Genetic improvement of sow longevity and its economic impact on commercial pork production

Sow longevity (sow productive lifetime) plays an important role in economically efficient piglet production. Direct selection for sow longevity is not commonly practiced in any pig-breeding program. In recent years, an increased number of peer reviewed articles addressing the economic impact, genetic parameter estimates, and genomic information (including markers and single nucleotide polymorphisms for sow longevity) have been published in the scientific literature. The studies in the literature indicate that sow longevity is a complex trait having economic value and is an animal well-being concern for commercial pork producers. Studies have concluded that sufficient genetic variation exists so that selection to improve sow longevity should be effective. Unlike the dairy industry, the primary parent animal used in the swine industry is a crossbred female, typically F1 (Landrace X Large White or Yorkshire). Sow longevity has shown to be genetically related with prolificacy and leg conformation traits. Sow longevity seems to be the ideal trait to utilize genomic selection when attempting to improve the trait. The genetic correlation between purebred and crossbred sow longevity is low. Since the crossbred sow is the breeding objective, phenotypic data from the crossbred females should ideally be used when estimating the breeding values for sow longevity that are used in the indexes to evaluate nucleus animals. Genomic selection is best suited for sex-limited traits, traits expressed later in life, and many animals do not reach some defined end-point parity, sow longevity seems ideally suited to be evaluated using the latest genome enabled selection technology. Keywords: heritability, leg conformation, selection, sow productive lifetim

Dietary lysine-to-energy ratios for managing growth and pubertal development in replacement gilts

Objective: Our objective was to determine growth rates, body composition, and pubertal development of replacement gilts fed diets with different ratios of standardized ileal digestible (SID) lysine to ME. Materials and Methods: Diets with low, medium, and high ratios of SID lysine to ME (grower: 2.3, 2.6, and 2.8; and, finisher; 1.7, 1.9, and 2.1 g/Mcal) were fed from 100 to 200 d of age, after which gilts were moved from the gilt development unit to sow farms. Boar exposure and estrus detection began at 160 d of age and continued until first detected estrus. Estimates of BW and body composition were determined at 100, 142, 160, and 200 d of age and at puberty. Results and Discussion: Body weights and growth rates were reduced (P \u3c 0.05) as dietary SID lysine–to– ME ratio decreased. Greater SID lysine–to–ME ratios increased the number of gilts that exhibited estrus upon boar exposure, increased the number of gilts with a spontaneous first estrus, reduced the number of gilts requiring P.G.600 (Merck Animal Health, Kenilworth, NJ), and decreased age at first estrus (P \u3c 0.05). Slower growing gilts that weighed less with less backfat were more likely to require P.G.600 to induce puberty (P \u3c 0.05). Implications and Applications: Reducing SID lysine– to–ME ratios in gilt diets can increase the number of gilts within optimal BW range at first estrus, but overall pubertal development is delayed if ratios are reduced below 2.8 and 2.1 g of SID lysine to megacalorie of ME in grower and finisher diets, respectively

Did the Construction of the Bhumibol Dam Cause a Dramatic Reduction in Sediment Supply to the Chao Phraya River?

The Bhumibol Dam on Ping River, Thailand, was constructed in 1964 to provide water for irrigation, hydroelectric power generation, flood mitigation, fisheries, and saltwater intrusion control to the Great Chao Phraya River basin. Many studies, carried out near the basin outlet, have suggested that the dam impounds significant sediment, resulting in shoreline retreat of the Chao Phraya Delta. In this study, the impact of damming on the sediment regime is analyzed through the sediment variation along the Ping River. The results show that the Ping River drains a mountainous region, with sediment mainly transported in suspension in the upper and middle reaches. By contrast, sediment is mostly transported as bedload in the lower basin. Variation of long-term total sediment flux data suggests that, while the Bhumibol Dam does effectively trap sediment, there was only a 5% reduction in sediment supply to the Chao Phraya River system because of sediment additions downstream

Magnetically Recoverable Biomass-Derived Carbon-Aerogel Supported ZnO (ZnO/MNC) Composites for the Photodegradation of Methylene Blue

Hydrothermally assisted magnetic ZnO/Carbon nanocomposites were prepared using the selective biowaste of pomelo orange. Initially, the carbon aerogel (CA) was prepared hydrothermally followed by a freeze-drying method. Furthermore, the iron oxide nanoparticles were deposited onto the surface of carbon using the co-precipitation method and we obtained magnetic carbon nanocomposite, i.e., Fe3O4/C (MNC). Moreover, the ZnO photocatalysts were incorporated onto the surface of MNC composites using a hydrothermal process, and we obtained ZnO/MNC composites. The ZnO/MNC (55%), ZnO/MNC (65%) and ZnO/MNC (75%) composites were prepared by a similar experimental method in order to change the weight ratio of ZnO NPs. Using a similar synthetic procedure, the standard ZnO and Fe3O4 nanoparticles were prepared without the addition of CA. The experimental results were derived from several analytical techniques, such as: X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman and diffuse reflectance spectroscopy (DRS-UV). The synthesized carbon, ZnO, Fe3O4, ZnO/MNC (55%), ZnO/MNC (65%) and ZnO/MNC (75%) composites were examined through the photocatalytic degradation of methylene blue (MB) under visible-light irradiation (VLI). The obtained results revealed that the composites were more active than carbon, ZnO and Fe3O4. In particular, the ZnO/MNC (75%) composites showed more activity than the rest of the composites. Furthermore, the recycling abilities of the prepared ZnO/MNC (75%) composites were examined through the degradation of MB under identical conditions and the activity remained constant up to the fifth cycle. The synthetic procedure and practical applications proposed here can be used in chemical industries, biomedical fields and energy applications

Dietary lysine-to-energy ratios for managing growth and pubertal development in replacement gilts

Objective: Our objective was to determine growth rates, body composition, and pubertal development of replacement gilts fed diets with different ratios of standardized ileal digestible (SID) lysine to ME. Materials and Methods: Diets with low, medium, and high ratios of SID lysine to ME (grower: 2.3, 2.6, and 2.8; and, finisher; 1.7, 1.9, and 2.1 g/Mcal) were fed from 100 to 200 d of age, after which gilts were moved from the gilt development unit to sow farms. Boar exposure and estrus detection began at 160 d of age and continued until first detected estrus. Estimates of BW and body composition were determined at 100, 142, 160, and 200 d of age and at puberty. Results and Discussion: Body weights and growth rates were reduced (P Implications and Applications: Reducing SID lysine– to–ME ratios in gilt diets can increase the number of gilts within optimal BW range at first estrus, but overall pubertal development is delayed if ratios are reduced below 2.8 and 2.1 g of SID lysine to megacalorie of ME in grower and finisher diets, respectively.This article is published as Lents, C. A., C. Supakorn, A. E. DeDecker, C. E. Phillips, R. D. Boyd, J. L. Vallet, G. A. Rohrer et al. "Dietary lysine-to-energy ratios for managing growth and pubertal development in replacement gilts." Applied Animal Science 36, no. 5 (2020): 701-714. doi: 10.15232/aas.2020-02016.</p