Phenotypic Relationships Between Residual Feed Intake, Feeding Behaviour and Temperament in Western Canadian Beef Cattle PDF Download

Author: Lindsey Lippens
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Languages : en
Pages : 0

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Feed costs have led the cattle industry to examine the merit of selecting cattle for inputs (feed efficiency) rather than for outputs exclusively (growth). Residual feed intake (RFI) has become a preferred measure of biological efficiency. Feeding behaviour traits (feeding event duration, frequency, head-down time, length and eating rate) and temperament may provide insight into the variation in feed efficiency. Feeding behaviour, RFI (n = 868) and temperament (n = 58) were examined using five classes of beef cattle. Cattle were sorted into low, medium and high RFI groups. Feeding behaviour traits were moderately (-0.21 to 0.56; P 0.05) related to RFI. Bulls fed a grain-based diet spent longer periods lying down than bulls fed a forage-based diet. No relationships (P 0.1) were observed between RFI and bull temperament, indicating that temperament is not correlated with RFI and selecting for low RFI cattle will not negatively impact temperament.

Author: Cameron Alexander Olson
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Category : Beef cattle
Languages : en
Pages : 0

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Reproductive efficiency in the Western Canadian beef cow herd has not improved over the past 3 decades, despite consistent and measurable improvement in several related areas of production. The general objective of this thesis was to evaluate the relationships between early-observation traits (feeding behaviour), weight change, and reproductive efficiency in beef cows. Estimates of total dry matter intake and the relationship between residual feed intake (adjusted for body composition; RFIFAT) observed in heifers and mature cows were also evaluated as traits of interest and use to the Canadian beef industry. Chapters 3 and 4 investigated the relationship between feeding behaviours and reproductive efficiency and provided phenotypic and genetic correlations that may be of use in selecting heifers with greater reproductive potential if those heifers have feeding behaviours reported. Feeding behaviour and reproductive efficiency were both correlated with dry matter intake; feeding behaviours that promote dry matter intake may be useful in the identification of heifers with greater reproductive potential. Chapter 5 evaluates the usefulness of tracking cow weights over time and the usefulness of comparing cow weights to an idealized growth curve estimation. Generally, cows that gained weight over time were more likely to be culled for reproductive failure, and the same was true for cows that were heavier than their estimated body weight. Producers may be able to use weight-monitoring technology currently available and in development to identify cows that abort their calves after a positive pregnancy evaluation and remove them from their herd at a time when feed resources are expensive. Chapter 6 was a comprehensive and unique estimation of cow dry matter intake over time, including energy estimates based on birth, weaning, residual feed intake tests as a heifer and as a cow, and subsequent calving events with associated energy expenditures for milk production. These estimates were compared to genomic retained heterozygosity, breed composition, and winter-feeding environment to evaluate the effects of those variables on dry matter intake predictions. Chapter 7 investigated the relationship between heifer residual feed intake and residual feed intake observed in the same animals as mature cows. Residual feed intake in heifers can be used to select cows that maintain a proportion of their efficiency observed as heifers, and ultimately provides evidence that the selection of feed-efficient heifer calves as replacement animals should result in a more efficient mature cow herd. This thesis provided evidence to support the selection of heifer replacements using feeding behaviours observed during a feed intake test, the use of weight monitoring technology to identify cows that may have had reproductive issues. This thesis also provided some of the first estimates of dry matter intake over the course of the production cycle in a large number of animals under normal production environments and provided estimates of the relationship between heifer and cow residual feed intake.

