Development of a novel stall design for dairy cattle: Part II. The effect of minimal stall partitioning on lying behavior,rumination, stall cleanliness,and preference

Free-stalls for dairy cows promote cleanliness, provide cows with a defined space to lie down, and decrease labor and bedding required for maintenance. However, current stall features can restrict behavior and reduce stall use. The objective of this study was to assess the short-term effect of a novel free-stall design (flexible single-bar partition, no neck rail, increased slope) on stall cleanliness and the lying behavior, rumination, milk production, and preferences of dairy cows in comparison to standard free-stalls (metal loop partitions, neck rail). In the first experiment, 60 Holstein cows were randomly divided into two groups and switched between standard and novel stalls in a replicated crossover design with four 7-day periods. Lying behavior and rumination were recorded continuously. Milk yields were recorded 2x/day, and stall cleanliness scores were collected on the last four days of weeks 3 and 4. The second experiment was a 6-day preference test where 14 cows from experiment 1 were given free access to 16 standard and 16 novel stalls. Lying behavior was recorded continuously. On day 6, standing, perching, and intention, lying, and rising movements were recorded. In experiment 1, cows spent 12 min less time lying down (14.1 vs 14.3 ± 0.48 h/d), had one fewer lying bouts (8.8 vs 9.8 ± 0.23 bouts/d), and had longer lying bouts by 6 min (1.4 vs 1.5 ± 0.05 h/bout) in novel stalls. Rumination time (547.3 vs 548.9 ± 4.66 min/d) and milk yield (35.0 vs 35.2 ± 0.51 kg/d) did not differ between stall types. However, novel stalls were more than twice as soiled as standard stalls (32.8 vs 14.2 ± 1.38% of rear half soiled). In experiment 2, the cows most recently housed in the novel stalls showed a clear preference for lying down in those stalls, whereas cows most recently housed in standard stalls showed no preference. Intention and lying down movements were longer in standard stalls when other cows were present in diagonally opposite stalls, but were similar between stall types when not occupied. All cows preferred standing in novel stalls. Novel stalls may have improved stall use compared to standard free-stalls, and the design requires further development to address cleanliness concerns. Future work is required to provide comfortable stalls without sacrificing cleanliness.     

Assessing cow comfort: effects of two floor types and two tie stall designs on the behaviour of lactating dairy cows

Our objective was to test the effects of two types of stall flooring and two tie stall designs on the behaviour of dairy cows. Using two cross-over designs, 16 lactating Holstein cows were housed for 3-week periods in each of four tie stalls to compare the effects of concrete versus mattress flooring, and a narrow versus a wide stall front opening. When cows were housed on a mattress flooring they increased their total lying time by 1.8h per day (51.0 versus 43.4% time per day). The duration of individual lying bouts was longer on concrete flooring (78 versus 62min) and the same was true for the duration of individual bouts of standing (80 versus 48min). On mattress flooring cows stood up and lay down more often than on concrete (28 versus 20 per day, respectively). On concrete cows spent more time standing without eating (35.2 versus 28.1% of sampling observations). Cows consistently made use of the additional space provided with the wide stall front opening, placing their head in the manger area during 70.6% of lying observations compared to only 43.4% of observations in the narrow stall front. However, measures of general activity were not significantly different for the two stall designs. Cows spent similar amounts of time eating and consumed similar quantities of feed in all four tie stalls. Our results suggest a lack of comfort may be apparent in reduced time spent lying and a subsequent increase in time spent standing without eating. A lower frequency of standing and lying and an increase in the bout duration of lying suggests that cows on concrete flooring have difficulty standing up and lying down.     

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.     

