Ovine dermatophilosis in young sheep associated with the grazing of Brassica spp. crops

The occurrence of dermatophilosis in five month old lambs associated with the grazing of Brassica spp. crops is reported on four farms. The prevalence of the disease varied from 3% to 45% within affected flocks. An additional finding was the occurrence of nervous signs in a small number of more severely affected lambs, characterised by a sudden lowering of the hindquarters.

The association between dermatophilosis and the grazing of Brassica spp. crops is discussed.     

Tapeworm (Moniezia expansa) in sheep: anthelmintic treatment studies to assess possible pathogenic effects and production loss in young infected animals in the field

Niclosamide and cupric acetoarsenite were both effective in removing tapeworm (Moniezia expansa) from unweaned lambs. In four trials there was no significant liveweight gain in niclosamide-drenched, compared with undrenched, animals. Post-mortem examination for tapeworm showed that although one lamb contained 200 ml (bulk volume) of strobila, 50% of 49 infected animals contained 50 ml or less. The greatest number of scoleces in one animal was 41, and 65% of lambs contained four or fewer. M. expansa is not indicated as a cause of diarrhoea in lambs.     

Performance of Djallonké Sheep under an Extensive System of Production in Faranah,Guinea

A total of 147 ewes, 4 rams and 188 lambs of their progeny of the Djallonké breed of sheep were used to study the factors affecting reproductive and growth traits and the causes of lamb mortality. Data on ewes were collected during a 12-month period, while those on the lambs born to 123 of the ewes were collected until they were 12 months of age. The average fertility and abortion rates were 0.84 and 0.09. The fertility rate increased and the abortion rate decreased with increasing age of the ewes (p<0.05). The number of lambs born per ewe joined, litter weight at birth per ewe joined and litter weight at weaning per ewe joined were 1.28, 3.5 kg and 17 kg, respectively. The average numbers of lambs born per ewe, lambs born alive per ewe, lambs born dead per ewe and lambs per ewe that died between birth and weaning were 1.53, 1.43, 0.03 and 0.3, respectively. The age of the ewes significantly (p<0.05) affected all these traits except the number of dead lambs and the index of fertility (94%). The age of the ewes significantly (p<0.05) affected the birth weight and the weight at 6 and 12 months of age, whereas the lambing season significantly (p<0.05) affected all the growth traits studied. The type of birth was the most important source of variation in body weights of lambs. Sex had no significant (p>0.05) effect on the growth traits studied. The complex `starvation–bad management–light body weight at birth' caused 48% of the lamb mortality between birth and weaning, while diarrhoea, pneumonia and internal and external parasites caused approximately 52% of the lamb mortality over the same period. The seasonal raw mortality rate of the lambs before weaning was highest in the humid season.     

Sexual behaviour of yearling Awassi,Charollais × Awassi and Romanov × Awassi rams exposed to oestrousAwassi ewes

This study was conducted to evaluate the sexual performance of 10-month-old, ram lambs of different breed groups. Eight ram lambs each of Awassi (A), F₁ Charollais × Awassi (CA) and F₁ Romanov × Awassi (RA) breed types were subjected to sexual performance tests by being individually exposed to two oestrous Awassi ewe lambs for four 20-min periods. Bouts of leg kicking and anogenital sniffing were similar among breed groups. Mounting frequency was greater (p < 0.05) in RA than in A and CA ram lambs. Tail-raising was greater (p < 0.05) and mating rate tended to be greater (p < 0.10) in A than in RA and CA ram lambs. The number of mounts per tail-raising (efficiency) was influenced by breed group and test day (p < 0.05). Awassi ram lambs maintained the best efficiency throughout the experiment. Efficiency in RA and CA ram lambs improved with each test day. Results of the present study indicate that RA ram lambs have greater mounting frequency than A and CA, while Awassi are more capable of mating with fat-tailed females than the CA and RA ram lambs.     

