Effect of Feeding Procedure and Intake Level on Steer Feedlot Performance and Carcass Composition: A Progress Report

Two feedlot trials were conducted to evaluate the effects of feeding frequency (once daily in the morning, once daily in the afternoon or twice daily) and feeding level (ad libitum, 95% of ad libitum, or 90% of ad libitum) on the feedlot performance and carcass composition of beef steers. Data were collected using 196 yearling beef steers. In both trials cattle fed once daily in the morning tended to have higher gains and better feed efficiencies than cattle fed once daily in the afternoon or cattle fed twice daily. Overall, cattle restricted to 95% and 90% of ad libitum intake levels had better feed efficiencies than cattle with ad libitum access to feed. Cattle fed once daily in the morning tended to have less backfat than cattle fed once daily in the afternoon or cattle fed twice daily.

Effects of Feeding Cobalt Dextro Lac (CDL) on Feedlot Performance and Carcass Value of Finishing Steers Fed Wet Corn Gluten Feed

A 192-day experiment involving 144 young Angus steers fed growing and finishing diets containing 20% corn gluten feed was conducted to evaluate feeding a soluble source of readily available cobalt. No benefits were observed in rate of gain, feed intake or carcass value by feeding the available source of cobalt.

The Effects of Feeding a Live Microbial Product on Feedlot Performance and Carcass Value of Finishing Steers Fed Wet Corn Gluten Feed

This experiment was conducted to evaluate the efficacy of daily feeding a live microbial preparation containing two live organisms to finishing cattle. One organism was a lactobacillus, and the other was a propionibacterium, thought to work in concert to improve fermentation in the rumen and overall digestion. The study was conducted with Angus steers with an average initial weight of 550 lbs that were fed a finishing ration containing 50% wet corn gluten feed on a dry basis for 184 days. Feeding the microbial product improved daily gain and feed efficiency 1.7% and 2.4%, respectively, but the differences were not statistically significant. The microbial preparation increased carcass weights 1% but had no effects on quality or yield grades. It is concluded that potential benefits of this product are more likely to be greater when cattle are fed high grain rations rather than diets containing high concentrations of corn gluten feed.

Programmed Feeding of Protein to Finishing Beef Steers

Six-hundred pound Angus steer calves were fed cornbased finishing diets for 180 days to determine the effects of stepwise reduction of protein in the diet on performance and carcass characteristics. Reducing protein in the diet, but satisfying the requirements projected by the National Research Council model for Nutrient Requirements of Beef Cattle, did not affect performance or carcass measurements. Further reduction in protein content of the diet, so the projected requirement of the rumen microorganisms was not being met, did not affect performance or carcass measurements. It is concluded that quantity of protein fed to finishing cattle can be programmed and abstantially reduced. These reductions will result in substantially less nitrogen excreted in manure from larger feedlots.

Relative Feeding Value of Wet Corn Steep Liquor When Fed to Finishing Cattle

Corn steep liquor is a liquid by-product containing condensed steep water and condensed distillers solubles from a wet corn milling plant. Finishing steers weighing nine hundred and seventy-five pounds were fed cornbased finishing diets containing 0%, 6%, or 12% corn steep liquor for 84 days. Feeding corn steep liquor did not affect performance of the steers or carcass characteristics. Based on value of feeds replaced in the diet, steep liquor had a value of $55 to $60/ton (50% dry matter) when used to replace corn and supplemental protein in a corn-based finishing diet.

Relative Feeding Value of Wet Corn Distillers Solubles as a Feed for Finishing Cattle

For 126 days, 850 lb. steers were fed diets of corn, corn silage, and ground hay containing either 0%, 4%, or 8% wet distillers solubles obtained from an Iowa dry mill ethanol plant. Addition of distillers solubles resulted in a linear decrease in feed consumption. Gains were increased 3.2% and decreased 6.4% by feeding 4% and 8% distillers solubles, respectively. Compared to the control diet, feed required per pound of gain was reduced 5% by low levels of distillers solubles and 1.5% by high levels. Feeding distillers solubles had no effect on carcass measurements. It was concluded that wet distillers solubles has value as a feed for cattle and can replace a portion of corn grain and supplemental nitrogen in a corn-based finishing diet for beef cattle. The decreased performance of steers fed the 8% level suggests that there might be a maximum amount of wet distiller solubles that can be fed to finishing cattle.

