Book Review

A. Funston, M. Gil & G. Gilmore (Eds). (2014). Strong starts, supportedtransitions and student success. UK: Cambridge Scholars Publishing.Reviewed by Birgit Schreiber

Impact of cow milk production on cow–calf performance in the Nebraska Sandhills

Livestock producers have tended to select for increased output traits like milk production and growth to increase productivity. Even with the increased selection for greater calf growth potential, some regions in the United States have seen a plateau in calf body weight (BW) at weaning (Lalman et al., 2019). When focusing on reaching maximum potential of these output traits, it is important to consider the multitude of variables that affect a production system. With increased milk production, nutrient requirements for cows become increased (Ferrell and Jenkins, 1984; Montaño-Bermudez et al., 1990), which may not be met if range and forage availability for grazing is already limited at meeting lactation demands. Historically, weaning weight and milk production have been associated with a positive relationship with greater milk production resulting in heavier calves at weaning (Clutter and Nielsen, 1987; Abdelsamei et al., 2005). In contrast, others have only observed the benefit of increased milk production improving calf performance within the first 60 d after birth (Clutter and Nielsen, 1987; Ansotegui et al, 1991; Edwards et al., 2017). Gleddie and Berg (1968) reported the correlation between average daily gain (ADG) of calves and milk yield estimates increased between the first and second month and continued to decrease thereafter as the forage consumption increased. The reliance on milk for dietary energy can result in increased calf BW at peak lactation (Edwards et al., 2017), but benefits of increased milk production may decrease as stage of lactation increases. Our hypothesis was that increasing milk production would negatively affect cow reproductive performance while having no effect on calf performance. Therefore, the objective of this study was to determine the impact milk production has on subsequent cow reproductive performance and calf performance throughout the preweaning and postweaning phases

Impact of cow milk production on cow–calf performance in the Nebraska Sandhills

Livestock producers have tended to select for increased output traits like milk production and growth to increase productivity. Even with the increased selection for greater calf growth potential, some regions in the United States have seen a plateau in calf body weight (BW) at weaning (Lalman et al., 2019). When focusing on reaching maximum potential of these output traits, it is important to consider the multitude of variables that affect a production system. With increased milk production, nutrient requirements for cows become increased (Ferrell and Jenkins, 1984; Montaño-Bermudez et al., 1990), which may not be met if range and forage availability for grazing is already limited at meeting lactation demands. Historically, weaning weight and milk production have been associated with a positive relationship with greater milk production resulting in heavier calves at weaning (Clutter and Nielsen, 1987; Abdelsamei et al., 2005). In contrast, others have only observed the benefit of increased milk production improving calf performance within the first 60 d after birth (Clutter and Nielsen, 1987; Ansotegui et al, 1991; Edwards et al., 2017). Gleddie and Berg (1968) reported the correlation between average daily gain (ADG) of calves and milk yield estimates increased between the first and second month and continued to decrease thereafter as the forage consumption increased. The reliance on milk for dietary energy can result in increased calf BW at peak lactation (Edwards et al., 2017), but benefits of increased milk production may decrease as stage of lactation increases. Our hypothesis was that increasing milk production would negatively affect cow reproductive performance while having no effect on calf performance. Therefore, the objective of this study was to determine the impact milk production has on subsequent cow reproductive performance and calf performance throughout the preweaning and postweaning phases

Bioeconomic Factors of Beef Heifer Maturity to Consider when Establishing Criteria to Optimally Select and/or Retain Herd Replacements