ORIGINAL ARTICLE: Description of development of rumen ecosystem by PCR assay in milk‐fed,weaned and finished lambs in an intensive fattening system

This study examined the reticulo‐rumen characteristics of the microbial community and its fermentative characteristics in milk‐fed, at weaning and finished lambs in a conventional fattening system. Five lambs were assigned to each of three groups: milk‐fed lambs slaughtered at 30 days (T30), weaned lambs slaughtered at 45 days (T45) and ‘finished lambs’ slaughtered at 90 days (T90). At slaughter, rumen size, fermentation parameters (pH, volatile fatty acids and microbial enzyme activity) and protozoal counts were recorded. Quantitative PCR was used to quantify the genes encoding 16S and 18S ribosomal DNA of the rumen bacterial and protozoal populations, respectively, and the sequential colonization of the rumen by cellulolytic (Ruminococcus albus, Ruminococcus flavefaciens) and amylolytic (Prevotella ruminicola, Streptococcus bovis) bacteria, and protozoa (Entodinium sp.). Denaturing gradient gel electrophoresis was used to study the development of rumen microbiota biodiversity. Intake of solid food before weaning caused a significant increase in rumen weight (p < 0.0001) and bacterial DNA (p < 0.05) and volatile fatty acid analysis concentration (p < 0.01), whereas pH declined. In milk‐fed lambs, cellulolytic bacteria were evident after 30 days. Thereafter, in the 45‐day and 90‐day groups, the proportions of R. flavefaciens decreased and R. albus increased. Amylolytic bacteria were present in milk‐fed lambs; the proportion of P. ruminicola increased in fattening lambs and S. bovis was the least abundant species. Protozoal concentrations were irregular; milk‐fed lambs had a significant number of protozoa species from Entodinium and subfamily Isotrichiidae, but they disappeared at weaning. Lamb rumen were refaunated in some individuals at 90 days (Entodinium and subfamily Diplodiniinae spp.), although individual concentrations were variable.     

Effects of two dietary crude protein levels on finishing performance,meat quality,and gene expression of market lambs

Seventeen crossbred lambs were assigned randomly to low-protein (LP; 8% crude protein [CP]; n = 9) and high-protein (HP; 13% CP; n = 8) diets for 9 weeks. The final body weight, average daily feed intake (ADFI), and average daily gain (ADG) of the HP lambs were significantly higher (P < 0.05) than the LP lambs; however, gain to feed ratio (G:F) for the LP lambs was significantly higher (P < 0.05) than the HP lambs. Hot carcass weight (HCW), adjusted fat thickness, and drip loss of longissimus dorsi (LD) muscle were significantly higher (P < 0.05) for the HP than LP lambs. In contrast, instrumental color values L*, a*, b*, C*, and hue angle (H) of meat from the LP lambs scored significantly higher (P < 0.05) than the HP lambs. The LD muscle from HP lambs had significantly greater CLA of cis-9 trans-11 isomer (P < 0.05) than the LP lambs. The gene expression of metabolism and meat quality-related genes of LP was significantly higher than HP (P < 0.05). These results suggest that a higher dietary CP level promotes growth performance for finishing lambs, whereas lower dietary CP level is beneficial for meat quality, especially when evaluating color characteristics in the final product.     

Plasma leptin, feed intake and body fat accumulation in fattening castrated male and female lambs

The main objective of this study was to investigate the relationships between changes in plasma leptin concentration and feed intake or bodyweight in female and castrated male lambs with fattening. Four female and four castrated male lambs were used and were fed roughage and concentrate supplemented with beef tallow ad libitum for 28 weeks. Although the feed intake and bodyweight increased with fattening in both the castrated male and female lambs, they decreased at 24–28 weeks in the female lambs. At the end of fattening, the crude fat content in the muscle (loin) of the female lambs was significantly higher than in the castrated male lambs (P < 0.05), while the crude protein content in the loin and fillet meat was higher in the castrated male than in the female lambs (P < 0.05). The plasma leptin concentration showed high values at a later stage of fattening (P < 0.05). In the female lambs the plasma insulin concentration increased at a later stage of fattening (P < 0.05) and was positively correlated (P < 0.0001, r = 0.78) with plasma leptin. Plasma metabolites (glucose, nonesterified fatty acid, total cholesterol and triglyceride) concentrations were also changed with fattening. Plasma total cholesterol was positively related to plasma leptin, more closely in the female than in the castrated male lambs (in females, r = 0.63, P < 0.001; in males, r = 0.38, P < 0.01). The accumulation of body fat was probably accelerated by the consumption of a lot of concentrate feed supplemented with treated beef tallow and by the stimulation of insulin with fattening. Consequently, the plasma leptin concentration increased, especially toward the end of the fattening period. The decrease in feed intake and bodyweight after the 24th week of fattening was possibly caused by an increase in leptin that is involved in the homeostatic regulation of body energy by regulating appetite.     

