Feeding behavior of feedlot lambs fed diets containing levels of cassava wastewater

In this study, we evaluated the effects of including cassava wastewater in the diet on the feeding behavior of feedlot lambs in 35 male uncastrated Santa Inês × Dorper crossbred lambs at an approximate age of 3 months, with an average live weight of 20.0?±?3.4 kg. Diets were formulated with hay of cassava shoots (roughage) and a concentrate based on corn and soybean, with a roughage:concentrate ratio of 50:50, plus inclusion of cassava wastewater at the levels of 0, 12, 24, 36, or 48 g/kg of the total diet. Feeding behavior was evaluated between the 46th and 52nd days of the experiment. Increasing cassava wastewater levels in the diet reduced (P?<?0.05) the intakes (kg/day) of dry matter and neutral detergent fiber as well as the efficiency of rumination (g/cud and g/h) of dry matter and neutral detergent fiber. The other behavioral parameters were not affected by wastewater inclusion in the diet. Therefore, the inclusion of up to 48 g/kg of cassava wastewater on fresh matter of diets is not recommended for feedlot lambs.     

The impact of truncating data on the predictive ability for single‐step genomic best linear unbiased prediction

Simulated and swine industry data sets were utilized to assess the impact of removing older data on the predictive ability of selection candidate estimated breeding values (EBV) when using single‐step genomic best linear unbiased prediction (ssGBLUP). Simulated data included thirty replicates designed to mimic the structure of swine data sets. For the simulated data, varying amounts of data were truncated based on the number of ancestral generations back from the selection candidates. The swine data sets consisted of phenotypic and genotypic records for three traits across two breeds on animals born from 2003 to 2017. Phenotypes and genotypes were iteratively removed 1 year at a time based on the year an animal was born. For the swine data sets, correlations between corrected phenotypes (Cp) and EBV were used to evaluate the predictive ability on young animals born in 2016–2017. In the simulated data set, keeping data two generations back or greater resulted in no statistical difference (p‐value > 0.05) in the reduction in the true breeding value at generation 15 compared to utilizing all available data. Across swine data sets, removing phenotypes from animals born prior to 2011 resulted in a negligible or a slight numerical increase in the correlation between Cp and EBV. Truncating data is a method to alleviate computational issues without negatively impacting the predictive ability of selection candidate EBV.     

Comparative ecologies of domestic and naturalised rainbow trout in northern Lake Huron

Northern Lake Huron (Ontario, Canada) supports the largest concentration of freshwater salmonid cage culture farms in Canada and receives inputs of domestic‐strain rainbow trout (Oncorhynchus mykiss) through escapement. We assessed the potential effects of these domestic fish on the naturalised rainbow trout of this ecosystem by comparing their respective ecologies. Mature adults were sampled from spawning tributaries, primarily in spring, and to a lesser extent in fall. Fish of domestic origin comprised ~80% of rainbow trout sampled from sites near cage culture facilities but <20% of rainbow trout sampled from more distant sites. Domestic adults in spawning condition (gametes free‐flowing) were present in the spawning tributaries in both spring and fall sampling seasons, whereas naturalised fish in spawning condition were only observed in the spring. Domestic adults were younger and smaller (in length), appeared to have shorter lifespan and had a higher male to female ratio compared with their naturalised counterparts. Growth rates (change in length with age) of naturalised and domestic females in the wild were similar, but domestic males grew more slowly than naturalised males. Domestic females also produced smaller eggs than naturalised females. Food web positions (inferred from δ¹³C and δ¹⁵N) of domestic and naturalised fish were very similar but varied more strongly with body size in the former. Domestic‐strain rainbow trout of cage culture origin can survive, grow and attempt to spawn in northern Lake Huron and have the potential to compete for food, mates and spawning habitat with naturalised rainbow trout.     

Surgical repair of femoral fractures in New World camelids: five cases (1996-2003)

Five New World camelids were admitted to the Western College of Veterinary Medicine between 1996 and 2003 for evaluation of femoral fractures. There were three alpacas and two llamas. Four of the animals were female and three were less than 3 months of age. Fracture configurations consisted of distal physeal fractures (three), a comminuted diaphyseal/metaphyseal fracture, and a transverse diaphyseal fracture. Fractures were diagnosed with a combination of physical examination and radiographs in all cases. All five fractures were repaired with internal fixation and three animals were discharged from the hospital with fractures that healed. One cria underwent successful internal fixation but died from pulmonary oedema during recovery from anaesthesia. Postoperative complications were rare and limited to inadequate fracture stability in one alpaca and prolonged recovery to weight bearing in another. One llama with a comminuted metaphyseal fracture, repaired with a 4.5 mm dynamic compression plate, subsequently had catastrophic failure of the bone 17 days after surgery. Overall the clients were pleased with the outcome of discharged animals. Although femoral fractures are considered rare, they pose a unique opportunity for the large animal veterinarian to successfully achieve fracture union with the aid of internal fixation.