Effect of grass silage and concentrate based finishing strategies on cull dairy cow performance, carcass and meat quality characteristics

Improving market (cull) dairy cows carcass traits and meat quality

Despite a high volume of market (cull) dairy cows entering the food chain every year, beef from market dairy cows is largely considered insignificant when compared with beef from beef cattle in the market and is widely thought to be used for ground beef only. Our study aimed to evaluate the effects of feeding dairy market cows on a lactating TMR diet before slaughter on carcass and beef quality traits. Forty-three Holstein market cows were randomly assigned into 2 treatments: Fed or Direct. Fed cows (n = 22) were dried off, then fed a lactating cow TMR ration for approximately 60 d whereas Direct cows (n = 21) were sent directly to slaughter. Hot carcass weight (HCW) was used to calculate the dressing percentage (DP) together with the animals' body weight recorded when animals left the farm to go to the abattoir. At 24h post-mortem, the rib fat thickness (RFT) and rib eye area (REA) were measured by a certified grader. Afterward, rib samples were collected between the 12th -10th ribs from one side of the carcass and divided into 5 ribeye steaks. The first steak was used for intramuscular fat (IMF) content analysis by NIRS. The other 4 steaks were then aged for 7, 14, 21, or 28 d. Following aging, the steaks available were assessed for tenderness using the Warner-Bratzler Shear Force protocol. Data were analyzed by mixed linear regression to compare experimental groups for continuous outcomes. HCW of the Fed cows was higher than the Direct cows, with a mean HCW of 408.3 kg and 326.1 kg, respectively (SE ± 9.0). Average DP in Fed cows was 49.1%, compared with 42.5% in Direct cows (SE ± 0.69). The average percentage of IMF in Fed cows was 8.1% and in Direct cows was 5.0% (SE ± 0.43). Fed cows had a mean REA of 68.1 cm2 and Direct cows had a mean of 57.7 cm2 (SE ± 11.9). No differences were found for RFT. The steaks aged for 14 d resulted in meat with a mean shear force (SF) of 4.19 kg in Fed cows, while Direct cows had a mean SF of 6.28 kg (SE ± 0.29) Feeding market dairy cows for 60 d before slaughter enhanced carcass weight and yield, IMF content, and tenderness. These results indicate that approximately 60 d of feeding can improve the quality of market dairy cow meat and may help improve market cow value.

Effect of age and diet on carcass and meat quality in ewes

This study elucidated the effect of age and diet on carcass characteristics and meat quality parameters of Rambouillet ewes. Forty ewes (n = 20 yearling ewes and n = 20 cull ewes) were fed with alfalfa hay (AH) or a 100 % concentrate diet (CD). Treatments were: a) 10 cull ewes were fed only with AH, b) 10 yearling ewes were fed only with AH, c) 10 cull ewes were fed with CD, d) 10 yearling ewes were fed with CD. Productive performance, carcass and meat quality were analyzed. Animals had ten days for adaptation and 35 days were used to collect data. Dry matter intake was greater (P < 0.05) for CD. Feed conversion rates were not affected by treatments. The pH at 45 min and 24 h, carcass length, leg length, leg width, thorax width, and thorax perimeter were not affected by treatments. Hot carcass weight was heavier (P < 0.05) in cull ewes, cold carcass weight was increased (P < 0.05) with CD. Carcass yield (CY) was heavier in CD (P < 0.05). Cull ewes had greater (P < 0.05) lean CIELAB L*, a*, b*, c*, and h* values compared to yearling ewes. The color changes increased with age at five days (P < 0.05), but a decrease (P < 0.05) with diet was observed at ten days. Cathepsins B, B + L, and Lowry protein content were not affected by treatments. In conclusion, feeding cull ewes with concentrate diets may enhance body weight gain and carcass yield compared to a diet based on 100 % alfalfa hay.

