The effects of creep feed composition and form and nursery diet complexity on small intestinal morphology and jejunal mucosa-specific enzyme activities after weaning in pigs.

Fifty-six litters from first-parity sows standardized to 12 piglets were used to determine the effects of creep feed composition and form and the provision of low- or high-complexity nursery diets on the evolution of small intestinal histomorphology and jejunal mucosa-specific enzyme activities postweaning. At 5 d of age, litters (initial bodyweight [BW] 2.31 ± 0.61 kg) were assigned to one of four creep feeding regimens (n = 14): 1) commercial creep feed (COM), 2) liquid milk replacer (LMR), 3) pelleted milk replacer (PMR), or 4) no creep feed (NO). At weaning (21 d of age), six pigs per litter were provided a HIGH- (contained highly digestible animal proteins) or LOW- (contained corn and soybean meal as main protein sources) complexity nursery diet (n = 7). At 21, 28, and 59 d of age, two pigs per pen (one castrated male and one female) were euthanized, and ileal and jejunal segments for histomorphological measurements and jejunal mucosal scrapings were collected to determine specific mucosa enzyme activities. At weaning, pigs provided COM had a greater ileal absorptive capacity (M) than LMR or NO, which were not different (14.1 vs. 10.4 and 10.5 ± 0.9 µm2; P < 0.05); PMR was intermediate. On days 28 and 59, M was not different among pigs regardless of creep feed treatments. Pigs fed LOW had reduced jejunal villus height (VH; P < 0.001) and M (P < 0.001) on day 28 vs. day 21. The VH and M were not different for pigs fed HIGH or LOW by the end of the nursery period. For all dietary treatments except COM-HIGH and COM-LOW, jejunal mucosal maltase-specific activity was not different between days 21 and 28 of age but greater on day 59 (P < 0.05). For pigs that received COM-HIGH, maltase-specific activity was not different between days 21 and 28 but greater on day 59 than day 28 (P < 0.05). For pigs that received COM-LOW, maltase-specific activity was not different between days 21, 28, and 59. Regardless of creep or nursery treatment, sucrase-specific activity was the greatest on day 59, followed by days 21 and 28 (P < 0.001), and lactase-specific activity was greater on day 21 than on days 28 and 59 (P < 0.001), which were not different. Therefore, pigs that provided LOW diet had greater villus atrophy and reduced M during the first week after weaning vs. pigs that provided HIGH, regardless of creep feeding regimen, but were able to recover by the end of the nursery period.

After weaning, the piglet digestive tract must adapt in order to effectively break down and absorb nutrients derived from plant-based ingredients, contributing to the postweaning growth lag. Feeding strategies applied both preweaning and postweaning with the intent to assist in intestinal adaptation have been developed; however, little work has been done examining the interaction between creep and nursery feeding strategies on intestinal histomorphology and jejunal mucosa-specific enzyme activities after weaning. In the current study, piglets that provided creep feed with higher starch content had greater jejunal mucosa maltase-specific enzyme activity and ileal absorptive capacity at weaning. However, these parameters were still negatively affected by weaning, regardless of nursery feeding strategy. Additionally, nursery diets with greater inclusion of soybean meal to replace animal protein sources (low complexity) exacerbated reductions in jejunal absorptive capacity. Conversely, by the end of the nursery period, there were no differences in intestinal histomorphology and jejunal mucosa-specific enzyme activities, regardless of creep or nursery feeding program. Therefore, exposing piglets to starch during creep feeding and reducing the inclusion of soybean meal in nursery diets improved intestinal morphology and mucosa disaccharidase activity directly following weaning, but benefits did not extend to the end of the nursery period.

The effect of creep feed composition and form on pre- and post-weaning growth performance of pigs and the utilization of low-complexity nursery diets.

