Feed efficiency and the liver proteome of fattening lambs are modified by feed restriction during the suckling period

Abstract

The present study was designed to describe the effects of early feed restriction of Merino lambs on feed efficiency during the fattening period by examining ruminal microbiota and fermentation parameters, gastrointestinal morphology, digestibility or liver proteome. In total, 24 male Merino lambs were randomly assigned to two experimental treatments (n=12 per treatment). Lambs of the first group (ad libitum (ADL)) were kept permanently with the dams, whereas the other 12 lambs (restricted (RES)) were milk restricted. When lambs reached a live BW (LBW) of 15 kg, all the animals were offered the same complete pelleted diet (35 g dry matter/kg LBW per day) until slaughter at a LBW of 27 kg. The RES lambs showed poorer feed efficiency during the fattening period when compared with the ADL group (feed to gain ratio, 3.69 v. 3.05, P<0.001). No differences were observed in ruminal microbiota, fermentation parameters or apparent digestibility. However, the proportion of the small intestine and the length of ileal villi were reduced in the RES lambs. In total, 26 spots/proteins were identified in the liver proteomic profile, with significant differences (P<0.05) between experimental treatments, suggesting a higher catabolism of proteins and a reduction in β-oxidation of fatty acids in RES lambs when compared with the ADL animals. In conclusion, early feed restriction of Merino lambs during the suckling period promotes long-term effects on the small intestine and the proteomic profile of the liver, which may influence the metabolic use of nutrients, thus negatively affecting feed efficiency during the fattening phase.

Effect of feeding regime on the performance and blood parameters of male and female broiler chickens

“…However, feed restriction in males and females significantly increased the heart yield compared with that in ADL chickens, and the trend continued during realimentation. Similar results have been observed in rabbits (Tůmová et al, 2007) and lambs (Santos et al, 2018). A larger heart size in restricted animals may lead to myocyte hypertrophy and is assumed to be an adaptive response (Santos et al, 2018).…”

“…Similar results have been observed in rabbits (Tůmová et al, 2007) and lambs (Santos et al, 2018). A larger heart size in restricted animals may lead to myocyte hypertrophy and is assumed to be an adaptive response (Santos et al, 2018). Mohammadalipour et al (2017) stated that the growing heart mass elevated HC to satisfy the oxygen demand of the increased metabolic rate.…”

Early feed restriction of lambs modifies ileal epimural microbiota and affects immunity parameters during the fattening period

“…When each lamb reached 13.5 kg of BW it was weaned progressively [free access to a complete pelleted diet and alfalfa, whereas it was allowed only two hours with the dam] until it weighed 15 kg. Then, all the animals were penned individually, had free access to fresh drinking water and were offered the same complete pelleted diet at the same level (35 g/kg BW per day) to avoid differences in DM intake during the fattening period as explained elsewhere (Santos et al, 2018b).…”

“…One of these factors might be related to early feed restriction of animals (Greenwood and Cafe, 2007) during the postnatal phases, when the colonization of mucosal epithelium of the gastrointestinal tract by commensal bacteria takes place (Taschuk and Griebel, 2012). Interestingly, once established the epimural microbiota seems to be less influenced by the diet than microbiota associated to digesta contents (Petri et al, 2013;Yáñez-Ruiz et al, 2015), so any factor (e.g., early feed restriction) modifying the composition of the microbiota firmly attached to these cells may modulate not only the nutrient processing (Santos et al, 2018a and2018b) but also the gut-associated lymphoid tissue, thus exerting nutritional programming of immune health and hence long-term effects on lifetime feed efficiency.…”

“…However, even though several studies have described the composition of microbiota in the rumen, jejunum, colon and caecum contents of steers or lambs differing in feed efficiency (Myer et al, 2015a(Myer et al, , 2015b(Myer et al, , 2015c(Myer et al, and 2016Santos et al, 2018b), there are scarce studies focused on ileal epimural microbiota of ruminants (Mao et al, 2015). This is surprising, since ileum is involved not only in nutrient absorption but also in the development of immune response (ileal Peyer´s patches, iPP) during early life.…”