health significance such as Fasciola spp, Toxocara vitulorum and Strongyloides papillosus indicates that they are abundant and that attention need to be given to their control under ruminant production system. In all, the study had shown the common gastrointestinal parasites found in the study location.Keywords: Prevalence, Maiduguri, Cattle, Sheep, Parasite

Partition of dietary energy by sheep fed fresh ryegrass (Lolium perenne) with a wide-ranging composition and quality

Context Perennial ryegrass (Lolium perenne L.) is an important forage in temperate ruminant agricultural systems, but its quality and composition is highly variable and can become dominated by senescent material during summer and dry periods. Nutritive value is often predicted on the basis of chemical composition and calculated metabolisable energy (ME), which is rarely measured. Aim To measure the partition of energy from ryegrasses with widely varying proportions of leaf and senescent material, among faeces, urine and methane (CH4) in sheep. Methods Three experiments were undertaken with two groups of young wether sheep, fed seven diets of freshly cut ryegrass, at maintenance levels of intake to measure the partition of dietary energy among faeces, urine and CH4, enabling ME to be calculated. Across the seven diets, green leaf accounted for 16.0–87.6% of feed offered, whereas senescent material ranged from 2.8% to 65.0% and nitrogen (N) ranged between 8.6 and 31.2 g/kg DM. Measured ME was compared with predicted values based on digestible energy. Methane emissions were determined by both open-circuit respiration chambers and sulfur hexafluoride marker dilution. Key results Apparent digestibility (g/100 g) of DM ranged from 51.8 to 75.3 and N from 26.7 to 73.9. The percentage of the gross energy of feeds partitioned to CH4 (chamber) was 6.01–7.42, and 1.77–5.69 to urine. Effects of digestibility on CH4 yields (g/kg DM intake) were minor and the sum of energy losses to CH4 and urine were 13.5–17.6% of digestible energy (DE) intake, suggesting an underestimation of ME when predicted from DE. Use of sulfur hexafluoride substantially overestimated CH4 emissions when the permeation tubes had been in the sheep for 80 days. Conclusions A high proportion of senescent material in ryegrass had little effect on CH4 yields from sheep and energy losses to urine were mostly less than 3% of energy intake and were related to dietary N concentration. Implications Dietary ME calculated from DE is likely to be underestimated when ryegrass contains a high proportion of senescent material, due to reduced urinary energy losses, as CH4 yields are largely unaffected by maturity or senescence.

An influence of the feed additives on sheep fat tissue composition and properties

The aim of the study was to undertake comparative evaluation of chemical composition and physical properties of the fat tissue of the Romanov sheep breed on condition of separate and joint use of natural additives Glaukonit and probiotic Biogumitel. A positive effect of their use has been established. The young stock consuming the tested additives at the dose of 0,1 g per 1 kg of live weight surpassed on weight of internal fat and carcass fat of control analogs by 0,04-0,21 kg (9,09-47,73%) and 0,12-0,29 kg (6,38-15,44%). The content of dry matter and chemically pure fat was higher in the fat tissue of the ram hogs of experimental groups in internal fat by 0,03-0,72% and 0,20-0,60%, subcutaneous fat by 0,02-0,08% and 0,04-0,15%; intermuscular fat by 0,09-0,22% and 0,05-0,13%, respectively. Internal fat had the greatest energy value, intermuscular fat had the lowest energy value, and subcutaneous fat took an intermediate position. In all cases, the ram hogs of experimental groups were in the lead and surpassed the control on the energy value of internal fat by 0,08-0,25 mJ (0,23-0,70%); intermuscular fat by 0,01-0,04 mJ (0,03-0,12%); subcutaneous fat by 0,02-0,06 mJ (0,06-0,18%). An increase in the iodine value in the fat samples of the experimental groups was established. All changes occurring in the fat tissue of young sheep were within the regulatory limits and corresponded to the breed characteristics. At all stages of research the maximum effect was achieved due to by joint use of tested additives.

Feeding capacity and meat productivity of sheep of different breeds in the Republic of Buryatia

In this article, we studied the feeding and meat productivity of young coarse sheep (Buryat, Mongolian, Tuva, Edilbaev breeds) raised in 4 sheep farms of the Republic of Buryatia. In addition, the paper analyzes the economic efficiency of different breeds.

