Feeding Sows Lucerne, or Diets with Similar Energy and Nutritional Profiles to Lucerne, Improves the Pre-Weaning Performance of Piglets

Feeding fibre and branched-chain amino acids (BCAA) to sows during late gestation and lactation, respectively, have been shown to improve litter weights at weaning. Therefore, supplementing primiparous sow diets with lucerne chaff, a feedstuff high in fibre, BCAA and tryptophan, may improve the performance of their progeny. Experiment 1 investigated the effects of feeding primiparous sows (n = 118) either (i) a control diet (CON); (ii) CON with 1 kg of lucerne chaff (LUC); or (iii) a diet formulated to have a similar digestible energy and BCAA content as CON + LUC (SIMLUC 1) until farrowing. The LUC and SIMLUC 1 diets improved day 21 litter weight (p = 0.055). In Experiment 2 primiparous (n = 111) and multiparous sows (parities 2–5, n = 112) were fed either the CON or SIMLUC diet (SIMLUC 2) from day 110 of gestation to farrowing (PreF), or to day 10 post-farrowing (PreF + PostF). The SIMLUC 2 diet tended to be more beneficial to primiparous compared to multiparous sows when fed PreF, as indicated by an interaction between diet and parity on day 21 average piglet weights (p = 0.078). Overall, SIMLUC is most effective in improving primiparous progeny performance as evidenced by their D21 weights.

Influence of Maternal Carbohydrate Source (Concentrate-Based vs. Forage-Based) on Growth Performance, Carcass Characteristics, and Meat Quality of Progeny

The objective of this research was to investigate the influence of maternal prepartum dietary carbohydrate source on growth performance, carcass characteristics, and meat quality of offspring. Angus-based cows were assigned to either a concentrate-based diet or forage-based diet during mid- and late-gestation. A subset of calves was selected for evaluation of progeny performance. Dry matter intake (DMI), body weight (BW), average daily gain (ADG), gain to feed (G:F), and ultrasound measurements (muscle depth, back fat thickness, and intramuscular fat) were assessed during the feeding period. Carcass measurements were recorded, and striploins were collected for Warner-Bratzler shear force (WBSF), trained sensory panel, crude fat determination and fatty acid profile. Maternal dietary treatment did not influence (p > 0.05) offspring BW, DMI, ultrasound measurements, percent moisture, crude fat, WBSF, or consumer sensory responses. The forage treatment tended to have decreased (p = 0.06) 12th rib backfat compared to the concentrate treatment and tended to have lower (p = 0.08) yield grades. The concentrate treatment had increased (p < 0.05) a* and b* values compared to the forage treatment. These data suggest variation in maternal diets applied in this study during mid- and late-gestation has limited influence on progeny performance.

Exposure to Maternal Faeces in Lactation Influences Piglet Enteric Microbiota, Growth and Survival Pre-weaning

It is known that gilt progeny performance is reduced compared to sow progeny. Previous research suggests that the presence of maternal faeces in early life improves the health and survival of offspring. Therefore, we aimed to determine whether contact with faeces from multiparous (MP) sows would improve the growth and survival of piglets born and reared on primiparous (P1) sows and if so, whether these differences are associated with the gut microbiota. Four treatments were applied for 10 days: Donor (n = 29) piglets had limited access to maternal faeces as, each morning, sow faeces were removed and placed in the crate of a P1 sow (P1-FT; n = 30 piglets); and P1-Con (n = 29) and MP-Con (n = 33) piglets had access to their own mothers’ faeces. All piglets were weighed on days 1, 3, 10 and 18. Faecal samples were collected from a subset of sows (n = 10/treatment) 3 days post-farrow and from 2 female piglets/litter on day 10 and 18 (n = 20/treatment) and subject to 16S rRNA amplicon analysis. Escherichia, Clostridium, Campylobacter and Treponema were more abundant in MP sows, while P1 sows had a higher abundance of Lactobacillus and Prevotella. At 10 days, P1 progeny faecal microbiota differed, and growth and survival were reduced when compared to MP progeny. No treatment effect was observed for P1-FT piglets (P &gt; 0.05). Donor piglets had a different faecal microbiota and improved weight and survival then all other treatments (P &lt; 0.05). Overall, the removal of sow faeces from the farrowing crate improved piglet microbiota development, growth and survival.

