Diet selection and eating behaviour of lactating goats subjected to time restricted feeding in choice and single feeding system

This study was carried out to investigate diet selection and eating behaviour of lactating German Fawn × Hair Crossbred goats in different feeding methods and levels. Twenty German Fawn × Hair first backcross does (B₁) were allocated into 4 treatment groups (2 feeding methods single (TMR) and choice feeding × 2 feeding levels ad libitum and restricted) with 5 replicates. Restricted feeding was applied only 4 h feed allocation during day. Barley, corn, soybean meal, corn gluten meal, wheat bran and alfalfa hay were feed ingredients for single and choice feeding. Eating patterns, milk yield and composition were determined for 8 weeks. The following results were obtained: (1) the meal criteria for goats restricted single and choice-fed, ad libitum single and choice-fed were determined as 1.00 and 0.63, 12.88 and 10.23 min, respectively. (2) Ad libitum feeding increased meal size, meal length, intermeal interval, total eating duration and decreased eating rate and meal number, compared to restricted feeding (P < 0.01). Choice feeding decreased meal size (P < 0.05), meal length (P < 0.01) and increased eating rate and meal number (P < 0.01), compared to single feeding. Restricted fed goats decreased intermeal interval in single feeding compared to choice feeding (P < 0.01), but increased meal number in choice feeding (P < 0.01). (3) Ad libitum choice-fed does made a diet containing 12.79% corn, 35.41% barley, 13.21% wheat bran, 5.35% soybean meal, 1.28% corn gluten meal and 29.80% alfalfa meal while restricted choice-fed does made a diet having more corn (27.69%), corn gluten meal (5.62%) and wheat bran (16.17%) and less barley (14.37%) and soybean meal (4.51%). (4) Choice feeding decreased RUP intake (P < 0.05) without affecting milk protein, irrespective to feeding levels, while having a tendency to increase in milk yield (14.2%) and 4% FCM (8.8%). (5) Restricted feeding decreased DM, ME, ADF and NDF intakes (P < 0.05) with concomitant decreases in 4% FCM, total milk solid, ash and fat compositions (P < 0.05), irrespective to feeding methods. (6) Choice-fed goats changed their preferences for a possible synchronized nutrient intake during a daytime, as sorted barley, soybean meal and alfalfa hay from early morning to late afternoon.It could be concluded that choice-fed goats have the ability to make their diet to meet nutrient requirements and had a tendency to increase in milk yield. Restriction in feeding time resulted in lower feed intake and milk yield, although the animal changed their feed preference in favour of high quality ingredients and eating pattern with lower meal criterion and intermeal interval.     

Effects of untreated and heat-treated canola presscake on milk yield and composition of dairy cows

Five primiparous and five multiparous Holstein cows were used in two Latin square design experiments to determine effects of feeding unheated and heated canola presscake on milk yield and composition, and milk fatty acid concentrations of lactating dairy cows. Five diets that differed in level and source of dietary fat were formulated: a low fat control diet with 30 g kg⁻¹ fat from tallow, an unheated canola presscake supplemented diet (50 g kg⁻¹ fat), a heated canola presscake supplemented diet (50 g kg⁻¹ fat), a high tallow plus unheated canola meal supplemented diet (50 g kg⁻¹ fat), and a high tallow plus heated canola meal supplemented diet (50 g kg⁻¹ fat). In sacco ruminal degradability of heated and unheated canola presscake was compared with that of heated and unheated canola meal in a randomized complete block design using two ruminally fistulated cows. Heat treatment reduced ruminal DM and CP degradability of canola presscake. Multiparous cows fed diets supplemented with heated or unheated canola presscake produced more milk than those fed diets containing similar levels of fat from tallow with heated or unheated canola meal, respectively. High levels of fat from any diet reduced milk fat percentage for cows of either parity. Feeding heated canola products increased milk and milk protein yields in primiparous cows only, but cows of both parities fed diets containing canola presscake produced milk with lower concentrations of C12:0, C14:0, and C16:0 fatty acids than cows fed the canola meal and tallow diets, although concentrations of C18:1 n-9 were unaffected by fat source or level. Feeding canola products to dairy cows can alter milk fatty acid profile, but only primiparous cows have increased productivity as a result of feeding heated, versus unheated, canola presscake.     