Long Versus Short Feeding Period for Steer Calves of Three Frame Sizes Fed High Energy Finishing Diets

An experiment was conducted using Angus cross steer calves of three frame sizes (small, medium, and large) to compare performance of two different grow/finish feeding programs. Half of the cattle in each frame size group were fed a high energy ration through the growing period, similar to calves going directly into the feedlot. The other half was fed a low energy ration, similar to a backgrounding diet, for a period prior to the finishing phase. All cattle were fed a high energy ration through the finishing period. The data showed the cattle fed the low energy growing diet experienced some compensatory gains as shown by ultrasound backfat and average daily gains coupled with intakes greater than the increases seen in the high energy treatment. Carcass data and overall performance data showed no ill effects due to the low energy growing ration.

Beef Cow Feeding Demonstration

Pregnant mature beef cows were fed one of five rations: tub ground hay, low corn supplementation plus hay, high corn plus hay, low corn gluten feed (CGF) pellets plus hay, and high CGF plus hay. All treatments resulted in weight gains and limited body condition score changes. The hay and high CGF pellet diet resulted in statistically different weight gains compared with the other supplementation programs.

Effects of Feeding Calcium Salts of Conjugated Linoleic Acid (CLA) to Finishing Steers

Thirty crossbred steers were randomly assigned to three treatment groups and fed corn-based finishing diets (88% concentrate) containing 0, 1.0 or 2.5% conjugated linoleic acid (CLA) for an average of 130 days. Steers fed 2.5% CLA consumed less feed and had lower daily gains than control steers. Carcass weights tended to be reduced, and marbling scores were decreased by feeding 2.5% CLA. There were no significant effects of feeding CLA on dressing percentages, yield grades and backfat measurements. The rounds from each animal were physically separated into tissue components. Rounds from steers fed CLA contained a higher percentage of lean tissue and a lower percentage of fat. Feeding CLA increased concentrations of CLA in lipids from fat and lean in rib steaks and rounds. Increasing CLA in beef had no effects on shelf life, tenderness, juiciness, flavor or flavor intensity of rib steaks. Although results indicated that feeding calcium salts of CLA to beef steers decreased performance, concentrations of CLA in tissues could be increased offering the availability of a leaner, more healthful meat product.

Effects of different types of solid feeds on health status and performance of Swiss veal calves. II. Basic feeding with whole milk

The objective of this study was to identify a suitable alternative to the current practice of complementing the feeding of whole milk with straw. The influence of 3 different solid supplements on the health and performance of Swiss veal calves was investigated during 3 production cycles of 90 veal calves each with a mean initial age of 42 days and a mean initial weight of 68.7 kg. The calves were housed in groups of 30 in stalls strewn with wheat straw without outside pen. Liquid feeding consisted of whole milk combined with an additional skim milk powder ad libitum. Groups were assigned to one of the three following experimental solid feeds provided ad libitum: Pellet mix (composition: oat hulls, corn [whole plant], barley, sunflower seeds, squeezed grains of corn, molasses and a pellet binder), whole plant corn pellets, and wheat straw as control. Calves of the straw group showed significantly more abomasal lesions in the fundic part as compared to the pellet mix and corn pellets groups (P < 0.001), the prevalence of insufficient papillae was highest (P < 0.05), and ruminating behavior was unsatisfactory. In contrast to the pellet mix and straw groups, performance of calves in the corn pellets group was good. Additionally, prevalence of abomasal fundic lesions was lowest (P < 0.001), and rumen development was best in calves of the corn pellets group (P < 0.01). As in part I, the results reveal that whole-plant corn pellets are most consistent with an optimal result combining the calves' health and fattening performance. Therefore, it can be recommended as a solid supplement for veal calves basically fed whole milk under Swiss conditions.