Carcass Characteristics and Meat Quality of Karacabey Merino lambs Reared under Triticale and Oat Pastures Compared with Stall-Fed Lambs

Fifty-eight Karacabey Merino lambs were used to study the effects of feeding system (triticale pasture, oat pasture, or stall-fed), birth type (single or multiple), gender (male or female), and birth year (2016 or 2017) on various carcass and meat quality characteristics. Stall lambs had higher conformation (CS) and fatness (FS) scores, and higher meat L* and h* values than the two pasture groups, possibly due to higher fat content, while oat pasture lambs had the most tender meat. Single-born lambs had higher CS, FS, and Longissimus thoracis muscle section area, while females had higher subcutaneous and non-carcass fat deposits than their counterparts. Both single-born lambs and 2016-born lambs had higher meat a* and C* values than their counterparts. In conclusion, a pasture-based feeding system is more suitable for Karacabey Merino lambs than a stall feeding system, if lean meat and/or meat products are preferred. However, it should not be ignored that stall-fed lambs showed a better fattening performance in terms of conformation and fatness, during the same period.

Does the Rearing Management following by Charolais Cull Cows Influence the Qualities of Carcass and Beef Meat?

This study characterized, for the first time, the rearing managements (from birth to slaughter) applied throughout the cull cows’ life and observed the effect of these managements on the carcass and meat properties. From the individual data of 371 Charolais cull cows, three rearing managements were defined and characterized with 60 rearing factors. The results showed that the rearing managements had low effects on the carcass and meat properties. For the carcass traits, only the carcass weight, and fat and longissimus (LM) colors at the level of the sixth rib were impacted. Concerning the meat, only the red color intensity, the fat aroma, the flavor intensity and persistence were affected. According to our results, this study confirmed that it is possible to produce carcass or meat with similar properties; consequently, it is difficult to favor a rearing management. However, to manage jointly both carcass and meat qualities, trade-offs are needed.

Effects of feeding starch sugar by-products on in situ rumen disappearance rate, growth performance, and carcass characteristics of late finishing Hanwoo steers

Objective

The aim of this study was to determine the effects of feeding starch sugar by-products (SSBs) on in situ disappearance rate, performance, and carcass characteristics of Hanwoo steers in the late finishing stage.

Methods

To determine the in situ disappearance rate, nylon bags filled with 5 g of SSB were inserted into the ventral sac of two cannulated Holsteins cows and incubated for 0, 2, 4, 8, 16, 24, and 48 h. A total of 30 Hanwoo steers were fed the experimental diets, which were basal diet (control) and 7% SSB on an as-fed basis (4.35% dry matter [DM]), formulated according to requirements of the Korean Feeding Standard for Hanwoo. The experiment was conducted over 80 days using a completely randomized block design.

Results

Soluble fraction a of DM and organic matter (OM) was 44.20% and 64.60% DM, fraction b was 23.00% and 19.40% DM, and c values (the rate of degradation of fraction b) were 0.04 and 0.04/h, respectively. The effective degradability of DM at rumen solid outflow rates of 0.02, 0.05, and 0.08/h was 59.83, 54.75, and 52.16, respectively, and for OM was 77.78, 73.52, and 71.34, respectively. Initial and final body weight, average daily gain, DM intake, and gain:feed did not differ significantly between control and SSB groups during the entire experimental period. Carcass traits of Hanwoo steers with SSB supplementation were not significantly different between treatments except for dressing percentage, which was greater with SSB treatment. The content of saturated fatty acid (SFA) was greater and that of unsaturated fatty acids (UFA) was lower in the SSB group than in the control group. The ratio of UFA to SFA was significantly lower in the SSB group than in the control group.

Conclusion

A total mixed ration containing less than 4.0% DM of SSBs can be used in Hanwoo steers without a decrease in productivity and carcass traits.

Beef production from cull dairy cows: a review from culling to consumption

Although more than 3 million head of dairy cows enter the food supply chain in the U.S. every year, research on this topic remains limited and scarce. Meat production from dairy cows is a significant component of beef production, accounting for almost 10% of U.S. commercial beef production. Thus, the purpose of this review is to demonstrate the importance of dairy cows as a beef source, and to provide an overview on topics from farm to meat product-culling, marketing, transportation, welfare, body composition and its relationship with lactation particularities, carcass characteristics, meat quality, and traceability. Current scientific evidence has shown that culling a dairy cow at an appropriate time has beneficial effects on cow welfare and, consequently, cow value. During marketing the dairy cow is visually evaluated for health and factors associated with its expected carcass value; thus, marketing a well-conditioned cow will ensure that the animal is fit for transportation and provides high carcass yield. However, limitations such as low body condition score, lameness or mobility problems, and visual defects remain persistent. Even though beef harvest plants accommodate cows in all body composition states, the current carcass grade system does not reflect the mature cow industry needs. Therefore, improvement of the grading system could maximize carcass utilization and increase cow carcass value by recognizing subprimal cuts that could be merchandised as whole muscle cuts. Lastly, implementation of a traceability system would unify information from the farm to harvest assisting the industry in making further advancements.