Study on prevalence of ovine Paramphistomiasis in Kutaber Woreda, South Wollo, Amhara Region, Ethiopia

A study was conducted to identify the current status of Paramphisthomum infections in small ruminants in Kutaber. A total of 384 fecal samples from small ruminants were collected and subjected to sedimentation technique. Out of 384 fecal samples inspected, 150 (39.1%) were positive for Paramphisthomum. The prevalence rates of 36.5 and 30.8% were observed in good and medium body condition, respectively. In adult and young sheep, the prevalence rates of 40.9 and 33.3 were identified from fecal samples inspected, respectively. The highest prevalence of Paramphistomiasis was observed in Lewcho (50.0%) followed by Beshilo (44.5%) and Elsa (42.1%) The lowest incidence of Paramphistomiasis was observed in Alansha (19.0%). Based on age groups, the highest prevalence rate was 40.9% observed in age category of adult and the lowest prevalence rate 33.3% was observed in young. When body condition was considered as a risk factor for the prevalence of Paramphistomiasis, 49.5, 30.8 and 36.5% was observed in poor, medium and good body condition respectively. The prevalence of Paramphistomiasis in male (33.9%) and female (41.3%) was recorded. This parasitic disease is distributed in every district and considered as one of the major setbacks to sheep product utilization causing direct and indirect losses.

Anatomo-pathological study of lung lesions in slaughtered sheep at Batna municipal Slaughterhouse (Eastern Algeria)

This study focused on the research of lung lesions in sheep slaughtered in the slaughterhouse of Batna city (Eastern Algeria). The objective of this study was to determine the frequency of lung lesions during the period from March to September 2013. Macroscopic examination was performed at the slaughterhouse to determine lung lesions and to take samples from injured lung areas for microscopic examination of anatomo-pathological lesions. Among 7420 inspected sheep, 2722 had pulmonary lesions (alone or in combination). The overall prevalence of lung affection was 36.68% (2722/7420), which is statistically significant (P < 0.001). Different pulmonary lesions were observed in the lungs with a rate of 43.91% (3258). The main pathologies of the lungs were heparization, verminous pneumonia, atelectasis, emphysema, edema, hydatid cysts, hemorrhage, pleurisy, suppurative broncho-pneumonia, abscess, and pulmonary congestion. Verminous pneumonia was the dominant pathology during the study period (745/3258) with a frequency of 22.87%. This lesion was preferentially localized in the caudal lobes, followed by atelectasis (22.16%) and hepatization (19.67%). The lesions of emphysema and suppurative broncho-pneumonia were observed only in young sheep with a frequency of 03.97% and 01.29%, respectively. Hydatid cyst was observed mainly in adults with 49 cases versus only one case in young animals. Season and age had a significant effect on the occurrence of some pulmonary lesions. Microscopic examination confirmed the macroscopic aspects of the lesions. The latter were well distributed on the different parts of the lung parenchyma, 05.27% of lesions were localized across the lung parenchyma. 73.79% of the lesions were localized in the right lung against 20.17% in the left lung.

Effects of Serratula coronata Infusion on Metabolism and Growth Rates in Young Sheep

The effects of the leaves of the crown-shaped saw-wort (Serratula coronata L.) used in the water infusion on the young sheep growth rates and serum biochemical profile have been studied. In the context of the deficient protein and excessive dietary fiber intake, a positive tendency for increasing the lamb growth rates dependent on the daily dosage of the crown-shaped saw-wort infusion was revealed. The young stock consuming a 300- and 400-mL infusion a day could increase their live weight over a 2-month period of the experiment by 1.68 kg and 1.86 kg more or 17.9 and 19.9% higher, respectively, than that in the reference animal group, respectively. Increases in the serum albumin level and the albumin : globulin ratio up to 24% and a simultaneous decline in the urea concentration to 28% were registered. It is shown that, under the effects of ecdysteroids, there is a tendency to normalize the blood glucose level in the young sheep as a result of the activation of the gluconeogenesis due to reamination of the amino acids. This has been proven by elevating the levels of aspartate aminotransferase (AST) and alanine aminotransferase (ALT). The obtained data on the multifaceted metabolic effects of the crown-shaped saw-wort infusion allows us to recommend it as a feed additive improving the growth performance of the young sheep.

