Nitrogen-containing fertilisers restrict grain intake by cattle

Supplements of barley, a barley-lupin mix (BL), or lupin grain containing urea plus ammonium sulfate (4% + 0.5%, low N; 6% + 1.0%, high N) were offered ad libitum to Holstein-Friesian steers. Supplement intake was restricted by increasing the amount of urea and ammonium sulfate (average intake of 1.7 and 1.4 kg DM/day.100 kg LW for cattle offered low and high N supplements). Supplement intakes were 14-56% greater than predicted from previous studies. Despite the high N content of the diet consumed by steers offered supplements containing lupin (up to 4.8% N with the high N supplement), feed conversion efficiency (FCE) of these cattle was better (P<0.01) than for cattle offered barley supplements (5.3, 5.8, 6.1 kg DM/kg LW gain for lupin, BL, barley). In another experiment, Holstein-Friesian steers offered grain immediately before an ad libitum supplement of barley containing 8% urea consumed 30-50% more grain than those without immediate prior exposure to grain. When the intakes of Holstein-Friesian steers offered ad libitum supplements of either barley or lupin containing either 8% urea or 5.7% diammonium phosphate (DAP) were compared, supplement intakes across grains averaged 1.3 and 0.6 kg DM/day. 100 kg LW. These levels of urea and DAP were predicted to result in similar intakes. However, to achieve a desired level of supplement intake, less DAP was required than urea. Both liveweight gain and FCE were 22-24% greater for cattle offered lupin than those offered barley supplements. Adding urea at 0, 0.5, or 1.0% to a barley supplement containing 4% DAP did not affect supplement or hay intakes by Holstein-Friesian steers, which averaged 0.8 and 1.7 kg DM/day.100 kg LW, respectively. Liveweight gain and FCE were increased by 25% by adding urea to a barley supplement containing DAP. Finally, 3 different methods of introducing a grain supplement containing DAP to Holstein-Friesian steers were compared: a 4-phase, 16-day introductory period; a 2-phase, 7-day introductory period; no introductory period. In steers with and without immediate prior exposure to grain, neither method of introduction nor previous exposure to grain affected supplement intake, liveweight gain, or FCE.

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Effect of forage to concentrate ratio and duration of feeding on growth and feed conversion efficiency of male lambs

Translational Animal Science ◽

10.1093/tas/txy071 ◽

2018 ◽

Vol 2 (4) ◽

pp. 419-427 ◽

Cited By ~ 2

Author(s):

Noel A Claffey ◽

Alan G Fahey ◽

Vasiliki Gkarane ◽

Aidan P Moloney ◽

Frank J Monahan ◽

...

Keyword(s):

Conversion Efficiency ◽

Carcass Weight ◽

Feed Conversion ◽

Fresh Weight ◽

Viable Option ◽

Financial Return ◽

Feed Conversion Efficiency ◽

Ad Libitum ◽

The Cost ◽

Concentrate Inclusion

Abstract Rations (DM basis) for spring-born male lambs consisting of concentrates ad libitum (CON), 50:50 (50% concentrate:50% forage), and forage ad libitum (FORG) were evaluated across feeding periods of three durations (36, 54, and 72 d). Lambs on CON diets were offered ad libitum access to concentrate along with 400 g of fresh weight silage (daily), while 50:50 diets were offered 0.9 and 3.0 kg of concentrate and silage, respectively. Lambs on FORG were offered ad libitum access to 25.5% DM silage. These rations were fed to 99 spring-born male Texel cross Scottish Blackface lambs which were assigned to a 3 × 3 factorial arrangement. Lambs were slaughtered following completion of their respective treatments. Lambs fed CON diets had greater ADG, FCE, and carcass weight (P < 0.001) and carcasses with greater conformation score (P < 0.001) than lambs fed 50:50 or FORG diets. Duration of feeding had no effect on production variables across all three concentrate inclusion levels. It was concluded that the inclusion of concentrates is needed to adequately finish lambs fed indoors. Feeding lamb’s 50:50 diets resulted in modest responses and may be a viable option for finishing lambs or to maintain growth in lambs when the cost of concentrate feed is high relative to the financial return on the lamb meat.