Dressing percentage and the differential between live weight and carcass weight in cattle are influenced by both genetic and non-genetic factors1

The objective of the present study was to quantify the genetic and non-genetic contributors to variability in both carcass dressing percentage and dressing difference (i.e., the difference between carcass weight and live weight immediately prior to slaughter) in young animals and cows. The datasets contained 18,479 young animals from 653 herds, and 2,887 cows from 665 herds. Live weight records within 7 d of slaughter and associated carcass weight were available for all animals. Association analyses were undertaken using linear mixed models with fixed effects for the model of young animals consisting of animal breed, days between the date of last recorded live weight and slaughter date, heterosis and recombination loss coefficients, dam parity, a 3-way interaction between whether the animal originated in a dairy or beef herd, animal sex, and age at slaughter, as well as a 2-way interaction between calendar year of slaughter and month of slaughter; contemporary group was included as a random effect. Fixed effects in the cow model were cow breed, the number of days between the date of last recorded live weight and slaughter date, heterosis and recombination loss coefficients, the number of days postcalving, parity of the cow, and a 2-way interaction between calendar year of slaughter and month of slaughter; contemporary group was included as a random effect. The mean dressing percentage (phenotypic standard deviation in parentheses) and dressing difference in young animals were 55.86% (3.21%) and 280.03 kg (41.44 kg), respectively. Steers had the heaviest dressing difference at 34.18 and 60.44 kg heavier than a 16-mo old bull and 22-mo old heifer, respectively. Dressing difference for 30-mo old Simmental steers (breed with heaviest dressing difference) was 41.66 kg heavier than 30-mo old Belgian Blue steers (breed with lightest dressing difference). The heritability of dressing percentage (0.48) and dressing difference (0.35) in young animals was relatively similar to each other, in contrast to dressing percentage (0.08) in cows which was considerably lower than dressing difference (0.28). Considerable genetic variability existed in dressing difference amongst young animals (genetic standard deviation of 15.03 kg), despite the near unity genetic correlation (0.93) between carcass weight and live weight. This therefore indicates that genetic selection for increased saleable product can be achieved by selecting for increased carcass weight while concurrently selecting for lighter animals although the opportunity is limited by the strong part-whole relationships that exists between carcass weight, live weight, and dressing difference.

Palatability and Biochemical Factors of Beef from Mature Cattle Finished on a Concentrate Diet Prior to Harvest

The objective of this study was to investigate the influence of grain-finishing on mature beef palatability. Beef strip loins (n = 15 per treatment) from 2 marbling score groups [Slight (SL) and Traces/Practically Devoid (TR/PD)] and 3 carcass types [young fed (YF), mature fed (MF), and mature unfed (MU)] were collected. Young fed and MF cattle were grain-finished prior to harvest, whereas, beef from MU cattle were not identified as being grain-finished prior to harvest. Consumer and trained sensory panels evaluated steaks for palatability characteristics. Additionally, Warner-Bratzler shear force (WBSF), collagen solubility, sarcomere length, and volatile compounds were evaluated. Consumer ratings were not influenced (P > 0.05) by an interaction of main effects. Slight samples were greater (P < 0.05) than TR/PD samples for tenderness, juiciness, flavor, and overall like. Trained panelists rated SL samples more tender (P < 0.01) than TR/PD samples. Additionally, YF and MU steaks were the most and least tender (P < 0.01), respectively. No differences (P > 0.05) were observed among SL samples for beef flavor, beef flavor intensity, or off-flavor intensity due to carcass type. However, TR/PD-MF and MU steaks had more intense (P < 0.01) off-flavors. Steaks from YF and MF carcasses had lower (P < 0.01) WBSF values than steaks from MU carcasses. Percentage of heat soluble collagen was greatest (P < 0.01) in YF carcasses. Among SL treatments, sarcomere length was not affected (P > 0.05) by carcass type; however, MF and MU carcasses with TR/PD marbling scores had shorter (P < 0.05) sarcomeres than YF carcasses. Various volatile compounds were influenced (P < 0.05) by treatment and showed relationships with sensory ratings. Improvements in palatability were observed due to grain-finishing mature cattle, suggesting an adequate degree of marbling could offset negative palatability traits typically associated with beef from mature cattle.

