Beef production systems with dairy × beef heifers based on forage and semi-natural grassland

Figures & data

Table 1. Proportion (% of dry matter) of grass-clover silage, rolled barley, rolled peas, and cold-pressed rapeseed cake in the total mixed ration fed to dairy × beef heifers at different liveweights in production systems with moderately high (HIGH) or low (LOW) indoor feed intensity (IP = indoor period, IP3 for LOW only).

Liveweight,	HIGH				LOW
kg	Silage	Barley	Peas	Rapeseed cake	Silage	Barley	Peas	Rapeseed cake
<125	50	0	25	25	58	14	14	14
125–175	70	0	15	15	73	9	9	9
175–225	80	0	10	10	94	6	0	0
225+ in IP1	100	0	0	0	100	0	0	0
225+ in IP2+3	80	20	0	0	100	0	0	0

Table 2. Chemical composition of rolled barley, rolled peas, and cold-pressed rapeseed cake (n = 1) fed to dairy × beef heifers in production systems with moderately high (HIGH) or low (LOW) indoor feed intensity (DM = dry matter, ME = metabolizable energy, CP = crude protein, NDF = neutral detergent fiber).

Item, kg^−1 DM	HIGH			LOW
	Barley	Peas	Rapeseed cake	Barley	Peas	Rapeseed cake
DM, g kg^−1	854	870	889	869	852	889
ME, MJ	13.4	13.6	15.2	13.4	14.0	15.2
CP, g	109	194	335	145	221	335
NDF, g	197	223	277	193	197	277
Starch, g	492	506	29	574	522	29
Crude fat, g	24	22	155	30	20	155
Ash, g	21	29	64	32	28	64

Table 3. Chemical composition of grass-clover silage fed during indoor period (IP) 1, 2, and 3 to dairy × beef heifers in production systems with moderately high (HIGH) or low (LOW) indoor feed intensity (s.d. = standard deviation, DM = dry matter, ME = metabolizable energy, CP = crude protein, NDF = neutral detergent fiber, NH₄-N = ammonium-nitrogen).

Item, kg^−1 DM	HIGH						LOW
	IP1			IP2			IP1			IP2			IP3
	Mean	s.d.	n	Mean	s.d.	n	Mean	s.d.	n	Mean	s.d.	n	Mean	s.d.	n
DM, g kg^−1	354	77	40	425	63	38	506	131	32	296	10	40	502	39	24
ME, MJ	11.8	0.1	9	10.5	0.2	7	10.6	0.2	7	10.3	0.7	7	10.3	0.3	5
CP, g	144	7	9	141	7	7	166	23	7	138	8	7	123	15	5
NDF, g	467	14	9	512	11	7	454	19	7	576	52	7	476	20	5
Ash, g	64	4	9	76	7	7	81	8	7	68	3	7	79	4	5
pH	4.7	0.7	2	4.9	0.2	2	5.2	0.4	2	4.6	0.5	3	5.0	0.4	3
NH4-N, g^a	158	40	2	258	17	2	163	72	2	186	43	3	204	32	3

^a Including N from the silage additive.

Table 4. Feed amounts and areas used to dairy × beef heifers with two sire breeds (Angus (ANG) or Charolais (CHA)) in production systems with moderately high indoor feed intensity and 20 months slaughter age (HIGH) or low indoor feed intensity and 27 months slaughter age (LOW), (DM = dry matter, ha = hectare).

Item	HIGH		LOW
	ANG	CHA	ANG	CHA
Grass-clover silage, kg DM	2881	3019	3737	3910
Barley, kg	753	796	92	82
Peas, kg	194	142	62	52
Rapeseed cake, kg	199	145	64	54
Arable land for silage making, ha	0.41	0.43	0.53	0.56
Semi-natural grasslands for grazing, ha	0.36	0.33	1.32	1.14

Figure 1. Herbage concentrations of crude protein (CP), metabolizable energy (ME), and neutral detergent fiber (NDF), and sward height in Deschampsia cespitosa-dominated semi-natural grassland grazed from May until October by dairy × beef heifers in production systems with moderately high (HIGH) or low (LOW) feed intensity. 2020 was the first grazing period for heifers in the LOW system, while 2021 was the second grazing period for heifers in the LOW system and the first for heifers in the HIGH system.

Table 5. Daily feed intake (I = intake; DM = dry matter; NDF = neutral detergent fiber), daily liveweight (LW) gain, and feed efficiency (FE; MJ = megajoule metabolizable energy) of dairy × beef heifers (n = 18) with two sire breeds (Angus (ANG) or Charolais (CHA)) in production systems (System) with moderately high indoor feed intensity and 20 months slaughter age (HIGH) or low indoor feed intensity and 27 months slaughter age (LOW). Least square means, pooled standard error of the mean (s.e.), and significance of the main effects of sire breed, production system, and their interaction.