The influence of dry period feeding on liver fat and postpartum performance of dairy cows

Animal performances were monitored in 30 Friesean dry cows (18 multiparous, MP-cows and 12 primiparous, PP-cows) starting six weeks before calving to eight weeks after calving. The cows were kept indoors and fed individually with a prepartum diet containing either low, moderate or high energy (0.75, 1.00 or 1.25 of the calculated ME requirement) and supplemented with low (0.3 kg day⁻¹) or high (1.5 kg day⁻¹) rapeseed meal (RSM). The diets were consisted of 1.5 kg hay, 20–25 kg wilted grass silage and grain (barley and oat, 1 : 1 DM basis) with RSM. The average ME intake during six weeks of prepartum was 75, 97 and 123 MJ day⁻¹ on three different energy levels. After calving the cows were fed grass silage ad lib, 6.5 kg (primiparous) or 8.5 kg (multiparous) grain and 1.5 kg RSM. Liver biopsy and blood samples were taken to determine differences in metabolites due to diet and parity. Reduction of prepartum energy allowance to 0.75 of the moderate level did not affect the calf's birth weight and colostrum composition. Cows fed prepartum low energy–high rapeseed meal diet (LEHR) showed a faster increase in feed intake and milk production after parturition. Continuous low feed intake and milk production were observed in cows fed a prepartum high energy–low rapeseed meal diet (HELR). Milk yield was constantly lower for cows fed prepartum high energy diet, the difference being significant (p<0.01 and p<0.05) at six and seven weeks of lactation. Overall milk yield also showed a linear decrease with energy feeding level and an increase (p<0.10) with RSM feeding levels. Prepartum high energy feeding increased (p<0.01) milk protein content. Neither energy nor RSM feeding level affected the liver fat infiltration of the experimental cows. Cow parity however showed a significant influence on liver fat content, β-hydroxybutyrate (BHBA) and plasma glucose. A week before calving, the plasma concentration of essential amino acids (EAA) was lower for cows fed prepartum low energy diet. During the first four weeks of lactation, the concentrations of plasma non-esterified fatty acids (NEFA) and insulin were similar for all the treatment group.     

The effect of breed and housing system on dairy cow feeding and lying behaviour

In Ireland there is growing interest in managing dairy cows on out-wintering pads (OWPs) during the winter, as a low cost alternative to housing indoors. This study investigated feeding and lying behaviour of two breeds of dairy cow (Holstein-Friesian and Norwegian Red) at pasture (PAS) and in winter (WIN) confinement. Cows (n = 36) were managed as one herd while lactating at PAS, then dried off on entering WIN on 17 November 2005 and assigned to one of the three treatments using a randomised complete block design: (1) indoor matted cubicles [IC], (2) unsheltered OWP [UP] and (3) sheltered OWP [CP] (feed system = concrete feedface). Feeding behaviour was recorded for 1 × 24 h period during PAS and WIN using IGER grazing behaviour recorders. Standing/lying was recorded every 5 min for 2 × 24 h periods at PAS and 1 × 24 h period during WIN using modified voltage dataloggers (Tinytag Plus, Chichester, UK). Although not compared statistically, cows spent more time feeding at PAS (530.7 ± 69.66 min/day) than in any winter confinement system (UP, IC, CP = 453.9 ± 37.36, IC = 462.7 ± 37.31 and CP = 505.9 ± 37.36 min/day). In contrast, cows spent more time lying during the winter period (UP, IC, CP = 11.7 ± 0.45, IC = 10.8 ± 0.39 and CP = 11.0 ± 0.39 h/day) than when at PAS (9.4 h/day). Holstein-Friesian cows had a higher bite rate and fewer mastications while feeding, than Norwegian Red cows (P < 0.05 for both). Shorter feeding times at WIN were likely primarily due to lower metabolic requirements associated with the dry period, although the higher fibre content of the silage may also have contributed. The increase in ruminating times between PAS and WIN is likely also due to the higher fibre content of silage than grass. Differences in feeding behaviour between breeds may be indicative of reduced motivation to ingest food quickly. This may be an indirect consequence of a selection index that has led to improvements in body condition and self-maintenance. The similarity in lying and feeding times during WIN indicates that during these winter weather conditions the feeding and lying behaviour of cows on unsheltered OWPs was not inhibited compared with sheltered cows.     