Fifty-six litters from first-parity sows standardized to 12 piglets were used to determine the effects of creep feed composition and form on pre- and post-weaning pig growth performance and the utilization of low-complexity nursery diets. At 5 days of age, litters (initial body weight [BW] 2.31 ± 0.61 kg) were assigned to one of four creep feeding regimens (n = 14): 1) pelleted commercial creep feed (COM), 2) liquid milk replacer (LMR), 3) pelleted milk replacer (PMR), or 4) no creep feed (NO); creep feeds contained 1.0% brilliant blue as a fecal marker. Individual piglet BW and fecal swabs were collected every 3 ± 1 days during the creep-feeding period. The latter was to identify piglets that regularly consumed creep feed via the visual appearance of blue dye in the feces. At weaning (21 ± 2 days of age), six pigs per litter with median BW that consumed creep feed were placed on either a HIGH- (contained highly digestible animal proteins) or LOW- (contained corn and soybean meal as the main protein sources) complexity nursery diet (n = 7) in a three-phase feeding program over 39 days. On day 8, two pigs per pen were sacrificed to collect organ weights and digesta. The LMR disappeared at the greatest rate (average 37.7 g/pig/d; dry matter-basis) versus COM and PMR (10.6 and 10.3 ± 1.5 g/pig/d, respectively; P < 0.001). Litters that received LMR had the greatest proportion of pigs with blue fecal swabs throughout the creep feeding period (85.0 vs. 54.9 and 63.0% ± 0.4% for COM and PMR, respectively; P < 0.05) and LMR piglets had greater BW at weaning versus all other treatments (6.32 vs. 6.02, 5.92, and 5.67 ± 0.14 kg, for LMR, COM, NO, and PMR, respectively; P < 0.001). Overall, pigs given LOW (vs. HIGH) diets in the nursery period had reduced average daily gain (25.1 vs. 27.7 ± 0.4 g/kg BW; P < 0.001), gain:feed (0.75 vs. 0.81 ± 0.02; P < 0.001), and exit BW (21.2 vs. 24.4 ± 0.6 kg; P < 0.001); no carryover effects of creep feeding program were observed. Creep feed regimen had limited effects on nutrient digestibility of nursery diets but the apparent ileal digestibility of organic matter tended to be less at 28 days of age for pigs that received the LOW nursery diet (64.2 vs. 68.8% ± 2.5%; P = 0.076). Providing supplemental nutrition during the suckling period via LMR improved piglet BW at weaning, which did not correspond to improved post-weaning growth performance, regardless of nursery diet complexity.

The development and maintenance of sex differences in dietary breadth and complexity in Bornean orangutans.

ABSTRACT: Orangutans show a pronounced sexual dimorphism, with flanged males (i.e., males with fully grown secondary sexual characteristics) reaching twice the size of adult females. Furthermore, adult orangutans show sex-specific dispersal and activity patterns. This study investigates sex differences in adult foraging behavior and sheds light on how these differences develop in immatures. We analyzed 11 years of feeding data on ten adult female, seven flanged male, and 14 immature Bornean orangutans (Pongo pygmaeus wurmbii) at Tuanan in Central Kalimantan, Indonesia. We found that the diets of the adult females were significantly broader and required more processing steps before ingestion than the diets of flanged males. We also found evidence for a similar difference in overall diet repertoire sizes. For the immatures, we found that whereas females reached 100% of their mothers' diet spectrum size by the age of weaning, males reached only around 80%. From the age of 4 years on (i.e., years before being weaned) females had significantly broader daily diets than males. We found no difference in daily or overall diet processing intensity of immature males and females but found preliminary evidence that immature males included fewer items of their mother's diet in their own diets that were processing-intensive. Overall, our results suggest that by eating a broader variety and more complex to process food items, female orangutans go to greater lengths to achieve a balanced diet than males do. These behavioral differences are not just apparent in adult foraging behavior but also reflected in immature development from an early age on. SIGNIFICANCE STATEMENT: In many species, males and females have different nutritional needs and are thus expected to show sex-specific foraging behavior. Sex differences in several aspects of foraging behavior have been found in various species, but it remains largely unclear when and how those develop during ontogeny, which is especially relevant for long-lived altricial species that learn foraging skills over many years. In our study, we analyzed a cross-sectional and longitudinal data set containing more than 750,000 feeding events of adult and immature Bornean orangutans (Pongo pygmaeus wurmbii). We found that adult females had significantly broader and more complex diets than males. We also found that these differences started to develop during infancy, suggesting that immature orangutans prepare for their sex-specific foraging niches long before those become physiologically relevant while they are still in constant association with their mothers and before being frequently exposed to other role models. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s00265-021-03014-3.