Author: Egleu Diomedes Marinho Mendes
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Languages : en
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The first objective of this study was to validate the feeding behavior measurements from a radio frequency electronic system (GrowSafe (TM) System Ltd., Airdrie, AB, Canada) and examine the software sensitivity to different parameter settings (MPS) to quantify feeding behavior traits. Data was continuously recorded 24 h per day using the GrowSafe (TM) system for 32 heifers over 81-d. Ten animals were randomly selected and evaluated over 6-d using time-lapse video recordings. Different parameter settings (MPS) from the electronic system (GrowSafe (TM)) used to record feeding behavior data, bunk visits (BV) frequency and BV duration, were compared with the observed (video) values. The second objective of this study was to quantify meal criterion; examine the associations between feeding behavior traits, performance, and feed efficiency; and the effects of breed type on feed efficiency (residual feed intake - RFI) and feeding behavior traits in heifers fed high-grain diets. Results from study one demonstrated that the GrowSafe (TM) system 4000E could accurately predict BV and meal data compared to observed data. The 100 s, used for the maximum duration between consecutive EID recordings to end an uninterrupted BV, was the appropriate MPS to predict BV frequency and duration, and meal frequency and duration compared to observed data using the GrowSafe (TM) 4000E system. The system's ability to detect the animal's presence or absence at the feed bunk was 86.4 and 99.6 percent, respectively. Results from the second study demonstrated that the meal criterion for heifers fed high-grain diets was 13.8 min. The 4 methods to calculate meal criterion demonstrated no differences in results of frequencies and durations of meal and the number of bunk visits per meal. Similar phenotypic correlations were found between the feeding behavior traits with RFI derived from the base model or with adjustments for final back fat. The adjustment of RFI to final back fat changed the RFI rank between breeds. The addition of feeding behavior traits to the RFI base model could accounted up to 40.4 percent of the variation in DMI not explained by ADG or MBW.

Author: Marcus McGee
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ISBN:
Category : Beef cattle
Languages : en
Pages : 310

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Feed efficiency is a necessary factor in beef production systems due to rising feed ingredient costs, population growth, and beef supply demands. With this known, it is important for researchers to delve into mechanisms involved in efficiency to provide producers with a knowledge base for future selection and breeding programs. Though the use of residual feed intake (RFI) is fairly well know, traditional traits are often considered more desirable due to costs associated with testing. However, previous research has provided evidence of benefits using a less biased measurement (RFI) in comparison with its counterparts (e.g. ADG, FCR, F:G etc.) Though RFI does provide indication of efficiency status, there are underlying mechanisms that also play a role in these measurements that are not completely understood. One attribute of efficiency often overlooked is feeding behavior, in which this body of work attempts to interpret via relationships with RFI. Previous research has provided has examined relationships between these two parameters, however further studies are necessary to gain a more solid foundation. Research within this dissertation will add to this knowledge base using two breeds of cattle examined for behavior traits (bunk visit frequency, bunk visit duration, feed bout frequency, feed bout duration, meal frequency, meal duration, and average meal intake) during the course of RFI evaluation. Niche breeds of beef cattle (e.g. Japanese Black Cattle) are often excluded from feed efficiency examinations, due to focuses of output, carcass quality traits, and increased specialty market value. However, the recent rise of feed ingredient costs are universal, and producers of niche breeds may benefit as well. Within this body of work, 3 cohorts of Wagyu cattle were evaluated for feeding behavior parameters with some insight towards relationships with efficiency. Red Angus cattle were also evaluated over both growing and finishing phase RFI to clarify feeding behaviors' role in efficiency. Results from these studies provide researchers with additional tools for elucidating these relationships as well as identifying specific feeding behaviors that contribute to efficiency status in beef cattle.

Author: Joseph Walter Golden
Publisher:
ISBN:
Category : Cattle
Languages : en
Pages : 178

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Feed represents 60 to 70% of the cost of raising an animal to market weight, and is thus a major determinant of profitability. The task of collecting and analyzing individual feed intakes and feed efficiencies has limited the amount of research conducted to improve feed efficiency, and thus profitability. Thus, selection for growth has received more emphasis in genetic improvement schemes in comparison to improvement of feed efficiency. The utilization of robust and innovative technologies has allowed for the collection of individual feed intakes and feeding behaviors and allowed for more expansive research in determining and understanding the variables linked to the phenotypic expression of feed efficiency. Two studies utilizing GrowSafe technologies were conducted to determine the relationship of mitochondrial function and feeding behavior to the phenotypic expression of feed efficiency. (Abstract shortened by UMI.).

Author: William C. Kayser
Publisher:
ISBN:
Category : Beef cattle
Languages : en
Pages : 124

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Feed is the largest variable cost associated with beef production, any reductions of feed inputs whilst maintaining outputs will result in direct increased profitability for the industry. Traditionally individual feed intake has been expensive and laborious to measure. Recent improvements in technologies for measuring individual feed intake have made incorporating the phenotype into breeding selection decisions possible. Residual feed intake (RFI) is defined as the amount of feed that an animal consumed adjusted for the expected consumption based upon requirements for maintenance and growth. RFI is independent of body weight (BW), gain (ADG), carcass and meat quality. RFI is highly correlated with feed intake (DMI) and moderately heritable (r = 0.40). There are differences in feeding behaviors amongst the divergent RFI classes, animals with low RFI tend to spend less time eating per day and have fewer overall meals per day. There are many documented differences between low and high RFI animals, by adding to the knowledge base on RFI there should be increased producer and industry adoption.