Field studies of the immunisation of lambs with drug-abbreviated infections of Trichostrongylus colubriformis and Ostertagia circumcincta

Fifty, 5–6 month-old lambs were randomly allocated to five equal groups. Three groups of lambs were immunised by three oxfendazole-abbreviated (artificial) infections of Trichostrongylus colubriformis and Ostertagia circutncincta. Group 1 was immunised with a high dose of larvae, Group 2 with a medium dose and Group 3 with a low dose. A fourth group was treated with oxfendazole only and a fifth group was not treated (control). All groups were grazed together on pasture naturally contaminated with nematode larvae. Immunisation significantly reduced the number of eggs per gram of faeces in all three groups, but the lowest faecal egg count was seen in Group 3 (immunised with the lowest number of larvae). Significantly better liveweight gains and wool weight were observed in Group 2 animals than in the control group. Of all anthelmintic-treated animals, only Group 1 lambs did not have a signscantly lower dag weight than controls.     

A mail survey of factors affecting performance in 627 selected sheep flocks in south-eastern Norway

Abstract

Factors influencing rate of barren ewes, number of lambs born per pregnant ewe, and autumn live weight of the lambs were studied in 627 Norwegian sheep flocks based on herd level data from the Norwegian Sheep Recording System and a mailed questionnaire to the sheep farmers. The following factors were significantly associated (P<0.05) with rate of barren ewes: breed, herd average lambing date, type of production/age of farmer, routines for treatments for parasites, and housing type. Number of lambs born per pregnant ewe was significantly associated with rate of barren ewes, herd average lambing date, breed, percentage grass silage of total roughage, and no separation of gimmers during the housing period. Corrected autumn live weight of the lambs was significantly associated with breed, flock size, lambs born per pregnant ewe, no separation of gimmers during the housing period, and type of summer pasture.     

Response of Corriedale and Crioula Lanada Sheep to Artificial Primary Infection with Haemonchus Contortus

Clinical, parasitological and biochemical parameters were evaluated in Corriedale and Crioula Lanada sheep after a single experimental infection with Haemonchus contortus. Ten 4-month-old worm-free lambs, of each breed, were infected with 200 L₃ H. contortus per kg live weight and four uninfected animals of each breed were used as controls. Every week, the animals were weighed and blood and faecal samples were collected for measurement of packed cell volume (PCV), total serum protein (TSP) and albumin (ALB), and the number of eggs per gram of faeces (EPG), respectively. Twelve weeks after infection, the animals were slaughtered. The worm burden was determined and samples of the abomasal mucosa were processed for determination of the number of eosinophils, mast cells and globule leukocytes. No significant differences in PCV, TSP, ALB, parasite burden or the cell populations of the abomasal mucosa were observed between breeds, but Crioula lambs had a lower EPG count. The comparison of the infected groups with their respective controls revealed significant alterations in PCV, TSP and ALB in the Corriedale lambs and in PCV, TSP, ALB and the density of eosinophils and mast cells in the Crioula lambs.     