Effects of Symbiodiniaceae Phylotypes in Clades A–E on Progeny Performance of Two Giant Clams (Tridacna squamosa and T. crocea) During Early History Life Stages in the South China Sea

Unlike most bivalves, giant clams (tridacnids) harbor symbiotic microalgae (zooxanthellae) in their other fleshy bodies. The effects of mixed populations of zooxanthellae on larval metamorphosis has been reported in several papers, but there have been very few studies on the effects of single zooxanthella species on the establishment of symbiosis in giant clams. In this study, we obtained five pure zooxanthella species (clades A3, B1, C1, D1, E1) from antler coral by molecular identification, and analyzed their effects on the larval metamorphosis and progeny performance of two giant clams, Tridacna squamosa and T. crocea, in the South China Sea. Clam larvae with all five zooxanthella species underwent larval settlement and metamorphosis, and formed the zooxanthellal tubular system. There was some variation in metamorphic rate and time to metamorphosis between clams with different zooxanthella species, but no significant differences in size at metamorphosis. After metamorphosis, larvae with all zooxanthella types continued to develop normally. Mantle color was consistent within clam species and zooxanthella species had no effect on mantle color. However, clam progeny with clade E1 zooxanthellae were smaller than progeny with the other four zooxanthella clades (A3, B1, C1, and D1). Survival rate was over 90% for all progeny and there were no significant differences in survival between progeny with Symbiodinium clades A–E during the entire culture process. Two-way ANOVA analysis revealed that giant clam species was the main factor influencing progeny growth, with some variation in growth attributable to zooxanthella type. Our results provide new information on both the symbiotic relationship between giant clams and zooxanthellae and the mantle coloration of giant clams, and will be useful in giant clam seed production and aquaculture.

405 WS Young Scholar Talk MS I: The impact of cow size on cow-calf and post-weaning progeny performance in the Nebraska Sandhills

Optimizing beef production system efficiency requires an understanding of genetic potential suitable for a given production environment. Therefore, the objectives of this retrospective analysis were to determine the influence of cow body weight (BW) adjusted to a common body condition score (BCS) of 5 at weaning influenced cow-calf performance and post-weaning steer and heifer progeny performance. Data were collected at the Gudmundsen Sandhills Laboratory, Whitman, NE, on crossbred, mature cows (n = 1,715) from 2005 to 2017. Cow BCS at calving, pre-breeding, and weaning were positively associated (P &lt; 0.01) with greater cow BW. Increasing cow BW was positively associated (P &lt; 0.01) with the percent of cows that conceived during a 45-d breeding season. For every additional 100-kg increase in cow BW, calf BW increased (P &lt; 0.01) at birth (2.70 kg) and adjusted 205-d weaning BW (14.76 kg). Calf pre-weaning average daily gain (ADG) increased (P &lt; 0.01) 0.06 kg/d for every additional 100-kg increase in cow BW. Heifer progeny BW increased (P &lt; 0.01) post-weaning with every addition 100-kg increase in dam BW. Dam BW did not influence (P ≥ 0.11) heifer puberty status prior to breeding, overall pregnancy rates, or the percent of heifers calving in the first 21-d of the calving season. Steer initial feedlot BW (7.20 kg¬), reimplant BW (10.47 kg), and final BW (10.29 kg) increased (P □ 0.01) for every additional 100-kg increase in dam BW. However, steer feedlot ADG was not influenced (P &gt; 0.67) by dam BW. Hot carcass weights of steers were increased (6.48 kg; P = 0.01) with every additional 100-kg increase in cow BW. In a hypothetical model using the regression coefficients from this study, total output (calf weaning and cull cow BW) would be 6,352 kg greater utilizing a 454 kg cowherd compared with a 554 kg cowherd. Overall, larger sized-cows within this herd and production system of the current study had increased reproductive performance and offspring BW; however, total production output and economic returns would be potentially greater when utilizing smaller-sized cows.