Supplementation with Rumen-Protected Methionine Reduced the Parasitic Effect of Haemonchus contortus in Goats.

The present study investigated the impact of rumen-protected (RP) methionine supplementation on the resistance and resilience to Haemonchus contortus experimental infection of goat kids. Twenty-seven 6-month-old goat kids (14.55 ± 2.7 kg body weight) were placed in individual pens during an experimental period of forty-two days. Each kid was placed under one of three distinct diets (n = 9 animals/diet) corresponding to the following experimental groups: Control (C, Hay + concentrate), Low Methionine (LM, Hay + concentrate + 3.5 g/Kg of Dry Matter (DM) of RP methionine, or High Methionine (HM, Hay + concentrate + 11.5 g/Kg of DM of RP methionine). After a 4-week period of adaptation to the diets, all the animals were experimentally infected with a single oral dose of 10,000 H. contortus third-stage infective larvae (L3). No significant effect of RP methionine supplementation was observed for feed intake, digestibility and growth performance. The faecal egg counts (FEC) and worm burdens were not impacted by RP methionine supplementation either. In contrast, Packed cell volume (PCV) and haemoglobin concentration were higher in kids supplemented with RP methionine. Similarly, the level of serum IgA directed against adult H. contortus excretion and secretion products (ESP) was higher in supplemented kids. These results suggested that RP methionine supplementation improved goat kids' resilience against H. contortus infection.

Comparative analysis of whole blood transcriptomics between European and local Caribbean pigs in response to feed restriction in a tropical climate.

BACKGROUND: Feed restriction occurs frequently during pig growth, either due to economic reasons or stressful environmental conditions. Local breeds are suggested to have better tolerance to periods of feed restriction. However, the mechanisms underlying the response to feed restriction in different breeds is largely unknown. The aims of the present study were (1) to compare the blood transcriptome profile in response to feed restriction and refeeding of two contrasted breeds, Large White (LW), which has been selected for high performance, and Creole (CR), which is adapted to tropical conditions, and (2) to investigate the effect of a moderate feed restriction and refeeding on whole blood transcriptome. Analysis of blood transcriptome allows to study the response to feed restriction and refeeding in a dynamic way. RNAseq was performed on blood samples of growing LW and CR pigs at two time points: after 3 weeks of feed restriction and after 3 weeks of refeeding. The data was compared with samples from control animals offered the same diet on an ad libitum basis throughout the whole experiment. RESULTS: In terms of performance (body weight and feed efficiency), CR pigs were less impacted by feed restriction than LW. The transcriptional response to feed restriction and refeeding between CR and LW was contrasted both in terms of number of DEGs and enriched pathways. CR demonstrated a stronger transcriptional response to feed restriction whereas LW had a stronger response to refeeding. Differences in the transcriptional response to feed restriction between CR and LW were related to cell stress response (Aldosterone Signalling, Protein ubiquitination, Unfolded Protein Signalling) whereas after refeeding, differences were linked to thermogenesis, metabolic pathways and cell proliferation (p38 MAPK, ERK/MAPK pathway). In both breeds, transcriptional changes related to the immune response were found after restriction and refeeding. CONCLUSIONS: Altogether, the present study indicates that blood transcriptomics can be a useful tool to study differential genetic response to feed restriction in a dynamic way. The results indicate a differential response of blood gene expression to feed restriction and refeeding between breeds, affecting biological pathways that are in accordance with performance and thermoregulatory results.

Effect of the nutritional status of Creole goats on the density-dependent prolificacy of Haemonchus contortus.

The objective of this study was to measure the effect of the nutritional status of Creole goat kids on the host responses and the nematode population established after an experimental H. contortus infection. Fifty six kids were fed with 4 diets corresponding to 2 nutritional statuses: the low nutritional status (HAY, hay ad libitum and HB, Hay ad libitum + banana) and the high nutritional status (HS, hay ad libitum + soya meal and HSB, hay ad libitum + banana + soya meal). For each diet, 8 kids were experimentally infected with 10,000 H. contortus infective larvae (L3) and 6 kids were kept as non-infected controls. From the day of infection until 6 weeks post-infection, samples were collected to measure individual intake, total tract digestibility, parasitological and hematological parameters. The dry matter intake (DMI), the average daily gain (ADG), the crude protein (CP) and the digestible CP intake were higher in goats fed the HS and HSB diets, but no statistically significant interaction between the nutritional status and the infection was observed. The packed cell volume (PCV), the red blood cell counts (RBC) and the mean corpuscular volume (MCV) were higher with the HS and the HSB diets. In kids with the high nutritional status the nematode burden and pathophysiological impact of the infection were significantly lower but not the FEC. In conclusion, this reduced establishment rate was associated with an increased production of eggs by the female parasites and suggested a phenomenon of density-dependent prolificacy of H. contortus probably inherent to the fitness of the parasite population.

Effect of feed restriction and refeeding on performance and metabolism of European and Caribbean growing pigs in a tropical climate.

Reduction in feed intake is a common physiological response of growing pigs facing stressful environmental conditions. The present experiment aims to study (1) the effects of a short-term feed restriction and refeeding on pig performance and metabolism and (2) the differential response between two breeds, Large White (LW), which has been selected for high performance, and Creole (CR), which is adapted to tropical conditions. A trial of 36 castrated male pigs (18 LW and 18 CR) was carried out. For each breed, half of the animals were restrictively fed at 50% of the standard feed allowance for 6 days and then fed normally for the next 14 days. Growth performance, thermoregulatory responses, plasma hormones and metabolites were measured. Results showed that, for all traits, the difference in response between the two breeds was small and rarely significant, which may be due to the short duration of the feed restriction. Irrespective of breed, feed restriction induced a reduction of growth rate and feed efficiency that was rapidly compensated for upon refeeding. Feed restriction also reduced skin temperature, rectal temperature and respiratory rate, as well as blood urea and cholesterol, which are of interest as potential biomarkers for feed restriction.