Fatty acid profile of plasma,muscle and adipose tissues in Chilota lambs grazing on two different low quality pasture types in Chiloé Archipelago (Chile)

There is no information about the effect of different pasture types on tissue fatty acid profiles of a native rustic lamb breed of the Chiloe Archipelago, the Chilota. Eight Chilota lambs were grazed on a ‘Calafatal’ pasture (CP), a typical secondary succession of Chiloé Archipelago (Chile) and eight Chilota lambs were located to graze on naturalized pasture (NP) of Chiloé. Botanical, chemical and lipid composition of the two types of pastures and of different lamb tissues (muscle, subcutaneous – and tail adipose tissues) and plasma were performed. Both pasture types induced high n‐3 polyunsaturated fatty acids (PUFA) and CLAcis‐9,trans‐11 proportions in Chilota meat. Thus, in muscle, Chilota lambs grazing CP showed higher sum PUFA, sum n‐6 PUFA proportion and n‐6/n‐3 PUFA ratio compared with Chilota lambs grazing NP. In tail fats of Chilota lambs grazing CP significantly higher proportions of 18:3n‐3, sum saturated fatty acids, sum PUFA, n‐3 and n‐6 PUFA were detected compared with Chilota lambs grazing NP. Feeding of different pasture types (CP vs. NP) caused significant differences in fatty acid composition of muscle and the two fat depots in Chilota lambs, but also point to tissue‐specific responses of de novo synthesized fatty acid deposition in the tissues.     

The distribution of Nematodirus spp. occurring in sheep in New Zealand

Extract

Most outbreaks of parasitic gastro-enteritis in sheep in New Zealand have been ascribed to the presence of nematodes of the family Trichostrongylidae, and in particular the genera, Haemonchus, Ostertagia, and Trichostrongylus. However, during the period 1956–58, a number of outbreaks of disease occurred in lambs and the condition was associated with heavy Neniatodirus infestation. Although Neinatodirus spp. are commonly foundin sheep in this country, only moderate numbers of worms are usually present in any individual and the worm has been regarded as non-pathogenic. Similar views were held in the British Isles until about 1951, when an acute disease condition of lambs, associated with heavy Neniatodirus burdens, caused serious losses.     

Effects of rearing system on meat quality,fatty acid and amino acid profiles of Hu lambs

To determine the effects of early rearing system on meat quality traits, fatty acid and amino acid profiles of meat, 48 Hu lambs were selected and randomly divided into four treatments: control lambs were ewe‐reared from birth to 60 days of age (ER), while treatment lambs were segregated from their dams at 10, 20 and 30 days of age, then artificially reared with milk replacer until 60 days of age (EW10, EW20 and EW30, respectively). All lambs had no access to the milk replacer or their dams from 61 to 90 days. Creep feed was supplied ad libitum to all lambs from 15 to 90 days of age. Artificially reared lambs (EW10, EW20 and EW30) had higher (p < .05) creep feed intake, average daily gain, slaughter weight, hot carcass weight, meat ether extract content, bright meat color (lightness and yellowness) than ewe‐reared lambs. The content of unsaturated fatty acids and monounsaturated fatty acids in EW10 and EW20 were greater (p < .05) than that in ER, whereas the proportions of saturated fatty acids in EW10 and EW20 were lower than that in ER (p < .05). The percentages of C18:0, C18:2, C18:3 and the ratio of polyunsaturated fatty acids and saturated fatty acids of artificially reared lambs were greater than ewe‐reared lambs (p < .05). The meat proportions of leucine, alanine and proline were higher (p < .05) in artificially reared lambs than ewe‐reared ones. Finally, the artificially reared system increased meat production and changed the fatty acid and amino acid profiles of meat, and it would be appropriate to rear Hu lambs artificially from 10 days with milk replacer.     

Shearing male lambs in the cold season improves the carcass yield without affecting fattening performance

This research was carried out to determine the effects of shearing of different genotypes of male lambs (one from pure Karayaka stock and two from its crossbreed) in winter on bodyweight gain, feed consumtion, feed conversion efficiency, rectal temperature and carcass yield. A total of 21 lambs aged 8 months were allocated randomly to experimental groups according to a 2 × 3 factorial arrangement for shorn and unshorn animals. The lambs were fed grass hay (100 g/lamb/day) and commercial concentrate feed ad libitum during a 54‐day of fattening period. The lambs were shorn in the middle of the experiment (27 days after beginning the trial). The interaction between the shearing treatment × genotype of the studied parameters was found to be insignificant. The shearing process increased the rectal temperature (P < 0.01), hot carcass yield (P < 0.05) and dressing percentage (P < 0.05) and decreased the weight of the edible inner organs (P < 0.01). Some of these parameters were affected by the genotypes. It was concluded that shearing male lambs in the winter can have a beneficial effect on the hot carcass weight and dressing percentage without affecting fattening performance, and the performance of Karayaka lambs and its crossbred male lambs were similar under the conditions of the present study.     