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Exogenous growth hormone releasing factors and cottonseed meal improve growth performance and composition of gain in lambs fed lucerne chaff ad libitum

Australian Journal of Agricultural Research ◽

10.1071/ar9941111 ◽

1994 ◽

Vol 45 (6) ◽

pp. 1111 ◽

Cited By ~ 1

Author(s):

RD Sainz ◽

BJ Hosking ◽

FJ Hart ◽

BR Schricker

Keyword(s):

Growth Hormone ◽

Growth Performance ◽

Cottonseed Meal ◽

Conversion Efficiency ◽

Meat Tenderness ◽

Feed Conversion ◽

Feed Conversion Efficiency ◽

Reduced Fat ◽

Ad Libitum ◽

Dressing Percentage

Forty-eight crossbred wether lambs (38 kg) were randomly assigned to two dietary groups (LUC, chaffed lucerne ad libitum; CSM, LUC plus 300 g cottonseed meal/lday) and two hormone treatment groups (rGRF, recombinant growth hormone-releasing factor (GRF); sGRF, synthetic GRF) plus controls (CON, excipient only), and slaughtered after treatment for 28 (n = 36) or 30 (n = 12) days. An initial slaughter group (n = 12) was killed on day 0. CSM reduced intake of lucerne chaff, but increased total feed intake. CSM also increased liveweight gain and wool growth, with no effect on feed conversion efficiency. CSM increased carcass weight and decreased subcutaneous fat depth, with no effect on dressing percentage or longissimus dorsi (LD) area. Meat tenderness tended to decrease with CSM supplementation. CSM increased carcass protein accretion ( P < 0.01), with no significant change in fat gain or final composition (P > 0.05). CSM increased weights of the pelt, liver and empty body, and decreased the proportion of digesta in liveweight. Weights of blood, forestomachs and small intestine tended to increase as well (P < 0.10). Both sources of GRF had similar effects. Intakes were not significantly affected by GRF, but feed conversion efficiency improved (P < 0.01) with GRF treatment (6.4 v. 9.2 feed:gain for GRF and CON respectively). Liveweight gains and final weights of the whole body and carcass were increased additively by CSM and GRF. GRF reduced fat depth and increased LD area, with no effect on dressing percentage, carcass length or meat tenderness. These changes reflected increased carcass protein and reduced fat contents, brought about by increased accretion of protein and water and reduced fat gain due to GRF. GRF increased weights of blood and liver beyond the general increase in body size. Cottonseed meal and GRF additively produced significant improvements in growth performance and carcass quality of young wether lambs fed a roughage diet. GRF may be a useful tool to improve livestock production under extensive and intensive conditions.

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Effect of probiotic Bacillus amyloliquefaciens strain H57 on productivity and the incidence of diarrhoea in dairy calves

Animal Production Science ◽

10.1071/an15776 ◽

2017 ◽

Vol 57 (5) ◽

pp. 912 ◽

Cited By ~ 4

Author(s):

Oanh T. Le ◽

Peter J. Dart ◽

Karen Harper ◽

Dagong Zhang ◽

Benjamin Schofield ◽

...

Keyword(s):

Conversion Efficiency ◽

Bacillus Amyloliquefaciens ◽

Rumen Fluid ◽

Animal Health ◽

Dairy Calves ◽

Feed Conversion ◽

Feed Conversion Efficiency ◽

Whole Milk ◽

Ad Libitum ◽

Animal House

A spore-forming probiotic, Bacillus amyloliquefaciens strain H57 (H57), was administered to dairy calves in starter pellets to determine effects on liveweight gain, feed conversion efficiency and animal health under summer feeding conditions, without antibiotics. Twenty-four male and female calves were allocated into two groups and from 4 weeks of age individually offered 6 L/day of whole milk and ad libitum starter pellets impregnated with H57 (3.16 × 108 cfu per kg DM) or without (Control) until 12 weeks of age. The calves were housed in a non-air-conditioned animal house, with deep-straw bedding over concrete, under typically challenging subtropical summer conditions. After 12 weeks the calves were released into a grazing paddock as one group and were supplemented ad libitum with control pellets and hay, until 19 weeks of age. From Weeks 4 to 12, liveweight and feed intakes were measured weekly and health status was monitored daily. Rumen fluid and blood were collected at Weeks 4 and 12, and to test for persistence after cessation of feeding H57, each were measured again at Week 19. From Weeks 4 to 12, the H57 calves grew faster (767 vs 551 g/day, P = 0.01), tended to consume more pellets (1013 vs 740 g DM/day, P = 0.07) and were 19% more feed conversion efficiency (2.43 vs 2.90 kg milk + starter DM/kg weight gain, P = 0.01) compared with the Control calves. The mean duration of each diarrhoea event was 2 days less for the H57 calves than the Control (P = 0.01). The H57 calves weaned 9 days earlier (P = 0.02) and were heavier at Week 19 (155 vs 139 kg, P = 0.03) than the Control calves. The only effect of H57 on rumen volatile fatty acid concentrations was an elevation in valerate at Week 12 (4.10 vs 2.47 mmol/L, P = 0.03). Plasma β-hydroxy butyrate was also elevated in the H57 calves at Week 19 (0.24 vs 0.20 mmol/L), indicating the potential of H57 to improve rumen development. H57 can be used to improve the nutritional performance and reduce the risk of diarrhoea in dairy calves as they transition from milk to dry feed.

