Lucerne Hay - Is 2nd Grade better than 1st?

1. Nutrition

Lucerne hay is considered one of the best and most available sources of feed in the Karoo region. It is used in combination with other feeds as roughage or in pelleted form (often with maize) and it is often fed ad lib on its own with a lot of success.

However some farmers have observed that their weaned kids have possibly done better on 2nd grade lucerne that first grade when fed on its own.

• Is this because the protein levels are too high and that mineral imbalances may be an issue when feeding just 1st grade lucerne?
• Does 2nd grade lucerne (with its mix of additional grass/weed material) have a lower and more efficient protein layer and better mineral balance?

Lucerne leaves contain 60% of the total digestible nutrients (TDN), 70% of the crude protein (CP) and 90% of the vitamins ²¹ and hence the leaf content has a significant contribution to differences in protein content in different grades of lucerne.

What levels of protein may be too much?

Excess protein above about 18% (no research to indicating tipping point) may be of little or no benefit at extra cost? Very high levels even be detrimental. (Authors interpretation from literature sources - see Article ‘Protein- How much of a good thing?’

Why it is that excess protein is a waste and may be detrimental in some cases?

Excess Protein in the diet is converted to ammonia by gut microbes. This ammonia is absorbed through the wall of the rumen and circulates in the blood stream. Excess ammonia can be toxic to the goat so must be converted from ammonia to urea. Urea is then excreted from the kidneys in the form of urine. There is an energy cost to the goat in converting and excreting the excess ammonia.

What levels of protein is ideal?

Jan Hoon, researcher at Grootfontein , suggests generally that protein levels around 15-16% would be optimum and 14-15% in case of high energy diets (11.7.& MJ energy). He indicated maximum levels of around 17-18% of Protein

How much Protein does South African lucerne contain?

Different Cultivars, different soil types and different grades of lucerne affects the Protein levels so the protein content in the Karoo does vary.

Communication regards Lucerne hay protein in the Karoo and surrounding areas:

• Jan Hoon (Groofontein) – Range 10/12% to 22-24% with a good average estimate around 15-16%
• Nico Brink - (Nutritionist) that the protein levels in the area depending on the grade of lucerne vary 12-14% and better grades 18% up to 22/23% and average around 15%.

Both these suggests that on average there are no issues with the protein levels in the local areas in most cases.

Literature searches give values of South African Lucerne:

• 168 samples analysed CP% on a DM basis: Varied from 13.9% – 27.8% (Mean 20,7%) ¹⁸
• 4 cultivars, 2 soil types varied: 8.85% – 21.24% ¹⁷
• Late budding 21.7%, early blooming 19.2% and blooming stages 17.6%.
• Crude protein after 4 weeks regrowth 22,1%, 5 weeks 19,3% and 6 weeks 18,0%²⁰

So what do some experts say about Lucerne?

In communication with Dr Johan van Rooyen (Grootfontein, recognised Specialist in Small stock).

Dr Van Rooyen felt that excess dietary protein can be a problem and 2nd grade lucerne was better due to the mixture of grasses- ‘going back to nature’.
Dr van Rooyen also felt that the high Calcium content of lucerne and the Ca:P ratio may be a problem and could be related to the shifting lameness seen in some cases.

Dr Van Rooyen also noted that when excess dietary protein sources occurred in field studies that higher urea urine levels and alkalosis occurred. This could also result in the overgrowth of Clostridium perfringens bacteria and resulting losses. Mixing lucerne with grass may be a better as a source of roughage.

In communication with Mr Jan Hoon (Grootfontein, specialises in nutritional dietary research in small stock) felt that max levels of 17-18% with optimum levels around 14-16% protein in high energy diets were best. He emphasised the importance of this in relation to the available energy and he also expressed the concern of the excess Calcium and the Ca:P ratio in lucerne as well as the relationship of the mineral components (Se, Mn, Zn, Fe and Cu).

There is little objective reference data is available on the impact of goats health when fed excess protein. Some studies have however shown no impact on different diet levels of protein supplementation on the health status of animals when goats were fed protein 23.5% and given Lucerne ad lib.¹⁴

Numerous studies have been conducted at Grootfontein where lucerne has been the basis of the research with no significant health issues reported but the amount of protein fed was not recorded (see some studies below).

Lucerne to concentrate ratio – the impact on production and growth

1. Trials at Grootfontein ¹² were done establish the optimal level of energy supplementation required for reproducing ewes receiving lucerne hay.
   The Angoras had access to ad lib Lucerne hay. The study was done in the days of chocolate maize as an energy source and study groups received additional maize (150, 300 and 450 grams per day). These groups were compared to those just having ad lib Lucerne. The body weights over time are reflected in the graph below. The Protein Energy content of lucerne was unknown.
   
