The occurrence and intensity of helminth infections were evaluated in sheep from pastures shared with cattle. In 2015 and 2016, young male sheep acquired in Santana do Livramento, Rio Grande do Sul, Brazil, were finished in integrated crop-livestock system. We selected the 12 sheep that showed the highest number of nematode eggs per gram of faeces to search for worms in the gastrointestinal tract. Haemonchus contortus and Trichostrongylus colubriformis were the major parasites. H. contortus presented mean intensities of 1,159 and 257 worms in 2015 and 2016, respectively. T. colubriformis displayed mean intensities of 4,149 and 2,427 worms in 2015 and 2016, respectively. Of the 127 male specimens of Haemonchus spp. analysed by Polymerase Chain Reaction (PCR), 125 were H. contortus, one Haemonchus placei and one hybrid. Other species detected were Cooperia punctata , Cooperia pectinata, Cooperia spatulata, Cooperia curticei, Ostertagia ostertagi, Teladorsagia circumcincta , Trichostrongylus axei, Nematodirus spathiger , and Trichuris ovis. Twenty lambs presented cysts of Taenia hydatigena in the liver and mesentery. One lamb presented Coenurus cerebralis, the larval stage of Taenia multiceps, in the brain. In conclusion, sheep from pasture shared with cattle presented a high diversity of nematode species. H. contortus and H. placei co-infection occur with consequent hybridization.

Natural infection by intestinal nematodes was assessed in Santa Ines and Ile de France sheep breeds, over a five-month grazing period, with emphasis on the development of the immune response in lambs under two anthelmintic treatment regimens. Nineteen Santa Ines and 19 Ile de France male lambs were allocated into two treatment groups: animals under suppressive treatment with anthelmintics; and animals under targeted selective treatment (TST). The nematodes Trichostrongylus colubriformis and Strongyloides papillosus showed the highest infection intensity in the TST animals in both breeds. Parasite-specific immunoglobulin G levels were significantly higher and more rapidly induced in Santa Ines lambs. Additionally, these lambs had higher levels of parasite-specific immunoglobulin A in intestinal mucus. Animals under TST had higher means of mast cells and globule leukocytes in the intestinal mucosa due to longer and greater parasite challenge in comparison with the suppressive group. A breed effect (P < 0.05) was recorded for mast cells, with Santa Ines lambs presenting the highest counts. Although Santa Ines lambs had lower intestinal nematode counts than Ile de France lambs, they had shown a large variation in T. colubriformis burden, with most of them presenting a marked worm burden, despite showing an earlier and more intense immune response to intestinal nematode infection.

This work aimed to evaluate the thiol-disulphide homeostasis in serum of lambs naturally infected by gastrointestinal nematodes presenting different levels of parasite load indirectly indicated by faecal worm egg counts (EPG). Furthermore, the possible changes in the thiol-disulphide dynamic after different procedures to reduce the parasitic charge, such as the integrated crop-livestock system or anthelmintic treatment, were assessed. The results were compared with a panel of various oxidative stress and inflammatory biomarkers. The lambs were divided into three groups: animals highly infected (EPG higher than 5000) and packed cell volume (PCV) lower than 24% (G1); animals highly infected (EPG higher than 5000) and normal PCV (>24%) (G2); and animals presenting EPG lower than 5000 and normal PCV (>24%) (G3). The highly infected lambs (G1 and G2) showed lower total thiol (TT) and native thiol (SH) (p ≤ 0.01) than those from G3. After treatment, TT and SH increased significantly in all groups (p ≤ 0.01), and the disulphide (SS)/TT and SS/SH ratios decreased significantly (p < 0.01) in G1 and G2. These results show that the thiol-disulphide balance was impaired in lambs infected by gastrointestinal nematodes and that it could be potentially used as a biomarker to monitor this disease.

The objective of this study was to evaluate the intake, digestibility, nitrogen balance, and performance of feedlot lambs fed diets containing crude glycerin. A total of 30 Ile de France lambs were confined to individual pens at an average age of 45 d: 15.1 kg initial body weight and 32.2 kg final body weight. The animals were distributed in a completely randomized design and fed three diets containing fresh sugarcane as forage (50 %) and concentrate (50 %), with or without the inclusion of 100 and 200 g vegetable crude glycerin per kilogram dry matter (DM) replacing corn. Dietary glycerin inclusion reduced the intake of ether extract (P<0.001) and total carbohydrates (P=0.048) as well as the apparent digestibility of ether extract (P<0.001), but it had no effect on the intake and digestibility of the other nutrients nor on lamb performance. The apparent nitrogen balance of lambs on the three diets was positive. Although it does not affect the intake and digestibility of most nutrients, the inclusion of 100 and 200 g kg⁻¹ DM of crude glycerin in the diet tends to worsen lamb performance, indicating that the ideal level of inclusion should be below 100 g kg⁻¹ DM of crude glycerin.

O experimento foi conduzido com o objetivo de avaliar o efeito da tosquia estratégica no comportamento ingestivo de ovelhas Ile de France em pastagem de capim vaquero (Cynodon dactylon) durante a estação de monta. Foram utilizados 20 ovinos, fêmea, da raça Ile de France, com idade média de 4 anos, e peso corporal médio de 71,10 kg, em pastejo, em delineamento experimental inteiramente casualizado, com dois tratamentos e dez repetições, em que os tratamentos foram constituídos de ovelhas tosquiadas e não tosquiadas. A duração da estação de monta foi de 90 dias, sendo que as avaliações ocorreram nos 86, 87 e 88º dia do período experimental. O tempo de pastejo (6,50 horas), ruminação (1,59 horas) e ócio (3,97 horas) não foram alterados (P>0,05) pela tosquia estratégica dos animais, assim como a frequência e o tempo por frequência de pastejo (18,33 pastejos e 21,49 min/pastejo), ruminação (10,71 ruminações e 8,83 min/ruminação) e ócio (18,83 ócios e 12,66 min/ócio). Da mesma forma, a quantidade de bocados por minuto (26,37 bocados) e o total de bocados diário (19.116 bocados) dos animais não foram afetados. Sendo assim, a tosquia estratégica em ovelhas Ile de France em pastagem de capim vaquero durante a estação de monta não altera o comportamento ingestivo dos animais.