Effect of suplemental nitrogen source and feeding frequency on nutrient supply to lambs fed a kikuyu grass (Pennisetum clandestinum) hay-based diet

Eight castrated male lambs (35 ± 4 kg live weight), fed a basal diet of kikuyu grass hay, were used in a replicated 4 × 4 Latin Square experiment with a 2 × 2 factorial arrangement of treatments to evaluate the effect of supplemental feeding frequency and source of rumen degradable N on intake, digestibility, ruminal fermentation, and microbial protein yield. Treatments were supplementation with cassava meal plus calcium caseinate or cassava meal plus urea offered at a rate of 7 g/kg live weight daily in one or two meals per day. Lambs were fed twice daily in such manner to allow ad libitum comsumption of forage. There was significant feeding frequency by N source interaction on variables of intake. In general, intake of feed components was higher (P ≤ 0.05) by lambs offered the caseinate-supplement twice daily over intake observed in lambs given the others diet treatments. Digestibility of feed components was neither affected by supplemental N source (DM, P = 0.541; OM, P = 0.585; NDF, P = 0.828) nor by feeding frequency (DM, P = 0.122; OM, P = 0.175; NDF, P = 0.591). Urinary excretion of N increased (P ≤ 0.05) in lambs supplemented twice daily whereas N retention was similar for all treatments (N source, P = 0.748; feeding frequency, P = 0.418). Microbial protein entering into the small intestine was affected by the interaction between feeding frequency and N source such as an increasing (P < 0.10) in this variable was observed when lambs received the caseinate but not the urea supplement twice daily. Efficiency of microbial protein synthesis, however, was not affected by treatments (N source, P = 0.588; feeding frequency, P = 0.334). Rumen pH averaged 6.70 and it was neither affected by N source (P = 0.827) nor by feeding frequency (P = 0.740). Ruminal concentration of ammonia N was not affected by feeding frequency (P = 0.144) while it increased (P < 0.05) when urea rather than caseinate was the supplemental N source (mean of 7.61 mg/dl vs. 6.00 mg/dl). Concentration of sugars in rumen fluid was higher (P ≤ 0.05) in lambs supplemented once a day compared to twice daily (mean of 49.4 mg/dl vs. 34.4 mg/dl) for both N sources. A significant (P ≤ 0.05) N source by feeding frequency interaction effect was observed for ruminal concentrations of α-amino N compounds. In urea treatment α-amino N concentration increased (P ≤ 0.05) in lambs receiving the supplement twice daily compared to once a day (mean of 4.59 mg/dl vs. 3.70 mg/dl) while in caseinate treatment it was higher (P ≤ 0.05) in lambs offered the supplement in one meal per day compared to twice daily (mean of 5.29 mg/dl vs. 4.07 mg/dl). In conclusion, for ruminants fed a tropical grass-based diet, starch-rich supplement containing non-protein N as N source may be offered only once a day whereas the supply of nutrients may be improved if degradable true protein is included as N source and supplement is offered in two meals per day.     

Feeding soybean meal increases the blood level of isoflavones and reduces the steroidogenic capacity in bovine corpora lutea,without affecting peripheral progesterone concentrations

Thirty-three Holstein-Friesian cows were followed from 14 days pre partum until the fourth ovulation post partum. Housing conditions and basic ration were identical for all animals. Concentrates were individually supplemented according to the daily milk production level, using two different types of protein rich concentrates: soybean meal and rapeseed meal. Soybean and rapeseed meal are known to be respectively high and low in isoflavones. Cows were randomly divided into three groups and blocked for parity. Group I (n = 11) was supplemented with soybean meal and acted as control group. Groups II (n = 11) and III (n = 11) were respectively supplemented with soybean and rapeseed meal and were subjected to a biopsy sampling of the corpus luteum at day 9 of the first three postpartal estrous cycles.Soybean meal supplementation to lactating dairy cows (1.72 kg on average) induced an increase in the blood concentration of equol, dihydrodaidzein, o-desmethylangolensin in both soy groups and resulted in a reduced area occupied by steroidogenic (P = 0.012) and endothelial cells (P = 0.0007) in the luteal biopsies. Blood concentrations of equol and glycitein were negatively correlated with the areas occupied by steroidogenic (r = −0.410 with P = 0.0002, respectively r = −0.351 with P = 0.008) and endothelial cells (r = −0.337 with P = 0.01, respectively r = −0.233 with P = 0.085) in the 3 first estrous cycles. The latter however did not affect the diestrous peripheral blood progesterone concentration.     