Author: Tera Elizabeth Loyd
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ISBN:
Category :
Languages : en
Pages :

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Heifers were ranked by RFI and placed into Low (most efficient; 0.5 SD; n = 24), Med (0.5 SD; n = 24), and High (least efficient;0.5 SD; n = 26) RFI groups. Initial BW, final BW and ADG were similar among groups. However, daily DMI differed for all groups (P

Author: Jayton Bailey
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ISBN:
Category :
Languages : en
Pages :

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The objective of the first study was to determine which combination of bimodal (2-population) distribution models best fit non-feeding interval data to distinguish intervals within (1st population) and between (2nd population) meals in beef cattle fed a corn-based diet. Feeding behavior traits were measured in 119 heifers fed a corn-based diet using a GrowSafe system. Bimodal distribution models were fitted to the log10-transformed interval lengths between bunk visit (BV) events for each animal using Gaussian (G); Weibull (W); Log-Normal; Gamma and Gumbel statistical functions. Criterion (AIC) and likelihood probability estimates. Objectives of the second study were to quantify individual meal criterion and examine the associations between feeding behavior traits, performance, and feed efficiency traits in heifers fed a corn-based diet. Results from study one indicate that the G-W bimodal distribution model is a statistically better fitting and likely a more appropriate model to define meal criterion compared to the standard G-G model used in previous literature. Results from the second study suggest that the meal criterion for heifers fed a corn-based diet is 11.48 min when applying the G-W bimodal model to log-transformed interval lengths between BV events. Moderate phenotypic correlations between feed efficiency (residual feed intake- RFI) and several feeding behavior traits were found. Inclusion of these feeding behavior traits to the base model for RFI accounted for an additional 25% of the variation in DMI not explained by ADG or mid-test BW0.75. Significant (P

Author: Jose Gilberto Moreno Rajo
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Languages : en
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Objectives of this study were to characterize feed efficiency traits and examine phenotypic relationships with feeding behavior traits in bulls. Performance, feed intake and feeding behavior traits were measured in bulls (n = 5,165) representing 2 breeds (4100 Angus and 952 Red Angus). Intake and feeding behavior traits were measured for 70-d using a GrowSafe system while fed a corn silage based diet (ME = 2.50 Mcal/kg DM). BW was measured at 14-d intervals. Residual feed intake (RFI) was calculated as the difference between actual DMI and that expected from regression of DMI on mid-test BW0.75 (MBW) and ADG, and residual gain (RG) as the difference between actual ADG and that expected from regression of ADG on MBW and DMI. Residual gain and intake (RIG) was computed as the sum of -1 x RFI and RG, both standardized to a variance of 1. Results from the study indicate that RFI was correlated with DMI (r = 0.71, P

Author: Glenda Marie Bingham
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Languages : en
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The objective of this study was to determine if feeding behavior traits are correlated with performance and feed efficiency traits in growing heifers. Individual dry matter intake (DMI) was measured in Brangus heifers (n = 115) fed a roughage-based diet (ME = 2.1 Mcal/kg) for 70 d using Calan gate feeders (6 heifers/pen). Residual feed intake (RFI) was computed as the residuals from linear regression of DMI on mid-test BW0.75 and average daily gain (ADG). Heifers with the highest (n = 18) and lowest (n = 18) RFI were identified for feeding behavior measurements. During days 28 through 56 of the 70-d feeding trial, continuous video recordings were obtained for all heifers. Video images of two sets of four 24-h periods, two weeks apart, were analyzed for the focal animals. All occurrences of feeding were timed and counted per day, and the eight 24-h periods averaged to derive the overall feeding event (FE) and meal duration and frequency for each focal heifer. Total feeding event duration was defined as the total min per day the animal0́9s head was down in the feed bunk. A meal included all visits an animal made to the feed bunk that were separated by less than 5 min. The mean RFI values for the low and high RFI heifers were (mean " SE) - 1.03 and 1.00 " 0.03 kg/d, respectively. Low RFI heifers consumed 21.9% less (P