Effect of infusion of serratula coronate on the metabolism and growth young sheep

The influence of water infusion of sickle leaves (Serratula coronata) on the growth of young sheep and biochemical profile of blood serum was studied. Against the background of protein deficiency and excessive fiber feeding, a positive trend of increasing the growth rate of lambs depending on the daily dose of the infusion of the sickle was revealed. Young animals, receiving 300 and 400 ml of infusion per day, increased their live weight for two months of experience by 1,68 and 1,86 kg more control, or 17,9 and 19,9%, respectively (p ≥ 0,05). An increase in serum albumin and A/G coefficient to 24% (p ≥ 0,05) while reducing urea to 28% (p ≤ 0,05). It is shown that under the influence of ecdysteroids there is a tendency to normalize the level of glucose in the blood of young animals as a result of the activation of gluconeogenesis due to the reamination of amino acids. This was confirmed by an increase in the activity of aspartate and alanine aminotransferase. The obtained data on the multifaceted metabolic effects of the infusion of sickle crowned allow us to recommend it as a feed additive that increases the growth rate of young sheep.

Features of formation of the lethal qualities of the young sheep edilbaevskoy depending on the milk yield of their mothers

The article presents the fertility of the Queens, the safety of young animals, slaughter indicators of young sheep of the edilbaev breed, obtained from ewes with different levels of productivity.&#x0D;

SEASONAL EVALUATION OF TRYCHOSTRONGYLESIS DISTRIBUTION IN SHEEP IN KABARDINO-BALKARIA

New data were obtained in the study of seasonal changes in the extensiveness and intensity of invasion of sheep trichostrongylosis in distant of pastures of the Kabardino-Balkaria Republic. The seasonal variability of the extensiveness and intensity of invasion of trichostrongylosis in the population of young sheep on mountain pastures of the region was determined by methods of helminthological autopsy according to K.I. Scryabin of the small intestine 35 heads. The epizootic process of trichostrongylosis in young sheep under 1 year of age is characterized by a two-peak climax of extensiveness and intensity of invasion. The first peak of the EI rise covers the end of spring (May) to the third decade of August, and the second peak covers the period from the end of summer to the second decade of November. Trichostrongylosis in young sheep under 1 year old in spring is found with EI – 17.4% and II – 54.8±6.3 copies / individual; in the summer season it is found of peak with EI – 36.2% and II – 123.0±11.4 copies / individual; in the autumn period – 58.6% and 185.9±16.7 individuals / individual; in the winter season – 58.6% and 27.3±2.5 copies / individual. In the small intestine of young sheep in all seasons of the year, except late autumn and winter, there were pathogens of trichostrongylosis in various stages of puberty. These data should be used to predict the epizootic situation on the trichostrongylosis of young sheep in the North Caucasus region, as well as when determining the optimal timing and frequency of deworming.

FEATURES OF THE REGIONAL PATHOLOGY OF ESOPHAGOSTOMOSIS IN THE NORTH CAUCASUS REGION CONSIDERING THE BREED AND AGE OF SHEEP

New data were obtained when studying the characteristics of the regional pathology of esophagostomosis in the North Caucasus region, taking into account the breed and age of the sheep. The research materials were sets of intestinal sections (90 sets each) and feces samples (300 samples each) of North Caucasian of meat-wool and Karachay breeds. In work the method of full helmintologic of opening according to K.I. Scryabin to account for nematodes of the genus Oesophagostomum, of as well as methods of coprolarvoscopy to account for the number of larvae in the feces. The determination of the species of nematodes was carried out according to the Kapustin determinant. Esophagostomosis in Kabardino-Balkaria is an enzootic invasion with coverage of 44.44–61.11% of the sheep population. The intensity of infection by nematodes of the genus Oesophagostomum ranges from 110.3±12.8 to 303.53±28.20 ekz. / head. In lambs up to 1 year, the EI of esophagostomosis was 63.33% with II – 328.6±28.3 ekz. / head; in Karachai lambs, 43.33% and 212.4±19.2 ekz. / head, respectively; in young sheep 1–2 years, the EI of esophagostomosis was 80.00% with II – 406.3±39.9 ekz. / head; in the Karachai breed – 63.33% and 289.6±25.7 ekz./ head. Conclusion. Esophagostomy of the most susceptible sheep of all ages of the North Caucasian meat-wool breed compared to Karachai, which is associated with the characteristics of the range and ecology. Esophagostomy, regardless of the breed, lambs up to 1 year old and young sheep of 1–2 years old are ill, which should be used when predicting the epizootic situation in the subjects of the Russian Federation.