Effects of different types of solid feeds on health status and performance of Swiss veal calves. I. Basic feeding with milk by-products

The objective of this study was to identify a suitable alternative to the current practice of complementing the feeding of milk by-products with straw. The influence of 5 different types of solid feeds on health and performance of Swiss veal calves was investigated in 2 production cycles of 200 veal calves each with a mean initial age of 40 days (d). The calves were housed in groups of 40 in stalls with outside pen. Liquid feeding consisted of a milk by-product combined with an additional skim milk powder ad libitum. Groups were assigned to 1 of the 5 following experimental solid feeds provided ad libitum: mix (composition: soy flakes, corn, barley, wheat, oat, barley middling, plant oil, molasses), whole plant corn pellets, corn silage, hay, and wheat straw as control. Daily dry matter intake per calf averaged 2.25 kg of the liquid food, 0.16 kg of straw, 0.33 kg of mix, 0.47 kg of corn silage, 0.38 kg of corn pellets, and 0.39 kg of hay. No significant differences (P > 0.05) among groups were found in calf losses that amounted to 4.8 % (68 % because of gastrointestinal disorders). Four percent of the calves were slaughtered prematurely. Daily doses of antibiotics were higher in the mix (36.9 d, P < 0.01) and in the corn silage groups (35 d, P < 0.01) compared to control. Compared to the 4 other groups, calves of the straw group showed the highest prevalence of abnormal ruminal content (73 %, P < 0.05), of abnormal ruminal papillae (42 %, P < 0.05), of abomasal fundic lesions (13.5 %, P < 0.1), and the lowest number of chewing movements per bolus (45, P < 0.05). The hemoglobin concentration averaged 85 g/l at the beginning and 99 g/l at the end of the fattening period with no significant differences among groups (P > 0.1). The duration of the fattening period averaged 114 d, slaughter age 157 d, and carcass weight 122 kg. The average daily weight gain (ADG) was highest in the control group straw (1.35 kg), and lowest in the hay group (1.22 kg, P < 0.01). The number of carcasses classified as C, H, and T (very high to medium quality) was lower in the hay group compared to straw (P < 0.01). No significant differences between groups were found in meat color (P > 0.1): 73 % of the carcasses were assessed as pale (267/364), 18 % as pink (66/364), and 9 % (31/364) as red. The results reveal that whole-plant corn pellets are most consistent with an optimal result combining the calves' health and fattening performance. Therefore, it can be recommended as an additional solid feed for veal calves under Swiss conditions.

Adaptive plasticity and genetic divergence in feeding efficiency during parallel adaptive radiation of whitefish (Coregonus spp.)

Parallel phenotypic divergence in replicated adaptive radiations could either result from parallel genetic divergence in response to similar divergent selec- tion regimes or from equivalent phenotypically plastic response to the repeated occurrence of contrasting environments. In post-glacial fish, repli- cated divergence in phenotypes along the benthic-limnetic habitat axis is commonly observed. Here, we use two benthic-limnetic species pairs of whitefish from two Swiss lakes, raised in a common garden design, with reciprocal food treatments in one species pair, to experimentally measure whether feeding efficiency on benthic prey has a genetic basis or whether it underlies phenotypic plasticity (or both). To do so, we offered experimental fish mosquito larvae, partially burried in sand, and measured multiple feed- ing efficiency variables. Our results reveal both, genetic divergence as well as phenotypically plastic divergence in feeding efficiency, with the pheno- typically benthic species raised on benthic food being the most efficient forager on benthic prey. This indicates that both, divergent natural selection on genetically heritable traits and adaptive phenotypic plasticity, are likely important mechanisms driving phenotypic divergence in adaptive radiation.

Energetics of byssus attachment and feeding in the green-lipped mussel Perna canaliculus.