Effect of feeding schedule on apparent energy and amino acid digestibility by growing pigs

An experiment was conducted to investigate the effects of feeding schedule on dry matter (DM), gross energy (GE), crude protein (CP), and amino acid (AA) digestibility by growing pigs. Six growing castrates (initial body weight: 40.5 ± 2.25 kg) were equipped with a T-cannula in the distal ileum and allotted to a repeated 3 × 3 Latin square design with three animals and three periods in each square. A maize–soybean meal based diet (181 g CP/kg) was formulated and fed to the pigs in three different feeding schedules; i.e., one meal per day, two meals per day, or free access to feed. Pigs fed one or two meals per day were allotted a daily amount of feed equivalent to three times the maintenance energy requirement. Fecal and ileal samples were collected from all pigs in each period. The coefficients of ileal apparent digestibility (CIAD) for DM, GE, CP, and AA were calculated as were the coefficients of total tract apparent digestibility (CTTAD) of DM and GE. Results of the experiment showed that there were no differences in the CIAD for DM, GE, or for any of the AA among the three feeding schedules. In contrast, pigs given free access to the diet had lower (P<0.002) CTTAD for DM and GE compared with pigs fed a restricted amount of feed either once or twice daily. Therefore, the concentration of digestible energy in the diet was lower if calculated from pigs given free access to the diet compared with pigs fed the diet once or twice daily (14.38 MJ/kg versus 14.83 MJ/kg and 15.13 MJ/kg). It is concluded that the feeding schedule does not influence the CIAD for DM, GE, CP, or AA by pigs. Therefore, any of the three feeding schedules that were used in the current experiment may be used in experiments aimed at measuring CIAD in pigs. However, if the CTTAD of DM and GE are measured, it is recommended that pigs are given free access to feed.     

Effect of moist heat treatment on in-vitro degradability and ruminal escape protein and amino acids of mustard meal

A study was conducted to determine the effects of moist heat treatment (127°C, 117 kPa steam pressure) for 10 min on protein fractions and in-vitro crude protein (CP) degradability of mustard meal. Rumen undegraded protein (RUP) and amino acid disappearance of unheated, and heated, mustard meal were measured following 12 h of rumen incubation using two ruminally fistulated cows. Intestinal availability of RUP was estimated using an enzymatic (pepsin–pancreatin) procedure. Heat treatment reduced (p<0.05) protein solubility and increased (p<0.05) neutral detergent insoluble CP without affecting acid detergent insoluble CP of mustard meal. Relative to the control, heated mustard meal had a lower (p<0.05) effective in-vitro CP degradability (445.2 vs. 746.8 g kg⁻¹ of CP) and a higher (p<0.05) ruminal escape CP (615.1 vs. 120.2 g kg⁻¹ of CP) value. Amino acid composition was not affected by heat treatment except for the concentration of arginine and lysine which was lower (p<0.05) in heated than in unheated mustard meal. Disappearance of all amino acids following 12 h of rumen incubation was lower (p<0.05) in unheated than in heated mustard meal. Heat treatment increased (p<0.05) the amount of protein available for digestion in the small intestine from 75.7 to 518.1 g kg⁻¹ of CP. It was concluded that moist heating of mustard meal for 10 min will reduce ruminal CP and amino acid degradability without compromising the intestinal availability of ruminal undegraded protein.     

Heat treatment of soybean meal and rapeseed meal suppresses rumen degradation of phytate phosphorus in sheep

The effect of heat treatment on rumen degradation of phytate in soybean meal and rapeseed meal was studied on three sheep fitted with rumen cannula. Soybean meal and rapeseed meal were roasted at 133°, 143° or 153°C for 3 h and the rumen degradation of phytate phosphorus in untreated and heat treated oilseed meals was examined using the nylon-bag technique. Effective degradability of phytate phosphorus in soybean and rapeseed meals, estimated at ruminal outflow rates of 0.02, 0.05 and 0.08 h⁻¹, was significantly (p < 0.05) reduced by heat treatment. The reduction was more marked in rapeseed meal than in soybean meal. These results suggest that heat processing of oilseed meals suppresses phytate degradation in the rumen and leads to a low availability of dietary phytate phosphorus.     