Effects of two stall flooring systems on the behaviour of tied dairy cows

Effects on dairy cow behaviour of a new type of flooring in tie-stalls, with the ability to drain faeces and urine, was studied in a controlled randomised trial in one Swedish university herd. Forty-two Swedish Red and White cows were kept tied in traditional long-stalls (2.20m). In 21 stalls (one stall row), the rearmost 0.74m of the solid stall floor had been replaced with nine rubber-coated 53mm wide slats, divided by 29mm slots. Stalls with rubber slats were equipped with 20mm ethyl-vinyl-acetate (EVA) mats in the front part and littered with 0.7kg of wood shavings daily, while stalls with a solid floor had standard rubber mats and received 3kg of chopped straw daily as bedding. Behaviour was compared between the two stall types, using video recordings of 12 matched pairs of cows for two complete 24h periods each. Statistical analysis was done using the Student's t-test for matched pairs or the sign test. Cows on the rubber slatted flooring lie down and rise normally and without any increased risk of slipping. They lay down more comfortably, i.e. spent on an average 23% less time preparing to lie down, and slipped less frequently during rising. There was some evidence of a preference for a solid floor when lying.     

Differences between single and paired heifers in residency in functional areas, length of travel path, and area used throughout days 1–6 after integration into a free stall dairy herd

The integration of heifers into free stall dairy herds is a frequent management procedure, but little systematic research has been conducted on its effect on cow behavior. Previous studies mainly focused on aggressive interactions, but it is also of interest how integration affects the spatial distribution of both the cows in the herd and the integrated heifers. In the present study we integrated a single and a pair of heifers on each of six Swiss working farms in a balanced order. Using an automatic tracking system, we recorded the positions of all the cows and of the integrated heifers at 1 min intervals for six continuous 24 h periods. From these data we calculated the proportion of time the animals spent in the activity area, at the feed rack and in the lying cubicles, their average path length and the area of the barn that they used. We then compared the behavior of the integrated heifers with that of the cows in the introductory weeks. We also compared the behavior of the cows recorded in the control weeks directly preceding the integration and in the introductory weeks. For evaluation we used linear mixed-effects models. Singly integrated heifers spent a higher proportion of time in the activity area (0.29 vs. 0.14; P < 0.001) and a lower proportion of time in the lying area (0.40 vs. 0.53; interaction with day, P = 0.011) than the cows, whereas the heifers of the pairs mainly spent a lower proportion of time in the feeding area than the cows (0.23 vs. 0.32; interaction with day, P = 0.044). Average path length was longer for the integrated heifers soon after introduction but approached the values of the cows later on (interaction with day, P = 0.012). The total barn area used by a given animal was largest in the cows and was reduced in heifers integrated singly or in pairs (cows: 341/373 m², pairs: 306 m², single heifer: 333 m²; P = 0.055). Cows were little influenced in their space use by the integration of a single or pair of heifers. In summary, the behavior of the singly integrated heifers differed more markedly from that of the cows than the behavior of the heifers introduced in pairs during the introductory week. We would therefore recommend integrating pairs rather than single heifers into herds of dehorned dairy cows to ease their integration.     

Lying laterality and the effect of IceTag data loggers on lying behaviour of dairy cows

Lying behaviour is a useful indicator of cow comfort, but can be time consuming to measure. Data loggers are commonly used to automatically record behavioural activity but may influence the animal's behaviour. We investigated the effect of a new model of the IceTag data logger (IceTag Sensor, IceRobotics© Ltd, Edinburgh, UK) on lying behaviour of forty dairy cows. Smaller Hobo^® Pendant G data loggers (Onset Computer Corporation, Pocasset, MA) were attached to the hindlegs of all cows balanced for left and right and measured total duration of lying time, frequency and mean duration of lying bouts and the percent of time lying down on each side. Sixteen cows were semi-randomly split into two groups depending on the position of the IceTags on the inside of the leg (medial) or the outside (lateral). Each cow experienced four treatments in a Latin square design: no IceTag data logger attached as a control (C); one IceTag data logger on the left hind leg (L), one IceTag data logger on the right hind leg (R), and a IceTag data logger on both hind legs (B). Each treatment lasted for 6 days. As part of a separate study, lying laterality data from 24 cows with an IceTag data logger attached to the lateral part of each hindleg was used. On average, cows (n = 39) spent 47.5% of their time lying on the right side during a 24-h period. However, there was a large variation of time spent lying on the right side ranging from 25.1% to 65.7%. There was no significant effect of IceTag location (medial or lateral) or treatment (C, L, R, B) on total lying time, frequency of lying time, duration of lying bouts or percentage of time lying on each side. In summary, IceTags did not affect lying behaviour in dairy cows, allowing them to be reliably used in research as a high tech tool to measure activity. Overall as a group, cows show no preference for lying on one particular side, but individual cows do show a distinct preference.     