In most animals, significant increases in metabolic rate are due to activity and to feeding (known as apparent specific dynamic action). We determined the energetic costs of activity and feeding in adult green-lipped mussels (Perna canaliculus). Maximal metabolic rate was determined, using closed-chamber respirometry, during byssus re-attachment, during specific dynamic action after 16 h of feeding with Isochrysis galbana, and for the two activities combined, in 23 mussels. Metabolic rate was significantly elevated above rest by about 1.9-fold during byssus attachment (17.1 ± 1.53 μg O(2) h(-1) g(-1) whole mussel wet weight at rest, increased to 27.9 ± 0.91 μg O(2) h(-1) g(-1)), and by 2.2-fold after feeding (31.4 ± 1.20 μg O(2) h(-1) g(-1)). Combined feeding and byssus attachment led to a still higher metabolic rate (34.0 ± 1.23 μg O(2) h(-1) g(-1)). Behavior was also significantly altered, with mussels being almost continuously open during attachment and after feeding (90%-99% of the time); however, the time spent open during the day decreased, reaching a minimum of 52% ± 9% 3 days after feeding, and remained low (67%-82%) for the following 45-day starvation period. Significant diurnal differences were observed, with mussels continuously (92%-100%) open at night. The key findings from this study are that green-lipped mussels (1) have an aerobic scope of approximately 2-fold; (2) reach a higher metabolic rate during feeding than during activity, and the two combined can raise the metabolic rate higher still; (3) display a marked diurnal behavior.

Does the choice of bottle nipple affect the oral feeding performance of very-low-birthweight (VLBW) infants?

BACKGROUND: There is a continuous debate regarding the best bottle nipple to be used to enhance the bottle-feeding performance of a preterm infant. Aim: To verify that feeding performance can be improved by using the bottle nipple with the physical characteristics that enhance infants' sucking skills. METHODS: Ten "healthy" VLBW infants (941+/-273 g) were recruited. Feeding performance was monitored at two time periods, when taking 1-2 and 6-8 oral feedings/d. At each time and within 24 h, performance was monitored using three different bottle nipples offered in a randomized order. Rate of milk transfer (ml/min) was the primary outcome measure. The sucking skills monitored comprised stage of sucking, suction amplitude, and duration of the generated negative intraoral suction pressure. RESULTS: At both times, infants demonstrated a similar rate of milk transfer among all three nipples. However, the stage of sucking, suction amplitude, and duration of the generated suction were significantly different between nipples at 1-2, but not 6-8 oral feedings/d.CONCLUSION: We did not identify a particular bottle nipple that enhanced bottle feeding in healthy VLBW infants. Based on the notion that afferent sensory feedback may allow infants to adapt to changing conditions, we speculate that infants can modify their sucking skills in order to maintain a rate of milk transfer that is appropriate with the level of suck-swallow-breathe coordination achieved at a particular time. Therefore, it is proposed that caretakers should be more concerned over monitoring the coordination of suck-swallow-breathe than over the selection of bottle nipples.

Maturation of oral feeding skills in preterm infants.

AIM: Safe and successful oral feeding requires proper maturation of sucking, swallowing and respiration. We hypothesized that oral feeding difficulties result from different temporal development of the musculatures implicated in these functions. METHODS: Sixteen medically stable preterm infants (26 to 29 weeks gestation, GA) were recruited. Specific feeding skills were monitored as indirect markers for the maturational process of oral feeding musculatures: rate of milk intake (mL/min); percent milk leakage (lip seal); sucking stage, rate (#/s) and suction/expression ratio; suction amplitude (mmHg), rate and slope (mmHg/s); sucking/swallowing ratio; percent occurrence of swallows at specific phases of respiration. Coefficients of variation (COV) were used as indices of functional stability. Infants, born at 26/27- and 28/29-week GA, were at similar postmenstrual ages (PMA) when taking 1-2 and 6-8 oral feedings per day. RESULTS: Over time, feeding efficiency and several skills improved, some decreased and others remained unchanged. Differences in COVs between the two GA groups demonstrated that, despite similar oral feeding outcomes, maturation levels of certain skills differed. CONCLUSIONS: Components of sucking, swallowing, respiration and their coordinated activity matured at different times and rates. Differences in functional stability of particular outcomes confirm that maturation levels depend on infants' gestational rather than PMA.