   
   • None of the treatment levels had any effect on body mass at any stage of the experiment. This was unexpected as Loubser (1983) (Van der Westhuysen et al. 1988) recorded an increase of 3,8 kg in body mass of Angora ewes grazing mixed Karoo veld supplemented with 400 g chocolate maize/ewe/day, compared to a control group receiving no supplementation. This was however under veld conditions.
     
     It thus seems that the lucerne fed in this experiment supplied sufficient nutrients to the ewes during periods of higher demand.
     
   • The rate of supplementation also had no significant effect on any of the mohair traits measured.
     
     This indicated the high level of production maintained by the Angora goats fed lucerne hay and is probably the reason for no effect of supplementation on mohair production with additional supplement.
     
     
   • The reproductive performance of the experimental animals also suggests that Angora goats could satisfy their energy requirements during all stages of the reproductive cycle when fed just ad lib lucerne hay.
     
     From the results obtained in this study it would seem that lucerne hay fed to reproducing Angora goats in pens, not only satisfies their energy requirements but also boosts production and reproduction to very high levels.
     
     
2. Trials by Grootfontein¹¹ where lambs were fed different amounts roughage in diet (Lucerne 20 to 70%). The diets were made up of very similar analysis of Crude Protein (14%), Energy (10MJ/Kg) Calcium 8.8g/Kg and Phosphorous 2.5g/Kg.
   
   
   • All the groups followed more or less the same trend with regard to their respective growth curves. However, the group receiving the diet with the highest roughage inclusion level showed better growth during the first few weeks of feeding. This is in agreement with the studies conducted by Shivambu et al. (2011; 2012) with Merino and Dorper lambs.

Lucerne: Adding Energy source to diet of benefit to kids

Studies in KIDS suggest the importance of Energy when feeding weaned kids with lucerne. (The Protein and energy levels of the lucerne was not known in the trial.)

1. Kids fed dietary 80% milled lucerne and 20 % mealie meal compared to Kids fed just Lucerne.
   • Here the additional maize meal resulted in an average ADI of 21,9 compared to feeding weaned kids just lucerne hay which had an average ADI of 9,6 g per day.¹⁰
     
     
2. Grootfontein ¹³ over a period of six months divided Angora kids into two groups. (The dietary protein and energy levels were unknown.)
   1. HIGH level of nutrition received a pelleted ration (10 % mealies, 10 % molasses and 80 % Lucerne)
   2. LOW level nutrition 30% milled wheat straw added to Lucerne.

• The High nutrition level resulted in a 60% higher body weight and 78.7% higher mohair production compared to a poor level of nutrition

Lucerne Mineral balance.

Lucerne is a rich source of Calcium (Ca), Magnesium (Mg), Potassium (K), Sulphur (S), Iron (Fe), Cobalt (Co), Manganese (Mn) and Zinc (Zn).

However, interactions between some of these minerals (especially calcium) may interfere with mineral availability or absorption.

See Mineral and Vitamin requirements in angora goats

Lucerne: The possible impact on reproduction:

Intake of Pasture lucerne before mating can reduce ovulation rates by 20% by reducing the number of eggs shed per oestrus and reducing the proportion of eggs fertilised. The symptoms of estrogenism also include excessive mammary development and on rare occasions dystocia.

Oestrogenic hormones may be produced either by the lucerne (plant oestrogens or phytoestrogens) or by soil-borne fungi that live on the lucerne. The presence of leaf diseases, insect damage and severe moisture stress can all increase coumestans levels. Coumestan-induced infertility is generally considered as temporary.²² ²³ ²⁴

However lucerne hay has much lower levels of oestrogenic hormones and has NOT reportedly affected fertility.

• The general advice is not to feed high risk Lucerne PASTURE to breeding Angora ewes in the 21 days prior to and during mating.