The effect of creep feed and diet complexity on growth performance in suckling and weaned pigs / Efecto de la dieta de pre-iniciación y su complejidad sobre el crecimiento de cerdos lactantes y destetados / Efeito da dieta pré-iniciada e sua complexidade no crescimento de porcos lactantes e desmamados

Abstract Background: Creep feed is offered to suckling piglets to introduce solid feed and provide extra nutrients in late lactation. However, the effect of creep feed is inconsistent; there is little information about the effect of creep diet complexity on piglet performance. Objective: Two experiments were conducted to evaluate the effect of creep feed and its complexity on growth performance of suckling and weaned pigs. Methods: In Exp. 1, eight litters (average 19.9 ± 1.1 d of age; initial piglet weight: 6.74 ± 1.2 kg) were allotted to two dietary treatments considering breed, litter size and weight, as follows: no creep feed (n=3) and creep feed (n=5; offered for 8 days before weaning). At weaning (d 28 of age), the pigs were divided into three treatments (6 pigs/pen, 3 replicates; initial body weight: 9.66 ± 0.34 kg) balanced by gender, body weight, and breed, as follows: creep feed eaters, creep feed non-eaters, and no creep feed. In Exp. 2, two different types of creep feed were offered to suckling piglets (initial piglet weight: 3.79 ± 0.55 kg) in seven litters from d 12 of age (average 12.0 ± 1.3 d of age) to weaning (d 25 of age). Treatments were: HCF (n=4): highly-complex creep diet containing 3% fish meal, 2.4% blood meal, and 15% whey; and 2) LCF (n=3): lowly-complex creep diet without the mentioned ingredients. At weaning, only eater pigs were divided into 2 treatments (6 pigs/pen, 3 replicates; initial body weight: 7.53 ± 0.97 kg) balanced by gender, breed and body weight as follows: HCF eaters and LCF eaters. In both experiments, creep feed was mixed with 1% Cr2O3 to measure fecal color for eater/non-eater categorization and the pigs were fed a common nursery diet for 21 days. Results: In both experiments, there were no differences on piglet weaning weight and overall nursery growth performance among the treatments. In Exp. 2, the creep feed intake and percentage of eaters per litter were not different between the HCF and LCF treatments, whereas the HCF eaters tended to have a greater average daily gain (p=0.08) and gain to feed ratio (p=0.09) than the LCF eaters during d 7-14 postweaning. Conclusion: Creep feed did not affect overall piglet growth in suckling and nursery phases, but its complexity might affect pig growth in the early nursery phase.

Resumen Antecedentes: El alimento de pre-iniciación se ofrece a los lechones lactantes para introducir la alimentación sólida y proporcionar nutrientes adicionales durante la lactancia tardía. Sin embargo, sus efectos son inconsistentes y hay poca información sobre el efecto de la complejidad de la dieta de pre-iniciación sobre el rendimiento de los cerdos. Objetivo: Se realizaron dos experimentos para evaluar el efecto del suministro de pre-iniciador y la complejidad del mismo sobre el crecimiento de lechones y cerdos destetados. Métodos: En el Exp. 1, ocho camadas (promedio 19,9 ± 1.1 d de edad; peso inicial: 6,74 ± 1,2 kg) se asignaron a dos tratamientos con base en raza, tamaño de camada, y peso, de la siguiente manera: sin suministro (n=3) y con suministro de pre-iniciador (n = 5; ofrecido durante 8 días antes del destete). Al destete (d 28 de edad) los cerdos se dividieron en 3 tratamientos (6 cerdos/corral y 3 réplicas; peso inicial: 9,66 ± 0,34 kg) balanceados por género, peso y raza, de la siguiente manera: consumidores de pre-iniciador, no consumidores de pre-iniciación, y sin suministro de pre-iniciación. En el Exp. 2 se ofrecieron dos tipos diferentes de pre-iniciador a los cerditos lactantes (peso inicial del lechón: 3,79 ± 0,55 kg) en siete camadas desde el día 12 de edad (promedio 12,0 ± 1,3 días de edad) hasta el destete (día 25 de edad). Los tratamientos fueron: HCF (n=4): dieta de pre-iniciación de alta complejidad conteniendo 3% de harina de pescado, 2,4% de harina de sangre y 15% de suero de leche; y 2) LCF (n=3): dieta de pre-iniciación de baja complejidad, sin esos ingredientes. Al destete, solo los cerdos que consumieron pre-iniciador se dividieron en 2 tratamientos (6 cerdos/corral, 3 repeticiones; peso corporal inicial: 7,53 ± 0,97 kg) balanceados por género, raza y peso, de la siguiente manera: consumidores de HCF o de LCF. En ambos experimentos el pre-iniciador se mezcló con Cr2O3 al 1% para medir el color fecal y categorizar los consumidores/ no consumidores, y los cerdos se alimentaron con una dieta común de iniciación durante 21 días. Resultados: En ambos experimentos no hubo diferencias en el peso al destete de los lechones y el rendimiento general de crecimiento en re-cría entre tratamientos. En el Exp. 2, la ingesta de pre-iniciador y el porcentaje de cerdos consumidores por camada no fueron diferentes entre los HCF y LCF, mientras que los consumidores de HCF tendieron a tener mayor ganancia diaria (p=0,08) y mayor relación ganancia/alimento (p=0,09) que los consumidores de LCF durante los días 7-14 pos-destete. Conclusión: el pre-iniciador no afecta el crecimiento general de los lechones en las fases de lactancia y re-cría, pero la complejidad de la dieta podría afectar el crecimiento de los cerditos al inicio de la re-cría.