Fan cooling of the resting area in a free stalls dairy barn

This summer study evaluated the effect of providing additional fans (cooling) in the resting area within a free-stall dairy barn that had fans and sprinklers in the feeding area and paddock availability. Thirty cows were divided into two homogenous groups and kept in two pens: one had the resting area equipped with two fans (FAN) while no fans were added to the other resting area (CON). Microclimatic parameters, rectal temperature (RT), breathing rate (BR), milk yield, and milk pH traits were recorded. Time budgeting and the behaviour of the cows (time spent in the feeding area, standing and lying in other areas) were also recorded using digital video technology. Two slight-to-moderate heat waves were observed. During the hottest period the daily maximum temperature recorded was 33.5 °C and the daily maximum THI was 81.6. During this period, the BR and RT increased only slightly in both groups, with lower BR (n.s.) in FAN compared with CON. Milk yield was better maintained (n.s.) in FAN compared with CON during the hottest period. The FAN cows showed a greater (P?<?0.05) lying time in the free stalls (9.5 and 8.6 h/day in FAN and CON, respectively), whereas CON cows made greater (P?<?0.05) use of the paddock during evening and late evening hours. Consequently, the total daily lying time was 13.5 h/day in both groups. In conclusion, the results suggest that using fans in the resting area improves cow comfort, which increases use of the resting area. The lying time results also suggest that the benefits of providing ventilation in the resting area might be more evident in barns where there is no paddock.     

Individual Intake of Free-Choice Mineral Mix by Grazing Beef Cows May Be Less Than Typical Formulation Assumptions and Form of Selenium in Mineral Mix Affects Blood Se Concentrations of Cows and Their Suckling Calves

The objectives of this study were to determine (1) the individual ad libitum intake of mineral mix by beef cows managed under a year-long, fall-calving, forage-based production regimen and (2) if Se form in the mineral mix affected the blood Se concentrations of cows and suckling calves. Twenty-four late-gestation (6 to 8 months) Angus-cross cows (2.7?±?0.8 years; body weight [BW]?=?585?±?58 kg) were blocked by BW and randomly assigned (n?=?8) to a mineral supplement treatment (TRT) containing 35 ppm Se as either inorganic (ISe; sodium selenite), organic (OSe; Sel-Plex®), or a 1:1 combination of ISe/OSe (MIX). Cows commonly grazed a 10.1-ha predominately tall fescue pasture and had individual ad libitum access to TRT using in-pasture Calan gates. Cows calved from August to November and calves had common ad libitum access to creep feed and a mineral supplement that lacked Se. Cow jugular blood was taken at 28-day intervals (13 periods) and calf blood was taken with cows from birth through weaning. Individual cow mineral mix (mean?=?54.0?±?7.0 g/day, range?=?97.3 to 27.9?±?7.4 g/day) and Se (mean?=?1.82?±?0.25 mg/day, range?=?3.31 to 0.95?±?0.25 mg/day) intakes were affected by period (P?<?0.0001), but not by cow Se TRT (P?>?0.30). Cow blood Se (0.109 to 0.229?±?0.01 μg/mL) was affected (P?<?0.002) by period, Se form, and their interaction, with ISe?< MIX for periods 8 and 11, ISe?<?OSe for all periods except period 1, and MIX?<?OSe for periods 2 to 4, 7, 8, 10, and 12. Calf blood Se (in micrograms Se per milliliter) was correlated with cow blood Se and affected (P?<?0.0001) by cow Se TRT, with ISe (0.07 to 0.11)?<?MIX (0.10 to 0.15)?=?OSe (0.16 to 0.19). These data reveal that (1) mean supplemental ad libitum cow mineral intake was 36 % less than the typical formulation intake expectations (85 g/day) and, correspondingly, mean supplemental Se intake was 33 % less than that allowed by the FDA and (2) cow Se TRT differentially affected both cow and calf blood Se concentrations, resulting in adequate concentrations for all cows but inadequate concentrations for ISe calves.     