Diaphragmatic lesions and fatal haemorrhage in Texel sheep

Twelve Texel sheep were found to have diaphragmatic lesions, with or without thoracic haemorrhage, at postmortem examination over a period of two-and-a-half years. Presenting clinical signs ranged from general malaise...

Plant Growth and Nutrient Uptake in Soil Amended with Mixes of Organic Materials Differing in C/N Ratio and Decomposition Stage

To determine the effect of low C/N organic amendments differing in decomposability and high C/N residue added to soil separately or as mixes with different ratios on plant growth and nutrient uptake, nutrient availability and microbial biomass over time. A sandy clay loam soil was amended with young faba bean shoot (C/N 9), sheep manure (C/N 6) and mature wheat straw (C/N 82) individually or as mixes of low and high C/N residues at different proportions. Wheat was planted on days 0, 35 and 70 and grown for 35 days. Soil and plants were sampled on days 35, 70 and 105. Shoot and root dry weights were low with high C/N residues alone but similar in the other treatments. Shoot N uptake was 0.3- to 2.5-fold higher than that of the control with low C/N residues alone and their mixes. Available N decreased with the proportion of low C/N residues. Increasing proportion of sheep manure in mixes with faba bean residues reduced shoot N uptake and available N. But in mixes with high C/N wheat straw, the proportion of sheep manure had little effect on shoot N uptake and available N. The effect of slowly decomposing sheep manure on the measured parameters depended on the other organic material in the mix. An increasing proportion of sheep manure increased shoot N uptake under N limiting conditions (mixed with wheat straw), but decreased it with faba bean residues that released large amounts of N.

Principal components analysis of body measurements of Sohagi sheep in Upper Egypt

SUMMARYThe current study was conducted to evaluate 383 Sohagi sheep in Sohag governorate, Egypt using a multivariate approach. Data were divided into two age groups of 294 young animals less than 10 months old (147 for each sex) and 89 adults animals from 10 months old and above (9 males and 80 females). Body weight (BW) and four body measurements (heart girth (HG), height at withers (HW), height at rump (HR) and body length (BL)) were measured through the period 2017 and 2018. In young and adult sheep, two factors (principal components) were extracted and accounted for 89.2% and 57.8% of the total variance, respectively. The first factor explained 46.4% and 30.6% of the total variance and the higher positive loading was observed for HW, RH and BL in young sheep whereas the higher positive loading was for HW and RH in adult sheep. The second factor accounted for 42.8% and 27.2% of the total variance and the higher positive loading was obtained for BW and HG in young sheep while was influenced by BW, HG and BL in adult sheep. The use of principal components was more proper than the use of original associated traits to explain body measurements in this study. Thus, extracted factors could be useful in breeding programs with enough decrease in the number of measurements traits to be registered to interpret the body conformation. Also, these principal components could be used as factor scores to predict body weight of Sohagi sheep.

WOOLLEN PRODUCTIVITY AND WOOL QUALITY INDICATORS IN THE SEMI-COARSE-WOOLED SHEEP OF ZUGALAY-TYPE AGINSKY BREED

The authors explored wool production and quality of wool of Aginsk zugalay breed sheep of different age and sex in the pedigree-breeding unit of Lenin agricultural cooperative located in Mogoituiskiy district of Trabs-Baikal region. The results obtained show that untrue unwashed wool of medium-wool breed varied ranged from 1.91±0.06 kg in the case of firsts to 3.92±0.07 kg in the case of producers in output of washed wool untrue 74.13-81.81%. The average thickness of rams’ wool is 32.82±1.27 mkm, ewe - 28.39±0.95, ram hogs - 28.21±0.95 and gimmer - 26.60±1.06 mkm when the strength was 10.89; 10.72; 9.21 and 9.00 cH/tex. Zugalay sheep have high concentration of wool, which varies from 66.61 to 81.72%, and rough beard hair (59.10-72.42 mkm). The highest content of wool was observed in young animals. Untrue wool of all sheep in different age and sex groups is 21.40-23.51 mkm (60-64th quality). The length of woolen fibers of the lower tier was 8.20-8.44, beard hair was 14.74-15.04 cm. The highest amount of fat and sweat was observed in servicing sheep and replacement ram hogs (Р˂0,05). The authors found out high correlation between the body weight and washed wool untrue in the sheep of all age and sex groups, especially in young sheep (0.629 in ram hogs and 0.717 in gimmers), as well as between wool thickness and its length (r=0.273-0.668) and between wool thickness and beard hair (r=0.306-0.687).

