Invited review: Development and expression of dairy calf feeding behaviour

Miller-Cushon, E. K. and DeVries, T. J. 2015. Invited review: Development and expression of dairy calf feeding behaviour. Can. J. Anim. Sci. 95: 341–350. Feeding and housing practices for dairy calves impact performance and growth early in life, as well as feeding behaviour. There is also increasing evidence that early exposure to different feeding and housing strategies influence the development of feeding behaviour. The dairy calf needs access to milk in sufficient quantities to maintain health and high-levels of growth. In addition, intake of solid feed, such as grain concentrate, is necessary early in life to establish fermentation and develop the rumen. In dairy calves, feeding behaviour patterns can have direct impact on nutrient consumption and, consequently, growth. Further, recent research has provided evidence that behaviour patterns that develop in response to management factors early in life may persist once learned, potentially having longer-term implications for health and welfare. Thus, there is potential for various nutritional, housing, and management factors to impact the learning of feeding behaviour early in the life of dairy calves. This review provides several examples of early management factors that influence feeding behaviour of dairy calves and, in turn, impact calf growth and welfare. For example, providing continuous, ad libitum access to milk results not only in greater growth, but also in meal patterns that more closely resemble the natural behaviour of a calf suckling its dam. Housing management also has the potential to influence when, and how much, a calf eats. Whereas social facilitation promotes intake, particularly at weaning, competition for feed in group-housed calves restricts feeding patterns and degree of feeding synchrony. With regards to provision of solid feed, recent data suggest that providing physically effective hay, in addition to grain concentrate, may be beneficial for the rumen environment and consequent growth and efficiency. However, the physical form and presentation of forage may also influence feeding behaviour of calves, in particular feed sorting, which can impact both immediate nutrient intakes as well as the development and persistence of that behaviour. For example, calves provided hay and concentrate as a mixture begin to sort their feed early in life, with the pattern of sorting depending on hay particle size. Feed sorting in young calves may reflect a motivation to consume a proportion of hay in the diet. In general, it appears to be beneficial for early growth and welfare to support milk and solid feed intake through unrestricted allowances and less-competitive feeding environments. Continued research in this area is needed to assess the longevity of learned behaviour patterns, and what factors may influence their persistence. </jats:p

Modelling and Sensitivity Analysis of Ice Motion Near Adams Island

WRI Project No. 308-12prepared for National Research Council Canadapr\ue9par\ue9 pour le Conseil national de recherches CanadaPeer reviewed: NoNRC publication: Ye

Feeding amount affects the sorting behavior of lactating dairy cows

The objective of this study was to determine whether feed sorting behavior in dairy cattle is influenced by the amount of feed provided. Six lactating Holstein cows, individually fed a total mixed ration once daily, were exposed to two treatments in a crossover design with 7-d periods. The treatments were: (1) lower feed amount (LFA; target 10% orts), and (2) higher feed amount (HFA; target 20% orts). Dry matter intake (DMI) was monitored daily for each animal. On the final 4 d of each treatment period, fresh feed and orts were sampled for particle size analysis. The particle size separator had three screens (19, 8, 1.18 mm) and a bottom pan, resulting in four fractions (long, medium, short, fine). Sorting was calculated as the actual intake of each particle size fraction expressed as a percentage of the predicted intake of that fraction. Actual orts percentage averaged 11.5% for the LFA and 18.0% for the HFA treatments. When on the HFA cows sorted for the medium particles to a greater extent than on the LFA (103.0 vs. 101.1%). Further, when on the HFA treatment cows sorted against short particles to a greater extent than on the LFA (95.2 vs. 98.6%). Despite greater sorting on the HFA treatment, the concentrations of neutral detergent fiber (NDF; 29.6%) and starch (27.1%) in the feed consumed were similar between treatments. Given this, and that DMI was greater on the HFA treatment compared with the LFA treatment (29.7 vs. 26.5 kg d-1), greater intakes of NDF (8.7 vs. 7.8 kg d-1) and starch (8.0 vs. 7.2 kg d-1) were also observed on the HFA treatment. The results suggest that, despite causing greater feed sorting, increasing the feeding amount for lactating dairy cows promoted higher DMI and did not prevent the consumption of a ration balanced to meet their nutritional requirements.Key words: Feeding amount, sorting behavior, dairy cow </jats:p

