Dairy Heifer Motivation for Access to a Shaded Area.

We used an operant conditioning paradigm to test the motivation of non-pregnant dairy heifers to access shade during the summer and autumn months (January to June) in southern Brazil. Dairy heifers (n = 18) were trained to push a weighted gate to access either an experimental area containing both a shaded (simple tree shade and shade cloth) and unshaded area (WITH SHADE) or an experimental area with no shade (BARREN). The latency to push the weighted gate, and the maximum weight pushed by each heifer, were recorded in both the summer and the autumn. Temperature and humidity were recorded continuously for the duration of the study and were used to calculate the heat index. The maximum weight pushed to enter the WITH SHADE area was greater in summer than in autumn, and was inversely related to the latency to push the weighted gate. Heifers refused to work for access to the BARREN environment. As expected, both the maximum ambient temperatures and heat index were higher in summer than in autumn, and also higher in the non-shaded areas than under the shade in both seasons. Heifers of higher social rank displaced other heifers more often, and spent more time in the shaded areas, particularly in the area with trees plus a shade cloth, than the intermediate and subordinate heifers. We conclude that shade is an important and valued resource for heifers reared on pasture-based systems in sub-tropical environments, particularly during the hot summer months.

Identification and antimicrobial susceptibility of milk pathogen isolated from dairy production systems.

Livestock has been recognized as a reservoir of antibiotic-resistant bacteria. Prevalence of resistance has been associated with herd size and intensification of animal production systems. Brazil is one of the emergent hotspots of bacterial resistance, which is also associated with animal husbandry. This study aimed to evaluate the resistance profile of pathogens that cause subclinical mastitis and the relationship between resistance status at farm level and different production systems. Milk samples from cows diagnosed with subclinical mastitis were collected from farms that adopt different husbandry systems with different production intensities, i.e., agroecological, low input, high input, Free-Stall and Compost-bedded pack barn. Etiological agents were isolated and microbiologically identified, and antibiotic susceptibility testing was conducted, using the disk diffusion method. The main isolated agents were Streptococcus spp. (n = 54, 30.5 %) and coagulase-positive Staphylococcus (CPS) (n = 54; 30.5 %). The recovered isolates displayed high antibiotic resistance against Sulfamethazine (80.2 %), Gentamicin (29.37 %), Penicillin (29.37 %), Oxacillin (28.82 %) and Ampicillin (26 %). Multidrug resistance was found for all agents and in all farming systems (39.54 %). Neither production systems (p = 0.26) nor farming systems (p = 0.24) significantly affected the resistance rates of samples. Therefore, intensive production systems may not be a root cause of increased rates of antimicrobial resistance in the milk production chain, suggesting that other environmental factors should be investigated. It is noteworthy that high levels of multidrug resistance were even found in bacteria earlier considered as minor pathogens. This development can be taken as a warning that environmental bacteria are potential transmitters of resistance genes to the environment.

Beef Cattle on Pasture Have Better Performance When Supplied With Water Trough Than Pond.

The behavior and performance of steers on pasture regarding water availability in troughs or in ponds were compared. Eight paddocks were randomly allocated to one treatment: POND (~30 m of diameter) or TROUGH (water trough, 120 cm diameter and 60 cm high and 500 L capacity). Eight groups of six beef steers were randomly assigned to one of the paddocks. The first 10 days were considered for animal habituation. Animals were individually weighed (days 0, 30, 60, and 90). Beginning in the day after each weighing on days 30 (Month 1), 60 (Month 2), and 90 (Month 3), behavior and animal distribution in the paddock were recorded by direct visual observation in three periods of 4 consecutive days. Water temperature and fecal and herbage DM were also recorded in these periods. Water intake was measured during 16 random days in the troughs. Data were analyzed using Generalized Linear Mixed Models, with treatment and period as fixed effects. TROUGH steers gained more weight (0.44 vs. 0.34 kg/day/animal; P ≤ 0.007) during the experiment and were heavier than the others at the end of the study (P ≤ 0.05). POND steers spent more time drinking water, but TROUGH steers increased the number of drinking events throughout the study (P ≤ 0.05), suggesting an adaptation for the new type of water source. Both treatments increased grazing time throughout the study, but not ruminating time (P ≤ 0.05). Walking time differed between treatments in all periods of behavior observation (P ≤ 0.05). Events of animal licking and ingesting salt of POND steers reduced throughout the study (P ≤ 0.05). The number of drinking events of TROUGH steers increased throughout the study, and drinking events were longer for POND steers than TROUGH steers (P ≤ 0.05). TROUGH steers spent more time on pasture on Month 2 (P ≤ 0.05). Period collection did not affect the water intake of TROUGH treatment (P > 0.05). This study demonstrates that water available in troughs rather than ponds for steers on pasture has positive effects on their weight gain and affects cattle behavior.