Resumo Antecedentes: A alimentação por fluência é oferecida aos leitões para introduzir alimentos sólidos e fornecer nutrientes extras no final da lactação. No entanto, o efeito ainda é inconsistente e há poucas informações sobre o efeito da complexidade da dieta de fluência no desempenho dos leitões. Objetivo: Dois experimentos foram conduzidos para avaliar o efeito da alimentação por fluência e a complexidade da dieta no desempenho do crescimento de porcos em aleitamento e desmame. Métodos: Em Exp. 1, oito ninhadas (média de 19,9 ± 1,1 d de idade; peso inicial do leitão: 6,74 ± 1,2 kg) foram distribuídos em 2 tratamentos com base na raça, tamanho e peso da ninhada, da seguinte forma: ausência de ração (n=3) e ração por creep (n=5; oferecido por 8 dias antes do desmame). No desmame (d 28 anos de idade), os porcos foram divididos em 3 tratamentos (6 porcos/caneta, 3 repetições; peso corporal inicial: 9,66 ± 0,34 kg) balanceados com gênero, peso corporal e raça, como a seguir: comedores de ração, creep feed não comedores, e creep feed. Em Exp. 2, foram oferecidos dois tipos diferentes de ração para leitões (peso inicial dos leitões: 3,79 ± 0,55 kg) em sete ninhadas de 12 anos de idade (média 12,0 ± 1,3 dias) até o desmame (25 anos). Os tratamentos foram: HCF (n=4): dieta de fluência de alta complexidade contendo 3% de farinha de peixe, 2,4% de farinha de sangue e 15% de soro de leite; e 2) LCF (n=3): dieta de fluência de baixa complexidade sem esses ingredientes. No desmame, apenas os porcos comedores foram divididos em 2 tratamentos (6 porcos/caneta, 3 repetições; peso corporal inicial: 7,53 ± 0,97 kg) balanceados com gênero, raça e peso corporal da seguinte forma: comedores de HCF e comedores de LCF. Em ambos os experimentos, a alimentação fluida foi misturada com 1% de Cr2O3 para medir a cor fecal para categorização de comedor/ não comedor e os porcos foram alimentados com uma dieta comum durante 21 dias. Resultados: Nos dois experimentos, não houve diferenças no peso ao desmame dos leitões e no desempenho geral do crescimento do viveiro entre os tratamentos. Em Exp. 2, o consumo de ração por creep e a porcentagem de comedores por ninhada não foram diferentes entre os tratamentos de HCF e LCF, enquanto os comedores de HCF tenderam a ter um maior ganho médio diário (p=0,08) e uma taxa de ganho para alimentação (p=0,09) do que os comedores de LCF durante d 7-14 pós-desmame. Conclusão: A alimentação por fluência não afetou o crescimento geral de leitões nas fases de amamentação e viveiro, mas a complexidade da dieta pode afetar o crescimento de leitões na fase inicial do viveiro.