Epidemiological Studies on Gastrointestinal Parasitic Infections of Lambs in the Coastal Savanna Regions of Ghana

The types of gastrointestinal parasites (Eimeria and helminths) encountered by 70 lambs and the seasonal pattern of both Eimeria and strongylate infections in these lambs in the derived Coastal Savanna were followed for three years. Eimeria oocysts and helminth eggs were detected in the faeces of lambs at the same time, indicating the concurrence of both Eimeria and helminth infections. Eimeria oocysts were first seen in the lambs 20 days after birth (DAB) and the level of oocyst output increased by the fourth week. Eimeria species identified in the lambs were E. parva, E. pallida, E. faurei, E. ahsata, E. bakuensis, E. intricata, E. granulosa, E. ovinoidalis and, occasionally, E. marsica. E. ovinoidalis, the most pathogenic species, dominated the oocyst output during the early part of the life of the lambs. Strongyloides papillosus eggs appeared at 46 DAB, preceding strongylate nematode eggs, which were seen at 57 DAB and those of Moniezia at 69 DAB. The pattern of Eimeria oocyst output paralleled that of the worm egg output, and high oocyst and strongylate worm egg counts corresponded with the period of high rainfall during the study period. Although oocyst and worm egg output fluctuated, high Eimeria oocyst counts were seen again in the lambs when they were 1 and 2 years old. Haemonchus species formed 71% of the infective larvae revealed by larval culture.     

Effect of dietary protein on the regulation of populations of Nematodirus battus by lambs

Two groups of seven and two groups of six lambs were offered either a complete basal ruminant diet (13·2 per cent crude protein [ ]) (groups 2 and 4) or the same diet supplemented with fish meal (18·3 per cent ) (groups 1 and 3). Groups 1 and 2 were infected daily for seven weeks with Nematodirus battus larvae (L₃) and groups 3 and 4 served as uninfected challenge controls. All the groups were treated with anthelmintic in the eighth week, challenged with a single dose of 30,000 N battus L₃ one week later and killed nine days after the challenge. Although protein supplementation tended to enhance the regulation of the population of N battus in the lambs which had been infected continuously, the effect was not statistically significant. The worm burdens in both the groups of previously infected lambs were significantly reduced both in number and size (P<0·001) and they had a lower proportion of male worms than the uninfected challenge controls. The lambs could be segregated into high or low responders on the basis of their worm burdens, and there was a significant reduction in worm burdens (P<0·001) and size (P<0·01) in parallel with the lambs' responsiveness. The identification of high and low responders shows that when the dietary protein supply is adequate the predominant effect of the host on the pathogenicity of its parasites is the host's genetically-determined susceptibility.     

Effect of sex and feeding system on feed intake, growth, and meat and carcass characteristics of fattening Assaf lambs