Biostable insect kinin analogs reduce blood meal and disrupt ecdysis in the blood-gorging Chagas’ disease vector,Rhodnius prolixus

Rhodnius prolixus is a blood-gorging hemipteran that takes blood meals that are approximately 10 times its body weight. This blood meal is crucial for growth and development and is needed to ensure a successful molt into the next instar. Kinins are a multifunctional family of neuropeptides which have been shown to play a role in the control of feeding in a variety of insects. In this study, two biostable Aib-containing kinin analogs were tested to see if they interfere with blood-feeding and subsequent development into the next instar. One of the analogs, 1729 (Ac-R[Aib]FF[Aib]WGa), had no effect on the size of the blood meal or on the subsequent molting of the insect into the next instar. This analog also did not interfere with either short-term or long-term diuresis. The second analog, 1728 ([Aib]FF[Aib]WGa), appeared to be an antifeedant. Insects feeding on blood containing this analog (15 μM) only consumed 60% of the blood meal taken by insects fed on blood without analog. Insects feeding on blood containing 1728 had a slower rate of rapid diuresis (diuresis in the first 3–5 h after feeding) leading to less urine being excreted by 5 days post feeding. The consequence of these effects was that insects fed on 1728 did not molt. This data indicates that the biostable Aib-containing analog 1728 disrupts normal growth and development in the blood-feeding insect, R. prolixus.     

Postprandial profiles of CCK after high fat and high carbohydrate meals and the relationship to satiety in humans

ContextCCK is understood to play a major role in appetite regulation. Difficulties in measuring CCK have limited the potential to assess its profile in relation to food-induced satiety. Improvements in methodology and progress in theoretical understanding of satiety/satiation make it timely for this to be revisited.ObjectiveFirst, examine how physiologically relevant postprandial CCK8/33(s) profiles are influenced by fat (HF) or carbohydrate (HCHO) meals. Second, to examine relationships between postprandial CCK and profiles of satiety (hunger/fullness) and satiation (meal size).Participants and designSixteen overweight/obese adults (11 females/5 males) participated in a randomised-crossover study (46 years, 29.8 kg/m²) in a university research centre. Plasma was collected preprandially and for 180 min postprandially. Simultaneously, ratings of hunger/fullness were tracked for 180 min before an ad libitum lunch was provided.ResultsCCK8/33(s) levels increased more rapidly and reached a higher peak following HF compared to HCHO breakfast (F_(1,15) = 14.737, p < 0.01). Profiles of hunger/fullness did not differ between conditions (F_(1,15) = 0.505, p = 0.488; F_(1,15) = 2.277, p = 0.152). There was no difference in energy intake from the ad libitum meal (HF-3958 versus HCHO-3925 kJ; t₍₁₄₎ = 0.201, p = 0.844). CCK8/33(s) profiles were not associated with subjective appetite during early and late phases of satiety; nor was there an association between CCK8/33(s) and meal size.ConclusionsThese results demonstrate CCK levels were higher after HF meal compared to HCHO isocaloric meal. There was no association between CCK levels and intensity of satiety, or with meal size. Under these circumstances, CCK does not appear to play a unique independent role in satiety/satiation. CCK probably acts in conjunction with other peptides and the action of the stomach.     

Antioxidant system response is modified by dietary fat in adipose tissue of metabolic syndrome patients

Metabolic syndrome (MetS) is associated with high oxidative stress, which is caused by an increased expression of NADPH-oxidase and a decreased expression of antioxidant enzymes in the adipose tissue. Our aim was to evaluate whether the quality and quantity of dietary fat can modify that process. A randomized, controlled trial conducted within the LIPGENE study assigned MetS patients to one of four diets for 12 wk each: (i) high-saturated fatty acid (HSFA), (ii) high-monounsaturated fatty acid (HMUFA), (iii) and (iv) two low-fat, high-complex carbohydrate diet supplemented with n-3 polyunsaturated fatty acids (LFHCC n3), or placebo (LFHCC). A fat challenge reflecting the same fatty acid composition as the original diets was conducted post-intervention. The intake of an HSFA meal induced a higher postprandial increase in gp91phox and p67phox mRNA levels than after the intake of HMUFA, LFHCC and LFHCC n-3 meals (all p-values < 0.05). The postprandial decrease in CAT, GPXs and TXNRD1 mRNA levels after the HSFA meal intake was higher than after the intake of HMUFA, LFHCC and LFHCC n-3 meals (all p-values < 0.05). The intake of an HSFA meal induced a higher postprandial increase in KEAP1 mRNA levels than after the consumption of the HMUFA (P = .007) and LFHCC n-3 (P = .001) meals. Our study demonstrated that monounsaturated fat consumption reduces oxidative stress as compared to saturated fat by inducing higher postprandial antioxidant response in adipose tissue, and thus, replacing SFA for MUFA may be an effective dietary strategy to reduce the oxidative stress in MetS patients and its pathophysiological consequences.     

