Mitigation of variability between competitively fed dairy cows through increased feed delivery frequency.

The objective of this study was to determine whether increased frequency of total mixed ration (TMR) delivery could mitigate the effects of feed bunk competition on the behavior and productivity of individual lactating dairy cows within a group. We hypothesized that, for competitively fed cows, a greater frequency of TMR delivery would improve access to feed, and reduce individual variability in behavior, meal patterns, and production between cows. Sixteen lactating Holstein dairy cows (first lactation = 4, second lactation = 5, ≥ third lactation = 7) averaging 72 ± 35 d in milk and producing 42 ± 6 kg of milk/d at the start of the trial, were categorized as either young (≤ second lactation) or mature (≥ third lactation) and paired to maximize difference in parity. Pairs were housed 4 at a time and competitively fed a TMR at a ratio of 2 cows:1 feed bin. Cow pairs were exposed, in a crossover design, to each of 2 feed delivery frequency treatments: low (2×/d) and high (6×/d) frequency. Treatments were applied for 10 d, with dry matter intake (DMI), feeding behavior (feeding time, feeding rate, and meal patterns), and replacement frequency for each cow recorded using an automated feed intake system on d 6 to 10 of each period. Rumination time, feed sorting, lying behavior, and productivity were also measured for this period. Variability in behavior within pairs of cows was determined by averaging the absolute difference within each pair over the recording period to provide 1 value per pair. Frequency of TMR delivery did not affect feeding time, feeding rate, DMI, replacement frequency, feed sorting, or productivity. At the high delivery frequency, there was a tendency for rumination time to increase [low = 519.3; high = 544.3 min/d; standard error of the difference (SED) = 11.32], and to be more variable within pairs (low = 38.0, high = 50.0 min/d; SED = 5.57). Cows also had longer lying bouts at the high delivery frequency (low = 53.0; high = 55.5 min/bout; SED = 1.00). No differences in daily meal patterns were found between treatments; however, the average first meal following each feeding indicated that cows under the high delivery frequency spent less time, consuming smaller meals during peak feeding periods. Comparing the young and mature individuals within each treatment pair revealed that feeding rate (young = 0.16; mature = 0.19 kg/min; SED = 0.014) and DMI (young = 25.6; mature = 28.6 kg of DM/d; SED = 1.36) were lower for the young cows on both treatments. Meal frequency was greater in young cows (young = 9.0; mature = 7.5 meals/d; SED = 0.71) and meal size was greater in mature cows (young = 3.2; mature = 4.2 kg of DM/meal; SED = 0.32) across treatments. These results suggest that for cows fed at a high level of competition, increasing TMR delivery frequency from 2 to 6×/d led to consumption of shorter, smaller meals during peak periods of feed consumption. However, under these conditions, the relative parity of competitively fed cows had a greater effect on feeding behavior, meal patterns, and production than did the frequency of feed delivery.

Feeding Behaviour and Bioavailability of Essential Amino Acids in Shrimp Penaeus monodon Fed Fresh and Leached Fishmeal and Fishmeal-Free Diets.

The complete replacement of fishmeal with terrestrial meals did not have a negative impact on the attractiveness, palatability, and apparent digestibility of the formulation. Shrimp were found on average to eat more and have similar appetite revival on the terrestrial meal-based formulation (TM) diet compared to the traditional fishmeal-based formulation (FM) diet. However, methionine (Met) and lysine (Lys) leached out rapidly from the TM diet, and as a result, this initially overfortified diet showed lower levels of those AA in comparison to FM after 60 min immersion. Both dietary Lys and Met were sub-optimal in TM within 120 min of immersion, whereas in comparison, the FM diet supplied consistent levels of EAA for up to 240 min immersion. Nonetheless, shrimp fed fresh TM had significantly higher peak haemolymph concentrations at 30 and 60 min for total AA, Met, and Lys than FM-fed shrimp. The over-supply of CAA far compensated leaching losses, and CAA were well absorbed and used by the shrimp within 120 min, with no obvious signs of asynchronous absorption of CAA to protein-bound AA. However, shrimp fed the TM diet that had leached out for 60 min, had haemolymph concentrations of Met and Lys that were only 41% and 44% of the ones on fresh feed respectively, while there was a negligible effect of leaching on FM. This study provides further insight into the feeding behaviour and bioavailability of dietary amino acids for P. monodon juveniles.