Incorporating a Fresh Mixed Annual Ryegrass and Berseem Clover Forage Into the Winter Diet of Dairy Cows Resulted in Reduced Milk Yield, but Reduced Nitrogen Excretion and Reduced Methane Yield.

The winter diet of dairy cows in Mediterranean climate regions is usually a total mixed ration with a base of conserved summer crops such as corn silage and alfalfa hay. However, there is increased labor and financial cost related to this kind of feeding, which could be reduced if fresh forages were used in place of some of the conserved forage in the cow diet. The objective of our study was to evaluate the effect of including fresh mixed annual ryegrass and berseem clover into the diet of dairy cows on milk, nitrogen utilization, and methane emission. Twenty-four lactating dairy cows were split into two groups and offered either a diet similar to that usually offered to the cows (CON) or one where a mixture of fresh annual ryegrass and berseem clover was used to partially substitute the corn silage and alfalfa hay in the diet (MIX). Milk yield was recorded automatically, and methane emissions were estimated using the SF6 tracer technique. The MIX diet had lower crude protein concentration (148 vs. 170 g/kg DM) but higher DM digestibility (81.6 vs. 78.6%) than the CON diet. Compared to the cows offered the CON diet, milk yield was reduced when cows were fed the MIX diet (36.4 vs. 31.9 kg/d), but methane emissions (381 vs. 332 g/d) and nitrogen excretion were also reduced (238 vs. 180 g/d). Nitrogen use efficiency was unaffected (30.8%). In addition, milk from cows fed the MIX diet had a fatty acid profile considered to be more beneficial to human health than that of the milk from cows fed the CON diet. Increasing the protein concentration in the MIX diet, either by direct supplementation or increasing the proportion of legume in the mixed herbage, could overcome the reduction on milk and positively affect methane emission and N use efficiency.

Time of Grain Supplementation and Social Dominance Modify Feeding Behavior of Heifers in Rotational Grazing Systems.

Social hierarchy affects the access of animals to feed resources. On daily rotational pasture systems, supplementation time may influence feeding behavior. This trial was designed to test the effect of grain delivery time on the feeding behavior of heifers. Heifers divided into two groups according to breed (n = 15 Braford and n = 19 Jersey) were tested in a crossover design with two treatments: INITIAL-supplement at 8 am (entry time to a fresh paddock), and MIDDLE-supplement at 4 pm (middle time of paddock use). Animals entered a new paddock every morning, and grain supplement at 2 kg/animal/day was offered at the fence line (1 m/animal). Then, ingestive and other behaviors were registered by direct visual observation through scan sampling at 2-min intervals for 1 h after grain supply. Agonistic interactions were recorded continuously (instigator-victim) to build a social matrix whereby each heifer was defined as dominant, intermediate, or subordinate. Weekly pasture samples were collected according to the order that animals left the feeding area, using the hand-plucking technique, to determine crude protein and fiber content. Heifers spent more time grazing on the INITIAL treatment (p < 0.0001) but exhibited more behaviors on the MIDDLE treatment (p < 0.0001). Dominant heifers spent more time eating grain (p = 0.0008), whereas subordinate heifers spent more time grazing along the paddock (p = 0.0067), but not along the fence (p = 0.0008). The crude protein content of pasture samples was higher for the INITIAL treatment (p < 0.0001). Behavioral interaction occurred with respect to the order of leaving the feeding area, social rank, and crude protein consumed (p = 0.04). Subordinate heifers consistently grazed more and ate less grain supplement than dominant and intermediate heifers. However, when grain supplement was offered at the time animals entered the paddock, more grazing activity took place during supplement feeding, and subordinate heifers could select a high-protein diet. In the INITIAL treatment, this means that subordinate animals could benefit from the better pasture available, keeping a distance from dominant heifers, reducing agonistic interactions and likely improving their welfare.