Ovarian follicular growth suppression by long-term treatment with a GnRH agonist and impact on small follicle number,oocyte yield,and in vitro embryo production in Zebu beef cows

The aim of the present study was to evaluate small follicle number, oocyte yield, and in vitro embryo production (IVEP) in Zebu beef cows treated long term with a GnRH agonist to suppress ovarian follicular growth. Nelore (Bos indicus) cows (n = 20) showing regular estrous cycles were randomly assigned to one of two groups: control (n = 10, placebo ear implant without a GnRH agonist); GnRH agonist (n = 10, GnRH agonist ear implant containing 9.4-mg deslorelin). All cows underwent an ovum pick-up (OPU) session 14 days (Day 14) before the start of treatments (Day 0) followed by seven OPU–IVEP procedures at 30-day intervals (Days 0, 30, 60, 90, 120, 150, and 180). Semen from a single batch of a previously tested bull was used for all the IVEP. Cows treated with agonist reported a decrease over time in the proportion of animals with a (CL; P ≤ 0.05) and large follicles (>10 mm, P ≤ 0.05). These cows had a lesser number of medium + large follicles (>5 mm; 1.74 ± 0.5 vs. 4.13 ± 0.5; P ≤ 0.05), greater number of small follicles (2–5 mm; 44.3 ± 2.8 vs. 30.8 ± 1.8; P ≤ 0.05), greater yield of cumulus-oocyte complexes (COCs; 21.0 ± 2.3 vs. 15.6 ± 1.9; P ≤ 0.05), greater proportion of COCs cultured (79.2 vs. 73.9%; P ≤ 0.05), COCs cleaved (10.6 ± 1.5 vs. 6.8 ± 1.1, P ≤ 0.05), and cleaved rate (52.8 vs. 44.3%; P ≤ 0.05) compared with control cows. The number (3.4 ± 0.7 vs. 3.0 ± 0.6; P > 0.05) and proportion (16.5 vs. 19.1%; P > 0.05) of blastocysts produced were similar between agonist and control cows, respectively. The study has shown that Zebu beef cows treated long term with a GnRH agonist had follicular growth restricted to small follicles. This did not compromise the ability of oocytes to undergo IVF and embryonic development.     

The effect of concentrate allocation on traffic and milk production of pasture-based cows milked by an automatic milking system

Increased economic, societal and environmental challenges facing agriculture are leading to a greater focus on effective way to combine grazing and automatic milking systems (AMS). One of the fundamental aspects of robotic milking is cows’ traffic to the AMS. Numerous studies have identified feed provided, either as fresh grass or concentrate supplement, as the main incentive for cows to return to the robot. The aim of this study was to determine the effect of concentrate allocation on voluntary cow traffic from pasture to the robot during the grazing period, to highlight the interactions between grazed pasture and concentrate allocation in terms of substitution rate and the subsequent effect on average milk yield and composition. Thus, 29 grazing cows, milked by a mobile robot, were monitored for the grazing period (4 months). They were assigned to two groups: a low concentrate (LC) group (15 cows) and a high concentrate (HC) group (14 cows) receiving 2 and 4 kg concentrate/cow per day, respectively; two allocations per day of fresh pasture were provided at 0700 and 1600 h. The cows had to go through the AMS to receive the fresh pasture allocation. The effect of concentrate level on robot visitation was calculated by summing milkings, refusals and failed milkings/cow per day. The impact on average daily milk yield and composition was also determined. The interaction between lactation number and month was used as an indicator of pasture availability. Concentrate allocation increased significantly robot visitations in HC (3.60±0.07 visitations/cow per day in HC and 3.10±0.07 visitations/cow per day in LC; P<0.001) while milkings/cow per day were similar in both groups (LC: 2.37±0.02/day and HC: 2.39±0.02/day; Ns). The average daily milk yield over the grazing period was enhanced in HC (22.39±0.22 kg/cow per day in HC and 21.33±0.22 kg/cow per day in LC; P<0.001). However the gain in milk due to higher concentrate supply was limited with regards to the amount of provided concentrates. Milking frequency in HC primiparous compared with LC was increased. In the context of this study, considering high concentrate levels as an incentive for robot visitation might be questioned, as it had no impact on milking frequency and limited impact on average milk yield and composition. By contrast, increased concentrate supply could be targeted specifically to primiparous cows.     