The common carotid artery provides significant pressure wave dampening in the young adult sheep

BackgroundIt has been established that the central elastic arteries of the mammalian circulation dampen the high pulse pressure emanating from the left ventricle, so that the pulsations in distal arterioles, such as in the cerebral circulation, are of lower amplitude than more centrally. However, the contribution of the common carotid artery (CCA) to protection of the cerebral microvasculature from high pulse pressure is not known, specifically to what extent viscoelastic energy dissipation in the arterial wall might contribute to the shock absorbing function of the large conduit arteries. MethodsYoung adult sheep (n = 6) were anaesthetised and their CCAs (n = 7) exposed. Pressure catheters were inserted 10–15 cm apart, proximally and distally in the CCA; a flow probe was placed proximally on the vessel. ResultsThe median dp/dtmax on the pressure rise of the arterial wave upstroke for the proximal CCA was 619 mm Hg/s and for the distal CCA it was significantly lower, at 197 mm Hg/s (p = 0.0156; n = 7). The median pulse pressure of the proximal CCA was 24 mm Hg/s; distal pulse pressure was significantly lower, at 18 mm Hg/s (p = 0.0156; n = 7). The median flow rate was 0.97 L/min with an interquartile range from 0.51 to 1.15 L/min. ConclusionsThe native CCA in the young adult sheep is an effective “pressure dampener” in the arterial circulation, reducing both pressure slope and pulse pressure, most likely via viscous dampening in the arterial wall.

Incidence of liver fluke infestation and pathological examination in sheep (Ovis aries) in Mirpur Azad Jammu and Kashmir

Abstract The study was carried out to examine the incidence of liverfluke infestation and pathological examination in sheep in Mirpur Azad Jammu &Kashmir. Abattoir and butchers shops were regularly monitored and 200 animals were examined before slaughter and 200 blood and liver samples were collected for biochemical, gross and histopathological study. On the basis of age of animals they were divided into young and adult age group having 100 animals in each group.A subjective evaluation of the gross lesions were performed based on the enlargement of liver, pale discoloration, friability, hemorrhages, discovery of extent of flukes, bile duct obstruction and cholangitis. The cumulative score of gross lesions in adult sheep was quite higher as compared to young sheep.Study has revealed that there was increase in the serum level of glucose, urea, creatinine, triglycerides, ALT, AST, ALP and GGT in adult group of sheep whereas there was apparent decrease of protein in adult sheep. However, in sheep of young age group all the serum biochemical parameters are unaffected. This study has showed that biochemical profile including blood glucose, liver enzymes (AST, ALT, ALP, GGT), urea and creatinine were elevated appreciably (P<0.05) and there was significantly decrease of total protein (P<0.05) in infected adult sheep in comparison with young age sheep. Microscopic changes revealed in the study have demonstrated structural changes in parenchyma and billiary tract. Histopathologically, atrophy, death of fatty tissues, multiple areas of death of hepatocytes, inflammation of liver, bile duct fibrosis and death of parenchyma were also examined in some cases of chronic fasciolosis. Keywords: Biochemical; Fascioliasis; Gross pathology; Necrosis; Seroepidemiology http://dx.doi.org/10.19045/bspab.2019.80017

Effect of increasing the proportion of chicory in forage-based diets on intake and digestion by sheep