Diet complexity and l-threonine supplementation: effects on growth performance, immune response, intestinal barrier function, and microbial metabolites in nursery pigs.

The aim of this study was to investigate the effects of diet complexity and l-Thr supplementation level on the growth performance, immune response, intestinal barrier function, and microbial metabolites in nursery pigs. Thirty-two weaned pigs (body weight 7.23 ± 0.48 kg) were randomly assigned to dietary treatments in a 2 × 2 factorial arrangement based on diet complexity (complex or simple) and dietary Thr content. The complex diet contained fish meal, plasma protein, and dried whey to mimic a conventional nursery diet. The simple diet was formulated with corn, wheat, and soybean meal and did not contain any animal products. l-Thr was supplemented to each diet to supply either 100% (STD Thr) or 115% (SUP Thr) of the NRC (2012) requirement for standardized ileal digestible Thr. Pigs were individually housed and fed experimental diets ad libitum for 14 d. Diet complexity, dietary Thr content, and their interactions were considered the main effects. Pigs fed the simple diet had greater (P < 0.05) plasma interleukin (IL)-10 and IL-6 concentrations compared with those fed the complex diet on days 7 and 14, respectively. Simple diet-fed pigs tended to show greater (P < 0.10) expression of genes encoding for tumor necrosis factor-α, claudin-1, and zonula occludens-1 in the jejunum compared with complex diet-fed pigs. The simple diet-fed pigs had greater (P < 0.05) concentrations of NH3-N in the jejunum digesta than did complex diet-fed pigs. The SUP Thr increased (P < 0.05) villus height and goblet cell (GC) density in villi and crypts in the jejunum and deepened (P < 0.05) crypts in the proximal colon. The SUP Thr resulted in the upregulation (P < 0.05) of occludin gene expression and a tendency toward the downregulation (P = 0.10) of IL-6 gene expression in the jejunum. Interactions (P < 0.05) between diet complexity and l-Thr supplementation level were observed in GC density in the crypt, NH3-N concentration in the jejunum, and the contents of acetate, propionate, and total volatile fatty acids in the colon. In conclusion, feeding a simple diet to nursery pigs resulted in systemic and intestinal inflammation. The SUP Thr diet did not normalize the simple diet-induced inflammation but improved gut integrity. SUP Thr seems to have greater benefits with a simple diet than with a complex diet. Therefore, SUP Thr in a simple diet could be a beneficial nutritional strategy for enhancing gut health.

Diet complexity and l-threonine supplementation: effects on nutrient digestibility, nitrogen and energy balance, and body composition in nursery pigs.

This study was conducted to investigate the effects of dietary complexity and l-Thr supplementation on energy and nutrient utilization in nursery pigs. Thirty-two nursery pigs (7.23 ± 0.48 kg) were randomly assigned to a 2 × 2 factorial treatment arrangement based on diet complexity (complex vs. simple) with different levels of l-Thr supplementation. The complex diet contained animal protein sources (e.g., fish meal and plasma) and a dairy product (e.g., dried whey) to mimic a conventional nursery diet. The simple diet was formulated with corn, wheat, and soybean meal. Both diets were supplemented with l-Thr to contain either 100% or 115% (SUP Thr) of the estimated standardized ileal digestible Thr requirement for 9 kg body weight pigs (NRC, 2012). The pigs were individually housed in metabolism crates and fed an experimental diet ad libitum for a 7-d adaptation period and 5 d of total but separate urine and fecal collection. On day 14, all pigs were euthanized to determine body composition. The diet complexity, l-Thr supplementation, and their interactions were considered main effects. Pigs fed the complex diet tended to exhibit greater (P < 0.10) apparent total tract digestibility (ATTD) of ash and urinary energy output than those fed the simple diet. The complex diet had greater (P < 0.05) digestible energy and net energy contents than the simple diet. Furthermore, the complex diet-fed pigs had lower (P < 0.05) plasma urea nitrogen concentration on day 14 than simple diet-fed pigs. The SUP Thr decreased (P < 0.05) ATTD of acid detergent fiber but trended (P < 0.10) toward a decrease in urinary nitrogen (N) output and an increase in N retention and body N mass. In conclusion, the simple diet for nursery pigs had lower digestible and net energy contents than a complex diet. The SUP Thr can improve N utilization and body protein deposition, irrespective of diet complexity.