The Equipment Used in the SF6 Technique to Estimate Methane Emissions Has No Major Effect on Dairy Cow Behavior.

The natural behavior of animals can be disrupted by the techniques and materials of research methodologies. This study aimed to evaluate the effect of the equipment used in the SF6 tracer technique to estimate enteric methane emissions on the behavior of lactating dairy cows. The cows (n = 24) were allocated to one of two diets: CONTROL and experimental diet (MIX). Behavior was assessed through video recordings between milking times during four phases: 3 days before fitting the cows with the SF6 equipment (PRE), first 2 days after the cows were fitted with the SF6 equipment (ADAP), 3 days during methane emission measurements (MEAS), and 2 days after the SF6 equipment removal (POST). The behaviors recorded included eating, ruminating or idling, resting, and others. Affiliative or agonistic and discomfort behaviors (scratching or pushing the equipment) were also recorded. Lying time was recorded over 14 days using dataloggers fitted to the cows' leg. Milk production and feed intake were recorded daily. MIX cows ruminated more than CONTROL cows (P = 0.05). The cows ruminated more at MEAS than in any other phase (P < 0.01). Time spent idling gradually decreased from PRE to MEAS for MIX cows (P < 0.01). The cows were lying down longer in MEAS than in ADAP and POST (P < 0.01). The time spent lying with the head down was shorter during PRE and ADAP than during POST (P < 0.05). No difference was observed in the occurrence of discomfort or agonistic behaviors (P > 0.05). Affiliative behaviors occurred more often in ADAP than in MEAS (P < 0.05). There was no difference between phases in daily lying time, number of lying bouts per day, or mean bout duration (P > 0.05). Milk production was not influenced by the SF6 equipment (P > 0.05). Dry matter intake was higher for CONTROL cows (P < 0.01), and it decreased from PRE to MEAS (P < 0.01). However, milk yield did not differ between cows wearing the SF6 equipment and those without it (P > 0.05). We conclude that the SF6 equipment had a minimal effect on dairy cow behavior.

Designing Better Water Troughs: Does Trough Color Influence Dairy Cows' Preference?

Eighteen lactating dairy cows were used to elucidate their preference for green, grey, or red troughs. The herd was managed under a rotational grazing system with ad-libitum access to water until 11:30 h. For 9 days, all cows were tested individually following the afternoon milking. Cows drank similar quantities, spent a similar amount of time drinking, and took a similar number of sips from the 3 trough colors (p > .05). In 75% of the tests, cows drank more than 95% of the test period from the same trough. Within this time, the percentage of choices did not differ among colors (33.3% green, 39.0% grey, and 27.7% red). When they chose the red trough, cows spent less time drinking (p ≤ .05) and tended to take fewer sips (p = .07), which could suggest a partial aversion to this color. Suboptimal water trough design may have long-term negative effects on both the production and welfare of dairy cattle; however, the results suggest that color does not play a major role in the drinking behavior of dairy cows.

Social Licking in Pregnant Dairy Heifers.

Housing affects social behaviors, such as competition, but little work has addressed affiliative behaviors. This study compared social licking (SL) in pregnant heifers housed indoors (in a free-stall barn) versus outdoors (on pasture), and relationships with competition, feeding and physical proximity to others. Six heifer groups were observed during two six-hour-periods in both treatments. The total number of social events (SL and agonistic interactions) was four times higher when heifers were housed indoors compared to pasture (546 ± 43 vs. 128 ± 7 events/group; P < 0.05). SL as a ratio of the total number of social events was similar in the two treatments (12% vs . 8% of interactions, free-stall and pasture, respectively; P > 0.05). Housing did not affect how the SL bout was initiated and terminated, the duration, the body part licked and behavior preceding licking ( P > 0.05). Animals in close proximity showed higher rates of SL ( P < 0.0001) but not agonistic interactions ( P > 0.05). A previous agonistic event did not predict occurrence or the role of heifers in the following licking event. The higher stocking density indoors likely resulted in increased social interactions.

The effect of gastrointestinal nematode infection level on grazing distance from dung.