The effect of feeding system and sex on intake, growth and carcass and meat characteristics of Assaf fattening lambs was studied. Twenty four weaned Assaf lambs, half males and half females were used. After an adaptation period, lambs were randomly assigned to one of the two feeding systems studied. Control lambs received ad libitum commercial concentrate (70% barley, 22% soybean meal, 4.8% wheat, 0.5% bicarbonate, 2.7% mineral–vitamin premix) and barley straw. Free Choice lambs had ad libitum and separate access to whole barley grain and a protein supplement (73.3% soyabean meal, 16% wheat, 1.7% bicarbonate, 9% mineral–vitamin premix). Lambs were slaughtered at 25 kg LBW. Feed intake was not significantly affected by sex (P > 0.05) but Free Choice lambs showed higher dry mater intake than the Control lambs. Nevertheless, only males from the Free Choice group showed an improvement in feed efficiency rate (P < 0.05) and average daily gain (P < 0.01) relating to the Control lambs. Neither feeding system nor feeding system × sex interaction significantly affected non-carcass weight, fat depots, cold carcass weight, dressing percentage, main proportions of commercial cuts and meat characteristics (P < 0.05). As it was expected, female lambs showed a lower average daily gain and a higher feed conversion efficiency than male lambs (P < 0.001) which was related to a greater fat deposition. Meat characteristics were unaffected by sex, with the exception of longissimus lumborum fat content, which was higher in female lambs.The present results suggest that Free Choice feeding system might be suitable for intensively reared male lambs since improvements in daily weight gain and feed conversion rate were achieved, with no adverse effect on carcass and meat quality. Despite the selected diet of both, males and females, did not differ in the crude protein content, the use of Free Choice feeding system for female lambs did not improve performance compared to the Control group.     

Effects of concentrate feeding systems,genotype and sex on productive performance and meat quality of Norwegian lambs

Abstract

Two factorial experiments, I and II, were carried out in this study using 84 lambs (140±1.24 days old, 40.00±0.75 kg live weight) divided into six groups. Two levels of concentrate supplementation; restricted (0.4 kg concentrate/lamb/day) or ad libitum, two breed types; Norwegian White lamb or Nor-X and two sex types; ram or ewe lambs, were investigated. In experiment I, a 2×2×2 factorial arrangement of treatments (level of supplementation, sex, and breed) was imposed whereas a 2×2 arrangement of treatments (level of supplementation and breeds) was studied in Experiment II. Each of the two experiments lasted for four weeks. Lambs on ad libitum access to concentrate grew at 231 g d^–1 and 125 g d^–1 faster than those on restricted access in Experiment I and II, respectively. Moreover, ram lambs grew at 64 g d^–1 faster than ewe lambs. Lambs on ad libitum access to concentrate had about 5 kg heavier carcasses than that on restricted access. Ewe and ram lambs on ad libitum allowance to concentrate had 4.2 kg and 5.6 kg, respectively, higher carcass weight than those on restricted allowance. The two levels of concentrate supplementation had limited effects on the meat sensory qualities. Meat taste intensity increased with level of concentrate supplementation. Difference in meat tenderness between ram and ewe lambs was only evidenced on ad libitum concentrate feeding. Irrespective of stage of growth (Experiment I vs. II) and concentrate supplementation level, Nor-X lambs were superior to Norwegian White lambs with respect to carcass conformation scores. Based on results from sensory assessments of meat, ram lambs should be slaughtered before October to avoid off-flavour on meat.     

Naturally acquired coccidia infection in lambs in Otago

The development of a naturally acquired coccidia infection in lambs in Otago is described using data derived from faecal oocyst counts and specific differentiation of the oocysts. Oocysts first appeared in faeces of lambs 19–37 days after birth. Oocyst production reached a mean peak of 250 000 oocysts per gram when lambs were 40–50 days old and slowly declined with increasing age of lambs. Coccidial infections did not appear to have any obvious effect on weight gain. The numerically most numerous species of coccidia were Eimeria ovina, E. crandallis, E. ninakohlyakimovae, E. parva and E. weybridgensis.     

Immune responsiveness of lambs selected for resistance to haemonchosis

Several parameters of immune competence were measured in lambs with genetic resistance to Haemonchus contortus and in lambs with average susceptibility to H contortus (random-bred). Increase in skinfold thickness following intradermal injection was greater in resistant lambs for concanavalin A and to a lesser extent for phytohaemagglutinin. Both mitogens induced infiltration of superficial and deep dermis by eosinophils, CD4+, CD8+ and T19+ lymphocytes, though the responses did not differ between groups. Primary but not secondary antibody responses to the T cell-dependent antigen, ovalbumin was greater in resistant lambs. In contrast, antibody responses to the T cell-independent antigen, Brucella abortus lipopolysaccharide, did not differ between groups. Taken together the data suggest that enhanced T lymphocyte function may contribute to the greater resistance to H contortus of genetically resistant lambs.