Cow traffic in relation to social rank and motivation of cows in an automatic milking system with control gates and an open waiting area

Cow traffic in automatic milking (AM) systems can be controlled with gates at the entrances to feeding areas, where cows are either let through (gate opens) or redirected (gate remains closed) to an open waiting area in front of the milking unit (MU). The motivation of a cow to enter the MU after a redirection is assumed to be reflected in redirection time, which is the elapsed time from a redirection in a control gate (CG) until the next registration in the MU (i.e. CG → milking in MU/passage through MU). In order to study the possibility of guiding cows in this kind of system and to increase the understanding for the emergence of redirection time, a behavior study was performed at the Swedish University of Agricultural Sciences, Uppsala, Sweden. Two groups of 12 cows each (high and low social rank, respectively) in an AM-system with control gates and an open waiting area were used as focal cows. After a redirection in a CG, the location of each focal cow was continuously observed until entrance in the MU or during a maximum observation time of 1 h. This was repeated five times for each focal cow, generating 120 observations in total. The social rank of the cows was established from registered visits to roughage stations. Cows of high social rank spent, on an average, 13 min in the waiting area during the observation period, compared to 20 min for cows of low social rank. In 22% of all observations, the cows entered cubicles in a resting area during the 1 h observation period and when they did, they, on an average, spent 41 min of the 1 h long observation time in the cubicles. Both time since last feeding and time since last milking were in negative relationship to redirection time. The number of cows in the waiting area significantly prolonged the redirection time. Redirection time was influenced by individual characteristics, such as social rank and by situation-specific factors, such as time since last feeding, time since last milking and the number of cows in the waiting area.     

Comparison of the behaviour of Awassi lambs in cafeteria feeding system with single diet feeding system

This study was carried out to compare behavioural activities of Awassi lambs in cafeteria feeding system with conventional feeding (control) that animals fed concentrate. Sixteen, 3-month-old male lambs were housed individually for 42 days. The main effect was on the feeding systems, cafeteria and control. Cafeteria lambs (n=8) were offered the main ingredients (barley, cotton seed meal (CSM), wheat bran and alfalfa straw), while control animals (n=8) were fed a single diet (48% barley, 22% cottonseed meal, 18% wheat bran, 10% alfalfa and 2% vitamin–mineral mixture; having 2467 Kcal ME and 161 g kg⁻¹) with the same main ingredients with slightly higher nutrient content for growth. Food and water intakes were recorded daily, while behavioural observations were recorded twice a week for a period of 1 h at 5 min intervals at 13:00, 16:00, 19:00, 22:00, 01:00, 04:00, 07:00 and 10:00 h after the initiation of daily feeding. After every 5 min, each lamb was monitored to determine its eating, ruminating, drinking, walking, standing, playing, resting and other activities.Cafeteria lambs selected a diet that matched their growth requirement as did control lambs. However, cafeteria lambs ate more (P<0.01). Cafeteria animals preferred cotton seed meal (42.4%) to barley (32.9%) without changing their water intake, final live weight and daily gain (P>0.05). Cafeteria lambs also had higher rates of eating (22% versus 19%, P<0.01), ruminating (24% versus 23%, P>0.05) and resting (29% versus 23%, P<0.01) than the control lambs. On the other hand, cafeteria lambs spent less time standing (19% versus 25%, P<0.01) and walking (1.5% versus 2.1%, P<0.01) compared with control animals. In conclusion, cafeteria lambs selected a diet that matched their presumed biological (behavioral and nutritional) needs without changing their growth performance.     