Item	HIGH		LOW		s.e.	Level of Significance
	ANG	CHA	ANG	CHA		System	Sire	S × S
Indoor period 1
Initial LW, kg	112^a	130^b	114^a	126^b	2.3	ns	0.0005	ns
Dietary I, kg DM	7.19^a	7.29^a	5.97^b	6.28^b	0.14	<0.0001	ns	ns
Dietary I, % of LW	3.01^a	2.73^b	2.90^ab	2.86^ab	0.04	ns	0.0114	0.0585
I of NDF, % of LW	1.21	1.15	1.14	1.15	0.02	ns	ns	ns
LW gain, kg day^−1	1.20	1.21	1.15	1.17	0.02	0.0772	ns	ns
FE^a, MJ kg gain^−1	77.2^a	74.5^a	62.8^b	64.3^b	1.0	<0.0001	ns	ns
Grazing period 1
Initial LW, kg	395^a	430^b	303^c	320^c	4.8	<0.0001	0.0032	ns
LW gain, kg day^−1	−0.16^a	−0.09^a	0.58^b	0.65^b	0.03	<0.0001	0.0773	ns
Indoor period 2
Initial LW, kg	376^c	412^ab	398^b	427^a	4.7	0.0186	0.0002	ns
Dietary I, kg DM	12.63^a	13.37^a	10.27^b	10.06^b	0.24	<0.0001	ns	ns
Dietary I, % of LW	2.53^a	2.42^a	2.12^b	1.97^b	0.04	<0.0001	0.0359	ns
I of NDF, % of LW	1.06^a	1.02^a	1.21^b	1.12^ab	0.02	0.0019	0.0955	ns
LW, kg day^−1	1.50^a	1.56^a	0.89^b	0.82^b	0.03	<0.0001	ns	ns
FE, MJ kg gain^−1	101.8^a	101.7^a	124.8^b	130.5^b	2.9	<0.0001	ns	ns
Grazing period 2
Initial LW, kg	–	–	586	605	10.7	–	ns	–
LW gain, kg day^−1	–	–	0.31	0.37	0.27	–	ns	–
Indoor period 3
Initial LW, kg	–	–	634	662	11.2	–	ns	–
Dietary I, kg DM	–	–	12.2^a	13.2^b	0.27	–	0.0239	–
Dietary I, % of LW	–	–	1.81	1.88	0.03	–	0.0910	–
I of NDF, % of LW	–	–	0.87	0.89	0.02	–	ns	–
LW gain, kg day^−1	–	–	1.25	1.35	0.08	–	ns	–
FE, MJ kg gain^−1	–	–	116.1	117.7	5.1	–	ns	–
From weaning to slaughter
LW gain^a, kg day^−1	0.99^a	1.04^b	0.80^c	0.83^c	0.01	<0.0001	0.0153	ns

Note: ^aWithin the four sire breed × production system combinations, nine of the heifers had a Swedish Red dam and nine a Swedish Holstein dam. The Holstein crosses gained more weight (0.90 vs. 0.93 kg day⁻¹; p = 0.0156) and tended to consume less energy relative to weight gained (p = 0.0596) than the Swedish Red crosses. Three-way interactions for sire breed, dam breed, and production system were found for feed efficiency (p = 0.0424) and liveweight gain (p = 0.0159).

Table 6. Carcass characteristics of dairy × beef heifers (n = 18) with two sire breeds (Angus (ANG) or Charolais (CHA)) in production systems with moderately high indoor feed intensity and 20 months slaughter age (HIGH) or low indoor feed intensity and 27 months slaughter age (LOW). Least square mean, pooled standard error of the mean (s.e.), and significance of the main effects of sire breed, production system, and their interaction.

Item	HIGH		LOW		s.e.	Level of Significance
	ANG	CHA	ANG	CHA		System	Sire	S × S
Slaughter
Liveweight, kg	634^c	678^b	705^ab	738^a	8.5	<0.0001	0.0059	ns
Carcass weight, kg	322^c	348^b	352^ab	372^a	4.6	0.0011	0.0084	ns
Dressing, %	50.8^ab	51.3^a	50.0^b	50.4^a	0.23	0.0295	ns	ns
Conformation^a	6.7^a	7.3^b	6.6^a	7.1^ab	0.12	ns	0.0055	ns
Fatness^b	10.4^a	10.1^a	9.8^a	8.6^b	0.15	0.0005	0.0020	0.0401
Marbling^c	3.3^a	2.0^bc	2.7^ab	1.5^c	0.18	0.0561	0.0001	ns
Cutting up
HQ^d, kg	80.6^a	89.8^b	89.8^b	93.7^b	1.07	0.0010	0.0007	ns
Retail cuts^e, % of HQ	35.3^c	37.5^b	36.3^bc	40.3^a	0.29	0.0006	<0.0001	0.0458
Grade 2 meat ass.^f, % of HQ	19.3^a	18.5^a	19.5^a	21.2^b	0.35	0.0136	ns	0.0272
Grade 3 meat ass.^g, % of HQ	9.8^ab	11.0^a	9.6^ab	8.7^b	0.41	0.0601	ns	0.0838
Trim fat, % of HQ	17.0^a	13.7^b	15.2^ab	9.6^c	0.50	0.0013	<0.0001	ns
Bone^h, % of HQ	18.6^c	19.2^bc	19.3^b	20.2^a	0.16	0.0033	0.0076	ns

Note: ^aEUROP system: 6 = O+, 7 = R-, 8 = R. ^bEUROP system: 8 = 3, 9 = 3+, 10 = 4-. ^cVisually determined in Musculus longissimus dorsi between the 10th and 11th ribs on a scale 1 = lean and 5 = well-marbled. ^dRight hindquarter (HQ). ^eHigh-value retail cuts; strip loin, fillet, topside, outside round, eye of round, top rump, and rump steak. ^fCommercial meat cuts estimated to contain 10% fat. ^gCommercial meat cuts estimated to contain 23% fat. ^hWithin the four sire breed and production system combinations, nine of the heifers had a Swedish Holstein dam and nine a Swedish Red dam, which had 19.0% and 19.6% bone, respectively (p = 0.0202). Swedish Holstein crosses also tended to have higher liveweight at slaughter (p = 0.0872), carcass weight (p = 0.0966), conformation score (p = 0.0513), and proportions of retail cuts (p = 0.0993) and grade 2 meat assortment (p = 0.0632), but a lower proportion of meat assortment grade 3 (p = 0.0518), in HQ.