Avoiding grazing near feces is an efficient strategy to prevent parasitic infection and contamination; therefore, in the evolution of herbivorous species, this behavior may have developed as a mechanism to protect the host against infection by gastrointestinal nematodes. The aim of this study was to assess whether grazing distance from dung is related to the level of parasitic infection in cattle. Based on Fecal Egg Count (FEC) means, 18 castrated male steers, aged 18 months, were divided into three groups: High (FEC ≥ 315); Medium (FEC = 130-160); and Low (FEC = 40-70). To analyze the response to a new natural infection by gastrointestinal nematodes and to standardize infection levels, all animals received anthelmintic treatment at twenty days prior to field observation. Three observers simultaneously collected data on grazing behavior for 2.5 hours/week for 12 weeks. Observers recorded the distance when grazing occurred at less than one meter from dung. Every two weeks, fecal samples were collected for FEC, as well as serum samples to measure immunoglobulin G (IgG) levels against larvae and adult antigens of the parasitic species Haemonchus placei. All groups grazed farther from the dung on days of greater insolation (r = 0.62; P = 0.03). Animals with high levels of parasitism grazed farther from the dung (P < 0.05) but had lower levels (P < 0.0001) of IgG serum levels compared to those with medium and low levels of infection. FEC values varied over the experiment, remaining below 200 for the low and medium group and reaching 1000 (P < 0.01) for the animals with the highest rates of parasitism. Our results indicate that cattle showing high levels of parasitism are more likely to avoid contaminated areas than animals with lower infection levels, and the immune system seems to be involved in such behavior.

Coçar-se, limpar-se e estabelecer vínculos sociais: o "grooming" e seu significado biológico nos ruminantes / Scratching, cleaning and social bonding: grooming and their biological meaning in ruminants / Rascarse, limpiarse y establecer vínculos sociales: el comportamiento de grooming y su significado biológico en rumiantes

Resumo A palavra grooming vem do inglês "groom", que significa "cuidar da aparência". O grooming ou catação é um comportamento que está presente em muitos grupos taxonômicos de animais; sendo um comportamento antigo que faz parte da história evolutiva deles. Reconhecem-se três tipos básicos desse comportamento: autogrooming, allogrooming e grooming baseado com o contato ambiental. A presente revisão de literatura objetiva aprofundar na análise desse comportamento nos ruminantes, com o intuito de oferecer uma visão geral que contempla aspectos da historia evolutiva, do valor adaptativo e da fisiologia dessa conduta. Também são feitas algumas referências sobre possíveis relações entre esse comportamento com o enriquecimento ambiental e o bem-estar animal dos ruminantes. Finalmente, é apresentada uma conclusão sobre as potencialidades que o estudo dessa conduta oferece para o fortalecimento do conhecimento científico desde diferentes áreas da ciência: evolução, fisiologia veterinária e zootecnia.

Abstract Grooming behavior is common in multiple animal species; apparently it has been present for a long time during evolutionary history. There are three basic types of this behavior: autogrooming, allogrooming, and grooming based on environmental contact. The aim of this review is to present a general analysis of this behavior in ruminants, including aspects related with evolution, adaptation, and physiology. Some references are made about possible relationships between grooming, environmental enrichment, and welfare in ruminants. Finally, it is concluded that the study of this behavior could enhance scientific knowledge from several areas: physiology, evolution, veterinary, and animal science.

Resumen Grooming es un comportamiento presente en diferentes grupos taxonómicos de animales y, al parecer, es un carácter bastante ancestral en la historia evolutiva de dichos grupos. Son reconocidos tres tipos básicos de este comportamiento: autogrooming, allogrooming y grooming basado en contacto ambiental. La presente revisión pretende profundizar en el análisis de dicho comportamiento en los rumiantes, con la idea de ofrecer un panorama general que contempla aspectos de la historia evolutiva, del valor adaptativo y la fisiología de esta conducta. De la misma manera, son discutidas algunas referencias sobre las posibles relaciones entre grooming, enriquecimiento ambiental y bienestar en rumiantes. Finalmente, se presenta una conclusión sobre las potencialidades que ofrece el estudio de esta conducta para el fortalecimiento del conocimiento científico desde diferentes áreas del conocimiento: evolución, fisiología, veterinaria y zootecnia.