Effect of dietary protein on responses of lambs to repeated Haemonchus contortus infection

Haemonchus contortus alters distribution and utilization of protein and amino acids in different tissues of host sheep

The objective was to determine host animal protein/amino acid redistribution and use among the abomasum, duodenum and muscle of sheep infected with Haemonchus contortus. Sixteen male Ujumqin sheep (32.4 ± 3.9 kg) were dewormed and randomly assigned to two groups, infected or not infected with H. contortus (GIN and CON). The GIN group had lower (P < 0.05) dry matter intake, average daily gain, and live body weight than CON, with extensive focal infiltration of lymphocytes in the lamina propria and bottom of the abomasal epithelium. In the abomasum and duodenum, there were 100 and 220 genes, respectively, that were up-regulated, whereas 56 and 149 were down-regulated. In the abomasum, the most enriched KEGG pathways were related to immunity and inflammation reaction, including: viral protein interaction with cytokine and cytokine receptor (P = 0.017), influenza A (P = 0.030), IL-17 signaling pathway (P = 0.030). In the duodenum, KEGG pathways were more enriched in nutrient metabolism, including pancreatic secretion (P < 0.001), protein digestion and absorption (P < 0.001), graft-versus-host disease (P = 0.004). Furthermore, most genes related with the above KEGG pathways were increased in the abomasum but decreased in the duodenum. Amino acid profiles in abomasum and duodenum of CON and GIN groups were clustered in a partial least-squares discriminant analysis model, with significant changes in 36 and 19 metabolites in abomasal and duodenal chyme, respectively. Further confirmed by transcriptome-targeted metabolome association analysis, GIN mainly enhanced metabolism of arginine and sulphur amino acids in abomasum and those metabolic pathways were associated. Meanwhile, GIN mainly decreased pyruvate related amino acid metabolism in duodenum. Moreover, concentrations of Arg (P = 0.036), His (P = 0.027), and Cys (P = 0.046) in longissimus thoracis et lumborum were decreased in GIN, whereas concentrations of Gly (P = 0.012) and Ala (P = 0.046) were increased. In conclusion, H. contortus enhanced metabolism of arginine and sulphur amino acids in the abomasum; decreased pyruvate metabolism in the duodenum; and drove more protein/amino acids for abomasal tissues to resist physical and immune damage, reducing protein and amino acids in duodenum and muscle for support host growth. Specific nutrients (such like arginine, histidine, and cysteine) may play important role in control gastrointestinal nematode infection for ruminant.

Dietary protein degradability effect on performance of lambs experimentally infected with Haemonchus contortus and Trichostrongylus colubriformis

The study investigated the effects of dietary protein degradation rate on growth performance and immune response of crossbred Dorper × short-tail Han ram lambs experimentally infected with Haemonchus contortus and Trichostrongylus colubriformis. Eighteen lambs were randomly assigned to three dietary treatments, rapidly degradable protein (RDP), moderately degradable protein (MDP), and slowly degradable protein (SDP) diets. Feed intake and body weight of the lambs were recorded weekly until 42 days post-infection. The fecal egg count (FEC), FAMACHA scores, and immunoglobulins (IgG, IgM and IgA) were also monitored during the experimental period. A metabolic trial was conducted to assess apparent digestibility and volatile fatty acids were also determined. The lambs in SDP and MDP groups had higher feed, nutrient intake, weight gain, and feed efficiency than those in the RDP group. Feed conversion ratio (FCR) of the lambs in RDP group was higher than those in the SDP and MDP groups. A significant (P < 0.001) decrease in FEC was observed in the SDP and MDP groups. Dietary treatment had no significant effect on FAMACHA scores and concentration of serum antibodies. Concentration of acetic acid was higher (P < 0.013) in the lambs fed RDP than those fed the SDP and MDP diets. The lambs fed SDP diet had higher apparent digestibility than those fed the RDP diet. The poor performances in RDP group could be overcome by including SDP that ensures adequate post-ruminal protein supply reaching the small intestine.

High energy levels in the diet reduce the parasitic effect of Haemonchus contortus in Pelibuey sheep

Nutritional aspects modulate the parasitological and immune response in infected sheep. The aim of the present study was to evaluate the parasitological and humoral immune response of Pelibuey sheep experimentally infected with Haemonchus contortus that were fed diets with two different energy (n = 12) and protein (n = 12) levels. Twenty-four Pelibuey lambs infected with H. contortus were evaluated over 12 weeks. An additional six animals were considered as a control group. Fecal egg count (FEC) was determined, in addition to packed cell volume (PCV), total plasma protein (TPP), and immunoglobulin levels (IgA, IgG, and IgM) by indirect enzyme-linked immunosorbent assay (iELISA). Data were analyzed by repeated measures over time. The lambs that received a high-energy (HighE) diet had the lowest FEC (P < 0.01) regardless of whether they received a high (HighP) or low (LowP) level of protein. The effect of energy level was also observed over time: FEC values decreased and PCV and TPP values increased. Higher immunoglobulin levels were obtained for females (P < 0.05) than males yet, overall, the energy and protein levels of the diets did not affect the response of the immunoglobulins. Over time, however, an increase in IgG and IgM was observed, whereas the IgA level remained basal.

