Weaning age and post-weaning nursery feeding regime are important in improving the performance of lightweight pigs

Abstract

The aim was to investigate the effect of weaning age, weaning weight, and nursery feeding regime on post-weaning performance. The focus was on pigs weaned light, as they may be better off when weaned at a later age and/or offered a specialist nursery feeding regime. Piglets (n = 1,448) from one farrowing batch of 110 sows that farrowed over 2 wk were individually weighed and their morphometric measurements were taken at birth. Pigs were weaned on the same day, but variation in birth date resulted in variable weaning ages (mean age day 34.1, SD = 2.5). The youngest 50% at weaning were classified Y and the oldest 50% as O; within an age class, the lightest 50% were classified L, the heaviest 50% as H, and housed accordingly. Pigs were individually weighed at weaning, 7 and 15 wk post-weaning. At weaning, Y were 6 d younger and 1.4 kg lighter than O pigs, whereas L were 3.2 kg lighter than H pigs. Pigs were randomly allocated to a 3-stage superior (SUP) or control (CON) nursery feeding regime, with SUP pigs having a 65% greater allowance (on a kg/pig basis) of the first and second stage feeds than the CON. Pigs weaned Y had a higher mortality rate from weaning to 7 wk post-weaning than pigs weaned O (9.14% vs. 4.98%; P = 0.046). As expected, age and weight significantly (P < 0.001) affected performance to both 7 and 15 wk post-weaning: at 15-wk pigs weaned Y were 5.5 kg lighter than pigs weaned O; pigs weaned L were 9.0 kg lighter than H pigs. It was estimated that pigs weaned YL needed ~4 d more (P = 0.018) to reach 60 kg BW than pigs weaned OL. Feed intake was not affected by feeding regime, age and weight, or their interactions. Performance was not affected by feeding regime (P > 0.05), but was affected by the weight × feeding regime interaction (P = 0.044) to 7 wk post-weaning: L pigs on SUP were 1.2 kg heavier than L pigs on the CON regime; this was not the case for the H pigs. Performance up to 7 wk post-weaning was positively associated with birth weight to cranial circumference ratio and weaning weight (P < 0.05) for both YL and OL pigs; for the latter, additional performance predictors were weaning age (P = 0.044) and feeding (P = 0.027). Improved growth for L pigs up to 7 wk post-weaning could be obtained by a greater allowance of the nursery diets. However, weaning at a later age benefitted the performance of L pigs to a common BW, suggesting that this might be a strategy with longer term benefits.

Increasing Dietary Lysine Impacts Differently Growth Performance of Growing Pigs Sorted by Body Weight

“…Similarly, other authors have reported a greater lysine disappearance as a percentage of total intake at low energy intakes [ 23 ]. Consequently, most nutritional studies have focused on feeding high density diets, by increasing amino acid or energy concentrations during the nursery phase, as they considered that early interventions might be more effective [ 12 , 24 , 25 , 26 ]. However, other studies have also reported positive effects of dietary interventions during the grow-finishing phase [ 17 , 27 , 28 ], and others reported no advantage [ 29 , 30 ].…”

Maintaining continuity of nutrient intake after weaning. I. Review of pre-weaning strategies

“…Underdevelopment was marked by lighter GI organs and accessory organ weights, as well as lower specific maltase, glucoamylose, and pancreatic enzyme activity. Similarly, when pigs were divided into young (<32.4 wean age) versus old (>35.9 wean age) groups at a common wean date, higher mortality rates were observed in young (9.1%) compared to old pigs (5.0%; Huting et al, 2019 ). However, when divided into light verses heavy groups, no statistical differences were detected.…”

Timely Control of Gastrointestinal Eubiosis: A Strategic Pillar of Pig Health

“…Considering the relevance of the specific classes of weight of the piglets at a given age was a first step in this direction. Delaying the weaning age by one week to an average of 32 days benefitted the performance of lighter pigs when reared to a common final weight (20 and 60 kg) [95]. Pigs weaned later, whatever the weight class, also had reduced mortality.…”

“…However, there is the need for defining the target profiles of the ideal mature GIT microbiota in order to optimize weaning age. Follow-up studies regarding pigs under both genetic selection and standard rearing have indicated that the presence of bacteria capable of degrading complex carbohydrates, including fiber degrading organisms, is the hallmark of a mature microbiota in the colon or feces (growing-finishing pigs), including the Prevotella and Treponema genera [95][96][97][98][99]. Furthermore, the operational taxonomic units (OTUs) assigned to the Prevotella genus were genetically associated with growth performance during different growing phases [100].…”