Grazing intensity affects the environmental impact of dairy systems

Dairy products are major components of the human diet but are also important contributors to global environmental impacts. This study evaluated greenhouse gas (GHG) emissions, net energy intensity (NEI), and land use of confined dairy systems with increasing levels of pasture in the diet. A Wisconsin farm was modeled to represent practices adopted by dairy operations in a humid continental climate typical in the Great Lakes region and other climates that have large differences in seasonal temperatures. Five grazing scenarios (all of which contained some portion of confinement) were modeled based on different concentrations of dry matter intake from pasture and feed supplementation from corn grain, corn silage, and soybean meal. Scenarios that incorporate grazing consisted of 5 mo of pasture feeding from May to September and 7 mo of confined feeding from October to April. Environmental impacts were compared within the 5 scenarios that incorporate grazing and across 2 entirely confined scenarios with and without on-farm electricity production through anaerobic digestion (AD). To conduct a fair comparison, all scenarios were evaluated based on the same total amount of milk produced per day where resource inputs were adjusted according to the characteristics of each scenario. A cradle-to-farm gate life cycle assessment evaluated the environmental burdens that were partitioned by allocation between milk and meat and by system expansion when biogas-based electricity was produced. Overall, results for all scenarios were comparable. Enteric methane was the greatest contributor to GHG emissions, and the production of crops was the most energy-intense process. For the confined scenario without AD, GHG emissions were 0.87 kg of CO₂ equivalents, NEI was 1.59 MJ, and land use was 1.59 m²/kg of fat- and protein-corrected milk (FPCM). Anaerobic digestion significantly reduced emissions to 0.28 kg of CO₂ equivalents/kg of FPCM and reduced NEI to -1.26 MJ/kg of FPCM, indicating a net energy producing system and highlighting the potential of AD to improve the sustainability of confined systems. For scenarios that combined confinement and grazing, GHG emissions ranged from 0.84 to 0.92 kg of CO₂ equivalents, NEI ranged from 1.42 to 1.59 MJ, and land use ranged from 1.19 to 1.26 m²/kg of FPCM. All environmental impacts were minimized in scenarios that supplemented enough feed to increase milk yield but maintained dry matter intake from pasture at a level high enough to reduce material and energy use.

The effect of feeding system on slaughter-carcass characteristics, meat quality, and fatty acid composition of lambs

Abstract. In this study, we aimed to determine the slaughter-carcass characteristics, meat quality, and fatty acid composition in lambs raised under intensive and extensive conditions. The animal material consisted of 30 Norduz male lambs, with an average age of 171 days. The lambs were divided into two groups: concentrate-fed lambs (CO) and pasture-fed lambs (PS). The results showed that the CO lambs had heavier carcasses (p< 0.001), a higher dressing percentage (p< 0.001), and higher intramuscular fat (p< 0.01) than the PS lambs. It was determined that the longissimus thoracis muscle of the CO lambs had a lower ultimate pH and higher L* and water-holding capacity than the PS lambs. In this study, intramuscular fat (longissimus thoracis, semimembranosus, triceps brachii), subcutaneous and tail fat samples were used to evaluate the effect of feeding system on fatty acid composition. The polyunsaturated fatty acid to saturated fatty acid ratio (PUFA ∕ SFA) of intramuscular fat was found to be significantly higher in the CO group than in the PS lambs, while similar subcutaneous and tail fat results were found in both groups. Moreover, the PS lambs had a lower n6 ∕ n3 ratio and higher percentage of omega-3 than the CO lambs in all tissues studied (p< 0.05). Overall, the CO lambs have heavier and fattier carcasses with better meat quality traits than the PS lambs. However, the effects of feeding system have varying results based on the fatty acid composition of different types of fat deposits.