Influence of metabolizable protein and minerals supplementation on detrimental effects of endoparasitic nematodes infection in small ruminants

Endoparasitic nematode infection could have negative impacts on performances of sheep and goats. However, supplementary protein and minerals can also affect nematodes. This paper reviews present information on the importance of protein and minerals supplementation as means to control nematode infection in small ruminants. Protein supplementation seems to improve host resilience by diverting metabolizable protein (MP) towards dealing with detrimental effects of the infection and thus improve production and reproductive performances of animal. A large body of evidence shows that supplementation of copper, iron, and zinc can also enhance host resistance against nematode infection as shown by decreased fecal egg count (FEC) and worm burdens. As such, protein and mineral supplementations can play a major role in sustainable control of parasitic nematode infection and thus reduce reliance on chemotherapic drugs.

Effects of long-term indiscriminate use of macrocyclic lactones in cattle: Parasite resistance, clinical helminthosis, and production losses

Our aims were to describe a case of clinical helminthosis caused by parasite resistance to macrocyclic lactones (MLs) after the long-term frequent use of these drugs in a cattle herd, and to evaluate the production losses prevented by the use of an effective anthelmintic treatment to control these resistant gastrointestinal nematodes (GINs). A case of clinical helminthosis culminating in the death of steers was investigated, the history of the antiparasitic treatments used during an 11-year period in the herd was assessed, and an efficacy test involving seven different drugs was performed. Thereafter, two groups of heifers naturally infected by ML-resistant GINs were formed and strategically treated with either a highly effective (levamisole) or less effective drug (doramectin) over a 9-month period. The heifers were evaluated monthly based on eggs per gram of feces (EPG) counts and liveweights. An evaluation of the history of parasite control in the farm revealed that MLs were used in 96.5% of the treatments aimed at controlling GINs, ticks, and myiasis in the herd. The efficacy test showed the presence of GINs resistance to all the MLs tested. However, levamisole and albendazole sulphoxide were highly effective against these parasites. Heifers treated with levamisole gained 12.1 kg more liveweight on average, compared to those treated with doramectin. Thus, we conclude that indiscriminate and long-term use of MLs in the studied herd led to the failure of GINs control, a critical situation resulting in significant production losses, and a surge of clinical helminthosis in young cattle. In addition, we showed increase in liveweight gain due to using a highly effective drug, in comparison to an ML, during a 9-month period, in heifers naturally infected by ML-resistant GINs.

The nutritional status affects the complete blood count of goats experimentally infected with Haemonchus contortus

BACKGROUND

Gastrointestinal nematode (GIN) remains the most important pathogenic constraint of small ruminant production worldwide. The improvement of the host immune response against GIN though breeding for improved animal resistance, vaccination and nutritional supplementation appear as very promising methods. The objective of this study was to investigate the effect of four nutritional status differing in protein and energy levels (Hay: 5.1 MJ/Kg of dry matter (DM) and 7.6% of crude protein (CP), Ban: 8.3 MJ/Kg of DM and 7.5% of CP, Soy: 7.6 MJ/Kg of DM and 17.3% of CP, BS: 12.7 MJ/Kg of DM and 7.4% of CP) on the haematological disturbances due to Haemonchus contortus infection in Creole kid goats.

RESULTS

No significant effect of the nutritional status was observed for faecal egg count (FEC) but the experimental infection induced haematological disturbances whose intensity and lengthening were dependent on the nutritional status. A transient marked regenerative macrocytic hypochromic anaemia as revealed by a decrease of packed cell volume (PCV), red blood cells (RBC) and hemoglobin and an increase of reticulocytes was observed in all infected groups except Hay. In this latter, the anaemia settled until the end of the experiment. Furthermore, H. contortus induced a thrombocytopenia significantly more pronounced in the group under the lowest nutritional status in term of protein (Hay and Ban). A principal component analysis revealed that the variables that discriminated the nutritional status were the average daily gain (ADG) and the PCV, considered as measures of the level of resilience to H. contortus infection. Moreover, the variables that discriminated infected and non-infected animals were mostly related to the biology of RBC (i.e. size and hemoglobin content) and they were correlated with FEC.

CONCLUSIONS

The severity and the lengthening of the regenerative anaemia and the thrombocytopenia induced by H. contortus have been affected by the nutritional status. The protein enriched diets induced resilience to the infection rather than resistance. This suggests that resilience is associated with an improved regenerative capacity of the bone marrow. However, this needs to be further investigated to understand the relationships between resistance, resilience and dietary supplementation.