Understanding the biology of heifer maturity and its relationship to calving difficulty and subsequent breeding success is a vital step in building abioeconomic model to identify optimal production and profitability. A limited dependent variable probit model is used to quantify the responses among heifer maturities, measured by a maturity index (MI), on dystocia and second pregnancy. The MI account for heifer age, birth BW, prebreeding BW, nutrition level, and dam size and age and is found to be inversely related to dystocia occurrence. On average there is a 2.2% increase in the probability of dystocia with every 1 point drop in the MI between the MI scores of 50 and 70. Statistically, MI does not directly alter second pregnancy rate; however, dystocia does. The presence of dystocia reduced second pregnancy rates by 10.67%. Using the probability of dystocia predicted from the MI in the sample, it is found that on average, every 1 point increase in MI added 0.62% to the probability of the occurrence of second pregnancy over the range represented by the data. Relationships among MI, dystocia, and second pregnancy are nonlinear and exhibit diminishing marginal effects. These relationships indicate optimal production and profitability occur at varying maturities, which are altered by animal type, economic environment, production system, and management regime. With these captured relationships, any single group of heifers may be ranked by profitability given their physical characteristics and the applicable production, management, and economic conditions

Influence of Maternal Protein Restriction in Primiparous Heifers During Mid- and/or Late-gestation on Dam and Suckling Calf Performance

Nutrient status in gestating beef cows has been shown to impact performance of the dam and offspring; however, most research has focused on energy or a total diet restriction and a single period of gestation. The objective of this study was to evaluate the effects of maternal metabolizable protein (MP) restriction in primiparous heifers during mid- and/or late gestation on dam and suckling calf performance through weaning

Influence of Maternal Protein Restriction in Primiparous Heifers During Mid- and/or Late Gestation on Progeny Feedlot Performance and Carcass Characteristics

Maternal nutrient restriction in beef cows impacts developmental processes in the fetus that may influence lifetime performance. This study investigated impacts of metabolizable protein (MP) restriction in primiparous heifers during mid- and/or late-gestation on progeny feedlot performance and carcass characteristics

Influence of Maternal Protein Restriction in Primiparous Heifers During Mid- and/or Late-gestation on Meat Quality and Fatty Acid Profile of Progeny

The objective of this study was to evaluate the influence of metabolizable protein (MP) restriction in mid- and/or late-gestation on meat quality, fatty acid profile, and carcass composition of progeny

Electron Energy Loss Spectroscopy Investigation into Symmetry in Gold Trimer and Tetramer Plasmonic Nanoparticle Structures.

We present a combined scanning transmission electron microscopy-electron energy loss spectroscopy (STEM-EELS) investigation into the mode symmetries of plasmonic nanoparticle trimer and tetramer structures. We obtain nanometer-resolved energy loss spectra for both trimer and tetramer structures and compare these to boundary element method simulations. We show that EELS, in conjunction with eigenmode simulations, offers a complete characterization of the individual superstructures, and we trace the evolution of both optically dark and bright modes and identify multipolar mode contributions. We then apply this technique to tetramer structures that exhibit an expanded range of mode symmetries for two-dimensional and three-dimensional self-assembled geometries. These findings provide a comprehensive experimental account of the available photonic states in self-assembled nanoparticle clusters.University of Melbourne (MATS Scholarship), Ernst and Grace Matthaei (Research Scholarship), Gates Cambridge (Scholarship), Royal Society (Newton International Fellowship scheme), European Research Council under the European Union’s Seventh Framework Program (Grant IDs: FP7/2007-2013)/ERC Grant Agreement No. 291522-3DIMAGE, Integrated Infrastructure Initiative (Reference No. 312483-ESTEEM2), Australian Research Council (ARC) (Grant IDs: LF 100100117, FT110100545, DP120101573), Natural Sciences and Engineering Research Council (NSERC), Canada (Discovery grant)This is the author accepted manuscript. The final version is available from the American Chemical Society via http://dx.doi.org/10.1021/acsnano.6b0379

Performance, Carcass Characteristics, and Life Cycle Assessment of Cattle Grown Utilizing Different Combinations of Growth Promoting Technologies

The objective of this study was to determine the impact of different combinations of growth promoting technologies on live animal performance, carcass characteristics, and environmental outcomes