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.     

Thermoregulatory responses of Holstein cows exposed to experimentally induced heat stress

Heat stress (HS) adversely influences productivity and welfare of dairy cattle. We hypothesized that the thermoregulatory mechanisms vary depending on the exposure time to HS, with a cumulative effect on the adaptive responses and thermal strain of the cow. To identify the effect of HS on adaptive thermoregulatory mechanisms and predictors of caloric balance, Holstein cows were housed in climate chambers and randomly distributed into thermoneutral (TN; n=12) or HS (n=12) treatments for 16 days. Vaginal temperature (VT), rectal temperature (Tre), respiratory rate (RR), heart rate (HR), and dry matter intake (DMI) were measured. The temperature and humidity under TN were 25.9±0.2 °C and 73.0±0.8%, respectively, and under HS were 36.3±0.3 °C and 60.9±0.9%, respectively. The RR of the HS cows increased immediately after exposure to heat and was higher (76.02±1.70bpm, p<0.001) than in the TN (39.70±0.71bpm). An increase in Tre (39.87±0.07 °C in the HS vs. 38.56±0.03 °C in the TN, p<0.001) and in VT (39.82±0.10 °C in the HS vs. 38.26±0.03 °C in the TN, p<0.001) followed the increase in RR. A decrease (p<0.05) in HR occurred in the HS (62.13±0.99bpm) compared with the TN (66.23±0.79bpm); however, the magnitude of the differences was not the same over time. The DMI was lower in HS cows from the third day (8.27±0.33 kg d⁻¹ in the HS vs. 14.03±0.29 kg d⁻¹ in the TN, p<0.001), and the reduction of DMI was strongly affected (r=−0.65) by changes in the temperature humidity index. The effect of environmental variables from the previous day on physiological parameters and DMI was more important than the immediate effect, and ambient temperature represented the most determinant factor for heat exchange. The difference in the responses to acute and chronic exposure to HS suggests an adaptive response. Thus, intense thermal stress strongly influence thermoregulatory mechanisms and the acclimation process depend critically on heat exposure time.     

Misting and fan cooling of the rest area in a dairy barn

This summer study aimed to evaluate the effect on dairy cows, kept in a free stall barn equipped with fans and sprinklers in the feeding area, of the delivery rate of misters in a cooling system in rest areas with different bedding materials. Thirty cows were divided into two homogenous groups according to milk yield and kept in two pens: one had beds with sand (SAMM) while the other had straw (STLM). Each pen was equipped with 2 fans (Ø 70 cm, 0.50 kW) and 2 misters (delivery rate of 11.2 and 22.5 L/h in STLM and SAMM, respectively) in the rest area. Microclimatic parameters, rectal temperature (RT), breathing rate (BR), milk yield, and some milk traits were recorded. Behavioural routines of the cows (standing and lying) were also continuously recorded during the hotter days. During the trial, two mild–moderate heat waves were observed. During these hotter periods, the daily maximum temperature recorded in the rest areas was 28.9 in SAMM and 31.2 in STLM, and the daily maximum THI was 78.2 in SAMM and 81.5 in STLM. In these periods, the cows in SAMM compared with those in STLM showed lower BR (P?相似文献   

Associations between peripartum lying and activity behaviour and blood non-esterified fatty acids and β-hydroxybutyrate in grazing dairy cows