Behavioral Comparisons of Ingestion and Excretion by Selected Species of Pentatomids: Evidence of Feeding on Different Food Sources Supports Pest Status.

Laboratory studies were conducted on food ingestion and excretion by selected species of pentatomids on different food sources to support their pest status. We compared the frequency and time of feeding on vegetative (stem) and reproductive (seed) structures of soybean, Glycine max (L.) Merrill and of maize, Zea mays L. by Piezodorus guildinii (Westwood), Dichelops melacanthus (Dallas), and Edessa meditabunda (F.); in addition, the amount of excreta (feces) produced were compared for D. melacanthus feeding on seed of soybean and stem of maize seedling. The feeding behavior of E. meditabunda and P. guildinii on soybean, and of D. melacanthus on maize was recorded using the electropenetrography (EPG) technique. Excretion was estimated using water sensitive paper recording number and area of fecal drops. Results indicated that E. meditabunda on soybean stem repeated events of ingestion (both xylem and phloem sap) over four times per bug during the 8 h of recording for ca. 53 min per event. Dichelops melacanthus on maize seedling repeated each ingestion event over three times per bug for ca. 24 min per event. Piezodorus guildinii feeding on soybean stem repeated each ingestion 1.2 times per bug for ca. 40 min per event; on seed endosperm, it fed for a longer time, ca. 80 min per event, each event repeated only 0.5 times per bug. Number of excretory drops was higher (9.9 drops per bug) when D. melacanthus fed on maize seedling than on soybean seed (1.4 drops per bug). A larger amount of saliva/regurgitate liquid food was expelled when bugs fed on the former than on the later food.

Daily feeding regimen impacts pig growth and behavior.

A primary swine production goal is to increase efficiency of lean tissue gains. While many swine production systems currently utilize ad libitum feeding, recent research suggests that altering feeding patterns may impact feed efficiency. Therefore, the objective of this study was to compare two feeding patterns and evaluate their impact on whole body tissue accretion, feeding behavior and activity in growing pigs. Forty eight individually housed gilts (55.9±5.2kg on test BW) were assigned into one of two feeding treatments: 1) Free access to the feeder (Free Access) or 2) twice daily access where gilts were allowed to eat ad libitum between 08:00-09:00h and again from 17:00-18:00h (2×). Pig performance was recorded weekly for 55days and average daily gain (ADG), average daily feed intake (ADFI), and gain:feed (G:F) was calculated. Body composition was assessed in 12 gilts per treatment using dual X-ray absorptiometry (DXA) at day -3 and 55 of treatment, and tissue accretion rates were calculated. Gilt behaviors were assessed via video analysis during week 7 and included time spent eating, feeding rate, enrichment interaction, postural changes, standing, sitting, and lying behaviors. Gilts fed 2× had lower ADG and ADFI compared to Free Access gilts (P≤0.01); however, no treatment difference in G:F was observed (P=0.83). At day 55 gilts fed 2× had a lower fat:protein compared to Free Access gilts (P=0.05). Fat, lean, and protein accretion rates were lower in gilts fed 2× compared to those fed Free Access (P=0.01). Gilts fed 2× ate less frequently and for a shorter duration of time, interacted with enrichment more frequently (P≤0.005), and tended to have less frequent postural changes compared to Free Access gilts (P=0.08). No treatment differences were observed in duration of time spent standing, sitting, or lying (P≥0.39). Although feed regimen did not alter feed efficiency, these data indicate that twice daily feeding reduced gilt adiposity and growth without altering the pig's behavioral expression of hunger. Therefore, twice daily feeding may be a method of increasing percent of lean tissue without negatively impacting gilt welfare.