Effects of pre-slaughter diet/management system and fasting period on physiological indicators and meat quality traits of lambs

This study determined the effects of pre-slaughter diet/management system on blood and rumen parameters and meat-quality traits of Norduz lambs. Eighty lambs were divided into two groups according to diet (AH: alfalfa hay; BAH: alfalfa supplemented with 500 g/head barley) for 21 days. Following this period, lambs from each group were distributed among four groups according to pre-slaughter fasting period as 0, 12, 24 or 48 h. Cortisol concentrations were found to be significantly higher in the 24 h and 48 h groups when compared to the 0 h group (p<0.01). Diet and fasting period had limited effect on muscle glycogen content and ultimate pH·L*, WHC and moisture decreased in line with increases in the fasting period (p<0.01). In conclusion, carcass conformation and some meat quality traits were better in BAH lambs. Fasting had a negative effect on some meat quality parameters, with significant increases in some physiological stress indicators after fasting periods of 24 h or longer.

Effect of flaxseed and forage type on carcass and meat quality of finishing cull cows

Hernández-Calva, L. M., He, M., Juárez, M., Aalhus, J. L., Dugan, M. E. R. and McAllister, T. A. 2011. Effect of flaxseed and forage type on carcass and meat quality of finishing cull cows. Can. J. Anim. Sci. 91: 613–622. Sixty-two cull cows were fed one of four diets in a 2×2 factorial arrangement, consisting of barley silage or grass hay with or without flaxseed to influence fatty acid composition. After slaughter, carcass grade, meat quality and sensory data were collected. Silage increased live (P=0.002) and carcass (P=0.001) weights of the cows as compared with hay. Muscle width (P=0.013) and score (P=0.010) and rib-eye area (P=0.002) were enhanced when silage was included in the diet, whereas supplementation with flaxseed increased (P=0.003) grade fat depth by 29%. Most subjective and objective retail evaluation traits in steaks from the left longissimus thoracis and ground meat were negatively affected (P<0.05) by the length of the retail display time. Moreover, dietary hay increased (P=0.015) the lean colour values in steaks and ground beef, which was corroborated by lower L* (P=0.009) and higher hue (P=0.010) in steaks and lower L* (P=0.049), chroma (P=0.005) in ground beef as compared with cows fed silage. A significant interaction between forage type and flax inclusion for thiobarbituric acid reactive substances (TBARS) (P=0.050) was observed. After sensory evaluation, steaks from cows fed silage had an increase (P=0.030) in beef flavour intensity when compared with cows fed hay, whereas inclusion of flaxseed in the diet decreased (P<0.001) beef flavour intensity in steaks from cows fed both forage sources. Sensory evaluation of ground beef found that hay-fed cows with flaxseed supplementation had decreased (P=0.03) beef flavour intensity, while the same effect was not observed in ground beef from cows fed silage with flaxseed. Results from this study show that inclusion of flaxseed in the diet reduced off-flavours in steak, but for ground beef this response depended on the source of forage in the diet.

An evaluation of over-wintering feeding strategies prior to finishing at pasture for cull dairy cows on live animal performance, carcass and meat quality characteristics

Fifty-six spring calving Holstein-Friesian dairy cows (body weight=607 kg and body condition score=2.75), destined for culling, were randomly assigned to one of four experimental treatments. Cows were confirmed non-pregnant by rectal palpation. The experiment was split into two periods: over-wintering period (OWP) and spring finishing period (SFP). Animals were assigned to one of four treatments: a control group (C) was slaughtered after am milking on day 0; three dietary treatments, two of which were dried pre-experiment; ad libitum grass silage (GS+G); 75% grass silage and 25% straw (GS+S); and one with the extended lactation concept applied, cows were offered grass silage plus 6 kg concentrate DM/cow/day and milked twice daily (EXTLAC). EXTLAC cows were dried-off 1 week prior to turnout. The OWP lasted 84 days. Subsequent to the OWP cows were turned out to pasture (SFP). All cows were finished to a pre-defined carcass specification; >272 kg cold carcass weight, P+carcass conformation class and 3 carcass fat class. Over the entire experimental period, average daily gain (ADG) was lower (P<0.001) for the EXTLAC treatment compared with the two other dietary treatments. The GS+G treatment finished 33 and 38 days (P<0.001) earlier than the GS+S and EXTLAC treatments, respectively. Total feed utilized on a DM basis was 1.9, 2.0 and 2.5 tonnes/cow for the GS+G, GS+S and EXTLAC dietary treatments, respectively. All finishing treatments resulted in a significant improvement in carcass weight, as well as carcass quality traits, compared to the C group. A significant improvement occurred in muscle redness between the C group and treatments offered a finishing period prior to slaughter.