The effect of different levels of crude protein on the pathophysiology of Haemonchus contortus infection in 2-year-old Boer dry does under confined conditions

The effect of dietary protein supplementation on the pathophysiology of a single Haemonchus contortus infection in 2-year-old Boer dry does under confined conditions was examined. Twenty-four does were randomly confined in individual pens and allocated into three groups balanced by their liveweight. The goats in the Control group were offered a basal diet whereas goats in Treatments 1 and 2 were fed the basal diet plus 25% and 50% dietary protein increments, respectively. Each animal was orally administrated 100 H. contortus L3 larvae/kg liveweight on Day 0 of the experiment. The goat liveweights and FAMACHA scores were recorded at weekly intervals. Packed cell volumes, eosinophil percentage, haemoglobin concentration, total serum protein, globulin, and albumin concentrations were recorded on Days 0 and 14, and then at weekly intervals during the experiments. Faecal egg counts were measured on Days 0, 21, and then at weekly intervals thereafter. Antigen-specific IgA, IgG, and IgM titres were determined from Enzyme-linked immunosorbent assays tests on Days 0, 28, and at the termination of the experiment. The results of this study showed that a single H. contortus L3 infection did not cause pathogenic effects in 2-year-old Boer dry does. Dietary protein supplementation significantly lowered faecal egg count and significantly enhanced IgG titres (P < 0.05). However, the higher protein diets did not have any significant effects on liveweight, packed cell volumes, haemoglobin concentration, biological parameters (total serum protein, albumin, and globulin concentrations), and peripheral antibodies (IgA and IgM titres) between the treatments. Further investigations are required to clarify the role of protein supplementation to control H. contortus infection in goats.

Replacement of mustard oil cake by urea in short-term strategic feeding of cull ewes to improve body condition and carcass traits

Strategic short-term feeding of culled Malpura ewes (age >6 years, average liveweight 26.8 ± 0.96 kg) was aimed at improving their body condition and increase marketability of their carcass following slaughter. Randomly, 8 out of 40 ewes were slaughtered to study initial (Day 0) carcass traits and the remaining ewes were equally divided into two groups: mustard cake (Control) and urea. They were stall fed with ad libitum guar straw (Cyamopsis tetragonoloba) and concentrate mixture at 25 g/kg liveweight after 4 h of morning grazing in the pasture. The Control group was offered concentrate with solvent extracted mustard cake whereas it was replaced on an equivalent nitrogen (N) basis with urea in the concentrate offered to the other group. Daily feed intake and weekly change in ewe liveweight and body condition score were measured during the 91 days of the experiment. There was no significant (P > 0.05) difference in digestibility of nutrients between the groups. Both groups had similar dry matter and metabolisable energy intake, but the mustard cake group recorded higher (P < 0.05) cumulative weight gain and body condition score. Ruminal fluid samples and blood biochemical measurements were analysed periodically (0, 45 and 91 days), with ruminal fluid samples during the post-feeding hours also analysed. There was periodic variation in rumen pH (P = 0.013), volatile fatty acid (P = 007), total N (P = 0.001) and ammonia-N (P = 0.025) concentration in both groups. Higher post-feeding volatile fatty acid (P = 0.031) and total N (P = 0.003) values were observed in the mustard cake group. Ruminal ciliate protozoal population showed a quadratic response over time after feeding with an initial decline post-grazing, but was not affected by treatment. Similar significant (P < 0.05) improvements in haemoglobin, glucose, total protein, urea and cholesterol levels were evident in both groups at 91 days. Both treatments showed similar improvement in carcass composition, distribution of fat and chemical composition of Longissimus dorsi after 91 days of realimentation compared with initial values. Short-term pre-slaughter feeding of cull ewes improved body condition, carcass traits and composition. Replacement of costly mustard cake with urea in the diet of cull ewes could be a means to improve profitability of this strategic feeding protocol, as well as enhancing their market value.

Interactions Between Nutrition and Infections With Haemonchus contortus and Related Gastrointestinal Nematodes in Small Ruminants

Interactions between host nutrition and feeding behaviour are central to understanding the pathophysiological consequences of infections of the digestive tract with parasitic nematodes. The manipulation of host nutrition provides useful options to control gastrointestinal nematodes as a component of an integrated strategy. Focussed mainly on the Haemonchus contortus infection model in small ruminants, this chapter (1) illustrates the relationship between quantitative (macro- and micro-nutrients) and qualitative (plant secondary metabolites) aspects of host nutrition and nematode infection, and (2) shows how basic studies aimed at addressing some generic questions can help to provide solutions, despite the considerable diversity of epidemiological situations and breeding systems.

The effect of Syphacia muris on nutrient digestibility in laboratory rats

This study was carried out to investigate how pinworm infection in rats affects nutrient digestibility in the hosts. Twenty-four male outbred Wistar rats were randomly divided into two groups of 12 rats each. The rats from the first group (GI) were kept in cages with bedding containing pinworm eggs, and the second (control) group (GII) were kept in a separate room in clean, uncontaminated filter-top cages. The animals were put into individual metabolic cages later. Metabolic trials lasted five days and records of animal weight, food ingestion, and faecal weight were taken daily. Based on laboratory analysis of the feed and faecal nutrient content, digestibility values were determined. On day 15 of the experiment, the animals were euthanized. Although Syphacia muris were found in all rats from the GI group, animals exhibited no clinical signs. In our experiment, S. muris infection reduced the overall digestibility of all measured nutrients (P < 0.01). The most significant differences in digestibility were observed in the case of crude fibre and mineral matter (P < 0.01).