During early lactation, most dairy cows experience negative energy balance (NEB). Failure to cope with this NEB, however, can place cows at greater risk of developing metabolic disease. Our objective was to characterise, retrospectively, lying behaviour and activity of grazing dairy cows grouped according to blood non-esterified fatty acids (NEFAs) and β-hydroxybutyrate (BHB) as indicators of postpartum metabolic state. Blood was sampled weekly for up to 4 weeks precalving, on the day of calving (day 0), daily between 1 and 4 days postcalving, and then at least weekly between week 1 and week 5 postcalving for analysis of plasma NEFAs and BHB concentrations. Two hundred and forty-four multiparous Holstein-Friesian and Holstein-Friesian × Jersey cows were classified into one of three metabolic status groups based on maximum blood NEFAs and BHB concentrations during week 1 and 2 postcalving. A cow was classified as having either: (1) low NEFAs and low BHB (Lo–Lo; n = 78), when all blood samples were <1.0 mmol/L for NEFAs and ≤1.0 mmol/L for BHB during the first 2 weeks postcalving; (2) high NEFAs and low BHB (Hi–Lo; n = 134), when blood NEFAs were ≥1.0 mmol/L and blood BHB was ≤1.0 mmol/L at the same sampling time point during the first 2 weeks postcalving; or (3) high NEFAs and high BHB (Hi–Hi; n = 32), when blood NEFAs were ≥1.0 mmol/L and blood BHB was ≥1.2 mmol/L at the same sampling time point during the first 2 weeks postcalving. Accelerometers (IceTag or IceQube devices; IceRobotics Ltd.) were used to monitor lying and activity behaviours peripartum (–21 to +35 days relative to calving). Changes in lying behaviour and activity occurred before the mean day that cows were classified Hi–Hi and Hi–Lo (2.2 and 3.5 d postcalving, respectively). Up to 3 weeks preceding calving, Hi–Hi cows were more active, had fewer daily lying bouts (LBs), and spent less time lying than Lo–Lo cows. In addition, Hi–Hi cows had fewer daily LBs and were less active up to 4 weeks postcalving than Lo–Lo cows, but these differences were biologically small. Groups of grazing cows classified as experiencing a more severe metabolic challenge behave differently up to 3 weeks precalving than their herdmates with lower blood NEFAs and BHB postcalving. These altered behaviours may allow identification of individual cows at risk of a metabolic challenge, but further research is required.     

Effect of feeding Rumen-protected capsule containing niacin,K2SO4, vitamin C,and gamma-aminobutyric acid on heat stress and performance of dairy cows

This study was conducted to evaluate the effects of supplemental rumen-protected capsule (RPC) on animal performance, serological indicators, and serum heat shock protein 70 (HSP70) of lactating Holstein cows under heat stress (HS). During summer months, 30 healthy multiparous lactating Holstein cows with a parity number of 3.1 ± 0.44, 70 ± 15 d in milk, an average body weight of 622 ± 62 kg, and an average milk yield of 32.28 ± 0.96 kg/d, were used. The cows were randomly allocated to two groups: a control group and an RPC-supplemented group (0.13373 kg K₂SO₄, 0.02488 kg vitamin C, 0.021148 kg niacin, and 0.044784 kg gamma-aminobutyric acid per cow). During the 42-d experiment, ambient air temperature and relative humidity inside and outside the barn were recorded hourly every day for the determination of temperature-humidity index (THI). Milk and blood samples were collected every week, and body weight and body condition scoring were measured on day 0. Based on the THI values, the animals had moderate HS. On day 42, the RPC group had lower HSP70, adrenocorticotropic hormone (P = 0.0001), lactate dehydrogenase (P = 0.0338), and IL-6 (P = 0.0724) levels than the control group, with no significant differences in creatine kinase, glucocorticoid, or IL-2 levels. Milk yield, energy-corrected milk, and dry matter intake were higher in RPC than in the control group (P = 0.0196). There were no significant differences in milk fat or daily protein levels between the two groups; however, daily protein and milk fat levels were higher in the RPC group than in the control group (P = 0.0114 and P = 0.0665, respectively). Somatic cell counts were no different between the two groups. In conclusion, RPC may alleviate HS and improve dairy cow performance.     