There is a lot of evidence that chicory could be a highly palatable and nutritious source of forage for ruminants, well adapted to climate change and dry conditions in summer, thanks to its resistance to drought and high water content. This study aimed to describe the effect of incorporating chicory to ryegrass or to a ryegrass–white clover mixture on feeding behaviour, digestive parameters, nitrogen (N) balance and methane (CH4) emissions in sheep. In total, three swards of ryegrass, white clover and chicory were established and managed in a manner ensuring the forage use at a constant vegetative stage throughout the experiment. In all, four dietary treatments (pure ryegrass; binary mixture: 50% ryegrass–50% chicory; ternary mixture: 50% ryegrass–25% white clover–25% chicory; and pure chicory) were evaluated in a 4×4 replicated Latin square design with eight young castrated Texel sheep. Each experimental period consisted of an 8-day diet adaptation phase, followed by a 6-day measuring phase during which intake dynamics, chewing activity, digestibility, rumen liquid passage rate, fermentation end-products, N balance and CH4 emissions were determined. Data were analysed using a mixed model and orthogonal contrasts were used to detect the potential associative effects between ryegrass and chicory. The daily voluntary dry matter intake was lower for pure ryegrass than for diets containing chicory (P<0.001) and increased quadratically from 1.39 to 1.74 kg/day with increasing proportion of chicory. Huge positive quadratic effects (P<0.001) between ryegrass and chicory were detected on eating time and eating rate just after feeding indicating an increase of the motivation to eat with mixtures, whereas rumination activity decreased linearly with the proportion of chicory (P<0.001). The organic matter digestibility was similar among treatments (around 80%), but a strong positive quadratic P<0.001) effect was observed on liquid passage rate suggesting that chicory allowed fast particle breakdown in the rumen. Animals fed with the ryegrass–white clover–chicory mixture had the higher urinary N losses (P<0.001), whereas retained N per day or per g N intake was greater when the proportion of chicory was at least 50% (P<0.001) being ~40% greater than for the other treatments. The CH4 yield was lower with pure chicory than with the other treatments (P<0.001) for which emissions were similar. In conclusion, mixing ryegrass and chicory in equal proportions produces a synergy on voluntary intake and an improved N use efficiency likely due to complementarity in chemical composition, increased motivation to eat and faster ruminal particle breakdown.

Response-Inhibition During Problem Solving in Sheep (Ovis Aries)

Response inhibition is a behavioural skill that is important for flexible behaviour and appropriate decision making. It requires the suppression of a prepotent, but inappropriate action, in order to achieve a more advantageous outcome. Response inhibition has been tested in many animal species using the cylinder task. This task requires the self-driven inhibition of an impulse to obtain a visible food reward via a detour, rather than a direct but blocked route. We have shown previously using the stop-signal task that sheep can successfully interrupt an already-started response, if a reward is going to be restricted. However, it is not known if sheep can show self-driven response inhibition in a task that provides a reward independent of performance. Here we tested two groups of sheep on the cylinder task (11 Lleyn sheep: aged 8 months; 8 Welsh mountain sheep aged ~8 years old). Sheep were trained using an opaque cylinder and all sheep successfully learned the task. When response inhibition was tested using the transparent cylinder, all sheep performed significantly better than chance, but the older sheep showed a reduced number of correct responses compared to the young sheep (72.5±5.0% and 86.4±4.3% respectively). The results show that sheep have a mechanism for self-regulating their actions in order to retrieve food faster.

Expression of worm resistance in sheep selected for low worm-egg counts fed at maintenance or above-maintenance level

The present study reports on changes in faecal worm-egg counts (WEC), larval composition, and the number of worms at different developmental stages in young sheep sourced from a flock selected for reduced faecal worm-egg counts over 15 years. The sheep were individually penned and fed a maintenance (1.0 M) or a 1.5 times maintenance (1.5 M) diet over two periods, namely, worm-free and infection phases. They were dosed weekly with 10000 Trichostrongylus colubriformis and 10000 Teladorsagia circumcincta L3 infective larvae for 11 weeks. Sheep on the 1.5 M diet had lower WEC and higher bodyweights than did sheep on the 1.0 M diet. A significant decline in the percentage T. colubriformis occurred during the experiment, but no concomitant change in T. circumcincta was noticed. Resistant sheep had significantly (P &amp;lt; 0.001) fewer worms at necropsy, and also shed significantly (P &amp;lt; 0.001) fewer worm eggs during the experiment. Restricted feeding reduced bodyweight significantly (P &amp;lt; 0.001) and had a small but significant (P &amp;lt; 0.04) effect on the faecal worm-egg output and on the number of T. colubriformis worms (P &amp;lt; 0.01) in both the control and resistant sheep. The study showed that sheep selected for low WEC resulted in significantly (P &amp;lt; 0.001) lower WEC than in an unselected control line fed at a maintenance (1.0 M) and at an above-maintenance (1.5 M) level. Restricted feeding reduced bodyweight and had a small negative, and inconsistent, effect on the faecal worm-egg output in both the control and resistant lines.