Deprivation and food access and balance in Saskatoon, Saskatchewan

Introduction We explored food access and balance in Saskatoon, Saskatchewan, Canada in relation to material and social deprivation. Methods We mapped the location of all large supermarkets and fast food retailers in Saskatoon. Supermarket accessibility index scores and food balance scores were compared to material and social deprivation indexes to determine significant associations. Results Our results indicate that the poorest access to supermarkets occurred in areas west of the South Saskatchewan River and also in suburban areas around the perimeter of the city. Areas west of the river are some of the most deprived areas in the city. Saskatoon's mean food balance ratio of 2.3 indicates that access favours fast food. However, we did not find a clear pattern or clear socio-economic gradient for most measures. Conclusion This study highlights the importance of contextual studies of food access. This study also highlighted a number of other issues that should be explored in the Saskatoon context such as individual-level food consumption patterns, mobility, temporal dimensions of food access and economic access as well as interventions that could improve food access in the city. </sec

Factors Associated with Childhood Depression in Saskatoon Students: A Multilevel Analysis

This study examined links between depression and multilevel factors among children from Saskatoon elementary schools. A total of 4,200 students participated in the Saskatoon Student Health Survey conducted in 2008–9. Covariates included demographics and family structure, relationships, physical activity, bullying experiences, and school refusal behaviours. A multilevel logistic regression model was used to examine the impact of individual-level and school-level (contextual) factors. The study revealed that depression disparity existed among schools, and students’ school refusal behaviours such as skipping or being suspended from school were among the main factors contributing to the disparity between schools.</jats:p

Long-term effects of preweaning social housing on response to a social and housing transition in pregnant heifers

ABSTRACT: Dairy cattle are routinely managed in social groups and subject to various management and social transitions, yet conventional approaches to rearing dairy calves limit social experience during early weeks of life. The objective of this study was to evaluate long-term effects of dairy calf social housing on behavioral responses observed in pregnant heifers following social regrouping and introduction to a novel housing environment. Holstein heifers were raised during the milk-feeding period (provided 8 L/d milk replacer) in either individual housing (IH; n = 20) or pair housing (PH; n = 20 pens; 1 focal heifer/pen) and subsequently identically managed in groups on pasture from 9 wk of age. At 30 d before expected calving, pregnant heifers were moved from pasture to a freestall barn, which represented introduction to a novel social group and an unfamiliar housing environment. Behavior was continuously recorded from video for 24 h, beginning at 0000 h on the day after introduction, to characterize feeding behavior, locomotor activity, and stall usage, as well as social proximity and competitive behavior surrounding the feed bunk and stall. Stocking density of the freestall barn fluctuated and was categorized as low (≤75%, 100 × animals in pen/available stalls), medium (>75%, 100%), or high (≥100%). Body weights obtained following calving indicated that previously PH heifers were heavier (632.3 vs. 593.4 kg; PH vs. IH), and BW was included as a covariate in analysis of feeding behavior. Upon introduction to the freestall pen, previously PH heifers spent more time walking (1.9 vs. 1.3 min/h) with no effect of calf social housing on duration of lying time. However, stall use was subject to an interaction between previous housing treatment and stocking density and differed overall between previous housing treatments; previously PH heifers spent less time in the stall, particularly at high stocking density (29.4 vs. 48 min/h), due to shorter (29.6 vs. 95.7 min/visit) but marginally more frequent stall visits. Previously PH heifers were also less likely to be displaced from a stall (44% vs. 85% of heifers replaced; PH vs. IH). Feeding behavior was similarly influenced by previous housing treatment, particularly at high stocking density, with previously PH heifers spending more time feeding (8.2 vs. 4.2 min/h) and visiting the feed bunk more frequently (1.5 vs. 0.8 visits/h). These results suggest that preweaning social housing had long-term effects on behavior and ability to adapt to a novel environment, which became most apparent under heightened competitive pressure