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The growth performance and carcass attributes of Merino and Poll Dorset × Merino lambs fed rumen-protected methionine (Smartamine™-M)

Australian Journal of Agricultural Research ◽

10.1071/ar02173 ◽

2003 ◽

Vol 54 (5) ◽

pp. 507 ◽

Cited By ~ 9

Author(s):

S. C. Wiese ◽

C. L. White ◽

D. G. Masters ◽

J. T. B. Milton ◽

R. H. Davidson

Keyword(s):

Growth Rate ◽

Conversion Efficiency ◽

Eating Quality ◽

Skin Thickness ◽

Feed Conversion ◽

Feed Conversion Efficiency ◽

Wool Growth ◽

Cereal Grain ◽

Methionine Supplementation ◽

Ad Libitum

This study investigated the effect of 5 levels of rumen-protected methionine (0, 1, 2, 3, or 5 g/head.day) on growth rate, feed conversion efficiency, carcass composition, and wool growth in lambs fed a production diet ad libitum. Merino and Poll Dorset × Merino (crossbred) wether lambs (120 of each genotype) were housed in group pens each of 6 sheep. After a 1-week adjustment period, all lambs were fed a pelleted diet of lupins, cereal grain, and hay ad libitum. Rumen-protected methionine was added to the diets in the form of Smartamine™-M. The crossbred lambs were slaughtered after 28 days on the treatment diet and the Merino lambs after 42 days.Increasing the level of methionine supplementation did not lead to an increase in growth rate, daily feed intake, feed conversion efficiency, wool growth, skin thickness, or final liveweight and condition score. The Merino lambs had a lower growth rate, thinner skin, faster rate of wool growth, and were less efficient at converting feed into liveweight gain than the crossbred lambs (P < 0.05). There was no interaction between breed and methionine treatment.Increasing the level of methionine treatment also did not improve hot carcass weight, dressing percentage, tissue depth over the rib, longissimus dorsi (LD) cross-sectional area, meat pH, or meat colour. The only beneficial effect of methionine supplementation on carcass attributes was a decline in fat depth over the deepest part of the LD as methionine level increased (P < 0.05).There were no differences in tenderness, juiciness, or flavour intensity between the breeds or as a main effect with methionine supplementation. However, there was an interaction between breed and methionine for flavour intensity, such that methionine supplementation reduced the flavour intensity of Merino meat but not that of the crossbred meat (P < 0.05).This work suggests that there are unlikely to be production gains in terms of liveweight gain, feed conversion efficiency, or wool growth in supplementing lambs with protected methionine if they are being fed a high performance diet ad libitum. However, there were 2 benefits that may have scope for further investigation. The first was a reduction in fat cover over the loin as the level of methionine supplementation increased. The second was a reduction in the intensity of flavour found in Merino lamb when the lambs were supplemented with methionine. The study also provided some useful guidelines for the differences in growth and carcass characteristics between Merino and crossbred lambs when they are finished under identical conditions to an even fat cover, and demonstrated that Merino lambs can produce carcasses of very acceptable eating quality when well finished.

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An assessment of immune and stress responsiveness in Holstein-Friesian cows selected for high and low feed conversion efficiency

Animal Production Science ◽

10.1071/an15406 ◽

2017 ◽

Vol 57 (2) ◽

pp. 244 ◽

Cited By ~ 3

Author(s):

J. W. Aleri ◽

B. C. Hine ◽

M. F. Pyman ◽

P. D. Mansell ◽

W. J. Wales ◽

...

Keyword(s):

Conversion Efficiency ◽

Plasma Cortisol ◽

Significant Negative Correlation ◽

Preliminary Evidence ◽

Immune Responsiveness ◽

Feed Conversion ◽

Feed Conversion Efficiency ◽

Holstein Friesian ◽

Stress Responsiveness ◽

Friesian Cows

The objective of this study was to assess the immune and stress responsiveness of cows identified as extremely high and low feed conversion efficiency phenotypes. The study utilised 16 Holstein-Friesian cows in their third to fourth lactation, and identified as having either extremely high (n = 8) or extremely low (n = 8) feed conversion efficiency. A commercial vaccine was used to induce measurable antibody- and cell-mediated adaptive immune responses and assess general immune responsiveness. Stress responsiveness was assessed by measuring changes in plasma cortisol concentrations in response to yarding and handling. No significant differences in antibody- or cell-mediated immune responsiveness were observed between the extreme high and low feed conversion efficiency phenotypes (P = 0.343 and 0.546, respectively). However, results suggested that plasma cortisol concentrations trended higher in the low feed conversion efficiency phenotype cows than their high feed conversion efficiency counterparts (P = 0.079) 48 h post-yarding and handling. A significant negative correlation was observed between antibody-mediated immune responsiveness and stress responsiveness (r = –0.44, P = 0.043) but not with cell-mediated immune responsiveness (r = 0.135, P = 0.309). This study provides preliminary evidence that cows selected for feed conversion efficiency may have improved stress-coping abilities and immune responsiveness.