Effect of increasing doses of a microencapsulated blend of essential oils on performance of lactating primiparous dairy cows

This study determined impacts of a commercial blend of microencapsulated essential oils (EO), fed at increasing dose levels to high yielding primiparous dairy cows, on milk yield and composition. Eight pregnant Holstein heifers, selected to have their parturition within a period of 30 d, were kept in tie stalls equipped for individual feeding, and with free access to water, from the 7th month of gestation. At an average of 40 d postpartum, cows were assigned to one of four dietary EO levels in a replicated 4 × 4 Latin square design. The experimental diets (i.e., corn silage, fescue hay and a compound feed, 6.5, 4.4 and 8.7 kg DM/d respectively) differed only in the addition level of a microencapsulated EO supplement (RumaXol Feed) mixed at different levels into the compound feed (fed at 1 kg/cow day) in order to provide 0, 0.32, 0.64 and 0.96 g/d of the EO mixture. The experiment had four experimental periods of 21 d, with the last 5 d used for collection of faeces and urine, for milk yield and composition recording and measurement of cow biometric data. The dietary EO supplementation had no effect on dry matter (DM) intake, water consumptions or faecal DM, while urine density was (P=0.01) lower at the intermediate EO dosages. Digestibility and biometric measures of cows were not modified by EO feeding. The protein content of milk tended (P=0.06) to be higher at the intermediate EO dosages, as did (P=0.05) the milk energy concentration. However milk and milk component yields were not affected by EO feeding level.     

Effect of chromium methionine supplementation on lactation performance,hepatic respiratory rate and anti-oxidative capacity in early-lactating dairy cows

Chromium may regulate dairy cow metabolism; a chelated formation of chromium methionine (Cr-Met) is available to the feed industry. The objective of this study was to investigate the effect of Cr-Met supplementation on lactation performance, hepatic respiratory rate and anti-oxidative capacity in early-lactating Holstein dairy cows. 64 multiparous cows were assigned to 16 blocks based on parity and milk yield and then the four cows in a block were randomly allocated to four treatment groups with 0, 4, 8 or 16 g/d of Cr-Met per cow supplemented to a basal diet. Cows were moved from an open dry lot to a naturally ventilated tie stall barn 2 weeks before treatment to adapt to this facility, fed and milked at 0630, 1400, and 1930 h every day. The experiment lasted for 12 weeks. Milk yield and composition were recorded weekly. Dry matter intake was measured every 2 weeks for a total of six times throughout the trial. The plasma variables were measured in weeks 4, 8 and 12 of the experiment. Supplementation of Cr-Met did not affect DM intake of cows. As the supplementation of Cr-Met increased, yields of milk, fat, energy corrected milk (P < 0.01) and lactose (P = 0.01) increased in a linear manner. In terms of plasma variables, insulin concentration decreased in a linear manner with Cr-Met supplementation. As for variables relating to hepatic respiration rate, concentrations of pyruvate and NAD in the plasma were increased in quadratic manners, and lactic dehydrogenase activity was linearly increased as Cr-Met feeding levels increased. Moreover, plasma glutathione peroxidase and superoxide dismutase activity were increased in a linear manner. In conclusion, our study suggested that Cr-Met supplementation improved lactation performance of early-lactating dairy cows through enhancing antioxidant capacity and hepatic cellular respiration.     

Suitability of feeding and chewing time for estimation of feed intake in dairy cows

Monitoring of feeding and rumination behaviour can provide useful information for dairy herd management. The feeding behaviour of dairy cows can be recorded by different techniques, such as video cameras, weighing troughs or chewing sensors. Among feeding characteristics, individual feed intake of cows is of utmost interest, but as weighing troughs have high space and cost requirements they are used primarily in research studies. The objective of the present study was to evaluate whether records on feeding time or chewing activity or a combination of both contain enough information to estimate feed intake with sufficient accuracy. Feed intake and feeding time per cow were recorded by means of weighing troughs. Concurrently, chewing activity of seven cows was recorded by MSR-ART pressure sensors during five to eight measuring days per cow. Feeding and chewing behaviour were evaluated in time slots (1 min) and additionally assigned to feeding bouts for further analysis. The 1 min time slots were classified into feeding/no feeding or chewing/no chewing by the two systems, and agreement was found in 92.2% of the records. On average, cows spent 270±39 min/day at the feeding troughs and chewed 262±48 min/day. The average fresh matter intake (FMI) was 49.6±5.1 kg/day. Feed intake was divided into 9.7 bouts/day during which cows fed in average 27.8±21.7 min/bout and chewed 27.0±23.1 min/bout. The correlation between FMI and feeding time was r=0.891 and between FMI and chewing time r=0.780 overall cows. Hence, both systems delivered suitable information for estimating feed intake.     