Effect of lipopolysaccharide-induced immune stimulation and maternal fish oil and microalgae supplementation during late pregnancy on nursery pig hypothalamic-pituitary-adrenal function1.

The present study used Escherichia coli lipopolysaccharide (LPS) to investigate whether maternal immune challenge during late gestation altered programming of the offspring hypothalamus and hypothalamic-pituitary-adrenal axis (HPAA). In addition, interactions of maternal diet, supplementation with fish oil (FO) or microalgae (AL), and complex vs. simple weaning diets were investigated. Briefly, Landrace × Yorkshire sows (N = 48) were randomly assigned to diets supplemented with FO, AL, or a standard gestation control diet (CON) from day 75 of gestation (gd 75) until parturition. On gd 112, half the sows from each dietary treatment were immune challenged with LPS (10 µg/kg BW) or saline as a control. At 21 d postpartum, the offspring were weaned, and half the animals from each maternal treatment were allocated to either a complex or simple weaning diet. At 28 d postpartum, the offspring's hourly fever and 2-h cortisol responses to LPS immune challenge (40 µg/kg BW) were measured to assess hypothalamus and HPAA function. Results indicated that the maternal temperature of sows on the FO diet returned to baseline levels faster than sows on the AL and CON diets after LPS immune challenge (P < 0.05). In contrast, there was no difference in the maternal cortisol response across the dietary treatments (P > 0.10). Regardless of the dietary treatments, the maternal LPS immune challenge induced a greater cortisol response in male offspring (P = 0.05) and a greater fever response in female offspring (P = 0.03) when they were LPS immune challenged post-weaning. Male offspring from LPS-immune-challenged sows fed the FO and AL diets had a greater fever response than male offspring from the maternal CON diet group (P ≤ 0.05). Last, no effect of the complex or simple weaning diets was observed for the nursery pig cortisol or fever responses to LPS immune challenge. In conclusion, LPS immune challenge during late pregnancy altered responsiveness of the offspring hypothalamus and HPAA to this same microbial stressor, and a sex-specific response was influenced by maternal dietary supplementation with FO and AL.

Post-weaning and whole-of-life performance of pigs is determined by live weight at weaning and the complexity of the diet fed after weaning.

The production performance and financial outcomes associated with weaner diet complexity for pigs of different weight classes at weaning were examined in this experiment. A total of 720 weaner pigs (360 entire males and 360 females) were selected at weaning (27 ± 3 d) and allocated to pens of 10 based on individual weaning weight (light weaning weight: pigs below 6.5 kg; medium weaning weight: 6.5 to 8 kg; heavy weaning weight: above 8.5 kg). Pens were then allocated in a 3 × 2 × 2 factorial arrangement of treatments with the respective factors being weaning weight (heavy, medium and light; H, M and L, respectively), weaner diet complexity (high complexity/cost, HC; low complexity/cost, LC), and gender (male and female). Common diets were fed to both treatment groups during the final 4 weeks of the weaner period (a period of 39 days). In the first 6 d after weaning, pigs offered the HC diets gained weight faster and used feed more efficiently than those offered the LC diets (P = 0.031). Pigs fed a HC diet after weaning tended to be heavier at the sale live weight of 123 d of age compared with pigs fed the LC diet (P = 0.056). There were no other main effects of the feeding program on growth performance through to slaughter. Weaning weight had a profound influence on lifetime growth performance and weight at 123 d of age, with H pigs at weaning increasing their weight advantage over the M and L pigs (101.3, 97.1, 89.6 kg respectively, P < 0.001). Cost-benefit analyses suggested there was a minimal benefit in terms of cost per unit live weight gain over lifetime when pigs were offered a HC feeding program to L, with a lower feed cost/kg gain. The results from this investigation confirm the impact of weaning weight on lifetime growth performance, and suggest that a HC feeding program should be focused on L weaner pigs (i.e., weaning weight less than 6.5 kg at 27 d of age) in order to maximise financial returns.