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Ad libitum versus restricted feeding of barley- and corn-based feedlot diets

Canadian Journal of Animal Science ◽

10.4141/cjas95-095 ◽

1995 ◽

Vol 75 (4) ◽

pp. 637-640 ◽

Cited By ~ 6

Author(s):

G. W. Mathison ◽

D. F. Engstrom

Keyword(s):

Key Words ◽

Conversion Efficiency ◽

Feed Restriction ◽

Restricted Feeding ◽

Feed Conversion ◽

Feed Conversion Efficiency ◽

Designed Experiment ◽

Ad Libitum ◽

Corn Grains

A 2 × 2 factorially designed experiment in which barley or corn grains were fed ad libitum or at 96% ad libitum to 100 steers was conducted to test the hypothesis that type of grain fed would affect any responses in feed conversion efficiency obtained by restricting intake. Feed restriction resulted in a 22% reduction (P = 0.01) in fat cover but the numerical improvement in feed conversion efficiency of 3% was not significant (P = 0.32). Grain type had no detectable influence on feed-lot performance. Key words: Ad libitum, restricted feeding, steers, barley, corn, feedlot

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UREA AS A NITROGEN SUPPLEMENT IN STARTER FEEDS FOR EARLY WEANED CALVES

Canadian Journal of Animal Science ◽

10.4141/cjas73-051 ◽

1973 ◽

Vol 53 (2) ◽

pp. 339-343 ◽

Cited By ~ 4

Author(s):

K. A. WINTER

Keyword(s):

Conversion Efficiency ◽

Soybean Meal ◽

Economic Advantage ◽

Feed Conversion ◽

Feed Conversion Efficiency ◽

Holstein Bull ◽

Bull Calves ◽

Ad Libitum ◽

Feed Costs ◽

Ad Libitum Feeding

Calf starter feeds containing either urea or soybean meal as a source of supplementary nitrogen were evaluated as the sole ration for Holstein bull calves weaned at 5 or 6 wk of age. In two experiments using a total of 56 calves, weight gains of the urea-fed calves (0.72–0.88 kg/day) were similar to or slightly less than the soybean meal-fed calves (0.77–0.90 kg/day). Except for one treatment in experiment 1, intake of the urea-supplemented starters was slightly less than intake of the soybean meal-supplemented starters. Feed conversion efficiency of the urea-supplemented starters was poorer in experiment 1, but comparable with the soybean meal-supplemented starters in experiment 2. The use of urea in the calf starters resulted in reduced feed costs ranging from $3.47 to $4.07 per 100 kg; and reductions in feed costs per 100 kg gain ranged from $9.34 to $12.90. Although animal performance may be slightly reduced by urea supplementation of calf starters, an economic advantage in feed costs was demonstrated with the use of urea when ad libitum feeding was practiced.

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Evolution in Configuration and Productivity of New Zealand Hill Country Sheep and Beef Cattle Systems

Agriculture ◽

10.3390/agriculture11060531 ◽

2021 ◽

Vol 11 (6) ◽

pp. 531

Author(s):

Januarius Gobilik ◽

Stephen Todd Morris ◽

Cory Matthew

Keyword(s):

New Zealand ◽

Beef Cattle ◽

Conversion Efficiency ◽

Production Systems ◽

Metabolic Energy ◽

Meat Production ◽

Feed Conversion ◽

Feed Conversion Efficiency ◽

Hill Country ◽

Cattle Systems

Metabolic energy budgeting (MEB) was used to evaluate evolution over 30 years (1980–1981 to 2010–2011) in New Zealand southern North Island ‘hill country’ sheep and beef cattle systems. MEB calculates energy required by animals for body weight maintenance, weight gain or loss, pregnancy, and lactation to estimate the system feed demand and thereby provide a basis for calculating feed conversion efficiency. Historic production systems were reconstructed and modeled using averaged data from industry surveys and data from owners’ diaries of three case-study farms and reviewed for patterns of change over time. The modeling indicated that pasture productivity was 11% lower and herbage harvested was 14% lower in 2010–2011 than in the early 1980s. This productivity decline is attributable to warmer, drier summer weather in recent years. However, primarily through increased lambing percentage, feed conversion efficiency based on industry data improved over the study period from 25 to 19 kg feed consumed per kg lamb weaned, while meat production rose from 137 to 147 kg per ha per year. Similar improvements were observed for the three case farms. The New Zealand MEB model was found effective for analysis of tropical beef production systems in Sabah, Malaysia.

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