Reproductive function in beef cows calving in the spring or fall

Plasma progesterone was determined twice weekly for approximately 100 days postpartum in suckled purebred (Hereford) and crossbred (beef x dairy) cows that calved in the spring or late summer/fall season. The progestèrone profiles and occurrence of estrus were used to determine ovulation times and to monitor ovarian function. Postpartum ovulations occurred significantly earlier in crossbred than in purebred cows (38.1 ± 18.5 vs. 58.1 ± 21.8, P<0.01) and in fall compared to spring calving cows (32 ± 13.9 vs. 59.1 ± 20.3, P<0.001). Rations providing either 70 or 100% of requirements for metabolizable energy were fed from 30 days prepartum until the end of the subsequent rebreeding period. Cows receiving the 70% energy ration ovulated slightly earlier but there was no effect of ration on days to pregnancy. The minimal effect of energy ration was not unexpected in this trial since many of the cows were overconditioned during late gestation.The correlation between calendar date of calving and interval to first ovulation was significant for spring (r = ?0.38, P<0.01) but not for fall calving animals. Since cows were confined and received a balanced ration of stored feeds throughout the year, photoperiod and/or temperature rather than nutritional factors would be the probable cause of delayed ovarian activity in spring calvers.Reproductive performance was assessed during the period when samples were collected and the response for purebred (n=105) and crossbreds (n=142), respectively were: ovulated by day 60 postpartum, 57 vs. 87%; mated by day 100 without conception, 17 vs. 26%; ovulated before day 100 without detection and mating, 10 vs. 4%; anovulatory to day 100, 7 vs. 0%; pregnant by day 100, 67 vs. 70%. Similar comparisons for spring (n=133) and summer/fall (n=144) calvers, respectively, were: ovulated by 60 days postpartum, 56 vs. 96%; mated by day 100 without conception, 27 vs. 17%; ovulated by day 100 without detection and mating, 8 vs. 5%; anovulatory to day 100, 5 vs. 0%; pregnant by day 100, 60 vs. 78%. The difference with the greatest practical significance is that a higher proportion of the late summer/fall calving animals were pregnant by day 100 postpartum (P<0.01) which indicates that reproductive performance is superior in fall calving beef cows.     

Analysis of stream water temperature changes during rainfall events in forested watersheds

Despite continued interest in stream water temperature (Tw) analysis, there are few studies of Tw response to rainfall events at forested watersheds. We examined 61 sets of data on Tw for 21 rainfall events at 16 watersheds with various slope gradients (from 0.08 to 0.56) in four regions of Japan from June 2004 to December 2005. The investigation focused on the changes of specific discharge (ΔQs) and ΔTw at medium-sized watersheds (0.5–100 ha). The results clearly demonstrated different flow patterns expressed by Qs vs. Tw hysteretic loops. Those were clockwise in Period I (April–September) and counterclockwise in Period II (October–March), except for lower slope gradient at Aichi, where counterclockwise loops were observed in both periods. These differences in hysteretic loops could be explained by the differences in Tw and in response times to rainfall between surface/subsurface and groundwater flows. The response times were probably determined by the slope gradient and the vertical level of groundwater. We also found that the changes in air temperature (ΔTa) influenced ΔTw to a lesser degree than Qs. The average rainfall intensities in Period I and Period II (9.3 ± 1.7 and 5.4 ± 0.2 mm/h, respectively) affected the average values of ΔQs and ΔTw (6.62 ± 4.08 mm/h and 1.7 ± 0.4°C; 0.85 ± 0.68 mm/h and 0.9 ± 0.3°C, respectively). This indicates that slope gradient and Qs influenced ΔTw by changing the relative proportions of flow paths. In addition, the water table changes influenced the percentage of groundwater flow to the stream.