CONCLUSION, CONSIDERATIONS

• Feed 2nd grade lucern in preference to 1st grade if you are not measuring Protein levels (feeding additional grass is of benefit as grasses also have low Ca levels so Ca:P balance is improved and average protein level is lowered.)
• Additional energy added to diet may be of benefit to kids.
• Mineral supplementation is advised when feeding Lucerne particularly Mn, Mg, Zn and Se.
• Speak to your Nutritionist if making up a concentrate diet along with your fibre source

REFERENCES

¹ Effects of Dietary Protein Level on Milk Production Performance and Serum Biochemical Indicators of Dairy Goat. Fansheng Meng, Cuilin Yuan and Ziyang Yu 

² Production of goats fed diets with increasing levels of protein: intake, milk yield and apparent digestibility. Carlos Elysio Moreira da Fonseca, Rilene Ferreira Diniz Valadares, Sebastião de Campos Valadares Filho, Marcelo Teixeira Rodrigues, Marcos Inácio Marcondes, Marlos Oliveira Porto, Douglas dos Santos Pina, Kamila Andreatta Kling de Moraes

³Crude protein levels in diets of lactating goats: nitrogen balance, urea excretion and microbial protein synthesis. Jesus dos Santos, Albuquerque Pereira, Pereira de Figueiredo, De Oliveira Silva, Ferreira Da Cruz, Oliveira Barreto, Borges Sousa

⁴ Effects of crude protein levels in total mixed rations on growth performance and meat quality in growing Korean Black goats. S Hwangbo, SH Choi, SW Kim, DS Son, HS Park, SH Lee, IH Jo

⁵ Effect of different protein-energy ratio in pulse by-product and residue based pelleted feeds on growth, rumen fermentation, carcass and sausage quality in Barbari kids. TK Dutta, MK Agnihotri, PK Sahoo, V Rajkumar, AK Das

Reducing protein content in the diet of growing goats: implications for nitrogen balance, intestinal nutrient digestion and absorption, and rumen microbiota.X.X. Zhang, Y.X. Li, Z.R. Tang, W.Z. Sun, L.T. Wu, R. An, H.Y. Chen, K. Wan, Z.H. Sun 

⁶ Effects of dietary crude protein levels on nutrient digestibility and growth performance of Thai indigenous male goats. Jeerasak Chobtang, Intharak Kabuan, Isuwan Auraiwan

⁷ Effect of dietary protein level on growth and body condition score of male Beetal goats during summer. MohsinI, M. Q. ShahidI, M.N. HaqueII, N. AhmadI, H. Mustafa 

⁸ Nutritional manipulation in goats: Supplementation of high protein concentrate, effect on performance and resilience of internal parasites. Yusuf, A. O.,Ajayi, T. O.,Ajayi, O. S. and Yusuf, O. A

⁹ Vet. Sci., 03 August 2023. Animal Nutrition and Metabolism. Mpho Sylvia Tsheole, Mulunda Mwanza

¹⁰ Die effect van energiebyvoeding aan jong groeiende Angora bokkie. P D Grobbelaar en C M M Landman.

¹¹ Effect of energy level in Lucerne hay based finishing diets on carcass characteritics of Dohne Merino lambs. V.N. Shivambu#, J.H. Hoon, W.J. Olivier & B.R. King

¹² Effect of level of supplementary feeding on Mohair production and reproductive performance of kraal-fed Angora ewes. P.R. King, V. Sumner, D. Wentzel, P. Schlebush and M.J. Herselman

¹³ Effect of Nutrition on certain Mohair Quality traits. Margaretha A Badenhorst, J C Diedericks & P A Schlebusch

¹⁴ Effect of different dietary protein levels on goats’ blood parameters of Tswana goats reared in extensive production systems 

¹⁵ Feeding and Nutrition. L. Rankins Jr, D.G. Pugh

¹⁶ Effect of different levels of urea supplementation on reproduction, production and physiological parameters of wool ewes. J.H. Hoon & J.A. van Rooyen

¹⁷ Nutritive Value of Four Lucerne Cultivars Planted in Two Soil Types at Bathurst Research Station, Mhlangabezi Solontsi, Mfundo Phakama Maqubela, Johan Adam van Niekerk, Jan Willem Swanepoel, Gideon Jordaan, Unathi Gulwa, Sive Tokozwayo

¹⁸ The nutritive value of South African Medicago sativa L. hay.G.D.J. ScholtzI, H.J. van der Merwe, T.P.     TylutkiII

²⁰ Cruywagen et al., 2011. S. Afr. J. Anim. Sci. vol. 4

²¹ Vough, L., 2001.  Evaluating hay quality. August 2008

²² Forage Plant Estrogens. A. L. Livingston, Journal of Toxicology and Environmental Health. 4: 301. 1978.

²³ Toxicological Problems in Food Animals Affecting Reproduction. M. R. Putnam, Clinical Toxicology, In: Veterinary Clinics of North America: Food Animal Practice. 5: 325. 1989.

²⁴ Detection of the Effects of Phytoestrogens on Sheep and Cattle. N. R. Adams, J. Animal Science. 73: 1509. 1995.