Choice of scan-sampling intervals—An example with quantifying neighbours in dairy cows

To date, only a few studies using scan-sampling intervals to record neighbours in groups of animals explain how the interval length was chosen. In this study, we investigated the effects of different scan-sampling intervals, behavioural context, and the definition of neighbours on the accuracy of data as compared to a quasi-continuous observation. The data was collected from dairy cows kept in cubicle housing systems. Dairy herds of 22–43 cows on 6 farms were observed once a minute with an automatic tracking system for 6 days, and both the nearest neighbour and all neighbours within a defined distance of each cow were recorded with references to the activity, feeding and lying area and stored in neighbourship matrices. In the analysis, we used data collected at intervals of 2, 3, 4, …, 30 min, and correlated this simulated data with the data based on the 1-min interval using a specialised correlation coefficient for matrices τ_Kr. This correlation coefficient was then used as the response variable in mixed-effects models. We found that the size of the correlation coefficients generally decreased as interval length increased. This decrease was less pronounced for all neighbours than for the nearest neighbour. Moreover, the decrease was greatest with data from the activity area and lowest with data from the lying area. We concluded that, even with the relatively slow dairy cows in a barn environment, neighbour recordings should be conducted at short scan-sampling intervals in order to achieve a minimum correlation of τ_Kr = 0.8 with the quasi-continuous data. Intervals of every 2, 8 and 17 min are recommended for observation of neighbours in dairy cows for the activity, feeding and lying areas, respectively, and species that move faster may well require even shorter sampling intervals.     

Supplemental energy and protein increase use of sagebrush by sheep

The ability of sheep to consume big sagebrush (Artemisia tridentata Nutt.), a shrub that contains terpenes, may be improved with supplemental energy and protein needed for detoxification processes. We compared feeding behavior of supplemented and unsupplemented ewes grazing separately in three 0.5 ha plots of 40 m × 120 m during October 2001. Supplemented ewes were offered a choice of a high-energy (50% corn and 50% beet pulp—3.62 Mcal/kg DE and 9.5% CP) and a high-protein (85% alfalfa and 15% soybean meal—2.89 Mcal/kg DE and 15% CP) supplement for 15 min/day. Supplemented ewes consumed 492 g (S.E. = 24.3) of the high-energy supplement and 140 g (S.E. = 9.8) of the high-protein supplement. The incidence of feeding on sagebrush was recorded using scan sampling at 10-min intervals from 09:00 to 17:00 h every other day for 10 days. Incidence of feeding on sagebrush increased gradually for both treatments from 0.4% on day 1 to 28% on day 10 (P < 0.01), but supplemented ewes increased feeding frequency on sagebrush to nearly twice that of unsupplemented ewes by the end of the trial. Averaged throughout the trial, incidence of eating sagebrush was twice as high for supplemented compared to unsupplemented ewes (22% versus 11% of the total time feeding, P < 0.01). The results of this study show that supplemental macronutrients increase use of sagebrush by ewes. Thus, strategic supplementation during fall and winter may be a way to increase intake of sagebrush by sheep and enhance and maintain biodiversity in areas of the sagebrush steppe where sagebrush is deemed too abundant.     

Lying patterns of high producing healthy dairy cows after calving in commercial herds as affected by age,environmental conditions and production

An animal expresses its physiological and well-being status by its behaviour. Changes in behaviour can be associated with health, production or well-being problems and therefore with the profitability of the farm. The objectives of the present study were to analyse lying patterns of healthy cows, collected with a commercial behaviour sensor, in early lactation in relation to environmental conditions, age of the cow and production performance. In future, these results may be used as a ‘baseline’ for detection of alterations in behaviour that indicate health problems. The study involved 210 healthy multiparous Israeli Holstein cows in three commercial dairy farms. Only healthy cows during the first 28 days after calving were included in this study. Data were analysed in relation to calving season, age of cows and correlation between milk production and lying time.The results show that lying time increased significantly with age and is significantly (P < 0.05) higher in winter than in summer (summer lactation 2: 491 ± 17 min/day (mean ± SD), summer lactation 3 and more: 520 ± 25 min/day, winter lactation 2: 531 ± 25 min/day, winter lactation 3 and more: 579 ± 38 min/day).The proportion of positively and negatively milk production and lying time correlated cows is affected by calving season.This study indicates that behaviour variables in early lactation are affected by calving season, lactation number and type of correlation between milk production and lying time.     

The effect of encapsulated glutamine on gut peptide secretion in human volunteers

ContextWeight loss and improved blood glucose control after bariatric surgery have been attributed in part to increased ileal nutrient delivery with enhanced release of glucagon-like peptide 1 (GLP-1). Non-surgical strategies to manage obesity are required. The aim of the current study was to assess whether encapsulated glutamine, targeted to the ileum, could increase GLP-1 secretion, improve glucose tolerance or reduce meal size.MethodsA single-center, randomised, double blind, placebo-controlled, cross-over study was performed in 24 healthy volunteers and 8 patients with type 2 diabetes. Fasting participants received a single dose of encapsulated ileal-release glutamine (3.6 or 6.0 g) or placebo per visit with blood sampling at baseline and for 4 h thereafter. Glucose tolerance and meal size were studied using a 75 g oral glucose tolerance test and ad libitum meal respectively.ResultsIn healthy volunteers, ingestion of 6.0 g glutamine was associated with increased GLP-1 concentrations after 90 min compared with placebo (mean 10.6 pg/ml vs 6.9 pg/ml, p = 0.004), increased insulin concentrations after 90 min (mean 70.9 vs 48.5, p = 0.048), and increased meal size at 120 min (mean 542 g eaten vs 481 g, p = 0.008). Ingestion of 6.0 g glutamine was not associated with significant differences in GLP-1, glucose or insulin concentrations after a glucose tolerance test in healthy or type 2 diabetic participants.ConclusionsSingle oral dosing of encapsulated glutamine did not provoke consistent increases in GLP-1 and insulin secretion and was not associated with beneficial metabolic effects in healthy volunteers or patients with type 2 diabetes.     

Scrotal,testicular and semen characteristics of young Boer bucks fed winter veld hay: The effect of nutritional supplementation

The aim of the work was to determine the effects of feeding winter veld hay plus a supplement on scrotal, testicular and semen characteristics in young Boer goat bucks. Fifteen Boer goat bucks (6–8 months of age), were allocated to two groups and fed ad libitum for a period of 29 days. The WH group (winter hay or control group; n = 8) received a chopped diet consisting of grass hay, predominantly Themeda triandra grass (cut during the winter) from natural pastures (veld). The WH + S group (winter hay plus supplement; n = 7) received the same diet consisting of Themeda triandra veld hay and supplemented with maize meal, molasses meal and urea. Body weights and feed intake were recorded, as well as scrotal, testicular and semen characteristics. Results indicate a detrimental effect of winter veld hay feeding on characteristics such as sperm cell abnormalities (43% in the WH group versus 24% in WH group), testicular volume (156 ml in the WH + S group versus 104 ml for WH animals) or scrotal circumference (20.7 cm in WH + S group versus 17.7 cm in WH group). It is essential to supplement the nutrition of small ruminants under winter environments, to maintain scrotal, testicular and semen characteristics, especially if the animals are to be used in the subsequent breeding season.     

The influence of feeding and fasting on plasma metabolites in the dogfish shark (Squalus acanthias)

Dogfish sharks are opportunistic predators, eating large meals at irregular intervals. Here we present a synthesis of data from several previous studies on responses in plasma metabolites after natural feeding and during prolonged fasting (up to 56 days), together with new data on changes in plasma concentrations of amino acids and non-esterified fatty acids. Post-prandial and long-term fasting responses were compared to control sharks fasted for 7 days, a typical inter-meal interval. A feeding frenzy was created in which dogfish were allowed to feed naturally on dead teleosts at two consumed ration levels, 2.6% and 5.5% of body weight. Most responses were more pronounced at the higher ration level. These included increases in urea and TMAO concentrations at 20 h, followed by stability through to 56 days of fasting. Ammonia levels were low and exhibited little short-term response to feeding, but declined to very low values during the extended fast. Glucose and β-hydroxybutyrate both fell after feeding, the latter to a greater and more prolonged extent (up to 60 h), whereas acetoacetate did not change. During prolonged fasting, glucose concentrations were well regulated, but β-hydroxybutyrate increased to 2–3-fold control levels. Total plasma amino acid concentrations increased in a biphasic fashion, with peaks at 6–20 h, and 48–60 h after the meal, followed by homeostasis during the extended fast. Essential and non-essential amino acids generally followed this same pattern, though some exhibited different trends after feeding: taurine, β-alanine, and glycine (decreases or stability), alanine and glutamine (modest prolonged increases), and threonine, serine, asparagine, and valine (much larger short-term increases). Plasma non-esterified fatty acid concentrations declined markedly through 48 h after the 2.6% meal. These data are interpreted in light of companion studies showing elevations in aerobic metabolic rate, urea production, rectal gland function, metabolic base excretion, and activation of ornithine–urea cycle and aerobic enzymes after the meal, and muscle N-depletion but maintenance of osmolality and urea production during long-term fasting.